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.

Formal methods in computer system design

NASA Astrophysics Data System (ADS)

Hoare, C. A. R.

1989-12-01

This note expounds a philosophy of engineering design which is stimulated, guided and checked by mathematical calculations and proofs. Its application to software engineering promises the same benifits as those derived from the use of mathematics in all other branches of modern science.

Discrete mathematics, formal methods, the Z schema and the software life cycle

NASA Technical Reports Server (NTRS)

Bown, Rodney L.

1991-01-01

The proper role and scope for the use of discrete mathematics and formal methods in support of engineering the security and integrity of components within deployed computer systems are discussed. It is proposed that the Z schema can be used as the specification language to capture the precise definition of system and component interfaces. This can be accomplished with an object oriented development paradigm.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacques Hugo

Traditional engineering methods do not make provision for the integration of human considerations, while traditional human factors methods do not scale well to the complexity of large-scale nuclear power plant projects. Although the need for up-to-date human factors engineering processes and tools is recognised widely in industry, so far no formal guidance has been developed. This article proposes such a framework.

Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

NASA Technical Reports Server (NTRS)

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

2004-01-01

A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including sensor networks and autonomous systems. 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 current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the classes of 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 in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

Improving engineering system design by formal decomposition, sensitivity analysis, and optimization

NASA Technical Reports Server (NTRS)

Sobieski, J.; Barthelemy, J. F. M.

1985-01-01

A method for use in the design of a complex engineering system by decomposing the problem into a set of smaller subproblems is presented. Coupling of the subproblems is preserved by means of the sensitivity derivatives of the subproblem solution to the inputs received from the system. The method allows for the division of work among many people and computers.

Increase in the Accuracy of Calculating Length of Horizontal Cable SCS in Civil Engineering

NASA Astrophysics Data System (ADS)

Semenov, A.

2017-11-01

A modification of the method for calculating the horizontal cable consumption of SCS established at civil engineering facilities is proposed. The proposed procedure preserves the prototype simplicity and provides a 5 percent accuracy increase. The values of the achieved accuracy are justified, their compliance with the practice of real projects is proved. The method is brought to the level of the engineering algorithm and formalized in the form of 12/70 rule.

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…

A Method for Capturing and Reconciling Stakeholder Intentions Based on the Formal Concept Analysis

NASA Astrophysics Data System (ADS)

Aoyama, Mikio

Information systems are ubiquitous in our daily life. Thus, information systems need to work appropriately anywhere at any time for everybody. Conventional information systems engineering tends to engineer systems from the viewpoint of systems functionality. However, the diversity of the usage context requires fundamental change compared to our current thinking on information systems; from the functionality the systems provide to the goals the systems should achieve. The intentional approach embraces the goals and related aspects of the information systems. This chapter presents a method for capturing, structuring and reconciling diverse goals of multiple stakeholders. The heart of the method lies in the hierarchical structuring of goals by goal lattice based on the formal concept analysis, a semantic extension of the lattice theory. We illustrate the effectiveness of the presented method through application to the self-checkout systems for large-scale supermarkets.

A Software Engineering Approach based on WebML and BPMN to the Mediation Scenario of the SWS Challenge

NASA Astrophysics Data System (ADS)

Brambilla, Marco; Ceri, Stefano; Valle, Emanuele Della; Facca, Federico M.; Tziviskou, Christina

Although Semantic Web Services are expected to produce a revolution in the development of Web-based systems, very few enterprise-wide design experiences are available; one of the main reasons is the lack of sound Software Engineering methods and tools for the deployment of Semantic Web applications. In this chapter, we present an approach to software development for the Semantic Web based on classical Software Engineering methods (i.e., formal business process development, computer-aided and component-based software design, and automatic code generation) and on semantic methods and tools (i.e., ontology engineering, semantic service annotation and discovery).

Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

NASA Technical Reports Server (NTRS)

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

2005-01-01

A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including distributed software systems, sensor networks, robot operation, complex scripts for spacecraft integration and testing, and autonomous systems. 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 current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the classes of 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 in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

NASA Technical Reports Server (NTRS)

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

2005-01-01

A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including distributed software systems, sensor networks, robot operation, complex scripts for spacecraft integration and testing, and autonomous systems. 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 current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the ciasses of 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 in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

Dynamic Gate Product and Artifact Generation from System Models

NASA Technical Reports Server (NTRS)

Jackson, Maddalena; Delp, Christopher; Bindschadler, Duane; Sarrel, Marc; Wollaeger, Ryan; Lam, Doris

2011-01-01

Model Based Systems Engineering (MBSE) is gaining acceptance as a way to formalize systems engineering practice through the use of models. The traditional method of producing and managing a plethora of disjointed documents and presentations ("Power-Point Engineering") has proven both costly and limiting as a means to manage the complex and sophisticated specifications of modern space systems. We have developed a tool and method to produce sophisticated artifacts as views and by-products of integrated models, allowing us to minimize the practice of "Power-Point Engineering" from model-based projects and demonstrate the ability of MBSE to work within and supersede traditional engineering practices. This paper describes how we have created and successfully used model-based document generation techniques to extract paper artifacts from complex SysML and UML models in support of successful project reviews. Use of formal SysML and UML models for architecture and system design enables production of review documents, textual artifacts, and analyses that are consistent with one-another and require virtually no labor-intensive maintenance across small-scale design changes and multiple authors. This effort thus enables approaches that focus more on rigorous engineering work and less on "PowerPoint engineering" and production of paper-based documents or their "office-productivity" file equivalents.

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; and Data-flow based Model Analysis.

RICIS Software Engineering 90 Symposium: Aerospace Applications and Research Directions Proceedings Appendices

NASA Technical Reports Server (NTRS)

1990-01-01

Papers presented at RICIS Software Engineering Symposium are compiled. The following subject areas are covered: flight critical software; management of real-time Ada; software reuse; megaprogramming software; Ada net; POSIX and Ada integration in the Space Station Freedom Program; and assessment of formal methods for trustworthy computer systems.

What is the Final Verification of Engineering Requirements?

NASA Technical Reports Server (NTRS)

Poole, Eric

2010-01-01

This slide presentation reviews the process of development through the final verification of engineering requirements. The definition of the requirements is driven by basic needs, and should be reviewed by both the supplier and the customer. All involved need to agree upon a formal requirements including changes to the original requirements document. After the requirements have ben developed, the engineering team begins to design the system. The final design is reviewed by other organizations. The final operational system must satisfy the original requirements, though many verifications should be performed during the process. The verification methods that are used are test, inspection, analysis and demonstration. The plan for verification should be created once the system requirements are documented. The plan should include assurances that every requirement is formally verified, that the methods and the responsible organizations are specified, and that the plan is reviewed by all parties. The options of having the engineering team involved in all phases of the development as opposed to having some other organization continue the process once the design has been complete is discussed.

What can formal methods offer to digital flight control systems design

NASA Technical Reports Server (NTRS)

Good, Donald I.

1990-01-01

Formal methods research begins to produce methods which will enable mathematic modeling of the physical behavior of digital hardware and software systems. The development of these methods directly supports the NASA mission of increasing the scope and effectiveness of flight system modeling capabilities. The conventional, continuous mathematics that is used extensively in modeling flight systems is not adequate for accurate modeling of digital systems. Therefore, the current practice of digital flight control system design has not had the benefits of extensive mathematical modeling which are common in other parts of flight system engineering. Formal methods research shows that by using discrete mathematics, very accurate modeling of digital systems is possible. These discrete modeling methods will bring the traditional benefits of modeling to digital hardware and hardware design. Sound reasoning about accurate mathematical models of flight control systems can be an important part of reducing risk of unsafe flight control.

Software Safety Risk in Legacy Safety-Critical Computer Systems

NASA Technical Reports Server (NTRS)

Hill, Janice; Baggs, Rhoda

2007-01-01

Safety-critical computer systems must be engineered to meet system and software safety requirements. For legacy safety-critical computer systems, software safety requirements may not have been formally specified during development. When process-oriented software safety requirements are levied on a legacy system after the fact, where software development artifacts don't exist or are incomplete, the question becomes 'how can this be done?' The risks associated with only meeting certain software safety requirements in a legacy safety-critical computer system must be addressed should such systems be selected as candidates for reuse. This paper proposes a method for ascertaining formally, a software safety risk assessment, that provides measurements for software safety for legacy systems which may or may not have a suite of software engineering documentation that is now normally required. It relies upon the NASA Software Safety Standard, risk assessment methods based upon the Taxonomy-Based Questionnaire, and the application of reverse engineering CASE tools to produce original design documents for legacy systems.

Towards an Automated Development Methodology for Dependable Systems with Application to Sensor Networks

NASA Technical Reports Server (NTRS)

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

2005-01-01

A general-purpose method to mechanically transform system requirements into a probably equivalent model has yet to appeal: Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including sensor networks and autonomous systems. Currently available tools and methods that start with a formal model of a system and mechanically produce a probably equivalent implementation are valuable but not su8cient. The "gap" unfilled by such tools and methods is that their. formal models cannot be proven to be equivalent to the system requirements as originated by the customel: For the classes of 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 in other appropriate graphical notations) into a probably equivalent formal model that can be used as the basis for code generation and other transformations.

7 CFR 1726.201 - Formal competitive bidding.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its engineer... § 1726.23). (b) Invitations to bid. The borrower (acting through its engineer, if applicable) is...

7 CFR 1726.201 - Formal competitive bidding.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its engineer... § 1726.23). (b) Invitations to bid. The borrower (acting through its engineer, if applicable) is...

7 CFR 1726.201 - Formal competitive bidding.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its engineer... § 1726.23). (b) Invitations to bid. The borrower (acting through its engineer, if applicable) is...

7 CFR 1726.201 - Formal competitive bidding.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its engineer... § 1726.23). (b) Invitations to bid. The borrower (acting through its engineer, if applicable) is...

7 CFR 1726.201 - Formal competitive bidding.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its engineer... § 1726.23). (b) Invitations to bid. The borrower (acting through its engineer, if applicable) is...

75 FR 34170 - Chrysler Group LLC, Formally Known as Chrysler LLC, Kenosha Engine Plant, Including On-Site...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

... automobile engines. The company reports that workers leased from Caravan Knight Facilities Management, LLC..., Formally Known as Chrysler LLC, Kenosha Engine Plant, Including On-Site Leased Workers From Caravan Knight..., Kenosha Engine Plant, Kenosha, Wisconsin. The notice was published in [[Page 34171

75 FR 52982 - Chrysler Group LLC, Formally Known as Chrysler LLC, Kenosha Engine Plant, Including On-Site...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-30

... automobile engines. The company reports that workers leased from Syncreon were employed on-site at the..., Formally Known as Chrysler LLC, Kenosha Engine Plant, Including On-Site Leased Workers From Caravan Knight... Chrysler, LLC, Kenosha Engine Plant, Kenosha, Wisconsin. The notice was published in the Federal Register...

Basic exploration geophysics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, E.S.

1988-01-01

An introduction to geophysical methods used to explore for natural resources and to survey earth's geology is presented in this volume. It is suitable for second-and third-year undergraduate students majoring in geology or engineering and for professional engineering and for professional engineers and earth scientists without formal instruction in geophysics. The author assumes the reader is familiar with geometry, algebra, and trigonometry. Geophysical exploration includes seismic refraction and reflection surveying, electrical resistivity and electromagnetic field surveying, and geophysical well logging. Surveying operations are described in step-by-step procedures and are illustrated by practical examples. Computer-based methods of processing and interpreting datamore » as well as geographical methods are introduced.« less

A Formal Specification and Verification Method for the Prevention of Denial of Service in Ada Services

DTIC Science & Technology

1988-03-01

Mechanism; Computer Security. 16. PRICE CODE 17. SECURITY CLASSIFICATION IS. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. UMrrATION OF ABSTRACT...denial of service. This paper assumes that the reader is a computer science or engineering professional working in the area of formal specification and...recovery from such events as deadlocks and crashes can be accounted for in the computation of the waiting time for each service in the service hierarchy

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.

Forum on Workforce Development

NASA Technical Reports Server (NTRS)

Hoffman, Edward

2010-01-01

APPEL Mission: To support NASA's mission by promoting individual, team, and organizational excellence in program/project management and engineering through the application of learning strategies, methods, models, and tools. Goals: a) Provide a common frame of reference for NASA s technical workforce. b) Provide and enhance critical job skills. c) Support engineering, program and project teams. d) Promote organizational learning across the agency. e) Supplement formal educational programs.

Highlights From the Third Annual Mayo Clinic Conference on Systems Engineering and Operations Research in Health Care

PubMed Central

Kamath, Janine R. A.; Osborn, John B.; Roger, Véronique L.; Rohleder, Thomas R.

2011-01-01

In August 2010, the Third Annual Mayo Clinic Conference on Systems Engineering and Operations Research in Health Care was held. The continuing mission of the conference is to gather a multidisciplinary group of systems engineers, clinicians, administrators, and academic professors to discuss the translation of systems engineering methods to more effective health care delivery. Education, research, and practice were enhanced via a mix of formal presentations, tutorials, and informal gatherings of participants with diverse backgrounds. Although the conference promotes a diversity of perspectives and methods, participants are united in their desire to find ways in which systems engineering can transform health care, especially in the context of health care reform and other significant changes affecting the delivery of health care. PMID:21803959

De novo reconstruction of gene regulatory networks from time series data, an approach based on formal methods.

PubMed

Ceccarelli, Michele; Cerulo, Luigi; Santone, Antonella

2014-10-01

Reverse engineering of gene regulatory relationships from genomics data is a crucial task to dissect the complex underlying regulatory mechanism occurring in a cell. From a computational point of view the reconstruction of gene regulatory networks is an undetermined problem as the large number of possible solutions is typically high in contrast to the number of available independent data points. Many possible solutions can fit the available data, explaining the data equally well, but only one of them can be the biologically true solution. Several strategies have been proposed in literature to reduce the search space and/or extend the amount of independent information. In this paper we propose a novel algorithm based on formal methods, mathematically rigorous techniques widely adopted in engineering to specify and verify complex software and hardware systems. Starting with a formal specification of gene regulatory hypotheses we are able to mathematically prove whether a time course experiment belongs or not to the formal specification, determining in fact whether a gene regulation exists or not. The method is able to detect both direction and sign (inhibition/activation) of regulations whereas most of literature methods are limited to undirected and/or unsigned relationships. We empirically evaluated the approach on experimental and synthetic datasets in terms of precision and recall. In most cases we observed high levels of accuracy outperforming the current state of art, despite the computational cost increases exponentially with the size of the network. We made available the tool implementing the algorithm at the following url: http://www.bioinformatics.unisannio.it. Copyright © 2014 Elsevier Inc. All rights reserved.

23 CFR 172.5 - Methods of procurement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... and ranked by the contracting agency using one of the following procedures: (1) Competitive negotiation. Contracting agencies shall use competitive negotiation for the procurement of engineering and... and selection phase. Alternatively, a formal procedure adopted by State Statute enacted into law prior...

Probabilistic structural analysis methods of hot engine structures

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Hopkins, D. A.

1989-01-01

Development of probabilistic structural analysis methods for hot engine structures at Lewis Research Center is presented. Three elements of the research program are: (1) composite load spectra methodology; (2) probabilistic structural analysis methodology; and (3) probabilistic structural analysis application. Recent progress includes: (1) quantification of the effects of uncertainties for several variables on high pressure fuel turbopump (HPFT) turbine blade temperature, pressure, and torque of the space shuttle main engine (SSME); (2) the evaluation of the cumulative distribution function for various structural response variables based on assumed uncertainties in primitive structural variables; and (3) evaluation of the failure probability. Collectively, the results demonstrate that the structural durability of hot engine structural components can be effectively evaluated in a formal probabilistic/reliability framework.

An overview of very high level software design methods

NASA Technical Reports Server (NTRS)

Asdjodi, Maryam; Hooper, James W.

1988-01-01

Very High Level design methods emphasize automatic transfer of requirements to formal design specifications, and/or may concentrate on automatic transformation of formal design specifications that include some semantic information of the system into machine executable form. Very high level design methods range from general domain independent methods to approaches implementable for specific applications or domains. Applying AI techniques, abstract programming methods, domain heuristics, software engineering tools, library-based programming and other methods different approaches for higher level software design are being developed. Though one finds that a given approach does not always fall exactly in any specific class, this paper provides a classification for very high level design methods including examples for each class. These methods are analyzed and compared based on their basic approaches, strengths and feasibility for future expansion toward automatic development of software systems.

Formalization of the Access Control on ARM-Android Platform with the B Method

NASA Astrophysics Data System (ADS)

Ren, Lu; Wang, Wei; Zhu, Xiaodong; Man, Yujia; Yin, Qing

2018-01-01

ARM-Android is a widespread mobile platform with multi-layer access control mechanisms, security-critical in the system. Many access control vulnerabilities still exist due to the course-grained policy and numerous engineering defects, which have been widely studied. However, few researches focus on the mechanism formalization, including the Android permission framework, kernel process management and hardware isolation. This paper first develops a comprehensive formal access control model on the ARM-Android platform using the B method, from the Android middleware to hardware layer. All the model specifications are type checked and proved to be well-defined, with 75%of proof obligations demonstrated automatically. The results show that the proposed B model is feasible to specify and verify access control schemes in the ARM-Android system, and capable of implementing a practical control module.

Operations planning and analysis handbook for NASA/MSFC phase B development projects

NASA Technical Reports Server (NTRS)

Batson, Robert C.

1986-01-01

Current operations planning and analysis practices on NASA/MSFC Phase B projects were investigated with the objectives of (1) formalizing these practices into a handbook and (2) suggesting improvements. The study focused on how Science and Engineering (S&E) Operational Personnel support Program Development (PD) Task Teams. The intimate relationship between systems engineering and operations analysis was examined. Methods identified for use by operations analysts during Phase B include functional analysis, interface analysis methods to calculate/allocate such criteria as reliability, Maintainability, and operations and support cost.

Helping System Engineers Bridge the Peaks

NASA Technical Reports Server (NTRS)

Rungta, Neha; Tkachuk, Oksana; Person, Suzette; Biatek, Jason; Whalen, Michael W.; Castle, Joseph; Castle, JosephGundy-Burlet, Karen

2014-01-01

In our experience at NASA, system engineers generally follow the Twin Peaks approach when developing safety-critical systems. However, iterations between the peaks require considerable manual, and in some cases duplicate, effort. A significant part of the manual effort stems from the fact that requirements are written in English natural language rather than a formal notation. In this work, we propose an approach that enables system engineers to leverage formal requirements and automated test generation to streamline iterations, effectively "bridging the peaks". The key to the approach is a formal language notation that a) system engineers are comfortable with, b) is supported by a family of automated V&V tools, and c) is semantically rich enough to describe the requirements of interest. We believe the combination of formalizing requirements and providing tool support to automate the iterations will lead to a more efficient Twin Peaks implementation at NASA.

NACA Conference on Turbojet-Engine Thrust Augmentation Research: A Compilation of the Papers Presented by NACA Staff Members

NASA Technical Reports Server (NTRS)

1948-01-01

The conference on Turbojet-Engine Thrust-Augmentation Research was organized by the NACA to present in summarized form the results of the latest experimental and analytical investigations conducted at the Lewis Flight Propulsion Laboratory on methods of augmenting the thrust of turbojet engines. The technical discussions are reproduced herewith in the same form in which they were presented. The original presentation in this record are considered as complementary to, rather than substitutes for, the committee's system of complete and formal reports.

Environmental Science and Engineering Merit Badges: An Exploratory Case Study of a Non-Formal Science Education Program and the U.S. Scientific and Engineering Practices

ERIC Educational Resources Information Center

Vick, Matthew E.; Garvey, Michael P.

2016-01-01

The Boy Scouts of America's Environmental Science and Engineering merit badges are two of their over 120 merit badges offered as a part of a non-formal educational program to U.S. boys. The Scientific and Engineering Practices of the U.S. Next Generation Science Standards provide a vision of science education that includes integrating eight…

Multi-Attribute Tradespace Exploration in Space System Design

NASA Astrophysics Data System (ADS)

Ross, A. M.; Hastings, D. E.

2002-01-01

The complexity inherent in space systems necessarily requires intense expenditures of resources both human and monetary. The high level of ambiguity present in the early design phases of these systems causes long, highly iterative, and costly design cycles. This paper looks at incorporating decision theory methods into the early design processes to streamline communication of wants and needs among stakeholders and between levels of design. Communication channeled through formal utility interviews and analysis enables engineers to better understand the key drivers for the system and allows a more thorough exploration of the design tradespace. Multi-Attribute Tradespace Exploration (MATE), an evolving process incorporating decision theory into model and simulation- based design, has been applied to several space system case studies at MIT. Preliminary results indicate that this process can improve the quality of communication to more quickly resolve project ambiguity, and enable the engineer to discover better value designs for multiple stakeholders. MATE is also being integrated into a concurrent design environment to facilitate the transfer knowledge of important drivers into higher fidelity design phases. Formal utility theory provides a mechanism to bridge the language barrier between experts of different backgrounds and differing needs (e.g. scientists, engineers, managers, etc). MATE with concurrent design couples decision makers more closely to the design, and most importantly, maintains their presence between formal reviews.

Open Source Patient-Controlled Analgesic Pump Requirements Documentation

PubMed Central

Larson, Brian R.; Hatcliff, John; Chalin, Patrice

2014-01-01

The dynamic nature of the medical domain is driving a need for continuous innovation and improvement in techniques for developing and assuring medical devices. Unfortunately, research in academia and communication between academics, industrial engineers, and regulatory authorities is hampered by the lack of realistic non-proprietary development artifacts for medical devices. In this paper, we give an overview of a detailed requirements document for a Patient-Controlled Analgesic (PCA) pump developed under the US NSF’s Food and Drug Administration (FDA) Scholar-in-Residence (SIR) program. This 60+ page document follows the methodology outlined in the US Federal Aviation Administrations (FAA) Requirements Engineering Management Handbook (REMH) and includes a domain overview, use cases, statements of safety & security requirements, and formal top-level system architectural description. Based on previous experience with release of a requirements document for a cardiac pacemaker that spawned a number of research and pedagogical activities, we believe that the described PCA requirements document can be an important research enabler within the formal methods and software engineering communities. PMID:24931440

Youth's Engagement as Scientists and Engineers in an Afterschool Making and Tinkering Program

NASA Astrophysics Data System (ADS)

Simpson, Amber; Burris, Alexandra; Maltese, Adam

2017-11-01

Making and tinkering is currently gaining traction as an interdisciplinary approach to education. However, little is known about how these activities and explorations in formal and informal learning spaces address the content and skills common to professionals across science, technology, engineering, and mathematics. As such, the purpose of this qualitative study was to examine how youth were engaged in the eight science and engineering practices outlined within the US Next Generation Science Standards within an informal learning environment utilizing principles of tinkering within the daily activities. Findings highlight how youth and facilitators engaged and enacted in practices common to scientists and engineers. Yet, in this study, enactment of these practices "looked" differently than might be expected in a formal learning environment such as a laboratory setting. For example, in this setting, students were observed carrying out trials on their design as opposed to carrying out a formal scientific investigation. Results also highlight instances of doing science and engineering not explicitly stated within parameters of formal education documents in the USA, such as experiences with failure.

Damage Tolerance and Reliability of Turbine Engine Components

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

1999-01-01

This report describes a formal method to quantify structural damage tolerance and reliability in the presence of a multitude of uncertainties in turbine engine components. The method is based at the material behavior level where primitive variables with their respective scatter ranges are used to describe behavior. Computational simulation is then used to propagate the uncertainties to the structural scale where damage tolerance and reliability are usually specified. Several sample cases are described to illustrate the effectiveness, versatility, and maturity of the method. Typical results from this method demonstrate that it is mature and that it can be used to probabilistically evaluate turbine engine structural components. It may be inferred from the results that the method is suitable for probabilistically predicting the remaining life in aging or deteriorating structures, for making strategic projections and plans, and for achieving better, cheaper, faster products that give competitive advantages in world markets.

Candidate Causes. Sediments. In: Causal Analysis, Diagnosis Decision Information System, USEPA Website

EPA Science Inventory

CADDIS is an online application that helps scientists and engineers in the Regions, States, and Tribes find, access, organize, use, and share information to conduct causal evaluations in aquatic systems. It is based on the USEPA stressor identification process, a formal method fo...

MatLab Programming for Engineers Having No Formal Programming Knowledge

NASA Technical Reports Server (NTRS)

Shaykhian, Linda H.; Shaykhian, Gholam Ali

2007-01-01

MatLab is one of the most widely used very high level programming languages for Scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. Also, stated are the current limitations of the MatLab, which possibly can be taken care of by Mathworks Inc. in a future version to make MatLab more versatile.

CrossTalk. The Journal of Defense Software Engineering. Volume 25, Number 1, Jan/Feb 2012

DTIC Science & Technology

2012-01-01

Considerations in Airborne Systems and Equipment Certification – RTCA/DO-178B,” Washington, D.C., 1992. 5. Ishikawa , Kaoru (Translator: J. H...significant, repeated issue, a formal root cause analysis process is performed. This method uses fishbone or Ishikawa diagrams [5], where possible

Beta Testing in Social Work

ERIC Educational Resources Information Center

Traube, Dorian E.; Begun, Stephanie; Petering, Robin; Flynn, Marilyn L.

2017-01-01

The field of social work does not currently have a widely adopted method for expediting innovations into micro- or macropractice. Although it is common in fields such as engineering and business to have formal processes for accelerating scientific advances into consumer markets, few comparable mechanisms exist in the social sciences or social…

Leading the Teacher Team--Balancing between Formal and Informal Power in Program Leadership

ERIC Educational Resources Information Center

Högfeldt, Anna-Karin; Malmi, Lauri; Kinnunen, Päivi; Jerbrant, Anna; Strömberg, Emma; Berglund, Anders; Villadsen, Jørgen

2018-01-01

This continuous research within Nordic engineering institutions targets the contexts and possibilities for leadership among engineering education program directors. The IFP-model, developed based on analysis of interviews with program leaders in these institutions, visualizes the program director's informal and formal power. The model is presented…

How to Compare the Security Quality Requirements Engineering (SQUARE) Method with Other Methods

DTIC Science & Technology

2007-08-01

Attack Trees for Modeling and Analysis 10 2.8 Misuse and Abuse Cases 10 2.9 Formal Methods 11 2.9.1 Software Cost Reduction 12 2.9.2 Common...modern or efficient techniques. • Requirements analysis typically is either not performed at all (identified requirements are directly specified without...any analysis or modeling) or analysis is restricted to functional re- quirements and ignores quality requirements, other nonfunctional requirements

Epistemology, software engineering and formal methods

NASA Technical Reports Server (NTRS)

Holloway, C. Michael

1994-01-01

One of the most basic questions anyone can ask is, 'How do I know that what I think I know is true?' The study of this question is called epistemology. Traditionally, epistemology has been considered to be of legitimate interest only to philosophers, theologians, and three year old children who respond to every statement by asking, 'Why?' Software engineers need to be interested in the subject, however, because a lack of sufficient understanding of epistemology contributes to many of the current problems in the field.

Damage Tolerance and Reliability of Turbine Engine Components

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

1999-01-01

A formal method is described to quantify structural damage tolerance and reliability in the presence of multitude of uncertainties in turbine engine components. The method is based at the materials behaviour level where primitive variables with their respective scatters are used to describe the behavior. Computational simulation is then used to propagate those uncertainties to the structural scale where damage tolerance and reliability are usually specified. Several sample cases are described to illustrate the effectiveness, versatility, and maturity of the method. Typical results from these methods demonstrate that the methods are mature and that they can be used for future strategic projections and planning to assure better, cheaper, faster, products for competitive advantages in world markets. These results also indicate that the methods are suitable for predicting remaining life in aging or deteriorating structures.

Damage Tolerance and Reliability of Turbine Engine Components

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

1998-01-01

A formal method is described to quantify structural damage tolerance and reliability in the presence of multitude of uncertainties in turbine engine components. The method is based at the materials behavior level where primitive variables with their respective scatters are used to describe that behavior. Computational simulation is then used to propagate those uncertainties to the structural scale where damage tolerance and reliability are usually specified. Several sample cases are described to illustrate the effectiveness, versatility, and maturity of the method. Typical results from these methods demonstrate that the methods are mature and that they can be used for future strategic projections and planning to assure better, cheaper, faster products for competitive advantages in world markets. These results also indicate that the methods are suitable for predicting remaining life in aging or deteriorating structures.

Colloquium: Modeling the dynamics of multicellular systems: Application to tissue engineering

NASA Astrophysics Data System (ADS)

Kosztin, Ioan; Vunjak-Novakovic, Gordana; Forgacs, Gabor

2012-10-01

Tissue engineering is a rapidly evolving discipline that aims at building functional tissues to improve or replace damaged ones. To be successful in such an endeavor, ideally, the engineering of tissues should be based on the principles of developmental biology. Recent progress in developmental biology suggests that the formation of tissues from the composing cells is often guided by physical laws. Here a comprehensive computational-theoretical formalism is presented that is based on experimental input and incorporates biomechanical principles of developmental biology. The formalism is described and it is shown that it correctly reproduces and predicts the quantitative characteristics of the fundamental early developmental process of tissue fusion. Based on this finding, the formalism is then used toward the optimization of the fabrication of tubular multicellular constructs, such as a vascular graft, by bioprinting, a novel tissue engineering technology.

Executable Architecture Research at Old Dominion University

NASA Technical Reports Server (NTRS)

Tolk, Andreas; Shuman, Edwin A.; Garcia, Johnny J.

2011-01-01

Executable Architectures allow the evaluation of system architectures not only regarding their static, but also their dynamic behavior. However, the systems engineering community do not agree on a common formal specification of executable architectures. To close this gap and identify necessary elements of an executable architecture, a modeling language, and a modeling formalism is topic of ongoing PhD research. In addition, systems are generally defined and applied in an operational context to provide capabilities and enable missions. To maximize the benefits of executable architectures, a second PhD effort introduces the idea of creating an executable context in addition to the executable architecture. The results move the validation of architectures from the current information domain into the knowledge domain and improve the reliability of such validation efforts. The paper presents research and results of both doctoral research efforts and puts them into a common context of state-of-the-art of systems engineering methods supporting more agility.

Lacking a Formal Concept of Limit: Advanced Non-Mathematics Students' Personal Concept Definitions

ERIC Educational Resources Information Center

Beynon, Kenneth A.; Zollman, Alan

2015-01-01

This mixed-methods study examines the conceptual understanding of limit among 22 undergraduate engineering students from two different sections of the same introductory differential equations course. The participants' concepts of limit (concept images and personal concept definitions) were examined using written tasks followed by one-on-one…

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…

Preface to MOST-ONISW 2009

NASA Astrophysics Data System (ADS)

Doerr, Martin; Freitas, Fred; Guizzardi, Giancarlo; Han, Hyoil

Ontology is a cross-disciplinary field concerned with the study of concepts and theories that can be used for representing shared conceptualizations of specific domains. Ontological Engineering is a discipline in computer and information science concerned with the development of techniques, methods, languages and tools for the systematic construction of concrete artifacts capturing these representations, i.e., models (e.g., domain ontologies) and metamodels (e.g., upper-level ontologies). In recent years, there has been a growing interest in the application of formal ontology and ontological engineering to solve modeling problems in diverse areas in computer science such as software and data engineering, knowledge representation, natural language processing, information science, among many others.

Closing the Gap between Formalism and Application--PBL and Mathematical Skills in Engineering

ERIC Educational Resources Information Center

Christensen, Ole Ravn

2008-01-01

A common problem in learning mathematics concerns the gap between, on the one hand, doing the formalisms and calculations of abstract mathematics and, on the other hand, applying these in a specific contextualized setting for example the engineering world. The skills acquired through problem-based learning (PBL), in the special model used at…

Working on the Boundaries: Philosophies and Practices of the Design Process

NASA Technical Reports Server (NTRS)

Ryan, R.; Blair, J.; Townsend, J.; Verderaime, V.

1996-01-01

While systems engineering process is a program formal management technique and contractually binding, the design process is the informal practice of achieving the design project requirements throughout all design phases of the systems engineering process. The design process and organization are systems and component dependent. Informal reviews include technical information meetings and concurrent engineering sessions, and formal technical discipline reviews are conducted through the systems engineering process. This paper discusses and references major philosophical principles in the design process, identifies its role in interacting systems and disciplines analyses and integrations, and illustrates the process application in experienced aerostructural designs.

AMPHION: Specification-based programming for scientific subroutine libraries

NASA Technical Reports Server (NTRS)

Lowry, Michael; Philpot, Andrew; Pressburger, Thomas; Underwood, Ian; Waldinger, Richard; Stickel, Mark

1994-01-01

AMPHION is a knowledge-based software engineering (KBSE) system that guides a user in developing a diagram representing a formal problem specification. It then automatically implements a solution to this specification as a program consisting of calls to subroutines from a library. The diagram provides an intuitive domain oriented notation for creating a specification that also facilitates reuse and modification. AMPHION'S architecture is domain independent. AMPHION is specialized to an application domain by developing a declarative domain theory. Creating a domain theory is an iterative process that currently requires the joint expertise of domain experts and experts in automated formal methods for software development.

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings.

PubMed

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P; Kravitz, Richard L; Owen, Richard R; Sullivan, J Greer; Wu, Albert W; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-09-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context.

Probabilistic Methods for Structural Design and Reliability

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Whitlow, Woodrow, Jr. (Technical Monitor)

2002-01-01

This report describes a formal method to quantify structural damage tolerance and reliability in the presence of a multitude of uncertainties in turbine engine components. The method is based at the material behavior level where primitive variables with their respective scatter ranges are used to describe behavior. Computational simulation is then used to propagate the uncertainties to the structural scale where damage tolerance and reliability are usually specified. Several sample cases are described to illustrate the effectiveness, versatility, and maturity of the method. Typical results from this method demonstrate, that it is mature and that it can be used to probabilistically evaluate turbine engine structural components. It may be inferred from the results that the method is suitable for probabilistically predicting the remaining life in aging or in deteriorating structures, for making strategic projections and plans, and for achieving better, cheaper, faster products that give competitive advantages in world markets.

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…

48 CFR 48.101 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ENGINEERING Policies and Procedures 48.101 General. (a) Value engineering is the formal technique by which... performing more economically. Value engineering attempts to eliminate, without impairing essential functions... two value engineering approaches: (1) The first is an incentive approach in which contractor...

The VATES-Diamond as a Verifier's Best Friend

NASA Astrophysics Data System (ADS)

Glesner, Sabine; Bartels, Björn; Göthel, Thomas; Kleine, Moritz

Within a model-based software engineering process it needs to be ensured that properties of abstract specifications are preserved by transformations down to executable code. This is even more important in the area of safety-critical real-time systems where additionally non-functional properties are crucial. In the VATES project, we develop formal methods for the construction and verification of embedded systems. We follow a novel approach that allows us to formally relate abstract process algebraic specifications to their implementation in a compiler intermediate representation. The idea is to extract a low-level process algebraic description from the intermediate code and to formally relate it to previously developed abstract specifications. We apply this approach to a case study from the area of real-time operating systems and show that this approach has the potential to seamlessly integrate modeling, implementation, transformation and verification stages of embedded system development.

Preface to RIGiM 2009

NASA Astrophysics Data System (ADS)

Rolland, Colette; Yu, Eric; Salinesi, Camille; Castro, Jaelson

The use of intentional concepts, the notion of "goal" in particular, has been prominent in recent approaches to requirement engineering (RE). Goal-oriented frameworks and methods for requirements engineering (GORE) have been keynote topics in requirements engineering, conceptual modelling, and more generally in software engineering. What are the conceptual modelling foundations in these approaches? RIGiM (Requirements Intentions and Goals in Conceptual Modelling) aims to provide a forum for discussing the interplay between requirements engineering and conceptual modelling, and in particular, to investigate how goal- and intention-driven approaches help in conceptualising purposeful systems. What are the fundamental objectives and premises of requirements engineering and conceptual modelling respectively, and how can they complement each other? What are the demands on conceptual modelling from the standpoint of requirements engineering? What conceptual modelling techniques can be further taken advantage of in requirements engineering? What are the upcoming modelling challenges and issues in GORE? What are the unresolved open questions? What lessons are there to be learnt from industrial experiences? What empirical data are there to support the cost-benefit analysis when adopting GORE methods? Are there application domains or types of project settings for which goals and intentional approaches are particularly suitable or not suitable? What degree of formalization and automation, or interactivity is feasible and appropriate for what types of participants during requirements engineering?

Usability engineering: domain analysis activities for augmented-reality systems

NASA Astrophysics Data System (ADS)

Gabbard, Joseph; Swan, J. E., II; Hix, Deborah; Lanzagorta, Marco O.; Livingston, Mark; Brown, Dennis B.; Julier, Simon J.

2002-05-01

This paper discusses our usability engineering process for the Battlefield Augmented Reality System (BARS). Usability engineering is a structured, iterative, stepwise development process. Like the related disciplines of software and systems engineering, usability engineering is a combination of management principals and techniques, formal and semi- formal evaluation techniques, and computerized tools. BARS is an outdoor augmented reality system that displays heads- up battlefield intelligence information to a dismounted warrior. The paper discusses our general usability engineering process. We originally developed the process in the context of virtual reality applications, but in this work we are adapting the procedures to an augmented reality system. The focus of this paper is our work on domain analysis, the first activity of the usability engineering process. We describe our plans for and our progress to date on our domain analysis for BARS. We give results in terms of a specific urban battlefield use case we have designed.

48 CFR 48.101 - General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... engineering effort is applied to areas of the contract that offer opportunities for considerable savings... ENGINEERING Policies and Procedures 48.101 General. (a) Value engineering is the formal technique by which... performing more economically. Value engineering attempts to eliminate, without impairing essential functions...

48 CFR 48.101 - General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... engineering effort is applied to areas of the contract that offer opportunities for considerable savings... ENGINEERING Policies and Procedures 48.101 General. (a) Value engineering is the formal technique by which... performing more economically. Value engineering attempts to eliminate, without impairing essential functions...

48 CFR 48.101 - General.

Code of Federal Regulations, 2012 CFR

2012-10-01

... engineering effort is applied to areas of the contract that offer opportunities for considerable savings... ENGINEERING Policies and Procedures 48.101 General. (a) Value engineering is the formal technique by which... performing more economically. Value engineering attempts to eliminate, without impairing essential functions...

Developing Non-Formal Education Competences as a Complement of Formal Education for STEM Lecturers

ERIC Educational Resources Information Center

Terrazas-Marín, Roy Alonso

2018-01-01

This paper focuses on a current practice piece on professional development for university lecturers, transformative learning, dialogism and STEM (Science, Technology, Engineering and Mathematics) education. Its main goals are to identify the key characteristics that allow STEM educators to experiment with the usage of non-formal education…

Towards Co-Engineering Communicating Autonomous Cyber-Physical Systems

NASA Technical Reports Server (NTRS)

Bujorianu, Marius C.; Bujorianu, Manuela L.

2009-01-01

In this paper, we sketch a framework for interdisciplinary modeling of space systems, by proposing a holistic view. We consider different system dimensions and their interaction. Specifically, we study the interactions between computation, physics, communication, uncertainty and autonomy. The most comprehensive computational paradigm that supports a holistic perspective on autonomous space systems is given by cyber-physical systems. For these, the state of art consists of collaborating multi-engineering efforts that prompt for an adequate formal foundation. To achieve this, we propose a leveraging of the traditional content of formal modeling by a co-engineering process.

Formal and heuristic system decomposition methods in multidisciplinary synthesis. Ph.D. Thesis, 1991

NASA Technical Reports Server (NTRS)

Bloebaum, Christina L.

1991-01-01

The multidisciplinary interactions which exist in large scale engineering design problems provide a unique set of difficulties. These difficulties are associated primarily with unwieldy numbers of design variables and constraints, and with the interdependencies of the discipline analysis modules. Such obstacles require design techniques which account for the inherent disciplinary couplings in the analyses and optimizations. The objective of this work was to develop an efficient holistic design synthesis methodology that takes advantage of the synergistic nature of integrated design. A general decomposition approach for optimization of large engineering systems is presented. The method is particularly applicable for multidisciplinary design problems which are characterized by closely coupled interactions among discipline analyses. The advantage of subsystem modularity allows for implementation of specialized methods for analysis and optimization, computational efficiency, and the ability to incorporate human intervention and decision making in the form of an expert systems capability. The resulting approach is not a method applicable to only a specific situation, but rather, a methodology which can be used for a large class of engineering design problems in which the system is non-hierarchic in nature.

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.

(abstract) Formal Inspection Technology Transfer Program

NASA Technical Reports Server (NTRS)

Welz, Linda A.; Kelly, John C.

1993-01-01

A Formal Inspection Technology Transfer Program, based on the inspection process developed by Michael Fagan at IBM, has been developed at JPL. The goal of this program is to support organizations wishing to use Formal Inspections to improve the quality of software and system level engineering products. The Technology Transfer Program provides start-up materials and assistance to help organizations establish their own Formal Inspection program. The course materials and certified instructors associated with the Technology Transfer Program have proven to be effective in classes taught at other NASA centers as well as at JPL. Formal Inspections (NASA tailored Fagan Inspections) are a set of technical reviews whose objective is to increase quality and reduce the cost of software development by detecting and correcting errors early. A primary feature of inspections is the removal of engineering errors before they amplify into larger and more costly problems downstream in the development process. Note that the word 'inspection' is used differently in software than in a manufacturing context. A Formal Inspection is a front-end quality enhancement technique, rather than a task conducted just prior to product shipment for the purpose of sorting defective systems (manufacturing usage). Formal Inspections are supporting and in agreement with the 'total quality' approach being adopted by many NASA centers.

Engineering Research Division publication report, calendar year 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, E.K.; Livingston, P.L.; Rae, D.C.

Each year the Engineering Research Division of the Electronics Engineering Department at Lawrence Livermore Laboratory has issued an internal report listing all formal publications produced by the Division during the calendar year. Abstracts of 1980 reports are presented.

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.

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings

PubMed Central

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P.; Kravitz, Richard L.; Owen, Richard R.; Sullivan, Greer; Wu, Albert W.; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-01-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context. PMID:25217100

Preparing Engineers for the Challenges of Community Engagement

ERIC Educational Resources Information Center

Harsh, Matthew; Bernstein, Michael J.; Wetmore, Jameson; Cozzens, Susan; Woodson, Thomas; Castillo, Rafael

2017-01-01

Despite calls to address global challenges through community engagement, engineers are not formally prepared to engage with communities. Little research has been done on means to address this "engagement gap" in engineering education. We examine the efficacy of an intensive, two-day Community Engagement Workshop for engineers, designed…

Formal Language Design in the Context of Domain Engineering

DTIC Science & Technology

2000-03-28

73 Related Work 75 5.1 Feature oriented domain analysis ( FODA ) 75 5.2 Organizational domain modeling (ODM) 76 5.3 Domain-Specific Software...However there are only a few that are well defined and used repeatedly in practice. These include: Feature oriented domain analysis ( FODA ), Organizational...Feature oriented domain analysis ( FODA ) Feature oriented domain analysis ( FODA ) is a domain analysis method being researched and applied by the SEI

A Bayesian formulation of behavioral control.

PubMed

Huys, Quentin J M; Dayan, Peter

2009-12-01

Helplessness, a belief that the world is not subject to behavioral control, has long been central to our understanding of depression, and has influenced cognitive theories, animal models and behavioral treatments. However, despite its importance, there is no fully accepted definition of helplessness or behavioral control in psychology or psychiatry, and the formal treatments in engineering appear to capture only limited aspects of the intuitive concepts. Here, we formalize controllability in terms of characteristics of prior distributions over affectively charged environments. We explore the relevance of this notion of control to reinforcement learning methods of optimising behavior in such environments and consider how apparently maladaptive beliefs can result from normative inference processes. These results are discussed with reference to depression and animal models thereof.

General formalism of local thermodynamics with an example: Quantum Otto engine with a spin-1/2 coupled to an arbitrary spin.

PubMed

Altintas, Ferdi; Müstecaplıoğlu, Özgür E

2015-08-01

We investigate a quantum heat engine with a working substance of two particles, one with a spin-1/2 and the other with an arbitrary spin (spin s), coupled by Heisenberg exchange interaction, and subject to an external magnetic field. The engine operates in a quantum Otto cycle. Work harvested in the cycle and its efficiency are calculated using quantum thermodynamical definitions. It is found that the engine has higher efficiencies at higher spins and can harvest work at higher exchange interaction strengths. The role of exchange coupling and spin s on the work output and the thermal efficiency is studied in detail. In addition, the engine operation is analyzed from the perspective of local work and efficiency. We develop a general formalism to explore local thermodynamics applicable to any coupled bipartite system. Our general framework allows for examination of local thermodynamics even when global parameters of the system are varied in thermodynamic cycles. The generalized definitions of local and cooperative work are introduced by using mean field Hamiltonians. The general conditions for which the global work is not equal to the sum of the local works are given in terms of the covariance of the subsystems. Our coupled spin quantum Otto engine is used as an example of the general formalism.

General formalism of local thermodynamics with an example: Quantum Otto engine with a spin-1 /2 coupled to an arbitrary spin

NASA Astrophysics Data System (ADS)

Altintas, Ferdi; Müstecaplıoǧlu, Ã.-zgür E.

2015-08-01

We investigate a quantum heat engine with a working substance of two particles, one with a spin-1 /2 and the other with an arbitrary spin (spin s ), coupled by Heisenberg exchange interaction, and subject to an external magnetic field. The engine operates in a quantum Otto cycle. Work harvested in the cycle and its efficiency are calculated using quantum thermodynamical definitions. It is found that the engine has higher efficiencies at higher spins and can harvest work at higher exchange interaction strengths. The role of exchange coupling and spin s on the work output and the thermal efficiency is studied in detail. In addition, the engine operation is analyzed from the perspective of local work and efficiency. We develop a general formalism to explore local thermodynamics applicable to any coupled bipartite system. Our general framework allows for examination of local thermodynamics even when global parameters of the system are varied in thermodynamic cycles. The generalized definitions of local and cooperative work are introduced by using mean field Hamiltonians. The general conditions for which the global work is not equal to the sum of the local works are given in terms of the covariance of the subsystems. Our coupled spin quantum Otto engine is used as an example of the general formalism.

Linear quadratic servo control of a reusable rocket engine

NASA Technical Reports Server (NTRS)

Musgrave, Jeffrey L.

1991-01-01

The paper deals with the development of a design method for a servo component in the frequency domain using singular values and its application to a reusable rocket engine. A general methodology used to design a class of linear multivariable controllers for intelligent control systems is presented. Focus is placed on performance and robustness characteristics, and an estimator design performed in the framework of the Kalman-filter formalism with emphasis on using a sensor set different from the commanded values is discussed. It is noted that loop transfer recovery modifies the nominal plant noise intensities in order to obtain the desired degree of robustness to uncertainty reflected at the plant input. Simulation results demonstrating the performance of the linear design on a nonlinear engine model over all power levels during mainstage operation are discussed.

Towards a controlled vocabulary on software engineering education

NASA Astrophysics Data System (ADS)

Pizard, Sebastián; Vallespir, Diego

2017-11-01

Software engineering is the discipline that develops all the aspects of the production of software. Although there are guidelines about what topics to include in a software engineering curricula, it is usually unclear which are the best methods to teach them. In any science discipline the construction of a classification schema is a common approach to understand a thematic area. This study examines previous publications in software engineering education to obtain a first controlled vocabulary (a more formal definition of a classification schema) in the field. Publications from 1988 to 2014 were collected and processed using automatic clustering techniques and the outcomes were analysed manually. The result is an initial controlled vocabulary with a taxonomy form with 43 concepts that were identified as the most used in the research publications. We present the classification of the concepts in three facets: 'what to teach', 'how to teach' and 'where to teach' and the evolution of concepts over time.

Petri net-based dependability modeling methodology for reconfigurable field programmable gate arrays

NASA Astrophysics Data System (ADS)

Graczyk, Rafał; Orleański, Piotr; Poźniak, Krzysztof

2015-09-01

Dependability modeling is an important issue for aerospace and space equipment designers. From system level perspective, one has to choose from multitude of possible architectures, redundancy levels, component combinations in a way to meet desired properties and dependability and finally fit within required cost and time budgets. Modeling of such systems is getting harder as its levels of complexity grow together with demand for more functional and flexible, yet more available systems that govern more and more crucial parts of our civilization's infrastructure (aerospace transport systems, telecommunications, exploration probes). In this article promising method of modeling complex systems using Petri networks is introduced in context of qualitative and quantitative dependability analysis. This method, although with some limitation and drawback offer still convenient visual formal method of describing system behavior on different levels (functional, timing, random events) and offers straight correspondence to underlying mathematical engine, perfect for simulations and engineering support.

Examining Teachers' Perspectives on an Implementation of Elementary Engineering Teacher Professional Development

ERIC Educational Resources Information Center

Boots, Nikki Kim

2013-01-01

The emphasis on engaging young learners in science, technology, engineering, and math (STEM) professions is driving calls for educational reform. One movement that is gaining momentum is exposing K-12 learners to engineering. With the advent of the "Next Generation Science Standards" (2012b), engineering is being more formally integrated…

Aerospace engineering design by systematic decomposition and multilevel optimization

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, J.; Giles, G. L.; Barthelemy, J.-F. M.

1984-01-01

This paper describes a method for systematic analysis and optimization of large engineering systems, e.g., aircraft, by decomposition of a large task into a set of smaller, self-contained subtasks that can be solved concurrently. The subtasks may be arranged in many hierarchical levels with the assembled system at the top level. Analyses are carried out in each subtask using inputs received from other subtasks, and are followed by optimizations carried out from the bottom up. Each optimization at the lower levels is augmented by analysis of its sensitivity to the inputs received from other subtasks to account for the couplings among the subtasks in a formal manner. The analysis and optimization operations alternate iteratively until they converge to a system design whose performance is maximized with all constraints satisfied. The method, which is still under development, is tentatively validated by test cases in structural applications and an aircraft configuration optimization. It is pointed out that the method is intended to be compatible with the typical engineering organization and the modern technology of distributed computing.

Case Study of 'Engineering Peer Meetings' in JPL's ST-6 Project

NASA Technical Reports Server (NTRS)

Chao, Lawrence P.; Tumer, Irem

2004-01-01

This design process error-proofing case study describes a design review practice implemented by a project manager at NASA Jet Propulsion Laboratory. There are many types of reviews at NASA: required and not, formalized and informal, programmatic and technical. Standing project formal reviews such as the Preliminary Design Review (PDR) and Critical Design Review (CDR) are a required part of every project and mission development. However, the engineering peer reviews that support teams technical work on such projects are often informal, ad hoc, and inconsistent across the organization. This case study discusses issues and innovations identified by a project manager at JPL and implemented in 'engineering peer meetings' for his group.

Case Study of "Engineering Peer Meetings" in JPL's ST-6 Project

NASA Technical Reports Server (NTRS)

Tumer, Irem Y.; Chao, Lawrence P.

2003-01-01

This design process error-proofing case study describes a design review practice implemented by a project manager at NASA Jet Propulsion Laboratory. There are many types of reviews at NASA: required and not, formalized and informal, programmatic and technical. Standing project formal reviews such as the Preliminary Design Review (PDR) and Critical Design Review (CDR) are a required part of every project and mission development. However, the engineering peer reviews that support teams technical work on such projects are often informal, ad hoc, and inconsistent across the organization. This case study discusses issues and innovations identified by a project manager at JPL and implemented in "engineering peer meetings" for his group.

Systems engineering principles for the design of biomedical signal processing systems.

PubMed

Faust, Oliver; Acharya U, Rajendra; Sputh, Bernhard H C; Min, Lim Choo

2011-06-01

Systems engineering aims to produce reliable systems which function according to specification. In this paper we follow a systems engineering approach to design a biomedical signal processing system. We discuss requirements capturing, specification definition, implementation and testing of a classification system. These steps are executed as formal as possible. The requirements, which motivate the system design, are based on diabetes research. The main requirement for the classification system is to be a reliable component of a machine which controls diabetes. Reliability is very important, because uncontrolled diabetes may lead to hyperglycaemia (raised blood sugar) and over a period of time may cause serious damage to many of the body systems, especially the nerves and blood vessels. In a second step, these requirements are refined into a formal CSP‖ B model. The formal model expresses the system functionality in a clear and semantically strong way. Subsequently, the proven system model was translated into an implementation. This implementation was tested with use cases and failure cases. Formal modeling and automated model checking gave us deep insight in the system functionality. This insight enabled us to create a reliable and trustworthy implementation. With extensive tests we established trust in the reliability of the implementation. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Modular Knowledge Representation and Reasoning in the Semantic Web

NASA Astrophysics Data System (ADS)

Serafini, Luciano; Homola, Martin

Construction of modular ontologies by combining different modules is becoming a necessity in ontology engineering in order to cope with the increasing complexity of the ontologies and the domains they represent. The modular ontology approach takes inspiration from software engineering, where modularization is a widely acknowledged feature. Distributed reasoning is the other side of the coin of modular ontologies: given an ontology comprising of a set of modules, it is desired to perform reasoning by combination of multiple reasoning processes performed locally on each of the modules. In the last ten years, a number of approaches for combining logics has been developed in order to formalize modular ontologies. In this chapter, we survey and compare the main formalisms for modular ontologies and distributed reasoning in the Semantic Web. We select four formalisms build on formal logical grounds of Description Logics: Distributed Description Logics, ℰ-connections, Package-based Description Logics and Integrated Distributed Description Logics. We concentrate on expressivity and distinctive modeling features of each framework. We also discuss reasoning capabilities of each framework.

Experiences with a Requirements-Based Programming Approach to the Development of a NASA Autonomous Ground Control System

NASA Technical Reports Server (NTRS)

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

2005-01-01

Requirements-to-Design-to-Code (R2D2C) is an approach to the engineering of computer-based systems that embodies the idea of requirements-based programming in system development. It goes further; however, in that the approach offers not only an underlying formalism, but full formal development from requirements capture through to the automatic generation of provably-correct code. As such, the approach has direct application to the development of systems requiring autonomic properties. We describe a prototype tool to support the method, and illustrate its applicability to the development of LOGOS, a NASA autonomous ground control system, which exhibits autonomic behavior. Finally, we briefly discuss other areas where the approach and prototype tool are being considered for application.

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.

Aerospace engineering design by systematic decomposition and multilevel optimization

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, J.; Barthelemy, J. F. M.; Giles, G. L.

1984-01-01

A method for systematic analysis and optimization of large engineering systems, by decomposition of a large task into a set of smaller subtasks that is solved concurrently is described. The subtasks may be arranged in hierarchical levels. Analyses are carried out in each subtask using inputs received from other subtasks, and are followed by optimizations carried out from the bottom up. Each optimization at the lower levels is augmented by analysis of its sensitivity to the inputs received from other subtasks to account for the couplings among the subtasks in a formal manner. The analysis and optimization operations alternate iteratively until they converge to a system design whose performance is maximized with all constraints satisfied. The method, which is still under development, is tentatively validated by test cases in structural applications and an aircraft configuration optimization.

A linear decomposition method for large optimization problems. Blueprint for development

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, J.

1982-01-01

A method is proposed for decomposing large optimization problems encountered in the design of engineering systems such as an aircraft into a number of smaller subproblems. The decomposition is achieved by organizing the problem and the subordinated subproblems in a tree hierarchy and optimizing each subsystem separately. Coupling of the subproblems is accounted for by subsequent optimization of the entire system based on sensitivities of the suboptimization problem solutions at each level of the tree to variables of the next higher level. A formalization of the procedure suitable for computer implementation is developed and the state of readiness of the implementation building blocks is reviewed showing that the ingredients for the development are on the shelf. The decomposition method is also shown to be compatible with the natural human organization of the design process of engineering systems. The method is also examined with respect to the trends in computer hardware and software progress to point out that its efficiency can be amplified by network computing using parallel processors.

Open Campus: Strategic Plan

DTIC Science & Technology

2016-05-01

The formal and informal interactions among scientists, engineers, and business and technology specialists fostered by this environment will lead...pathways for highly trained graduates of science, technology, engineering, and mathematics (STEM) academic programs, and help academic institutions...engineering and mathematics (STEM) disciplines relevant to ARL science and technology programs. Under EPAs, visiting students and professors

Educating Engineers in Information Utilization.

ERIC Educational Resources Information Center

Borovansky, Vladimir T.

1987-01-01

Traditionally engineers are not heaviest users of information resources. This can be traced to lack of emphasis on information sources in engineering education. Failure to use available knowledge leads to reinventing the wheel and losing the race for technological superiority. Few U.S. universities offer formal courses in information resources in…

Engineering in Communities: Learning by Doing

ERIC Educational Resources Information Center

Goggins, J.

2012-01-01

Purpose: The purpose of this paper is to focus on a number of initiatives in civil engineering undergraduate programmes at the National University of Ireland, Galway (NUIG) that allow students to complete engineering projects in the community, enabling them to learn by doing. Design/methodology/approach: A formal commitment to civic engagement was…

Knowledge-Based Aircraft Automation: Managers Guide on the use of Artificial Intelligence for Aircraft Automation and Verification and Validation Approach for a Neural-Based Flight Controller

NASA Technical Reports Server (NTRS)

Broderick, Ron

1997-01-01

The ultimate goal of this report was to integrate the powerful tools of artificial intelligence into the traditional process of software development. To maintain the US aerospace competitive advantage, traditional aerospace and software engineers need to more easily incorporate the technology of artificial intelligence into the advanced aerospace systems being designed today. The future goal was to transition artificial intelligence from an emerging technology to a standard technology that is considered early in the life cycle process to develop state-of-the-art aircraft automation systems. This report addressed the future goal in two ways. First, it provided a matrix that identified typical aircraft automation applications conducive to various artificial intelligence methods. The purpose of this matrix was to provide top-level guidance to managers contemplating the possible use of artificial intelligence in the development of aircraft automation. Second, the report provided a methodology to formally evaluate neural networks as part of the traditional process of software development. The matrix was developed by organizing the discipline of artificial intelligence into the following six methods: logical, object representation-based, distributed, uncertainty management, temporal and neurocomputing. Next, a study of existing aircraft automation applications that have been conducive to artificial intelligence implementation resulted in the following five categories: pilot-vehicle interface, system status and diagnosis, situation assessment, automatic flight planning, and aircraft flight control. The resulting matrix provided management guidance to understand artificial intelligence as it applied to aircraft automation. The approach taken to develop a methodology to formally evaluate neural networks as part of the software engineering life cycle was to start with the existing software quality assurance standards and to change these standards to include neural network development. The changes were to include evaluation tools that can be applied to neural networks at each phase of the software engineering life cycle. The result was a formal evaluation approach to increase the product quality of systems that use neural networks for their implementation.

SU-E-T-785: Using Systems Engineering to Design HDR Skin Treatment Operation for Small Lesions to Enhance Patient Safety

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saw, C; Baikadi, M; Peters, C

2015-06-15

Purpose: Using systems engineering to design HDR skin treatment operation for small lesions using shielded applicators to enhance patient safety. Methods: Systems engineering is an interdisciplinary field that offers formal methodologies to study, design, implement, and manage complex engineering systems as a whole over their life-cycles. The methodologies deal with human work-processes, coordination of different team, optimization, and risk management. The V-model of systems engineering emphasize two streams, the specification and the testing streams. The specification stream consists of user requirements, functional requirements, and design specifications while the testing on installation, operational, and performance specifications. In implementing system engineering tomore » this project, the user and functional requirements are (a) HDR unit parameters be downloaded from the treatment planning system, (b) dwell times and positions be generated by treatment planning system, (c) source decay be computer calculated, (d) a double-check system of treatment parameters to comply with the NRC regulation. These requirements are intended to reduce human intervention to improve patient safety. Results: A formal investigation indicated that the user requirements can be satisfied. The treatment operation consists of using the treatment planning system to generate a pseudo plan that is adjusted for different shielded applicators to compute the dwell times. The dwell positions, channel numbers, and the dwell times are verified by the medical physicist and downloaded into the HDR unit. The decayed source strength is transferred to a spreadsheet that computes the dwell times based on the type of applicators and prescribed dose used. Prior to treatment, the source strength, dwell times, dwell positions, and channel numbers are double-checked by the radiation oncologist. No dosimetric parameters are manually calculated. Conclusion: Systems engineering provides methodologies to effectively design the HDR treatment operation that minimize human intervention and improve patient safety.« less

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.

Survey of Verification and Validation Techniques for Small Satellite Software Development

NASA Technical Reports Server (NTRS)

Jacklin, Stephen A.

2015-01-01

The purpose of this paper is to provide an overview of the current trends and practices in small-satellite software verification and validation. This document is not intended to promote a specific software assurance method. Rather, it seeks to present an unbiased survey of software assurance methods used to verify and validate small satellite software and to make mention of the benefits and value of each approach. These methods include simulation and testing, verification and validation with model-based design, formal methods, and fault-tolerant software design with run-time monitoring. Although the literature reveals that simulation and testing has by far the longest legacy, model-based design methods are proving to be useful for software verification and validation. Some work in formal methods, though not widely used for any satellites, may offer new ways to improve small satellite software verification and validation. These methods need to be further advanced to deal with the state explosion problem and to make them more usable by small-satellite software engineers to be regularly applied to software verification. Last, it is explained how run-time monitoring, combined with fault-tolerant software design methods, provides an important means to detect and correct software errors that escape the verification process or those errors that are produced after launch through the effects of ionizing radiation.

Quantum dynamical framework for Brownian heat engines

NASA Astrophysics Data System (ADS)

Agarwal, G. S.; Chaturvedi, S.

2013-07-01

We present a self-contained formalism modeled after the Brownian motion of a quantum harmonic oscillator for describing the performance of microscopic Brownian heat engines such as Carnot, Stirling, and Otto engines. Our theory, besides reproducing the standard thermodynamics results in the steady state, enables us to study the role dissipation plays in determining the efficiency of Brownian heat engines under actual laboratory conditions. In particular, we analyze in detail the dynamics associated with decoupling a system in equilibrium with one bath and recoupling it to another bath and obtain exact analytical results, which are shown to have significant ramifications on the efficiencies of engines involving such a step. We also develop a simple yet powerful technique for computing corrections to the steady state results arising from finite operation time and use it to arrive at the thermodynamic complementarity relations for various operating conditions and also to compute the efficiencies of the three engines cited above at maximum power. Some of the methods and exactly solvable models presented here are interesting in their own right and could find useful applications in other contexts as well.

Studies on behaviour of information to extract the meaning behind the behaviour

NASA Astrophysics Data System (ADS)

Nasution, M. K. M.; Syah, R.; Elveny, M.

2017-01-01

Web as social media can be used as a reference for determining social behaviour. However, the information extraction involves a search engine is not easy to give that picture. There are several properties of the search engine to be formally disclosed to provide assurance that the information is feasible. Although quite a lot of research that has revealed the interest of the Web as social media, but a few of them that have revealed behaviour of information related to social behaviour. In this case, it needs the formal steps to present possibilities related properties. There are 12 properties that are interconnected as behaviour of information and then it reveals several meanings based on the simulation results of any search engine.

Automated Reuse of Scientific Subroutine Libraries through Deductive Synthesis

NASA Technical Reports Server (NTRS)

Lowry, Michael R.; Pressburger, Thomas; VanBaalen, Jeffrey; Roach, Steven

1997-01-01

Systematic software construction offers the potential of elevating software engineering from an art-form to an engineering discipline. The desired result is more predictable software development leading to better quality and more maintainable software. However, the overhead costs associated with the formalisms, mathematics, and methods of systematic software construction have largely precluded their adoption in real-world software development. In fact, many mainstream software development organizations, such as Microsoft, still maintain a predominantly oral culture for software development projects; which is far removed from a formalism-based culture for software development. An exception is the limited domain of safety-critical software, where the high-assuiance inherent in systematic software construction justifies the additional cost. We believe that systematic software construction will only be adopted by mainstream software development organization when the overhead costs have been greatly reduced. Two approaches to cost mitigation are reuse (amortizing costs over many applications) and automation. For the last four years, NASA Ames has funded the Amphion project, whose objective is to automate software reuse through techniques from systematic software construction. In particular, deductive program synthesis (i.e., program extraction from proofs) is used to derive a composition of software components (e.g., subroutines) that correctly implements a specification. The construction of reuse libraries of software components is the standard software engineering solution for improving software development productivity and quality.

Probabilistic simulation of concurrent engineering of propulsion systems

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Singhal, S. N.

1993-01-01

Technology readiness and the available infrastructure is assessed for timely computational simulation of concurrent engineering for propulsion systems. Results for initial coupled multidisciplinary, fabrication-process, and system simulators are presented including uncertainties inherent in various facets of engineering processes. An approach is outlined for computationally formalizing the concurrent engineering process from cradle-to-grave via discipline dedicated workstations linked with a common database.

DoD Science and Engineering Apprenticeship Program for High School Students, 1996-󈨥 Activities

DTIC Science & Technology

1997-05-01

including lectures, laboratory demonstrations, scientific films, field trips and a formal course and a weekly discussion session on the history of science using...lectures, laboratory demonstrations, scientific films, field trips and a formal course and a weekly discussion session on the history of science using

Proceedings of the first switch tube advanced technology meeting held at EG G, Salem, Massachusetts, May 23, 1990

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shuman, A.; Beavis, L.

Early in 1990, J. A. Wilder, Supervisor of Sandia National Laboratories (SNLA), Division 2565 requested that a meeting of the scientists and engineers responsible for developing and producing switch tubes be set up to discuss in a semi-formal way the science and technology of switch tubes. Programmatic and administrative issues were specifically exempted from the discussions. L. Beavis, Division 7471, SNL and A. Shuman, EG G, Salem were made responsible for organizing a program including the materials and processes of switch tubes. The purpose of the Switch Tube Advanced Technology meeting was to allow personnel from Allied Signal Kansas Citymore » Division (AS/KCD); EG G, Salem and Sandia National Laboratories (SNL) to discuss a variety of issues involved in the development and production of switch tubes. It was intended that the formal and informal discussions would allow a better understanding of the production problems by material and process engineers and of the materials and processes by production engineers. This program consisted of formal presentations on May 23 and informal discussions on May 24. The topics chosen for formal presentation were suggested by the people of AS/KCD, EG G, Salem, and SNL involved with the design, development and production of switch tubes. The topics selected were generic. They were not directed to any specific switch tube but rather to all switch tubes in production and development. This document includes summaries of the material presented at the formal presentation on May 23.« less

Formal Abstraction in Engineering Education--Challenges and Technology Support

ERIC Educational Resources Information Center

Neuper, Walther A.

2017-01-01

This is a position paper in the field of Engineering Education, which is at the very beginning in Europe. It relates challenges in the new field to the emerging technology of (Computer) Theorem Proving (TP). Experience shows, that "teaching" abstract models, for instance the wave equation in mechanical engineering and in electrical…

Advancing Systems Engineering Excellence: The Marshall Systems Engineering Leadership Development Program

NASA Technical Reports Server (NTRS)

Hall, Philip; Whitfield, Susan

2011-01-01

As NASA undertakes increasingly complex projects, the need for expert systems engineers and leaders in systems engineering is becoming more pronounced. As a result of this issue, the Agency has undertaken an initiative to develop more systems engineering leaders through its Systems Engineering Leadership Development Program; however, the NASA Office of the Chief Engineer has also called on the field Centers to develop mechanisms to strengthen their expertise in systems engineering locally. In response to this call, Marshall Space Flight Center (MSFC) has developed a comprehensive development program for aspiring systems engineers and systems engineering leaders. This presentation will summarize the two-level program, which consists of a combination of training courses and on-the-job, developmental training assignments at the Center to help develop stronger expertise in systems engineering and technical leadership. In addition, it will focus on the success the program has had in its pilot year. The program hosted a formal kickoff event for Level I on October 13, 2009. The first class includes 42 participants from across MSFC and Michoud Assembly Facility (MAF). A formal call for Level II is forthcoming. With the new Agency focus on research and development of new technologies, having a strong pool of well-trained systems engineers is becoming increasingly more critical. Programs such as the Marshall Systems Engineering Leadership Development Program, as well as those developed at other Centers, help ensure that there is an upcoming generation of trained systems engineers and systems engineering leaders to meet future design challenges.

Managing Analysis Models in the Design Process

NASA Technical Reports Server (NTRS)

Briggs, Clark

2006-01-01

Design of large, complex space systems depends on significant model-based support for exploration of the design space. Integrated models predict system performance in mission-relevant terms given design descriptions and multiple physics-based numerical models. Both the design activities and the modeling activities warrant explicit process definitions and active process management to protect the project from excessive risk. Software and systems engineering processes have been formalized and similar formal process activities are under development for design engineering and integrated modeling. JPL is establishing a modeling process to define development and application of such system-level models.

Confined Detonations and Pulse Detonation Engines

DTIC Science & Technology

2003-01-01

chemically reacting flow was described by the 2D Euler equations &q OF(q) +G(q) W (1) 75 CONFINED DETONATIONS AND PULSE DETONATION ENGINES where q = (p...DETONATIONS AND PULSE DETONATION ENGINES 5 CONCLUDING REMARKS Numerical investigations of RR and MR in a supersonic chemically reacting flows have...formalism of hetero- geneous medium mechanics supplemented with an overall chemical reaction was 141 CONFINED DETONATIONS AND PULSE DETONATION ENGINES

Practical Guidance on Science and Engineering Ethics Education for Instructors and Administrators: Papers and Summary from a Workshop, December 12, 2012

ERIC Educational Resources Information Center

Benya, Frazier F., Ed.; Fletcher, Cameron H.,Ed.; Hollander, Rachelle D.,Ed.

2013-01-01

Over the last two decades, colleges and universities in the United States have significantly increased the formal ethics instruction they provide in science and engineering. Today, science and engineering programs socialize students into the values of scientists and engineers as well as their obligations in the conduct of scientific research and…

Formal Methods Tool Qualification

NASA Technical Reports Server (NTRS)

Wagner, Lucas G.; Cofer, Darren; Slind, Konrad; Tinelli, Cesare; Mebsout, Alain

2017-01-01

Formal methods tools have been shown to be effective at finding defects in safety-critical digital systems including avionics systems. The publication of DO-178C and the accompanying formal methods supplement DO-333 allows applicants to obtain certification credit for the use of formal methods without providing justification for them as an alternative method. This project conducted an extensive study of existing formal methods tools, identifying obstacles to their qualification and proposing mitigations for those obstacles. Further, it interprets the qualification guidance for existing formal methods tools and provides case study examples for open source tools. This project also investigates the feasibility of verifying formal methods tools by generating proof certificates which capture proof of the formal methods tool's claim, which can be checked by an independent, proof certificate checking tool. Finally, the project investigates the feasibility of qualifying this proof certificate checker, in the DO-330 framework, in lieu of qualifying the model checker itself.

Thermodynamics of the mesoscopic thermoelectric heat engine beyond the linear-response regime.

PubMed

Yamamoto, Kaoru; Hatano, Naomichi

2015-10-01

Mesoscopic thermoelectric heat engine is much anticipated as a device that allows us to utilize with high efficiency wasted heat inaccessible by conventional heat engines. However, the derivation of the heat current in this engine seems to be either not general or described too briefly, even inappropriately in some cases. In this paper, we give a clear-cut derivation of the heat current of the engine with suitable assumptions beyond the linear-response regime. It resolves the confusion in the definition of the heat current in the linear-response regime. After verifying that we can construct the same formalism as that of the cyclic engine, we find the following two interesting results within the Landauer-Büttiker formalism: the efficiency of the mesoscopic thermoelectric engine reaches the Carnot efficiency if and only if the transmission probability is finite at a specific energy and zero otherwise; the unitarity of the transmission probability guarantees the second law of thermodynamics, invalidating Benenti et al.'s argument in the linear-response regime that one could obtain a finite power with the Carnot efficiency under a broken time-reversal symmetry [Phys. Rev. Lett. 106, 230602 (2011)]. These results demonstrate how quantum mechanics constrains thermodynamics.

Proceedings 3rd NASA/IEEE Workshop on Formal Approaches to Agent-Based Systems (FAABS-III)

NASA Technical Reports Server (NTRS)

Hinchey, Michael (Editor); Rash, James (Editor); Truszkowski, Walt (Editor); Rouff, Christopher (Editor)

2004-01-01

These preceedings contain 18 papers and 4 poster presentation, covering topics such as: multi-agent systems, agent-based control, formalism, norms, as well as physical and biological models of agent-based systems. Some applications presented in the proceedings include systems analysis, software engineering, computer networks and robot control.

Factors Influencing Postsecondary STEM Students' Views of the Public Communication of an Emergent Technology: a Cross-National Study from Five Universities

NASA Astrophysics Data System (ADS)

Gardner, Grant E.; Jones, M. Gail; Albe, Virginie; Blonder, Ron; Laherto, Antti; Macher, Daniel; Paechter, Manuela

2017-10-01

Recent efforts in the science education community have highlighted the need to integrate research and theory from science communication research into more general science education scholarship. These synthesized research perspectives are relatively novel but serve an important need to better understand the impacts that the advent of rapidly emerging technologies will have on a new generation of scientists and engineers including their formal communication with engaged citizenry. This cross-national study examined postsecondary science and engineering students' ( n = 254 from five countries: Austria, Finland, France, Israel, and USA) perspectives on the role of science communication in their own formal science and engineering education. More broadly, we examined participants' understanding of their perceived responsibilities of communicating science and engineering to the general public when an issue contains complex social and ethical implications (SEI). The study is contextualized in the emergent technology of nanotechnology for which SEI are of particular concern and for which the general public often perceives conflicting risks and benefits. Findings indicate that student participants' hold similar views on the need for their own training in communication as future scientists and engineers. When asked about the role that ethics and risk perception plays in research, development, and public communication of nanotechnology, participants demonstrate similar trajectories of perspectives that are, however, often anchored in very different levels of beginning concern. Results are discussed in the context of considerations for science communication training within formal science education curricula globally.

Embryo mechanics: balancing force production with elastic resistance during morphogenesis.

PubMed

Davidson, Lance A

2011-01-01

Morphogenesis requires the spatial and temporal control of embryo mechanics, including force production and mechanical resistance to those forces, to coordinate tissue deformation and large-scale movements. Thus, biomechanical processes play a key role in directly shaping the embryo. Additional roles for embryo mechanics during development may include the patterning of positional information and to provide feedback to ensure the success of morphogenetic movements in shaping the larval body and organs. To understand the multiple roles of mechanics during development requires familiarity with engineering principles of the mechanics of structures, the viscoelastic properties of biomaterials, and the integration of force and stress within embryonic structures as morphogenesis progresses. In this chapter, we review the basic engineering principles of biomechanics as they relate to morphogenesis, introduce methods for quantifying embryo mechanics and the limitations of these methods, and outline a formalism for investigating the role of embryo mechanics in birth defects. We encourage the nascent field of embryo mechanics to adopt standard engineering terms and test methods so that studies of diverse organisms can be compared and universal biomechanical principles can be revealed. Copyright © 2011 Elsevier Inc. All rights reserved.

Applications of formal simulation languages in the control and monitoring subsystems of Space Station Freedom

NASA Technical Reports Server (NTRS)

Lacovara, R. C.

1990-01-01

The notions, benefits, and drawbacks of numeric simulation are introduced. Two formal simulation languages, Simpscript and Modsim are introduced. The capabilities of each are discussed briefly, and then the two programs are compared. The use of simulation in the process of design engineering for the Control and Monitoring System (CMS) for Space Station Freedom is discussed. The application of the formal simulation language to the CMS design is presented, and recommendations are made as to their use.

Ontology or formal ontology

NASA Astrophysics Data System (ADS)

Žáček, Martin

2017-07-01

Ontology or formal ontology? Which word is correct? The aim of this article is to introduce correct terms and explain their basis. Ontology describes a particular area of interest (domain) in a formal way - defines the classes of objects that are in that area, and relationships that may exist between them. Meaning of ontology consists mainly in facilitating communication between people, improve collaboration of software systems and in the improvement of systems engineering. Ontology in all these areas offer the possibility of unification of view, maintaining consistency and unambiguity.

T/BEST: Technology Benefit Estimator for Composites and Applications to Engine Structures

NASA Technical Reports Server (NTRS)

Chamis, Christos

1997-01-01

Progress in the field of aerospace propulsion has heightened the need to combine advanced technologies. These benefits will provide guidelines for identifying and prioritizing high-payoff research areas, will help manage research with limited resources, and will show the link between advanced and basic concepts. An effort was undertaken at the NASA Lewis Research Center to develop a formal computational method, T/BEST (Technology Benefit Estimator), to assess advanced aerospace technologies, such as fibrous composites, and credibly communicate the benefits of research. Fibrous composites are ideal for structural applications such as high-performance aircraft engine blades where high strength-to-weight and stiffness-to-weight ratios are required. These factors - along with the flexibility to select the composite system and layup, and to favorably orient fiber directions - reduce the displacements and stresses caused by large rotational speeds in aircraft engines.

Semantically-Rigorous Systems Engineering Modeling Using Sysml and OWL

NASA Technical Reports Server (NTRS)

Jenkins, J. Steven; Rouquette, Nicolas F.

2012-01-01

The Systems Modeling Language (SysML) has found wide acceptance as a standard graphical notation for the domain of systems engineering. SysML subsets and extends the Unified Modeling Language (UML) to define conventions for expressing structural, behavioral, and analytical elements, and relationships among them. SysML-enabled modeling tools are available from multiple providers, and have been used for diverse projects in military aerospace, scientific exploration, and civil engineering. The Web Ontology Language (OWL) has found wide acceptance as a standard notation for knowledge representation. OWL-enabled modeling tools are available from multiple providers, as well as auxiliary assets such as reasoners and application programming interface libraries, etc. OWL has been applied to diverse projects in a wide array of fields. While the emphasis in SysML is on notation, SysML inherits (from UML) a semantic foundation that provides for limited reasoning and analysis. UML's partial formalization (FUML), however, does not cover the full semantics of SysML, which is a substantial impediment to developing high confidence in the soundness of any conclusions drawn therefrom. OWL, by contrast, was developed from the beginning on formal logical principles, and consequently provides strong support for verification of consistency and satisfiability, extraction of entailments, conjunctive query answering, etc. This emphasis on formal logic is counterbalanced by the absence of any graphical notation conventions in the OWL standards. Consequently, OWL has had only limited adoption in systems engineering. The complementary strengths and weaknesses of SysML and OWL motivate an interest in combining them in such a way that we can benefit from the attractive graphical notation of SysML and the formal reasoning of OWL. This paper describes an approach to achieving that combination.

Assessing the Higher National Diploma Chemical Engineering Programme in Ghana: Students' Perspective

ERIC Educational Resources Information Center

Boateng, Cyril D.; Bensah, Edem Cudjoe; Ahiekpor, Julius C.

2012-01-01

Chemical engineers have played key roles in the growth of the chemical and allied industries in Ghana but indigenous industries that have traditionally been the domain of the informal sector need to be migrated to the formal sector through the entrepreneurship and innovation of chemical engineers. The Higher National Diploma Chemical Engineering…

Suicide and the Internet: Changes in the accessibility of suicide-related information between 2007 and 2014.

PubMed

Biddle, Lucy; Derges, Jane; Mars, Becky; Heron, Jon; Donovan, Jenny L; Potokar, John; Piper, Martyn; Wyllie, Clare; Gunnell, David

2016-01-15

Following the ongoing concerns about cyber-suicide, we investigate changes between 2007 and 2014 in material likely to be accessed by suicidal individuals searching for methods of suicide. 12 search terms relating to suicide methods were applied to four search engines and the top ten hits from each were categorised and analysed for content. The frequency of each category of site across all searches, using particular search terms and engines, was counted. Key changes: growth of blogs and discussion forums (from 3% of hits, 2007 to 18.5% of hits, 2014); increase in hits linking to general information sites - especially factual sites that detail and evaluate suicide methods (from 9%, 2007 to 21.7%, 2014). Hits for dedicated suicide sites increased (from 19% to 23%), while formal help sites were less visible (from 13% to 6.5%). Overall, 54% of hits contained information about new high-lethality methods. We did not search for help sites so cannot assess the balance of suicide promoting versus preventing sites available online. Social media was beyond the scope of this study. Working with ISPs and search engines would help optimise support sites. Better site moderation and implementation of suicide reporting guidelines should be encouraged. Copyright © 2015 Elsevier B.V. All rights reserved.

Formalizing the Austrian Procedure Catalogue: A 4-step methodological analysis approach.

PubMed

Neururer, Sabrina Barbara; Lasierra, Nelia; Peiffer, Karl Peter; Fensel, Dieter

2016-04-01

Due to the lack of an internationally accepted and adopted standard for coding health interventions, Austria has established its own country-specific procedure classification system - the Austrian Procedure Catalogue (APC). Even though the APC is an elaborate coding standard for medical procedures, it has shortcomings that limit its usability. In order to enhance usability and usefulness, especially for research purposes and e-health applications, we developed an ontologized version of the APC. In this paper we present a novel four-step approach for the ontology engineering process, which enables accurate extraction of relevant concepts for medical ontologies from written text. The proposed approach for formalizing the APC consists of the following four steps: (1) comparative pre-analysis, (2) definition analysis, (3) typological analysis, and (4) ontology implementation. The first step contained a comparison of the APC to other well-established or elaborate health intervention coding systems in order to identify strengths and weaknesses of the APC. In the second step, a list of definitions of medical terminology used in the APC was obtained. This list of definitions was used as input for Step 3, in which we identified the most important concepts to describe medical procedures using the qualitative typological analysis approach. The definition analysis as well as the typological analysis are well-known and effective methods used in social sciences, but not commonly employed in the computer science or ontology engineering domain. Finally, this list of concepts was used in Step 4 to formalize the APC. The pre-analysis highlighted the major shortcomings of the APC, such as the lack of formal definition, leading to implicitly available, but not directly accessible information (hidden data), or the poor procedural type classification. After performing the definition and subsequent typological analyses, we were able to identify the following main characteristics of health interventions: (1) Procedural type, (2) Anatomical site, (3) Medical device, (4) Pathology, (5) Access, (6) Body system, (7) Population, (8) Aim, (9) Discipline, (10) Technique, and (11) Body Function. These main characteristics were taken as input of classes for the formalization of the APC. We were also able to identify relevant relations between classes. The proposed four-step approach for formalizing the APC provides a novel, systematically developed, strong framework to semantically enrich procedure classifications. Although this methodology was designed to address the particularities of the APC, the included methods are based on generic analysis tasks, and therefore can be re-used to provide a systematic representation of other procedure catalogs or classification systems and hence contribute towards a universal alignment of such representations, if desired. Copyright © 2015 Elsevier Inc. All rights reserved.

Formally verifying human–automation interaction as part of a system model: limitations and tradeoffs

PubMed Central

Bass, Ellen J.

2011-01-01

Both the human factors engineering (HFE) and formal methods communities are concerned with improving the design of safety-critical systems. This work discusses a modeling effort that leveraged methods from both fields to perform formal verification of human–automation interaction with a programmable device. This effort utilizes a system architecture composed of independent models of the human mission, human task behavior, human-device interface, device automation, and operational environment. The goals of this architecture were to allow HFE practitioners to perform formal verifications of realistic systems that depend on human–automation interaction in a reasonable amount of time using representative models, intuitive modeling constructs, and decoupled models of system components that could be easily changed to support multiple analyses. This framework was instantiated using a patient controlled analgesia pump in a two phased process where models in each phase were verified using a common set of specifications. The first phase focused on the mission, human-device interface, and device automation; and included a simple, unconstrained human task behavior model. The second phase replaced the unconstrained task model with one representing normative pump programming behavior. Because models produced in the first phase were too large for the model checker to verify, a number of model revisions were undertaken that affected the goals of the effort. While the use of human task behavior models in the second phase helped mitigate model complexity, verification time increased. Additional modeling tools and technological developments are necessary for model checking to become a more usable technique for HFE. PMID:21572930

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.

Formalization of the classification pattern: survey of classification modeling in information systems engineering.

PubMed

Partridge, Chris; de Cesare, Sergio; Mitchell, Andrew; Odell, James

2018-01-01

Formalization is becoming more common in all stages of the development of information systems, as a better understanding of its benefits emerges. Classification systems are ubiquitous, no more so than in domain modeling. The classification pattern that underlies these systems provides a good case study of the move toward formalization in part because it illustrates some of the barriers to formalization, including the formal complexity of the pattern and the ontological issues surrounding the "one and the many." Powersets are a way of characterizing the (complex) formal structure of the classification pattern, and their formalization has been extensively studied in mathematics since Cantor's work in the late nineteenth century. One can use this formalization to develop a useful benchmark. There are various communities within information systems engineering (ISE) that are gradually working toward a formalization of the classification pattern. However, for most of these communities, this work is incomplete, in that they have not yet arrived at a solution with the expressiveness of the powerset benchmark. This contrasts with the early smooth adoption of powerset by other information systems communities to, for example, formalize relations. One way of understanding the varying rates of adoption is recognizing that the different communities have different historical baggage. Many conceptual modeling communities emerged from work done on database design, and this creates hurdles to the adoption of the high level of expressiveness of powersets. Another relevant factor is that these communities also often feel, particularly in the case of domain modeling, a responsibility to explain the semantics of whatever formal structures they adopt. This paper aims to make sense of the formalization of the classification pattern in ISE and surveys its history through the literature, starting from the relevant theoretical works of the mathematical literature and gradually shifting focus to the ISE literature. The literature survey follows the evolution of ISE's understanding of how to formalize the classification pattern. The various proposals are assessed using the classical example of classification; the Linnaean taxonomy formalized using powersets as a benchmark for formal expressiveness. The broad conclusion of the survey is that (1) the ISE community is currently in the early stages of the process of understanding how to formalize the classification pattern, particularly in the requirements for expressiveness exemplified by powersets, and (2) that there is an opportunity to intervene and speed up the process of adoption by clarifying this expressiveness. Given the central place that the classification pattern has in domain modeling, this intervention has the potential to lead to significant improvements.

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.

A planning and scheduling lexicon

NASA Technical Reports Server (NTRS)

Cruz, Jennifer W.; Eggemeyer, William C.

1989-01-01

A lexicon related to mission planning and scheduling for spacecraft is presented. Planning and scheduling work is known as sequencing. Sequencing is a multistage process of merging requests from both the science and engineering arenas to accomplish the objectives defined in the requests. The multistage process begins with the creation of science and engineering goals, continues through their integration into the sequence, and eventually concludes with command execution onboard the spacecraft. The objective of this publication is to introduce some formalism into the field of spacecraft sequencing-system technology. This formalism will make it possible for researchers and potential customers to communicate about system requirements and capabilities in a common language.

Enhancing Individual Employability: The Perspective of Engineering Graduates

ERIC Educational Resources Information Center

Nilsson, Staffan

2010-01-01

Purpose: Employability includes the ability to find employment and remain employed. Employability includes both hard and soft skills, including formal and actual competence, interpersonal skills, and personal characteristics. This paper aims to focus on illuminating perceptions engineering graduates have regarding employability. More specifically,…

A Generic Software Safety Document Generator

NASA Technical Reports Server (NTRS)

Denney, Ewen; Venkatesan, Ram Prasad

2004-01-01

Formal certification is based on the idea that a mathematical proof of some property of a piece of software can be regarded as a certificate of correctness which, in principle, can be subjected to external scrutiny. In practice, however, proofs themselves are unlikely to be of much interest to engineers. Nevertheless, it is possible to use the information obtained from a mathematical analysis of software to produce a detailed textual justification of correctness. In this paper, we describe an approach to generating textual explanations from automatically generated proofs of program safety, where the proofs are of compliance with an explicit safety policy that can be varied. Key to this is tracing proof obligations back to the program, and we describe a tool which implements this to certify code auto-generated by AutoBayes and AutoFilter, program synthesis systems under development at the NASA Ames Research Center. Our approach is a step towards combining formal certification with traditional certification methods.

A medical ontology for intelligent web-based skin lesions image retrieval.

PubMed

Maragoudakis, Manolis; Maglogiannis, Ilias

2011-06-01

Researchers have applied increasing efforts towards providing formal computational frameworks to consolidate the plethora of concepts and relations used in the medical domain. In the domain of skin related diseases, the variability of semantic features contained within digital skin images is a major barrier to the medical understanding of the symptoms and development of early skin cancers. The desideratum of making these standards machine-readable has led to their formalization in ontologies. In this work, in an attempt to enhance an existing Core Ontology for skin lesion images, hand-coded from image features, high quality images were analyzed by an autonomous ontology creation engine. We show that by exploiting agglomerative clustering methods with distance criteria upon the existing ontological structure, the original domain model could be enhanced with new instances, attributes and even relations, thus allowing for better classification and retrieval of skin lesion categories from the web.

Security Hardened Cyber Components for Nuclear Power Plants: Phase I SBIR Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franusich, Michael D.

SpiralGen, Inc. built a proof-of-concept toolkit for enhancing the cyber security of nuclear power plants and other critical infrastructure with high-assurance instrumentation and control code. The toolkit is based on technology from the DARPA High-Assurance Cyber Military Systems (HACMS) program, which has focused on applying the science of formal methods to the formidable set of problems involved in securing cyber physical systems. The primary challenges beyond HACMS in developing this toolkit were to make the new technology usable by control system engineers and compatible with the regulatory and commercial constraints of the nuclear power industry. The toolkit, packaged as amore » Simulink add-on, allows a system designer to assemble a high-assurance component from formally specified and proven blocks and generate provably correct control and monitor code for that subsystem.« less

Designing an architectural style for Pervasive Healthcare systems.

PubMed

Rafe, Vahid; Hajvali, Masoumeh

2013-04-01

Nowadays, the Pervasive Healthcare (PH) systems are considered as an important research area. These systems have a dynamic structure and configuration. Therefore, an appropriate method for designing such systems is necessary. The Publish/Subscribe Architecture (pub/sub) is one of the convenient architectures to support such systems. PH systems are safety critical; hence, errors can bring disastrous results. To prevent such problems, a powerful analytical tool is required. So using a proper formal language like graph transformation systems for developing of these systems seems necessary. But even if software engineers use such high level methodologies, errors may occur in the system under design. Hence, it should be investigated automatically and formally that whether this model of system satisfies all their requirements or not. In this paper, a dynamic architectural style for developing PH systems is presented. Then, the behavior of these systems is modeled and evaluated using GROOVE toolset. The results of the analysis show its high reliability.

Ontological analysis of SNOMED CT.

PubMed

Héja, Gergely; Surján, György; Varga, Péter

2008-10-27

SNOMED CT is the most comprehensive medical terminology. However, its use for intelligent services based on formal reasoning is questionable. The analysis of the structure of SNOMED CT is based on the formal top-level ontology DOLCE. The analysis revealed several ontological and knowledge-engineering errors, the most important are errors in the hierarchy (mostly from an ontological point of view, but also regarding medical aspects) and the mixing of subsumption relations with other types (mostly 'part of'). The found errors impede formal reasoning. The paper presents a possible way to correct these problems.

Thermodynamics of the mesoscopic thermoelectric heat engine beyond the linear-response regime

NASA Astrophysics Data System (ADS)

Yamamoto, Kaoru; Hatano, Naomichi

2015-10-01

Mesoscopic thermoelectric heat engine is much anticipated as a device that allows us to utilize with high efficiency wasted heat inaccessible by conventional heat engines. However, the derivation of the heat current in this engine seems to be either not general or described too briefly, even inappropriately in some cases. In this paper, we give a clear-cut derivation of the heat current of the engine with suitable assumptions beyond the linear-response regime. It resolves the confusion in the definition of the heat current in the linear-response regime. After verifying that we can construct the same formalism as that of the cyclic engine, we find the following two interesting results within the Landauer-Büttiker formalism: the efficiency of the mesoscopic thermoelectric engine reaches the Carnot efficiency if and only if the transmission probability is finite at a specific energy and zero otherwise; the unitarity of the transmission probability guarantees the second law of thermodynamics, invalidating Benenti et al.'s argument in the linear-response regime that one could obtain a finite power with the Carnot efficiency under a broken time-reversal symmetry [Phys. Rev. Lett. 106, 230602 (2011), 10.1103/PhysRevLett.106.230602]. These results demonstrate how quantum mechanics constrains thermodynamics.

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.

HDL to verification logic translator

NASA Technical Reports Server (NTRS)

Gambles, J. W.; Windley, P. J.

1992-01-01

The increasingly higher number of transistors possible in VLSI circuits compounds the difficulty in insuring correct designs. As the number of possible test cases required to exhaustively simulate a circuit design explodes, a better method is required to confirm the absence of design faults. Formal verification methods provide a way to prove, using logic, that a circuit structure correctly implements its specification. Before verification is accepted by VLSI design engineers, the stand alone verification tools that are in use in the research community must be integrated with the CAD tools used by the designers. One problem facing the acceptance of formal verification into circuit design methodology is that the structural circuit descriptions used by the designers are not appropriate for verification work and those required for verification lack some of the features needed for design. We offer a solution to this dilemma: an automatic translation from the designers' HDL models into definitions for the higher-ordered logic (HOL) verification system. The translated definitions become the low level basis of circuit verification which in turn increases the designer's confidence in the correctness of higher level behavioral models.

Practical Formal Verification of MPI and Thread Programs

NASA Astrophysics Data System (ADS)

Gopalakrishnan, Ganesh; Kirby, Robert M.

Large-scale simulation codes in science and engineering are written using the Message Passing Interface (MPI). Shared memory threads are widely used directly, or to implement higher level programming abstractions. Traditional debugging methods for MPI or thread programs are incapable of providing useful formal guarantees about coverage. They get bogged down in the sheer number of interleavings (schedules), often missing shallow bugs. In this tutorial we will introduce two practical formal verification tools: ISP (for MPI C programs) and Inspect (for Pthread C programs). Unlike other formal verification tools, ISP and Inspect run directly on user source codes (much like a debugger). They pursue only the relevant set of process interleavings, using our own customized Dynamic Partial Order Reduction algorithms. For a given test harness, DPOR allows these tools to guarantee the absence of deadlocks, instrumented MPI object leaks and communication races (using ISP), and shared memory races (using Inspect). ISP and Inspect have been used to verify large pieces of code: in excess of 10,000 lines of MPI/C for ISP in under 5 seconds, and about 5,000 lines of Pthread/C code in a few hours (and much faster with the use of a cluster or by exploiting special cases such as symmetry) for Inspect. We will also demonstrate the Microsoft Visual Studio and Eclipse Parallel Tools Platform integrations of ISP (these will be available on the LiveCD).

Mathematical Building-Blocks in Engineering Mechanics

ERIC Educational Resources Information Center

Boyajian, David M.

2007-01-01

A gamut of mathematical subjects and concepts are taught within a handful of courses formally required of the typical engineering student who so often questions the relevancy of being bound to certain lower-division prerequisites. Basic classes at the undergraduate level, in this context, include: Integral and Differential Calculus, Differential…

Employees' Perceptions of Barriers to Participation in Training and Development in Small Engineering Businesses

ERIC Educational Resources Information Center

Susomrith, Pattanee; Coetzer, Alan

2015-01-01

Purpose: This paper aims to investigate barriers to employee participation in voluntary formal training and development opportunities from the perspective of employees in small engineering businesses. Design/methodology/approach: An exploratory qualitative methodology involving data collection via site visits and in-depth semi-structured…

Incorporating interfacial phenomena in solidification models

NASA Technical Reports Server (NTRS)

Beckermann, Christoph; Wang, Chao Yang

1994-01-01

A general methodology is available for the incorporation of microscopic interfacial phenomena in macroscopic solidification models that include diffusion and convection. The method is derived from a formal averaging procedure and a multiphase approach, and relies on the presence of interfacial integrals in the macroscopic transport equations. In a wider engineering context, these techniques are not new, but their application in the analysis and modeling of solidification processes has largely been overlooked. This article describes the techniques and demonstrates their utility in two examples in which microscopic interfacial phenomena are of great importance.

Integrated analysis of large space systems

NASA Technical Reports Server (NTRS)

Young, J. P.

1980-01-01

Based on the belief that actual flight hardware development of large space systems will necessitate a formalized method of integrating the various engineering discipline analyses, an efficient highly user oriented software system capable of performing interdisciplinary design analyses with tolerable solution turnaround time is planned Specific analysis capability goals were set forth with initial emphasis given to sequential and quasi-static thermal/structural analysis and fully coupled structural/control system analysis. Subsequently, the IAC would be expanded to include a fully coupled thermal/structural/control system, electromagnetic radiation, and optical performance analyses.

Investigation of the effect of scattering centers on low dimensional nanowire channel

NASA Astrophysics Data System (ADS)

Cariappa, K. S.; Shukla, Raja; Sarkar, Niladri

2018-05-01

In this work, we studied the effect of scattering centers on the electron density profiles of a one dimensional Nanowire channel. Density Matrix Formalism is used for calculating the local electron densities at room temperature. Various scattering centers have been simulated in the channel. The nearest neighbor tight binding method is applied to construct the Hamiltonian of nanoscale devices. We invoke scattering centers by adding local scattering potentials to the Hamiltonian. This analysis could give an insight into the understanding and utilization of defects for device engineering.

Recent Developments: PKI Square Dish for the Soleras Project

NASA Technical Reports Server (NTRS)

Rogers, W. E.

1984-01-01

The Square Dish solar collectors are subjected to rigorous design attention regarding corrosion at the site, and certification of the collector structure. The microprocessor controls and tracking mechanisms are improved in the areas of fail safe operations, durability, and low parasitic power requirements. Prototype testing demonstrates performance efficiency of approximately 72% at 730 F outlet temperature. Studies are conducted that include developing formal engineering design studies, developing formal engineering design drawing and fabrication details, establishing subcontracts for fabrication of major components, and developing a rigorous quality control system. The improved design is more cost effective to product and the extensive manuals developed for assembly and operation/maintenance result in faster field assembly and ease of operation.

Recent developments: PKI square dish for the Soleras Project

NASA Astrophysics Data System (ADS)

Rogers, W. E.

1984-03-01

The Square Dish solar collectors are subjected to rigorous design attention regarding corrosion at the site, and certification of the collector structure. The microprocessor controls and tracking mechanisms are improved in the areas of fail safe operations, durability, and low parasitic power requirements. Prototype testing demonstrates performance efficiency of approximately 72% at 730 F outlet temperature. Studies are conducted that include developing formal engineering design studies, developing formal engineering design drawing and fabrication details, establishing subcontracts for fabrication of major components, and developing a rigorous quality control system. The improved design is more cost effective to product and the extensive manuals developed for assembly and operation/maintenance result in faster field assembly and ease of operation.

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.

Modeling and formal representation of geospatial knowledge for the Geospatial Semantic Web

NASA Astrophysics Data System (ADS)

Huang, Hong; Gong, Jianya

2008-12-01

GML can only achieve geospatial interoperation at syntactic level. However, it is necessary to resolve difference of spatial cognition in the first place in most occasions, so ontology was introduced to describe geospatial information and services. But it is obviously difficult and improper to let users to find, match and compose services, especially in some occasions there are complicated business logics. Currently, with the gradual introduction of Semantic Web technology (e.g., OWL, SWRL), the focus of the interoperation of geospatial information has shifted from syntactic level to Semantic and even automatic, intelligent level. In this way, Geospatial Semantic Web (GSM) can be put forward as an augmentation to the Semantic Web that additionally includes geospatial abstractions as well as related reasoning, representation and query mechanisms. To advance the implementation of GSM, we first attempt to construct the mechanism of modeling and formal representation of geospatial knowledge, which are also two mostly foundational phases in knowledge engineering (KE). Our attitude in this paper is quite pragmatical: we argue that geospatial context is a formal model of the discriminate environment characters of geospatial knowledge, and the derivation, understanding and using of geospatial knowledge are located in geospatial context. Therefore, first, we put forward a primitive hierarchy of geospatial knowledge referencing first order logic, formal ontologies, rules and GML. Second, a metamodel of geospatial context is proposed and we use the modeling methods and representation languages of formal ontologies to process geospatial context. Thirdly, we extend Web Process Service (WPS) to be compatible with local DLL for geoprocessing and possess inference capability based on OWL.

Generating Phenotypical Erroneous Human Behavior to Evaluate Human-automation Interaction Using Model Checking

PubMed Central

Bolton, Matthew L.; Bass, Ellen J.; Siminiceanu, Radu I.

2012-01-01

Breakdowns in complex systems often occur as a result of system elements interacting in unanticipated ways. In systems with human operators, human-automation interaction associated with both normative and erroneous human behavior can contribute to such failures. Model-driven design and analysis techniques provide engineers with formal methods tools and techniques capable of evaluating how human behavior can contribute to system failures. This paper presents a novel method for automatically generating task analytic models encompassing both normative and erroneous human behavior from normative task models. The generated erroneous behavior is capable of replicating Hollnagel’s zero-order phenotypes of erroneous action for omissions, jumps, repetitions, and intrusions. Multiple phenotypical acts can occur in sequence, thus allowing for the generation of higher order phenotypes. The task behavior model pattern capable of generating erroneous behavior can be integrated into a formal system model so that system safety properties can be formally verified with a model checker. This allows analysts to prove that a human-automation interactive system (as represented by the model) will or will not satisfy safety properties with both normative and generated erroneous human behavior. We present benchmarks related to the size of the statespace and verification time of models to show how the erroneous human behavior generation process scales. We demonstrate the method with a case study: the operation of a radiation therapy machine. A potential problem resulting from a generated erroneous human action is discovered. A design intervention is presented which prevents this problem from occurring. We discuss how our method could be used to evaluate larger applications and recommend future paths of development. PMID:23105914

The Role of Formal Experiment Design in Hypersonic Flight System Technology Development

NASA Technical Reports Server (NTRS)

McClinton, Charles R.; Ferlemann, Shelly M.; Rock, Ken E.; Ferlemann, Paul G.

2002-01-01

Hypersonic airbreathing engine (scramjet) powered vehicles are being considered to replace conventional rocket-powered launch systems. Effective utilization of scramjet engines requires careful integration with the air vehicle. This integration synergistically combines aerodynamic forces with propulsive cycle functions of the engine. Due to the highly integrated nature of the hypersonic vehicle design problem, the large flight envelope, and the large number of design variables, the use of a statistical design approach in design is effective. Modern Design-of-Experiments (MDOE) has been used throughout the Hyper-X program, for both systems analysis and experimental testing. Application of MDOE fall into four categories: (1) experimental testing; (2) studies of unit phenomena; (3) refining engine design; and (4) full vehicle system optimization. The MDOE process also provides analytical models, which are also used to document lessons learned, supplement low-level design tools, and accelerate future studies. This paper will discuss the design considerations for scramjet-powered vehicles, specifics of MDOE utilized for Hyper-X, and present highlights from the use of these MDOE methods within the Hyper-X Program.

Making Sense of the Arrow-Pushing Formalism among Chemistry Majors Enrolled in Organic Chemistry

ERIC Educational Resources Information Center

Ferguson, Robert; Bodner, George M.

2008-01-01

This paper reports results of a qualitative study of sixteen students enrolled in a second year organic chemistry course for chemistry and chemical engineering majors. The focus of the study was student use of the arrow-pushing formalism that plays a central role in both the teaching and practice of organic chemistry. The goal of the study was to…

Systems Engineering Leadership Development: Advancing Systems Engineering Excellence

NASA Technical Reports Server (NTRS)

Hall, Phil; Whitfield, Susan

2011-01-01

This slide presentation reviews the Systems Engineering Leadership Development Program, with particular emphasis on the work being done in the development of systems engineers at Marshall Space Flight Center. There exists a lack of individuals with systems engineering expertise, in particular those with strong leadership capabilities, to meet the needs of the Agency's exploration agenda. Therefore there is a emphasis on developing these programs to identify and train systems engineers. The presentation reviews the proposed MSFC program that includes course work, and developmental assignments. The formal developmental programs at the other centers are briefly reviewed, including the Point of Contact (POC)

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.

Using Life-Cycle Human Factors Engineering to Avoid $2.4 Million in Costs: Lessons Learned from NASA's Requirements Verification Process for Space Payloads

NASA Technical Reports Server (NTRS)

Carr, Daniel; Ellenberger, Rich

2008-01-01

The Human Factors Implementation Team (HFIT) process has been used to verify human factors requirements for NASA International Space Station (ISS) payloads since 2003, resulting in $2.4 million in avoided costs. This cost benefit has been realized by greatly reducing the need to process time-consuming formal waivers (exceptions) for individual requirements violations. The HFIT team, which includes astronauts and their technical staff, acts as the single source for human factors requirements integration of payloads. HFIT has the authority to provide inputs during early design phases, thus eliminating many potential requirements violations in a cost-effective manner. In those instances where it is not economically or technically feasible to meet the precise metric of a given requirement, HFIT can work with the payload engineers to develop common sense solutions and formally document that the resulting payload design does not materially affect the astronaut s ability to operate and interact with the payload. The HFIT process is fully ISO 9000 compliant and works concurrently with NASA s formal systems engineering work flow. Due to its success with payloads, the HFIT process is being adapted and extended to ISS systems hardware. Key aspects of this process are also being considered for NASA's Space Shuttle replacement, the Crew Exploration Vehicle.

Health care professional workstation: software system construction using DSSA scenario-based engineering process.

PubMed

Hufnagel, S; Harbison, K; Silva, J; Mettala, E

1994-01-01

This paper describes a new method for the evolutionary determination of user requirements and system specifications called scenario-based engineering process (SEP). Health care professional workstations are critical components of large scale health care system architectures. We suggest that domain-specific software architectures (DSSAs) be used to specify standard interfaces and protocols for reusable software components throughout those architectures, including workstations. We encourage the use of engineering principles and abstraction mechanisms. Engineering principles are flexible guidelines, adaptable to particular situations. Abstraction mechanisms are simplifications for management of complexity. We recommend object-oriented design principles, graphical structural specifications, and formal components' behavioral specifications. We give an ambulatory care scenario and associated models to demonstrate SEP. The scenario uses health care terminology and gives patients' and health care providers' system views. Our goal is to have a threefold benefit. (i) Scenario view abstractions provide consistent interdisciplinary communications. (ii) Hierarchical object-oriented structures provide useful abstractions for reuse, understandability, and long term evolution. (iii) SEP and health care DSSA integration into computer aided software engineering (CASE) environments. These environments should support rapid construction and certification of individualized systems, from reuse libraries.

Warfighting Concepts to Future Weapon System Designs (WARCON)

DTIC Science & Technology

2003-09-12

34* Software design documents rise to litigation. "* A Material List "Cost information that may support, or may * Final Engineering Process Maps be...document may include design the system as derived from the engineering design, software development, SRD. MTS Technologies, Inc. 26 FOR OFFICIAL USE...document, early in the development phase. It is software engineers produce the vision of important to establish a standard, formal the design effort. As

Review of Estelle and LOTOS with respect to critical computer applications

NASA Technical Reports Server (NTRS)

Bown, Rodney L.

1991-01-01

Man rated NASA space vehicles seem to represent a set of ultimate critical computer applications. These applications require a high degree of security, integrity, and safety. A variety of formal and/or precise modeling techniques are becoming available for the designer of critical systems. The design phase of the software engineering life cycle includes the modification of non-development components. A review of the Estelle and LOTOS formal description languages is presented. Details of the languages and a set of references are provided. The languages were used to formally describe some of the Open System Interconnect (OSI) protocols.

Cyber-physical approach to the network-centric robotics control task

NASA Astrophysics Data System (ADS)

Muliukha, Vladimir; Ilyashenko, Alexander; Zaborovsky, Vladimir; Lukashin, Alexey

2016-10-01

Complex engineering tasks concerning control for groups of mobile robots are developed poorly. In our work for their formalization we use cyber-physical approach, which extends the range of engineering and physical methods for a design of complex technical objects by researching the informational aspects of communication and interaction between objects and with an external environment [1]. The paper analyzes network-centric methods for control of cyber-physical objects. Robots or cyber-physical objects interact with each other by transmitting information via computer networks using preemptive queueing system and randomized push-out mechanism [2],[3]. The main field of application for the results of our work is space robotics. The selection of cyber-physical systems as a special class of designed objects is due to the necessity of integrating various components responsible for computing, communications and control processes. Network-centric solutions allow using universal means for the organization of information exchange to integrate different technologies for the control system.

Topology reconstruction for B-Rep modeling from 3D mesh in reverse engineering applications

NASA Astrophysics Data System (ADS)

Bénière, Roseline; Subsol, Gérard; Gesquière, Gilles; Le Breton, François; Puech, William

2012-03-01

Nowadays, most of the manufactured objects are designed using CAD (Computer-Aided Design) software. Nevertheless, for visualization, data exchange or manufacturing applications, the geometric model has to be discretized into a 3D mesh composed of a finite number of vertices and edges. But, in some cases, the initial model may be lost or unavailable. In other cases, the 3D discrete representation may be modified, for example after a numerical simulation, and does not correspond anymore to the initial model. A reverse engineering method is then required to reconstruct a 3D continuous representation from the discrete one. In previous work, we have presented a new approach for 3D geometric primitive extraction. In this paper, to complete our automatic and comprehensive reverse engineering process, we propose a method to construct the topology of the retrieved object. To reconstruct a B-Rep model, a new formalism is now introduced to define the adjacency relations. Then a new process is used to construct the boundaries of the object. The whole process is tested on 3D industrial meshes and bring a solution to recover B-Rep models.

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.

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.

Five Years of NASA Science and Engineering in the Classroom: The Integrated Product Team/NASA Space Missions Course

NASA Astrophysics Data System (ADS)

Hakkila, Jon; Runyon, Cassndra; Benfield, M. P. J.; Turner, Matthew W.; Farrington, Phillip A.

2015-08-01

We report on five years of an exciting and successful educational collaboration in which science undergraduates at the College of Charleston work with engineering seniors at the University of Alabama in Huntsville to design a planetary science mission in response to a mock announcement of opportunity. Alabama high schools are also heavily involved in the project, and other colleges and universities have also participated. During the two-semester course students learn about scientific goals, past missions, methods of observation, instrumentation, and component integration, proposal writing, and presentation. More importantly, students learn about real-world communication and teamwork, and go through a series of baseline reviews before presenting their results at a formal final review for a panel of NASA scientists and engineers. The project is competitive, with multiple mission designs competing with one another for the best review score. Past classes have involved missions to Venus, Europa, Titan, Mars, asteroids, comets, and even the Moon. Classroom successes and failures have both been on epic scales.

Knowledge Engineering as a Component of the Curriculum for Medical Cybernetists.

PubMed

Karas, Sergey; Konev, Arthur

2017-01-01

According to a new state educational standard, students who have chosen medical cybernetics as their major must develop a knowledge engineering competency. Previously, in the course "Clinical cybernetics" while practicing project-based learning students were designing automated workstations for medical personnel using client-server technology. The purpose of the article is to give insight into the project of a new educational module "Knowledge engineering". Students will acquire expert knowledge by holding interviews and conducting surveys, and then they will formalize it. After that, students will form declarative expert knowledge in a network model and analyze the knowledge graph. Expert decision making methods will be applied in software on the basis of a production model of knowledge. Project implementation will result not only in the development of analytical competencies among students, but also creation of a practically useful expert system based on student models to support medical decisions. Nowadays, this module is being tested in the educational process.

Software reliability perspectives

NASA Technical Reports Server (NTRS)

Wilson, Larry; Shen, Wenhui

1987-01-01

Software which is used in life critical functions must be known to be highly reliable before installation. This requires a strong testing program to estimate the reliability, since neither formal methods, software engineering nor fault tolerant methods can guarantee perfection. Prior to the final testing software goes through a debugging period and many models have been developed to try to estimate reliability from the debugging data. However, the existing models are poorly validated and often give poor performance. This paper emphasizes the fact that part of their failures can be attributed to the random nature of the debugging data given to these models as input, and it poses the problem of correcting this defect as an area of future research.

Formal Analysis of Privacy Requirements Specifications for Multi-Tier Applications

DTIC Science & Technology

2013-07-30

Requirements Engineering Lab and co- founder of the Requirements Engineering and Law Workshop and has several publications in ACM- and IEEE- sponsored journals...Advertising that serves the online ad “Buying Razors Sucks” in this game. Zynga also produces a version of this game for the Android and iPhone mobile

Engineering Aid 3 & 2, Vol. 1. Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Naval Education and Training Command, Washington, DC.

Designed for individual study and not formal classroom instruction, this rate training manual provides subject matter that relates directly to the occupational qualifications of the Engineering Aid (EA) rating. This eight-chapter volume focuses on administrative matters, mathematics, and basic drafting. Chapter 1 discusses the scope of the EA…

Baseball Stadium Design: Teaching Engineering Economics and Technical Communication in a Multi-Disciplinary Setting.

ERIC Educational Resources Information Center

Dahm, Kevin; Newell, James

2001-01-01

Reports on a course at Rowan University, based on the economic design of a baseball stadium, that offers an introduction to multidisciplinary engineering design linked with formal training in technical communication. Addresses four pedagogical goals: (1) developing public speaking skills in a realistic, business setting; (2) giving students…

Attitudes towards Communication Skills among Engineering Students

ERIC Educational Resources Information Center

Kovac, Mirjana M.; Sirkovic, N.

2017-01-01

Good communication skills are of utmost importance in the education of engineering students. It is necessary to promote not only their education, but also to prepare them for the demanding and competitive job market. The purpose of this study was to compare the attitudes towards communication skills after formal instruction between the students of…

High School Physics: An Interactive Instructional Approach That Meets the Next Generation Science Standards

ERIC Educational Resources Information Center

Huang, Shaobo; Mejia, Joel Alejandro; Becker, Kurt; Neilson, Drew

2015-01-01

Improving high school physics teaching and learning is important to the long-term success of science, technology, engineering, and mathematics (STEM) education. Efforts are currently in place to develop an understanding of science among high school students through formal and informal educational experiences in engineering design activities…

Engineering Aid 3 & 2, Vol. 2. Rate Training Manual.

ERIC Educational Resources Information Center

Bernal, Benito C., Jr.

Designed for individual study and not formal classroom instruction, this rate training manual provides subject matter that relates directly to the occupational qualifications of the Engineering Aid (EA) rating. This volume contains 10 chapters which deal with: (1) wood and light frame structures (examining the uses, kinds, sizes, and grades of…

Transactional, Cooperative, and Communal: Relating the Structure of Engineering Engagement Programs with the Nature of Partnerships

ERIC Educational Resources Information Center

Thompson, Julia D.; Jesiek, Brent K.

2017-01-01

This paper examines how the structural features of engineering engagement programs (EEPs) are related to the nature of their service-learning partnerships. "Structure" refers to formal and informal models, processes, and operations adopted or used to describe engagement programs, while "nature" signifies the quality of…

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 36: Technical uncertainty as a correlate of information use by US industry-affiliated aerospace engineers and scientists

NASA Technical Reports Server (NTRS)

Pinelli, Thomas E.; Glassman, Nanci A.; Affelder, Linda O.; Hecht, Laura M.; Kennedy, John M.; Barclay, Rebecca O.

1994-01-01

This paper reports the results of an exploratory study that investigated the influence of technical uncertainty on the use of information and information sources by U.S. industry-affiliated aerospace engineers and scientists in completing or solving a project, task, or problem. Data were collected through a self-administered questionnaire. Survey participants were U.S. aerospace engineers and scientists whose names appeared on the Society of Automotive Engineers (SAE) mailing list. The results support the findings of previous research and the following study assumptions. Information and information-source use differ for projects, problems, and tasks with high and low technical uncertainty. As technical uncertainty increases, information-source use changes from internal to external and from informal to formal sources. As technical uncertainty increases, so too does the use of federally funded aerospace research and development (R&D). The use of formal information sources to learn about federally funded aerospace R&D differs for projects, problems, and tasks with high and low technical uncertainty.

Examining elementary students' perceptions of engineers

NASA Astrophysics Data System (ADS)

Oware, Euridice A.

There has been a national focus on improving K-12 Science, Technology, Engineering, and Mathematics (STEM) education. The integration of engineering education from kindergarten through high school (K-12) has been identified as key to sustaining the U.S. economy and standard of living. Misconceptions about the nature of engineering may deter children from even considering this profession. Currently, there are few research studies on young children's perceptions of engineers, and such research can be used to support children along STEM pathways. The purpose of this research was to investigate elementary students' perceptions of engineers for children enrolled in a gifted and talented outreach program. Participants included students enrolled in two structural engineering classes: one for 3rd and 4th graders and another for 5th and 6th grade students. Participants represented an age group that is not typically exposed to engineering. This research was framed within a constructivist theoretical framework, and qualitative research methods were utilized to develop a rich understanding of the perspectives of students enrolled in the engineering classes. Data collection included student pre- and post-questionnaires, Draw-an-Engineer tasks, and semi-structured interviews. Data analysis entailed the use of open and axial coding. Trustworthiness of data was determined through triangulation of multiple data sources. Results demonstrated how children describe the work of engineers, objects associated with engineering, tools used or created by engineers, and professional characteristics of engineers. In addition, images of engineers were discussed and influences on students' perceptions of engineers were identified. The findings of this study have implications for the development of formal and informal K-12 curricula and programs that focus on improving students' understanding and engagement in engineering. Implications for researchers interested in studying children's perceptions were also discussed.

Structuring Formal Requirements Specifications for Reuse and Product Families

NASA Technical Reports Server (NTRS)

Heimdahl, Mats P. E.

2001-01-01

In this project we have investigated how formal specifications should be structured to allow for requirements reuse, product family engineering, and ease of requirements change, The contributions of this work include (1) a requirements specification methodology specifically targeted for critical avionics applications, (2) guidelines for how to structure state-based specifications to facilitate ease of change and reuse, and (3) examples from the avionics domain demonstrating the proposed approach.

Agile Methods for Open Source Safety-Critical Software

PubMed Central

Enquobahrie, Andinet; Ibanez, Luis; Cheng, Patrick; Yaniv, Ziv; Cleary, Kevin; Kokoori, Shylaja; Muffih, Benjamin; Heidenreich, John

2011-01-01

The introduction of software technology in a life-dependent environment requires the development team to execute a process that ensures a high level of software reliability and correctness. Despite their popularity, agile methods are generally assumed to be inappropriate as a process family in these environments due to their lack of emphasis on documentation, traceability, and other formal techniques. Agile methods, notably Scrum, favor empirical process control, or small constant adjustments in a tight feedback loop. This paper challenges the assumption that agile methods are inappropriate for safety-critical software development. Agile methods are flexible enough to encourage the right amount of ceremony; therefore if safety-critical systems require greater emphasis on activities like formal specification and requirements management, then an agile process will include these as necessary activities. Furthermore, agile methods focus more on continuous process management and code-level quality than classic software engineering process models. We present our experiences on the image-guided surgical toolkit (IGSTK) project as a backdrop. IGSTK is an open source software project employing agile practices since 2004. We started with the assumption that a lighter process is better, focused on evolving code, and only adding process elements as the need arose. IGSTK has been adopted by teaching hospitals and research labs, and used for clinical trials. Agile methods have matured since the academic community suggested they are not suitable for safety-critical systems almost a decade ago, we present our experiences as a case study for renewing the discussion. PMID:21799545

Agile Methods for Open Source Safety-Critical Software.

PubMed

Gary, Kevin; Enquobahrie, Andinet; Ibanez, Luis; Cheng, Patrick; Yaniv, Ziv; Cleary, Kevin; Kokoori, Shylaja; Muffih, Benjamin; Heidenreich, John

2011-08-01

The introduction of software technology in a life-dependent environment requires the development team to execute a process that ensures a high level of software reliability and correctness. Despite their popularity, agile methods are generally assumed to be inappropriate as a process family in these environments due to their lack of emphasis on documentation, traceability, and other formal techniques. Agile methods, notably Scrum, favor empirical process control, or small constant adjustments in a tight feedback loop. This paper challenges the assumption that agile methods are inappropriate for safety-critical software development. Agile methods are flexible enough to encourage the rightamount of ceremony; therefore if safety-critical systems require greater emphasis on activities like formal specification and requirements management, then an agile process will include these as necessary activities. Furthermore, agile methods focus more on continuous process management and code-level quality than classic software engineering process models. We present our experiences on the image-guided surgical toolkit (IGSTK) project as a backdrop. IGSTK is an open source software project employing agile practices since 2004. We started with the assumption that a lighter process is better, focused on evolving code, and only adding process elements as the need arose. IGSTK has been adopted by teaching hospitals and research labs, and used for clinical trials. Agile methods have matured since the academic community suggested they are not suitable for safety-critical systems almost a decade ago, we present our experiences as a case study for renewing the discussion.

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.

Retooling Predictive Relations for non-volatile PM by Comparison to Measurements

NASA Astrophysics Data System (ADS)

Vander Wal, R. L.; Abrahamson, J. P.

2015-12-01

Non-volatile particulate matter (nvPM) emissions from jet aircraft at cruise altitude are of particular interest for climate and atmospheric processes but are difficult to measure and are normally approximated. To provide such inventory estimates the present approach is to use measured, ground-based values with scaling to cruise (engine operating) conditions. Several points are raised by this approach. First is what ground based values to use. Empirical and semi-empirical approaches, such as the revised first order approximation (FOA3) and formation-oxidation (FOX) methods, each with embedded assumptions are available to calculate a ground-based black carbon concentration, CBC. Second is the scaling relation that can depend upon the ratios of fuel-air equivalence, pressure, and combustor flame temperature. We are using measured ground-based values to evaluate the accuracy of present methods towards developing alternative methods for CBCby smoke number or via a semi-empirical kinetic method for the specific engine, CFM56-2C, representative of a rich-dome style combustor, and as one of the most prevalent engine families in commercial use. Applying scaling relations to measured ground based values and comparison to measurements at cruise evaluates the accuracy of current scaling formalism. In partnership with GE Aviation, performing engine cycle deck calculations enables critical comparison between estimated or predicted thermodynamic parameters and true (engine) operational values for the CFM56-2C engine. Such specific comparisons allow tracing differences between predictive estimates for, and measurements of nvPM to their origin - as either divergence of input parameters or in the functional form of the predictive relations. Such insights will lead to development of new predictive tools for jet aircraft nvPM emissions. Such validated relations can then be extended to alternative fuels with confidence in operational thermodynamic values and functional form. Comparisons will then be made between these new predictive relationships and measurements of nvPM from alternative fuels using ground and cruise data - as collected during NASA-led AAFEX and ACCESS field campaigns, respectively.

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.

Determining the privacy policy deficiencies of health ICT applications through semi-formal modelling.

PubMed

Croll, Peter R

2011-02-01

To ensure that patient confidentiality is securely maintained, health ICT applications that contain sensitive personal information demand comprehensive privacy policies. Determining the adequacy of these policies to meet legal conformity together with clinical users and patient expectation is demanding in practice. Organisations and agencies looking to analyse their Privacy and Security policies can benefit from guidance provided by outside entities such as the Privacy Office of their State or Government together with law firms and ICT specialists. The advice given is not uniform and often open to different interpretations. Of greater concern is the possibility of overlooking any important aspects that later result in a data breach. Based on three case studies, this paper considers whether a more formal approach to privacy analysis could be taken that would help identify the full coverage of a Privacy Impact Analysis and determine the deficiencies with an organisation's current policies and approach. A diagrammatic model showing the relationships between Confidentiality, Privacy, Trust, Security and Safety is introduced. First the validity of this model is determined by mapping it against the real-world case studies taken from three healthcare services that depend on ICT. Then, by using software engineering methods, a formal mapping of the relationships is undertaken to identify a full set of policies needed to satisfy the model. How effective this approach may prove as a generic method for deriving a comprehensive set of policies in health ICT applications is finally discussed. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Autonomous and Autonomic Swarms

NASA Technical Reports Server (NTRS)

Hinchey, Michael G.; Rash, James L.; Truszkowski, Walter F.; Rouff, Christopher A.; Sterritt, Roy

2005-01-01

A watershed in systems engineering is represented by the advent of swarm-based systems that accomplish missions through cooperative action by a (large) group of autonomous individuals each having simple capabilities and no global knowledge of the group s objective. Such systems, with individuals capable of surviving in hostile environments, pose unprecedented challenges to system developers. Design and testing and verification at much higher levels will be required, together with the corresponding tools, to bring such systems to fruition. Concepts for possible future NASA space exploration missions include autonomous, autonomic swarms. Engineering swarm-based missions begins with understanding autonomy and autonomicity and how to design, test, and verify systems that have those properties and, simultaneously, the capability to accomplish prescribed mission goals. Formal methods-based technologies, both projected and in development, are described in terms of their potential utility to swarm-based system developers.

Concept similarity and related categories in information retrieval using formal concept analysis

NASA Astrophysics Data System (ADS)

Eklund, P.; Ducrou, J.; Dau, F.

2012-11-01

The application of formal concept analysis to the problem of information retrieval has been shown useful but has lacked any real analysis of the idea of relevance ranking of search results. SearchSleuth is a program developed to experiment with the automated local analysis of Web search using formal concept analysis. SearchSleuth extends a standard search interface to include a conceptual neighbourhood centred on a formal concept derived from the initial query. This neighbourhood of the concept derived from the search terms is decorated with its upper and lower neighbours representing more general and special concepts, respectively. SearchSleuth is in many ways an archetype of search engines based on formal concept analysis with some novel features. In SearchSleuth, the notion of related categories - which are themselves formal concepts - is also introduced. This allows the retrieval focus to shift to a new formal concept called a sibling. This movement across the concept lattice needs to relate one formal concept to another in a principled way. This paper presents the issues concerning exploring, searching, and ordering the space of related categories. The focus is on understanding the use and meaning of proximity and semantic distance in the context of information retrieval using formal concept analysis.

Ten Commandments of Formal Methods...Ten Years Later

NASA Technical Reports Server (NTRS)

Bowen, Jonathan P.; Hinchey, Michael G.

2006-01-01

More than a decade ago, in "Ten Commandments of Formal Methods," we offered practical guidelines for projects that sought to use formal methods. Over the years, the article, which was based on our knowledge of successful industrial projects, has been widely cited and has generated much positive feedback. However, despite this apparent enthusiasm, formal methods use has not greatly increased, and some of the same attitudes about the infeasibility of adopting them persist. Formal methodists believe that introducing greater rigor will improve the software development process and yield software with better structure, greater maintainability, and fewer errors.

NASA systems engineering handbook

NASA Astrophysics Data System (ADS)

Shishko, Robert; Aster, Robert; Chamberlain, Robert G.; McDuffee, Patrick; Pieniazek, Les; Rowell, Tom; Bain, Beth; Cox, Renee I.; Mooz, Harold; Polaski, Lou

1995-06-01

This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts were drawn from NASA field center handbooks, NMI's/NHB's, the work of the NASA-wide Systems Engineering Working Group and the Systems Engineering Process Improvement Task team, several non-NASA textbooks and guides, and material from independent systems engineering courses taught to NASA personnel. Five core chapters cover systems engineering fundamentals, the NASA Project Cycle, management issues in systems engineering, systems analysis and modeling, and specialty engineering integration. It is not intended as a directive.

Tacit Knowledge Capture and the Brain-Drain at Electrical Utilities

NASA Astrophysics Data System (ADS)

Perjanik, Nicholas Steven

As a consequence of an aging workforce, electric utilities are at risk of losing their most experienced and knowledgeable electrical engineers. In this research, the problem was a lack of understanding of what electric utilities were doing to capture the tacit knowledge or know-how of these engineers. The purpose of this qualitative research study was to explore the tacit knowledge capture strategies currently used in the industry by conducting a case study of 7 U.S. electrical utilities that have demonstrated an industry commitment to improving operational standards. The research question addressed the implemented strategies to capture the tacit knowledge of retiring electrical engineers and technical personnel. The research methodology involved a qualitative embedded case study. The theories used in this study included knowledge creation theory, resource-based theory, and organizational learning theory. Data were collected through one time interviews of a senior electrical engineer or technician within each utility and a workforce planning or training professional within 2 of the 7 utilities. The analysis included the use of triangulation and content analysis strategies. Ten tacit knowledge capture strategies were identified: (a) formal and informal on-boarding mentorship and apprenticeship programs, (b) formal and informal off-boarding mentorship programs, (c) formal and informal training programs, (d) using lessons learned during training sessions, (e) communities of practice, (f) technology enabled tools, (g) storytelling, (h) exit interviews, (i) rehiring of retirees as consultants, and (j) knowledge risk assessments. This research contributes to social change by offering strategies to capture the know-how needed to ensure operational continuity in the delivery of safe, reliable, and sustainable power.

Multi-topic assignment for exploratory navigation of consumer health information in NetWellness using formal concept analysis

PubMed Central

2014-01-01

Background Finding quality consumer health information online can effectively bring important public health benefits to the general population. It can empower people with timely and current knowledge for managing their health and promoting wellbeing. Despite a popular belief that search engines such as Google can solve all information access problems, recent studies show that using search engines and simple search terms is not sufficient. Our objective is to provide an approach to organizing consumer health information for navigational exploration, complementing keyword-based direct search. Multi-topic assignment to health information, such as online questions, is a fundamental step for navigational exploration. Methods We introduce a new multi-topic assignment method combining semantic annotation using UMLS concepts (CUIs) and Formal Concept Analysis (FCA). Each question was tagged with CUIs identified by MetaMap. The CUIs were filtered with term-frequency and a new term-strength index to construct a CUI-question context. The CUI-question context and a topic-subject context were used for multi-topic assignment, resulting in a topic-question context. The topic-question context was then directly used for constructing a prototype navigational exploration interface. Results Experimental evaluation was performed on the task of automatic multi-topic assignment of 99 predefined topics for about 60,000 consumer health questions from NetWellness. Using example-based metrics, suitable for multi-topic assignment problems, our method achieved a precision of 0.849, recall of 0.774, and F1 measure of 0.782, using a reference standard of 278 questions with manually assigned topics. Compared to NetWellness’ original topic assignment, a 36.5% increase in recall is achieved with virtually no sacrifice in precision. Conclusion Enhancing the recall of multi-topic assignment without sacrificing precision is a prerequisite for achieving the benefits of navigational exploration. Our new multi-topic assignment method, combining term-strength, FCA, and information retrieval techniques, significantly improved recall and performed well according to example-based metrics. PMID:25086916

Finding Patterns of Emergence in Science and Technology

DTIC Science & Technology

2012-09-24

formal evaluation scheduled – Case Studies, Eight Examples: Tissue Engineering, Cold Fusion, RF Metamaterials, DNA Microarrays, Genetic Algorithms, RNAi...emerging capabilities Case Studies, Eight Examples: • Tissue Engineering, Cold Fusion, RF Metamaterials, DNA Microarrays, Genetic Algorithms...Evidence Quality (i.e., the rubric ) and deliver comprehensible evidential support for nomination • Demonstrate proof-of-concept nomination for Chinese

Faculty Consulting in Natural Sciences and Engineering: Between Formal and Informal Knowledge Transfer

ERIC Educational Resources Information Center

Amara, Nabil; Landry, Rejean; Halilem, Norrin

2013-01-01

Academic consulting is a form of knowledge and technology transfer largely under-documented and under-studied that raises ethical and resources allocation issues. Based on a survey of 2,590 Canadian researchers in engineering and natural sciences, this paper explores three forms of academic consulting: (1) paid consulting; (2) unpaid consulting…

Automotive Stirling Engine Development Program

NASA Technical Reports Server (NTRS)

Nightingale, N.; Richey, A.; Farrell, R.; Riecke, G.; Ernst, W.; Howarth, R.; Cronin, M.; Simetkosky, M.; Smith, G.; Meacher, J.

1985-01-01

Development test activities on Mod I engines directed toward evaluating technologies for potential inclusion in the Mod II engine are summarized. Activities covered include: test of a 12-tube combustion gas recirculation combustor; manufacture and flow-distribution test of a two-manifold annular heater head; piston rod/piston base joint; single-solid piston rings; and a digital air/fuel concept. Also summarized are results of a formal assessment of candidate technologies for the Mod II engine, and preliminary design work for the Mod II. The overall program philosophy weight is outlined, and data and test results are presented.

A Foundational Approach to Designing Geoscience Ontologies

NASA Astrophysics Data System (ADS)

Brodaric, B.

2009-05-01

E-science systems are increasingly deploying ontologies to aid online geoscience research. Geoscience ontologies are typically constructed independently by isolated individuals or groups who tend to follow few design principles. This limits the usability of the ontologies due to conceptualizations that are vague, conflicting, or narrow. Advances in foundational ontologies and formal engineering approaches offer promising solutions, but these advanced techniques have had limited application in the geosciences. This paper develops a design approach for geoscience ontologies by extending aspects of the DOLCE foundational ontology and the OntoClean method. Geoscience examples will be presented to demonstrate the feasibility of the approach.

Provably trustworthy systems.

PubMed

Klein, Gerwin; Andronick, June; Keller, Gabriele; Matichuk, Daniel; Murray, Toby; O'Connor, Liam

2017-10-13

We present recent work on building and scaling trustworthy systems with formal, machine-checkable proof from the ground up, including the operating system kernel, at the level of binary machine code. We first give a brief overview of the seL4 microkernel verification and how it can be used to build verified systems. We then show two complementary techniques for scaling these methods to larger systems: proof engineering, to estimate verification effort; and code/proof co-generation, for scalable development of provably trustworthy applications.This article is part of the themed issue 'Verified trustworthy software systems'. © 2017 The Author(s).

Mentoring Among Scientists: Implications of Interpersonal Relationships within a Formal Mentoring Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan D. Maughan

2006-11-01

Mentoring is an established strategy for learning that has its root in antiquity. Most, if not all, successful scientists and engineers had an effective mentor at some point in their career. In the context of scientists and engineers, mentoring has been undefined. Reports addressing critical concerns regarding the future of science and engineering in the U.S. mention the practice of mentoring a priori, leaving organizations without guidance in its application. Preliminary results from this study imply that formal mentoring can be effective when properly defined and operationalized. Recognizing the uniqueness of the individual in a symbiotic mentor-protégé relationship significantly influencesmore » a protégé’s learning experience which carries repercussions into their career intentions. The mentor-protégé relationship is a key factor in succession planning and preserving and disseminating critical information and tacit knowledge essential to the development of leadership in the science and technological industry.« less

Intellectual technologies in the problems of thermal power engineering control: formalization of fuzzy information processing results using the artificial intelligence methodology

NASA Astrophysics Data System (ADS)

Krokhin, G.; Pestunov, A.

2017-11-01

Exploitation conditions of power stations in variable modes and related changes of their technical state actualized problems of creating models for decision-making and state recognition basing on diagnostics using the fuzzy logic for identification their state and managing recovering processes. There is no unified methodological approach for obtaining the relevant information is a case of fuzziness and inhomogeneity of the raw information about the equipment state. The existing methods for extracting knowledge are usually unable to provide the correspondence between of the aggregates model parameters and the actual object state. The switchover of the power engineering from the preventive repair to the one, which is implemented according to the actual technical state, increased the responsibility of those who estimate the volume and the duration of the work. It may lead to inadequacy of the diagnostics and the decision-making models if corresponding methodological preparations do not take fuzziness into account, because the nature of the state information is of this kind. In this paper, we introduce a new model which formalizes the equipment state using not only exact information, but fuzzy as well. This model is more adequate to the actual state, than traditional analogs, and may be used in order to increase the efficiency and the service period of the power installations.

Modified subaperture tool influence functions of a flat-pitch polisher with reverse-calculated material removal rate.

PubMed

Dong, Zhichao; Cheng, Haobo; Tam, Hon-Yuen

2014-04-10

Numerical simulation of subaperture tool influence functions (TIF) is widely known as a critical procedure in computer-controlled optical surfacing. However, it may lack practicability in engineering because the emulation TIF (e-TIF) has some discrepancy with the practical TIF (p-TIF), and the removal rate could not be predicted by simulations. Prior to the polishing of a formal workpiece, opticians have to conduct TIF spot experiments on another sample to confirm the p-TIF with a quantitative removal rate, which is difficult and time-consuming for sequential polishing runs with different tools. This work is dedicated to applying these e-TIFs into practical engineering by making improvements from two aspects: (1) modifies the pressure distribution model of a flat-pitch polisher by finite element analysis and least square fitting methods to make the removal shape of e-TIFs closer to p-TIFs (less than 5% relative deviation validated by experiments); (2) predicts the removal rate of e-TIFs by reverse calculating the material removal volume of a pre-polishing run to the formal workpiece (relative deviations of peak and volume removal rate were validated to be less than 5%). This can omit TIF spot experiments for the particular flat-pitch tool employed and promote the direct usage of e-TIFs in the optimization of a dwell time map, which can largely save on cost and increase fabrication efficiency.

Canonical formalism for modelling and control of rigid body dynamics.

PubMed

Gurfil, P

2005-12-01

This paper develops a new paradigm for stabilization of rigid-body dynamics. The state-space model is formulated using canonical elements, known as the Serret-Andoyer (SA) variables, thus far scarcely used for engineering applications. The main feature of the SA formalism is the reduction of the dynamics via the underlying symmetry stemming from conservation of angular momentum and rotational kinetic energy. The controllability of the system model is examined using the notion of accessibility, and is shown to be accessible from all points. Based on the accessibility proof, two nonlinear asymptotic feedback stabilizers are developed: a damping feedback is designed based on the Jurdjevic-Quinn method, and a Hamiltonian controller is derived by using the Hamiltonian as a natural Lyapunov function for the closed-loop dynamics. It is shown that the Hamiltonian control is both passive and inverse optimal with respect to a meaningful performance index. The performance of the new controllers is examined and compared using simulations of realistic scenarios from the satellite attitude dynamics field.

Systems, methods and apparatus for modeling, specifying and deploying policies in autonomous and autonomic systems using agent-oriented software engineering

NASA Technical Reports Server (NTRS)

Sterritt, Roy (Inventor); Hinchey, Michael G. (Inventor); Penn, Joaquin (Inventor)

2011-01-01

Systems, methods and apparatus are provided through which in some embodiments, an agent-oriented specification modeled with MaCMAS, is analyzed, flaws in the agent-oriented specification modeled with MaCMAS are corrected, and an implementation is derived from the corrected agent-oriented specification. Described herein are systems, method and apparatus that produce fully (mathematically) tractable development of agent-oriented specification(s) modeled with methodology fragment for analyzing complex multiagent systems (MaCMAS) and policies for autonomic systems from requirements through to code generation. The systems, method and apparatus described herein are illustrated through an example showing how user formulated policies can be translated into a formal mode which can then be converted to code. The requirements-based programming systems, method and apparatus described herein may provide faster, higher quality development and maintenance of autonomic systems based on user formulation of policies.

Toward Synthesis, Analysis, and Certification of Security Protocols

NASA Technical Reports Server (NTRS)

Schumann, Johann

2004-01-01

Implemented security protocols are basically pieces of software which are used to (a) authenticate the other communication partners, (b) establish a secure communication channel between them (using insecure communication media), and (c) transfer data between the communication partners in such a way that these data only available to the desired receiver, but not to anyone else. Such an implementation usually consists of the following components: the protocol-engine, which controls in which sequence the messages of the protocol are sent over the network, and which controls the assembly/disassembly and processing (e.g., decryption) of the data. the cryptographic routines to actually encrypt or decrypt the data (using given keys), and t,he interface to the operating system and to the application. For a correct working of such a security protocol, all of these components must work flawlessly. Many formal-methods based techniques for the analysis of a security protocols have been developed. They range from using specific logics (e.g.: BAN-logic [4], or higher order logics [12] to model checking [2] approaches. In each approach, the analysis tries to prove that no (or at least not a modeled intruder) can get access to secret data. Otherwise, a scenario illustrating the &tack may be produced. Despite the seeming simplicity of security protocols ("only" a few messages are sent between the protocol partners in order to ensure a secure communication), many flaws have been detected. Unfortunately, even a perfect protocol engine does not guarantee flawless working of a security protocol, as incidents show. Many break-ins and security vulnerabilities are caused by exploiting errors in the implementation of the protocol engine or the underlying operating system. Attacks using buffer-overflows are a very common class of such attacks. Errors in the implementation of exception or error handling can open up additional vulnerabilities. For example, on a website with a log-in screen: multiple tries with invalid passwords caused the expected error message (too many retries). but let the user nevertheless pass. Finally, security can be compromised by silly implementation bugs or design decisions. In a commercial VPN software, all calls to the encryption routines were incidentally replaced by stubs, probably during factory testing. The product worked nicely. and the error (an open VPN) would have gone undetected, if a team member had not inspected the low-level traffic out of curiosity. Also, the use secret proprietary encryption routines can backfire, because such algorithms often exhibit weaknesses which can be exploited easily (see e.g., DVD encoding). Summarizing, there is large number of possibilities to make errors which can compromise the security of a protocol. In today s world with short time-to-market and the use of security protocols in open and hostile networks for safety-critical applications (e.g., power or air-traffic control), such slips could lead to catastrophic situations. Thus, formal methods and automatic reasoning techniques should not be used just for the formal proof of absence of an attack, but they ought to be used to provide an end-to-end tool-supported framework for security software. With such an approach all required artifacts (code, documentation, test cases) , formal analyses, and reliable certification will be generated automatically, given a single, high level specification. By a combination of program synthesis, formal protocol analysis, certification; and proof-carrying code, this goal is within practical reach, since all the important technologies for such an approach actually exist and only need to be assembled in the right way.

Knowledge-based system verification and validation

NASA Technical Reports Server (NTRS)

Johnson, Sally C.

1990-01-01

The objective of this task is to develop and evaluate a methodology for verification and validation (V&V) of knowledge-based systems (KBS) for space station applications with high reliability requirements. The approach consists of three interrelated tasks. The first task is to evaluate the effectiveness of various validation methods for space station applications. The second task is to recommend requirements for KBS V&V for Space Station Freedom (SSF). The third task is to recommend modifications to the SSF to support the development of KBS using effectiveness software engineering and validation techniques. To accomplish the first task, three complementary techniques will be evaluated: (1) Sensitivity Analysis (Worchester Polytechnic Institute); (2) Formal Verification of Safety Properties (SRI International); and (3) Consistency and Completeness Checking (Lockheed AI Center). During FY89 and FY90, each contractor will independently demonstrate the user of his technique on the fault detection, isolation, and reconfiguration (FDIR) KBS or the manned maneuvering unit (MMU), a rule-based system implemented in LISP. During FY91, the application of each of the techniques to other knowledge representations and KBS architectures will be addressed. After evaluation of the results of the first task and examination of Space Station Freedom V&V requirements for conventional software, a comprehensive KBS V&V methodology will be developed and documented. Development of highly reliable KBS's cannot be accomplished without effective software engineering methods. Using the results of current in-house research to develop and assess software engineering methods for KBS's as well as assessment of techniques being developed elsewhere, an effective software engineering methodology for space station KBS's will be developed, and modification of the SSF to support these tools and methods will be addressed.

The role of the user within the medical device design and development process: medical device manufacturers' perspectives

PubMed Central

2011-01-01

Background Academic literature and international standards bodies suggest that user involvement, via the incorporation of human factors engineering methods within the medical device design and development (MDDD) process, offer many benefits that enable the development of safer and more usable medical devices that are better suited to users' needs. However, little research has been carried out to explore medical device manufacturers' beliefs and attitudes towards user involvement within this process, or indeed what value they believe can be added by doing so. Methods In-depth interviews with representatives from 11 medical device manufacturers are carried out. We ask them to specify who they believe the intended users of the device to be, who they consult to inform the MDDD process, what role they believe the user plays within this process, and what value (if any) they believe users add. Thematic analysis is used to analyse the fully transcribed interview data, to gain insight into medical device manufacturers' beliefs and attitudes towards user involvement within the MDDD process. Results A number of high-level themes emerged, relating who the user is perceived to be, the methods used, the perceived value and barriers to user involvement, and the nature of user contributions. The findings reveal that despite standards agencies and academic literature offering strong support for the employment formal methods, manufacturers are still hesitant due to a range of factors including: perceived barriers to obtaining ethical approval; the speed at which such activity may be carried out; the belief that there is no need given the 'all-knowing' nature of senior health care staff and clinical champions; a belief that effective results are achievable by consulting a minimal number of champions. Furthermore, less senior health care practitioners and patients were rarely seen as being able to provide valuable input into the process. Conclusions Medical device manufacturers often do not see the benefit of employing formal human factors engineering methods within the MDDD process. Research is required to better understand the day-to-day requirements of manufacturers within this sector. The development of new or adapted methods may be required if user involvement is to be fully realised. PMID:21356097

NASA Systems Engineering Handbook

NASA Technical Reports Server (NTRS)

Shishko, Robert; Aster, Robert; Chamberlain, Robert G.; Mcduffee, Patrick; Pieniazek, Les; Rowell, Tom; Bain, Beth; Cox, Renee I.; Mooz, Harold; Polaski, Lou

1995-01-01

This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts were drawn from NASA field center handbooks, NMI's/NHB's, the work of the NASA-wide Systems Engineering Working Group and the Systems Engineering Process Improvement Task team, several non-NASA textbooks and guides, and material from independent systems engineering courses taught to NASA personnel. Five core chapters cover systems engineering fundamentals, the NASA Project Cycle, management issues in systems engineering, systems analysis and modeling, and specialty engineering integration. It is not intended as a directive. Superseded by: NASA/SP-2007-6105 Rev 1 (20080008301).

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.

An Overview of Starfish: A Table-Centric Tool for Interactive Synthesis

NASA Technical Reports Server (NTRS)

Tsow, Alex

2008-01-01

Engineering is an interactive process that requires intelligent interaction at many levels. My thesis [1] advances an engineering discipline for high-level synthesis and architectural decomposition that integrates perspicuous representation, designer interaction, and mathematical rigor. Starfish, the software prototype for the design method, implements a table-centric transformation system for reorganizing control-dominated system expressions into high-level architectures. Based on the digital design derivation (DDD) system a designer-guided synthesis technique that applies correctness preserving transformations to synchronous data flow specifications expressed as co- recursive stream equations Starfish enhances user interaction and extends the reachable design space by incorporating four innovations: behavior tables, serialization tables, data refinement, and operator retiming. Behavior tables express systems of co-recursive stream equations as a table of guarded signal updates. Developers and users of the DDD system used manually constructed behavior tables to help them decide which transformations to apply and how to specify them. These design exercises produced several formally constructed hardware implementations: the FM9001 microprocessor, an SECD machine for evaluating LISP, and the SchemEngine, garbage collected machine for interpreting a byte-code representation of compiled Scheme programs. Bose and Tuna, two of DDD s developers, have subsequently commercialized the design derivation methodology at Derivation Systems, Inc. (DSI). DSI has formally derived and validated PCI bus interfaces and a Java byte-code processor; they further executed a contract to prototype SPIDER-NASA's ultra-reliable communications bus. To date, most derivations from DDD and DRS have targeted hardware due to its synchronous design paradigm. However, Starfish expressions are independent of the synchronization mechanism; there is no commitment to hardware or globally broadcast clocks. Though software back-ends for design derivation are limited to the DDD stream-interpreter, targeting synchronous or real-time software is not substantively different from targeting hardware.

Volcanic hazards at distant critical infrastructure: A method for bespoke, multi-disciplinary assessment

NASA Astrophysics Data System (ADS)

Odbert, H. M.; Aspinall, W.; Phillips, J.; Jenkins, S.; Wilson, T. M.; Scourse, E.; Sheldrake, T.; Tucker, P.; Nakeshree, K.; Bernardara, P.; Fish, K.

2015-12-01

Societies rely on critical services such as power, water, transport networks and manufacturing. Infrastructure may be sited to minimise exposure to natural hazards but not all can be avoided. The probability of long-range transport of a volcanic plume to a site is comparable to other external hazards that must be considered to satisfy safety assessments. Recent advances in numerical models of plume dispersion and stochastic modelling provide a formalized and transparent approach to probabilistic assessment of hazard distribution. To understand the risks to critical infrastructure far from volcanic sources, it is necessary to quantify their vulnerability to different hazard stressors. However, infrastructure assets (e.g. power plantsand operational facilities) are typically complex systems in themselves, with interdependent components that may differ in susceptibility to hazard impact. Usually, such complexity means that risk either cannot be estimated formally or that unsatisfactory simplifying assumptions are prerequisite to building a tractable risk model. We present a new approach to quantifying risk by bridging expertise of physical hazard modellers and infrastructure engineers. We use a joint expert judgment approach to determine hazard model inputs and constrain associated uncertainties. Model outputs are chosen on the basis of engineering or operational concerns. The procedure facilitates an interface between physical scientists, with expertise in volcanic hazards, and infrastructure engineers, with insight into vulnerability to hazards. The result is a joined-up approach to estimating risk from low-probability hazards to critical infrastructure. We describe our methodology and show preliminary results for vulnerability to volcanic hazards at a typical UK industrial facility. We discuss our findings in the context of developing bespoke assessment of hazards from distant sources in collaboration with key infrastructure stakeholders.

Implementation of Scene Shadows in the Target Acquistion TDA (TARGAC).

DTIC Science & Technology

1994-11-01

B-2 APPENDIX C: ENGINEERING CHANGE REPORTS .......................... C-1 APPENDIX D: TASK...Appendix C contains the details of each change made. Each change is accompanied by an Engineering Change Report (ECR) and in-line documentation of the source...code. Appendix D is a formal design document of the changes needed to implement shadowing by small-scale features. The implementation presented in

A Study of Technical Engineering Peer Reviews at NASA

NASA Technical Reports Server (NTRS)

Chao, Lawrence P.; Tumer, Irem Y.; Bell, David G.

2003-01-01

This report describes the state of practices of design reviews at NASA and research into what can be done to improve peer review practices. There are many types of reviews at NASA: required and not, formalized and informal, programmatic and technical. Standing project formal reviews such as the Preliminary Design Review and Critical Design Review are a required part of every project and mission development. However, the technical, engineering peer reviews that support teams' work on such projects are informal, some times ad hoc, and inconsistent across the organization. The goal of this work is to identify best practices and lessons learned from NASA's experience, supported by academic research and methodologies to ultimately improve the process. This research has determined that the organization, composition, scope, and approach of the reviews impact their success. Failure Modes and Effects Analysis (FMEA) can identify key areas of concern before or in the reviews. Product definition tools like the Project Priority Matrix, engineering-focused Customer Value Chain Analysis (CVCA), and project or system-based Quality Function Deployment (QFD) help prioritize resources in reviews. The use of information technology and structured design methodologies can strengthen the engineering peer review process to help NASA work towards error-proofing the design process.

A systematic approach to embedded biomedical decision making.

PubMed

Song, Zhe; Ji, Zhongkai; Ma, Jian-Guo; Sputh, Bernhard; Acharya, U Rajendra; Faust, Oliver

2012-11-01

An embedded decision making is a key feature for many biomedical systems. In most cases human life directly depends on correct decisions made by these systems, therefore they have to work reliably. This paper describes how we applied systems engineering principles to design a high performance embedded classification system in a systematic and well structured way. We introduce the structured design approach by discussing requirements capturing, specifications refinement, implementation and testing. Thereby, we follow systems engineering principles and execute each of these processes as formal as possible. The requirements, which motivate the system design, describe an automated decision making system for diagnostic support. These requirements are refined into the implementation of a support vector machine (SVM) algorithm which enables us to integrate automated decision making in embedded systems. With a formal model we establish functionality, stability and reliability of the system. Furthermore, we investigated different parallel processing configurations of this computationally complex algorithm. We found that, by adding SVM processes, an almost linear speedup is possible. Once we established these system properties, we translated the formal model into an implementation. The resulting implementation was tested using XMOS processors with both normal and failure cases, to build up trust in the implementation. Finally, we demonstrated that our parallel implementation achieves the speedup, predicted by the formal model. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Separating essentials from incidentals: an execution architecture for real-time control systems

NASA Technical Reports Server (NTRS)

Dvorak, Daniel; Reinholtz, Kirk

2004-01-01

This paper describes an execution architecture that makes such systems far more analyzable and verifiable by aggressive separation of concerns. The architecture separates two key software concerns: transformations of global state, as defined in pure functions; and sequencing/timing of transformations, as performed by an engine that enforces four prime invariants. The important advantage of this architecture, besides facilitating verification, is that it encourages formal specification of systems in a vocabulary that brings systems engineering closer to software engineering.

A brief overview of NASA Langley's research program in formal methods

NASA Technical Reports Server (NTRS)

1992-01-01

An overview of NASA Langley's research program in formal methods is presented. The major goal of this work is to bring formal methods technology to a sufficiently mature level for use by the United States aerospace industry. Towards this goal, work is underway to design and formally verify a fault-tolerant computing platform suitable for advanced flight control applications. Also, several direct technology transfer efforts have been initiated that apply formal methods to critical subsystems of real aerospace computer systems. The research team consists of six NASA civil servants and contractors from Boeing Military Aircraft Company, Computational Logic Inc., Odyssey Research Associates, SRI International, University of California at Davis, and Vigyan Inc.

Expecting the Unexpected: Towards Robust Credential Infrastructure

NASA Astrophysics Data System (ADS)

Xu, Shouhuai; Yung, Moti

Cryptographic credential infrastructures, such as Public key infrastructure (PKI), allow the building of trust relationships in electronic society and electronic commerce. At the center of credential infrastructures is the methodology of digital signatures. However, methods that assure that credentials and signed messages possess trustworthiness and longevity are not well understood, nor are they adequately addressed in both literature and practice. We believe that, as a basic engineering principle, these properties have to be built into the credential infrastructure rather than be treated as an after-thought since they are crucial to the long term success of this notion. In this paper we present a step in the direction of dealing with these issues. Specifically, we present the basic engineering reasoning as well as a model that helps understand (somewhat formally) the trustworthiness and longevity of digital signatures, and then we give basic mechanisms that help improve these notions.

OMOGENIA: A Semantically Driven Collaborative Environment

NASA Astrophysics Data System (ADS)

Liapis, Aggelos

Ontology creation can be thought of as a social procedure. Indeed the concepts involved in general need to be elicited from communities of domain experts and end-users by teams of knowledge engineers. Many problems in ontology creation appear to resemble certain problems in software design, particularly with respect to the setup of collaborative systems. For instance, the resolution of conceptual conflicts between formalized ontologies is a major engineering problem as ontologies move into widespread use on the semantic web. Such conflict resolution often requires human collaboration and cannot be achieved by automated methods with the exception of simple cases. In this chapter we discuss research in the field of computer-supported cooperative work (CSCW) that focuses on classification and which throws light on ontology building. Furthermore, we present a semantically driven collaborative environment called OMOGENIA as a natural way to display and examine the structure of an evolving ontology in a collaborative setting.

Formal Assurance Certifiable Tooling Formal Assurance Certifiable Tooling Strategy Final Report

NASA Technical Reports Server (NTRS)

Bush, Eric; Oglesby, David; Bhatt, Devesh; Murugesan, Anitha; Engstrom, Eric; Mueller, Joe; Pelican, Michael

2017-01-01

This is the Final Report of a research project to investigate issues and provide guidance for the qualification of formal methods tools under the DO-330 qualification process. It consisted of three major subtasks spread over two years: 1) an assessment of theoretical soundness issues that may affect qualification for three categories of formal methods tools, 2) a case study simulating the DO-330 qualification of two actual tool sets, and 3) an investigation of risk mitigation strategies that might be applied to chains of such formal methods tools in order to increase confidence in their certification of airborne software.

NASA Langley Research and Technology-Transfer Program in Formal Methods

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Caldwell, James L.; Carreno, Victor A.; Holloway, C. Michael; Miner, Paul S.; DiVito, Ben L.

1995-01-01

This paper presents an overview of NASA Langley research program in formal methods. The major goals of this work are to make formal methods practical for use on life critical systems, and to orchestrate the transfer of this technology to U.S. industry through use of carefully designed demonstration projects. Several direct technology transfer efforts have been initiated that apply formal methods to critical subsystems of real aerospace computer systems. The research team consists of five NASA civil servants and contractors from Odyssey Research Associates, SRI International, and VIGYAN Inc.

On recent advances in human engineering.

PubMed

Anton, Roman

2016-01-01

Advances in embryology, genetics, and regenerative medicine regularly attract attention from scientists, scholars, journalists, and policymakers, yet implications of these advances may be broader than commonly supposed. Laboratories culturing human embryos, editing human genes, and creating human-animal chimeras have been working along lines that are now becoming intertwined. Embryogenic methods are weaving traditional in vivo and in vitro distinctions into a new "in vivitro" (in life in glass) fabric. These and other methods known to be in use or thought to be in development promise soon to bring society to startling choices and discomfiting predicaments, all in a global effort to supply reliably rejuvenating stem cells, to grow immunologically nonprovocative replacement organs, and to prevent, treat, cure, or even someday eradicate diseases having genetic or epigenetic mechanisms. With humanity's human-engineering era now begun, procedural prohibitions, funding restrictions, institutional controls, and transparency rules are proving ineffective, and business incentives are migrating into the most basic life-sciences inquiries, wherein lie huge biomedical potentials and bioethical risks. Rights, health, and heritage are coming into play with bioethical presumptions and formal protections urgently needing reassessment.

On recent advances in human engineering Provocative trends in embryology, genetics, and regenerative medicine.

PubMed

Anton, Roman

2016-01-01

Advances in embryology, genetics, and regenerative medicine regularly attract attention from scientists, scholars, journalists, and policymakers, yet implications of these advances may be broader than commonly supposed. Laboratories culturing human embryos, editing human genes, and creating human-animal chimeras have been working along lines that are now becoming intertwined. Embryogenic methods are weaving traditional in vivo and in vitro distinctions into a new "in vivitro" (in life in glass) fabric. These and other methods known to be in use or thought to be in development promise soon to bring society to startling choices and discomfiting predicaments, all in a global effort to supply reliably rejuvenating stem cells, to grow immunologically non-provocative replacement organs, and to prevent, treat, cure, or even someday eradicate diseases having genetic or epigenetic mechanisms. With humanity's human-engineering era now begun, procedural prohibitions, funding restrictions, institutional controls, and transparency rules are proving ineffective, and business incentives are migrating into the most basic life-sciences inquiries, wherein lie huge biomedical potentials and bioethical risks. Rights, health, and heritage are coming into play with bioethical presumptions and formal protections urgently needing reassessment.

Why are Formal Methods Not Used More Widely?

NASA Technical Reports Server (NTRS)

Knight, John C.; DeJong, Colleen L.; Gibble, Matthew S.; Nakano, Luis G.

1997-01-01

Despite extensive development over many years and significant demonstrated benefits, formal methods remain poorly accepted by industrial practitioners. Many reasons have been suggested for this situation such as a claim that they extent the development cycle, that they require difficult mathematics, that inadequate tools exist, and that they are incompatible with other software packages. There is little empirical evidence that any of these reasons is valid. The research presented here addresses the question of why formal methods are not used more widely. The approach used was to develop a formal specification for a safety-critical application using several specification notations and assess the results in a comprehensive evaluation framework. The results of the experiment suggests that there remain many impediments to the routine use of formal methods.

Air Force Space Command. Space and Missile Systems Center Standard. Configuration Management

DTIC Science & Technology

2008-06-13

Aerospace Corporation report number TOR-2006( 8583 )-1. 3. Beneficial comments (recommendations, additions, deletions) and any pertinent data that...Engineering Drawing Practices IEEE STD 610.12 Glossary of Software Engineering Terminology, September 28,1990 ISO /IEC 12207 Software Life...item, regardless of media, formally designated and fixed at a specific time during the configuration item’s life cycle. (Source: ISO /IEC 12207

Using Maxwell's Demon to Tame the "Devil in the Details" that are Encountered During System Development

NASA Technical Reports Server (NTRS)

Richardson, David

2018-01-01

Model-Based Systems Engineering (MBSE) is the formalized application of modeling to support system requirements, design, analysis, verification and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases . This presentation will discuss the value proposition that MBSE has for Systems Engineering, and the associated culture change needed to adopt it.

On introduction of artificial intelligence elements to heat power engineering

NASA Astrophysics Data System (ADS)

Dregalin, A. F.; Nazyrova, R. R.

1993-10-01

The basic problems of 'the thermodynamic intelligence' of personal computers have been outlined. The thermodynamic intellect of personal computers as a concept has been introduced to heat processes occurring in engines of flying vehicles. In particular, the thermodynamic intellect of computers is determined by the possibility of deriving formal relationships between thermodynamic functions. In chemical thermodynamics, a concept of a characteristic function has been introduced.

Multi-topic assignment for exploratory navigation of consumer health information in NetWellness using formal concept analysis.

PubMed

Cui, Licong; Xu, Rong; Luo, Zhihui; Wentz, Susan; Scarberry, Kyle; Zhang, Guo-Qiang

2014-08-03

Finding quality consumer health information online can effectively bring important public health benefits to the general population. It can empower people with timely and current knowledge for managing their health and promoting wellbeing. Despite a popular belief that search engines such as Google can solve all information access problems, recent studies show that using search engines and simple search terms is not sufficient. Our objective is to provide an approach to organizing consumer health information for navigational exploration, complementing keyword-based direct search. Multi-topic assignment to health information, such as online questions, is a fundamental step for navigational exploration. We introduce a new multi-topic assignment method combining semantic annotation using UMLS concepts (CUIs) and Formal Concept Analysis (FCA). Each question was tagged with CUIs identified by MetaMap. The CUIs were filtered with term-frequency and a new term-strength index to construct a CUI-question context. The CUI-question context and a topic-subject context were used for multi-topic assignment, resulting in a topic-question context. The topic-question context was then directly used for constructing a prototype navigational exploration interface. Experimental evaluation was performed on the task of automatic multi-topic assignment of 99 predefined topics for about 60,000 consumer health questions from NetWellness. Using example-based metrics, suitable for multi-topic assignment problems, our method achieved a precision of 0.849, recall of 0.774, and F₁ measure of 0.782, using a reference standard of 278 questions with manually assigned topics. Compared to NetWellness' original topic assignment, a 36.5% increase in recall is achieved with virtually no sacrifice in precision. Enhancing the recall of multi-topic assignment without sacrificing precision is a prerequisite for achieving the benefits of navigational exploration. Our new multi-topic assignment method, combining term-strength, FCA, and information retrieval techniques, significantly improved recall and performed well according to example-based metrics.

Optimal tuning of a confined Brownian information engine.

PubMed

Park, Jong-Min; Lee, Jae Sung; Noh, Jae Dong

2016-03-01

A Brownian information engine is a device extracting mechanical work from a single heat bath by exploiting the information on the state of a Brownian particle immersed in the bath. As for engines, it is important to find the optimal operating condition that yields the maximum extracted work or power. The optimal condition for a Brownian information engine with a finite cycle time τ has been rarely studied because of the difficulty in finding the nonequilibrium steady state. In this study, we introduce a model for the Brownian information engine and develop an analytic formalism for its steady-state distribution for any τ. We find that the extracted work per engine cycle is maximum when τ approaches infinity, while the power is maximum when τ approaches zero.

Deductive Evaluation: Formal Code Analysis With Low User Burden

NASA Technical Reports Server (NTRS)

Di Vito, Ben. L

2016-01-01

We describe a framework for symbolically evaluating iterative C code using a deductive approach that automatically discovers and proves program properties. Although verification is not performed, the method can infer detailed program behavior. Software engineering work flows could be enhanced by this type of analysis. Floyd-Hoare verification principles are applied to synthesize loop invariants, using a library of iteration-specific deductive knowledge. When needed, theorem proving is interleaved with evaluation and performed on the fly. Evaluation results take the form of inferred expressions and type constraints for values of program variables. An implementation using PVS (Prototype Verification System) is presented along with results for sample C functions.

A Model-based Approach to Reactive Self-Configuring Systems

NASA Technical Reports Server (NTRS)

Williams, Brian C.; Nayak, P. Pandurang

1996-01-01

This paper describes Livingstone, an implemented kernel for a self-reconfiguring autonomous system, that is reactive and uses component-based declarative models. The paper presents a formal characterization of the representation formalism used in Livingstone, and reports on our experience with the implementation in a variety of domains. Livingstone's representation formalism achieves broad coverage of hybrid software/hardware systems by coupling the concurrent transition system models underlying concurrent reactive languages with the discrete qualitative representations developed in model-based reasoning. We achieve a reactive system that performs significant deductions in the sense/response loop by drawing on our past experience at building fast prepositional conflict-based algorithms for model-based diagnosis, and by framing a model-based configuration manager as a prepositional, conflict-based feedback controller that generates focused, optimal responses. Livingstone automates all these tasks using a single model and a single core deductive engine, thus making significant progress towards achieving a central goal of model-based reasoning. Livingstone, together with the HSTS planning and scheduling engine and the RAPS executive, has been selected as the core autonomy architecture for Deep Space One, the first spacecraft for NASA's New Millennium program.

Integrated analysis of engine structures

NASA Technical Reports Server (NTRS)

Chamis, C. C.

1981-01-01

The need for light, durable, fuel efficient, cost effective aircraft requires the development of engine structures which are flexible, made from advaced materials (including composites), resist higher temperatures, maintain tighter clearances and have lower maintenance costs. The formal quantification of any or several of these requires integrated computer programs (multilevel and/or interdisciplinary analysis programs interconnected) for engine structural analysis/design. Several integrated analysis computer prorams are under development at Lewis Reseach Center. These programs include: (1) COBSTRAN-Composite Blade Structural Analysis, (2) CODSTRAN-Composite Durability Structural Analysis, (3) CISTRAN-Composite Impact Structural Analysis, (4) STAEBL-StruTailoring of Engine Blades, and (5) ESMOSS-Engine Structures Modeling Software System. Three other related programs, developed under Lewis sponsorship, are described.

Systems, methods and apparatus for implementation of formal specifications derived from informal requirements

NASA Technical Reports Server (NTRS)

Hinchey, Michael G. (Inventor); Rouff, Christopher A. (Inventor); Rash, James L. (Inventor); Erickson, John D. (Inventor); Gracinin, Denis (Inventor)

2010-01-01

Systems, methods and apparatus are provided through which in some embodiments an informal specification is translated without human intervention into a formal specification. In some embodiments the formal specification is a process-based specification. In some embodiments, the formal specification is translated into a high-level computer programming language which is further compiled into a set of executable computer instructions.

Ten Commandments Revisited: A Ten-Year Perspective on the Industrial Application of Formal Methods

NASA Technical Reports Server (NTRS)

Bowen, Jonathan P.; Hinchey, Michael G.

2005-01-01

Ten years ago, our 1995 paper Ten Commandments of Formal Methods suggested some guidelines to help ensure the success of a formal methods project. It proposed ten important requirements (or "commandments") for formal developers to consider and follow, based on our knowledge of several industrial application success stories, most of which have been reported in more detail in two books. The paper was surprisingly popular, is still widely referenced, and used as required reading in a number of formal methods courses. However, not all have agreed with some of our commandments, feeling that they may not be valid in the long-term. We re-examine the original commandments ten years on, and consider their validity in the light of a further decade of industrial best practice and experiences.

Inverse problems in quantum chemistry

NASA Astrophysics Data System (ADS)

Karwowski, Jacek

Inverse problems constitute a branch of applied mathematics with well-developed methodology and formalism. A broad family of tasks met in theoretical physics, in civil and mechanical engineering, as well as in various branches of medical and biological sciences has been formulated as specific implementations of the general theory of inverse problems. In this article, it is pointed out that a number of approaches met in quantum chemistry can (and should) be classified as inverse problems. Consequently, the methodology used in these approaches may be enriched by applying ideas and theorems developed within the general field of inverse problems. Several examples, including the RKR method for the construction of potential energy curves, determining parameter values in semiempirical methods, and finding external potentials for which the pertinent Schrödinger equation is exactly solvable, are discussed in detail.

Asian Universities' Collaboration for Advanced Environmental Engineering via Simultaneous Distant Learning Classes Using Video Playback

NASA Astrophysics Data System (ADS)

Araki, Mituhiko; Nakamura, Yuichi; Fujii, Shigeo; Tsuno, Hiroshi

Three international simultaneous lectures of the post graduate level in the field of environmental science and engineering are under preparation in Kyoto University. They are planned to be opened in three Asian universities (Tsinghua University in China, University of Malaya in Malaysia, and Kyoto University in Japan) as formal courses. The contents of the lectures, purpose of the project and technical problems are reported.

Joint Logistics Commanders’ Biennial Software Workshop (4th) Orlando II: Solving the PDSS (Post Deployment Software Support) Challenge Held in Orlando, Florida on 27-29 January 87. Volume 2. Proceedings

DTIC Science & Technology

1987-06-01

described the state )f ruaturity of software engineering as being equivalent to the state of maturity of Civil Engineering before Pythagoras invented the...formal verification languages, theorem provers or secure configuration 0 management tools would have to be maintained and used in the PDSS Center to

Two-Step Formal Advertisement: An Examination.

DTIC Science & Technology

1976-10-01

The purpose of this report is to examine the potential application of the Two-Step Formal Advertisement method of procurement. Emphasis is placed on...Step formal advertising is a method of procurement designed to take advantage of negotiation flexibility and at the same time obtain the benefits of...formal advertising . It is used where the specifications are not sufficiently definite or may be too restrictive to permit full and free competition

Functional groups of ecosystem engineers: a proposed classification with comments on current issues.

PubMed

Berke, Sarah K

2010-08-01

Ecologists have long known that certain organisms fundamentally modify, create, or define habitats by altering the habitat's physical properties. In the past 15 years, these processes have been formally defined as "ecosystem engineering", reflecting a growing consensus that environmental structuring by organisms represents a fundamental class of ecological interactions occurring in most, if not all, ecosystems. Yet, the precise definition and scope of ecosystem engineering remains debated, as one should expect given the complexity, enormity, and variability of ecological systems. Here I briefly comment on a few specific current points of contention in the ecosystem engineering concept. I then suggest that ecosystem engineering can be profitably subdivided into four narrower functional categories reflecting four broad mechanisms by which ecosystem engineering occurs: structural engineers, bioturbators, chemical engineers, and light engineers. Finally, I suggest some conceptual model frameworks that could apply broadly within these functional groups.

Formal Methods for Verification and Validation of Partial Specifications: A Case Study

NASA Technical Reports Server (NTRS)

Easterbrook, Steve; Callahan, John

1997-01-01

This paper describes our work exploring the suitability of formal specification methods for independent verification and validation (IV&V) of software specifications for large, safety critical systems. An IV&V contractor often has to perform rapid analysis on incomplete specifications, with no control over how those specifications are represented. Lightweight formal methods show significant promise in this context, as they offer a way of uncovering major errors, without the burden of full proofs of correctness. We describe a case study of the use of partial formal models for V&V of the requirements for Fault Detection Isolation and Recovery on the space station. We conclude that the insights gained from formalizing a specification are valuable, and it is the process of formalization, rather than the end product that is important. It was only necessary to build enough of the formal model to test the properties in which we were interested. Maintenance of fidelity between multiple representations of the same requirements (as they evolve) is still a problem, and deserves further study.

Formal hardware verification of digital circuits

NASA Technical Reports Server (NTRS)

Joyce, J.; Seger, C.-J.

1991-01-01

The use of formal methods to verify the correctness of digital circuits is less constrained by the growing complexity of digital circuits than conventional methods based on exhaustive simulation. This paper briefly outlines three main approaches to formal hardware verification: symbolic simulation, state machine analysis, and theorem-proving.

Peer Learning in a MATLAB Programming Course

NASA Astrophysics Data System (ADS)

Reckinger, Shanon

2016-11-01

Three forms of research-based peer learning were implemented in the design of a MATLAB programming course for mechanical engineering undergraduate students. First, a peer learning program was initiated. These undergraduate peer learning leaders played two roles in the course, (I) they were in the classroom helping students' with their work, and, (II) they led optional two hour helps sessions outside of the class time. The second form of peer learning was implemented through the inclusion of a peer discussion period following in class clicker quizzes. The third form of peer learning had the students creating video project assignments and posting them on YouTube to explain course topics to their peers. Several other more informal techniques were used to encourage peer learning. Student feedback in the form of both instructor-designed survey responses and formal course evaluations (quantitative and narrative) will be presented. Finally, effectiveness will be measured by formal assessment, direct and indirect to these peer learning methods. This will include both academic data/grades and pre/post test scores. Overall, the course design and its inclusion of these peer learning techniques demonstrate effectiveness.

Universal Quantum Computing with Arbitrary Continuous-Variable Encoding.

PubMed

Lau, Hoi-Kwan; Plenio, Martin B

2016-09-02

Implementing a qubit quantum computer in continuous-variable systems conventionally requires the engineering of specific interactions according to the encoding basis states. In this work, we present a unified formalism to conduct universal quantum computation with a fixed set of operations but arbitrary encoding. By storing a qubit in the parity of two or four qumodes, all computing processes can be implemented by basis state preparations, continuous-variable exponential-swap operations, and swap tests. Our formalism inherits the advantages that the quantum information is decoupled from collective noise, and logical qubits with different encodings can be brought to interact without decoding. We also propose a possible implementation of the required operations by using interactions that are available in a variety of continuous-variable systems. Our work separates the "hardware" problem of engineering quantum-computing-universal interactions, from the "software" problem of designing encodings for specific purposes. The development of quantum computer architecture could hence be simplified.

Universal Quantum Computing with Arbitrary Continuous-Variable Encoding

NASA Astrophysics Data System (ADS)

Lau, Hoi-Kwan; Plenio, Martin B.

2016-09-01

Implementing a qubit quantum computer in continuous-variable systems conventionally requires the engineering of specific interactions according to the encoding basis states. In this work, we present a unified formalism to conduct universal quantum computation with a fixed set of operations but arbitrary encoding. By storing a qubit in the parity of two or four qumodes, all computing processes can be implemented by basis state preparations, continuous-variable exponential-swap operations, and swap tests. Our formalism inherits the advantages that the quantum information is decoupled from collective noise, and logical qubits with different encodings can be brought to interact without decoding. We also propose a possible implementation of the required operations by using interactions that are available in a variety of continuous-variable systems. Our work separates the "hardware" problem of engineering quantum-computing-universal interactions, from the "software" problem of designing encodings for specific purposes. The development of quantum computer architecture could hence be simplified.

MatLab Script and Functional Programming

NASA Technical Reports Server (NTRS)

Shaykhian, Gholam Ali

2007-01-01

MatLab Script and Functional Programming: MatLab is one of the most widely used very high level programming languages for scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. The MatLab seminar covers the functional and script programming aspect of MatLab language. Specific expectations are: a) Recognize MatLab commands, script and function. b) Create, and run a MatLab function. c) Read, recognize, and describe MatLab syntax. d) Recognize decisions, loops and matrix operators. e) Evaluate scope among multiple files, and multiple functions within a file. f) Declare, define and use scalar variables, vectors and matrices.

Fast Formal Analysis of Requirements via "Topoi Diagrams"

NASA Technical Reports Server (NTRS)

Menzies, Tim; Powell, John; Houle, Michael E.; Kelly, John C. (Technical Monitor)

2001-01-01

Early testing of requirements can decrease the cost of removing errors in software projects. However, unless done carefully, that testing process can significantly add to the cost of requirements analysis. We show here that requirements expressed as topoi diagrams can be built and tested cheaply using our SP2 algorithm, the formal temporal properties of a large class of topoi can be proven very quickly, in time nearly linear in the number of nodes and edges in the diagram. There are two limitations to our approach. Firstly, topoi diagrams cannot express certain complex concepts such as iteration and sub-routine calls. Hence, our approach is more useful for requirements engineering than for traditional model checking domains. Secondly, out approach is better for exploring the temporal occurrence of properties than the temporal ordering of properties. Within these restrictions, we can express a useful range of concepts currently seen in requirements engineering, and a wide range of interesting temporal properties.

A study of education and KSAOs on career entry for product engineers: What employers really want

NASA Astrophysics Data System (ADS)

Thornburgh, James

The purpose of the study was to investigate the ways that employers of product engineers evaluate potential employees' job readiness, and which theories related to the education-work transaction are supported by practice. This study used a mixed methods approach and consisted of a state-wide survey (N=106) and local interviews (N=8). The results of the research indicate that attributes of both the Theory of Individual Differences and Credentialing Theory are present in the hiring practices of product engineers. Consistent with the Theory of Individual Differences, employers indicate they look for evidence of various job-related Knowledge, Skills, Abilities, and Other attributes (KSAOs) and they indicate they are willing to hire applicants who have less than a bachelor's degree. Consistent with Credentialing Theory, employers advertise a formal education minimum which represents only one way that individuals may learn to be an engineer. This study also confirmed prior research that most employers use primarily non-evidence based predictors to evaluate applicants. The primary initial screening predictors were experience, GPA, and major, while the primary finalist selection predictors were unstructured interviews, and applications, followed by structured interviews, job knowledge tests, and work sample test. Contrary to previous findings, this study did not find any major differences between what HR professionals, engineering managers, or other manager look for in terms of qualifications or what predictors they use when evaluating applicants for product engineer positions.

Engineering and Software Engineering

NASA Astrophysics Data System (ADS)

Jackson, Michael

The phrase ‘software engineering' has many meanings. One central meaning is the reliable development of dependable computer-based systems, especially those for critical applications. This is not a solved problem. Failures in software development have played a large part in many fatalities and in huge economic losses. While some of these failures may be attributable to programming errors in the narrowest sense—a program's failure to satisfy a given formal specification—there is good reason to think that most of them have other roots. These roots are located in the problem of software engineering rather than in the problem of program correctness. The famous 1968 conference was motivated by the belief that software development should be based on “the types of theoretical foundations and practical disciplines that are traditional in the established branches of engineering.” Yet after forty years of currency the phrase ‘software engineering' still denotes no more than a vague and largely unfulfilled aspiration. Two major causes of this disappointment are immediately clear. First, too many areas of software development are inadequately specialised, and consequently have not developed the repertoires of normal designs that are the indispensable basis of reliable engineering success. Second, the relationship between structural design and formal analytical techniques for software has rarely been one of fruitful synergy: too often it has defined a boundary between competing dogmas, at which mutual distrust and incomprehension deprive both sides of advantages that should be within their grasp. This paper discusses these causes and their effects. Whether the common practice of software development will eventually satisfy the broad aspiration of 1968 is hard to predict; but an understanding of past failure is surely a prerequisite of future success.

Verifying Hybrid Systems Modeled as Timed Automata: A Case Study

DTIC Science & Technology

1997-03-01

Introduction Researchers have proposed many innovative formal methods for developing real - time systems [9]. Such methods can give system developers and...customers greater con dence that real - time systems satisfy their requirements, especially their crit- ical requirements. However, applying formal methods...specifying and reasoning about real - time systems that is designed to address these challenging problems. Our approach is to build formal reasoning tools

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.

Integrating ethics in design through the value-sensitive design approach.

PubMed

Cummings, Mary L

2006-10-01

The Accreditation Board of Engineering and Technology (ABET) has declared that to achieve accredited status, 'engineering programs must demonstrate that their graduates have an understanding of professional and ethical responsibility.' Many engineering professors struggle to integrate this required ethics instruction in technical classes and projects because of the lack of a formalized ethics-in-design approach. However, one methodology developed in human-computer interaction research, the Value-Sensitive Design approach, can serve as an engineering education tool which bridges the gap between design and ethics for many engineering disciplines. The three major components of Value-Sensitive Design, conceptual, technical, and empirical, exemplified through a case study which focuses on the development of a command and control supervisory interface for a military cruise missile.

Preparing engineers for the challenges of community engagement

NASA Astrophysics Data System (ADS)

Harsh, Matthew; Bernstein, Michael J.; Wetmore, Jameson; Cozzens, Susan; Woodson, Thomas; Castillo, Rafael

2017-11-01

Despite calls to address global challenges through community engagement, engineers are not formally prepared to engage with communities. Little research has been done on means to address this 'engagement gap' in engineering education. We examine the efficacy of an intensive, two-day Community Engagement Workshop for engineers, designed to help engineers better look beyond technology, listen to and learn from people, and empower communities. We assessed the efficacy of the workshop in a non-experimental pre-post design using a questionnaire and a concept map. Questionnaire results indicate participants came away better able to ask questions more broadly inclusive of non-technological dimensions of engineering projects. Concept map results indicate participants have a greater understanding of ways social factors shape complex material systems after completing the programme. Based on the workshop's strengths and weaknesses, we discuss the potential of expanding and supplementing the programme to help engineers account for social aspects central to engineered systems.

Using a Formal Approach for Reverse Engineering and Design Recovery to Support Software Reuse

NASA Technical Reports Server (NTRS)

Gannod, Gerald C.

2002-01-01

This document describes 3rd year accomplishments and summarizes overall project accomplishments. Included as attachments are all published papers from year three. Note that the budget for this project was discontinued after year two, but that a residual budget from year two allowed minimal continuance into year three. Accomplishments include initial investigations into log-file based reverse engineering, service-based software reuse, and a source to XML generator.

Experiences applying Formal Approaches in the Development of Swarm-Based Space Exploration Systems

NASA Technical Reports Server (NTRS)

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

2006-01-01

NASA is researching advanced technologies for future exploration missions using intelligent swarms of robotic vehicles. One of these missions is the Autonomous Nan0 Technology Swarm (ANTS) mission that will explore the asteroid belt using 1,000 cooperative autonomous spacecraft. The emergent properties of intelligent swarms make it a potentially powerful concept, but at the same time more difficult to design and ensure that the proper behaviors will emerge. NASA is investigating formal methods and techniques for verification of such missions. The advantage of using formal methods is the ability to mathematically verify the behavior of a swarm, emergent or otherwise. Using the ANTS mission as a case study, we have evaluated multiple formal methods to determine their effectiveness in modeling and ensuring desired swarm behavior. This paper discusses the results of this evaluation and proposes an integrated formal method for ensuring correct behavior of future NASA intelligent swarms.

ENGINEERING BULLETIN: PYROLYSIS TREATMENT

EPA Science Inventory

Pyrolysis is formally defined as chemical decomposition induced in organic materials by heat in the absence of oxygen. In practice, it is not possible to achieve a completely oxygen-free atmosphere; actual pyrolytic systems are operated with less than stoichiometric quantities of...

Bridging the Gulf between Formal Calculus and Physical Reasoning.

ERIC Educational Resources Information Center

Van Der Meer, A.

1980-01-01

Some ways to link calculus instruction with the mathematical models used in physics courses are presented. The activity of modelling is presented as a major tool in synchronizing physics and mathematics instruction in undergraduate engineering programs. (MP)

Light UAV Support Ship (ASW) (LUSSA)

DTIC Science & Technology

2011-08-01

35 9.5 TriSWACH Model Test Data...7 Figure 8: TriSWACH Model ...Innovation in Ship Design (CISD) used the Northrop Grumman Bat UAV (formally known as the Swift Engineering Killer Bee KB4) to model launch, recovery, and

48 CFR 1509.170-3 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-10-01

... PLANNING CONTRACTOR QUALIFICATIONS Contractor Performance Evaluations 1509.170-3 Applicability. (a) This....604 provides detailed instructions for architect-engineer contractor performance evaluations. (b) The... simplified acquisition procedures do not require the creation or existence of a formal database for past...

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.

Using Formal Methods to Assist in the Requirements Analysis of the Space Shuttle GPS Change Request

NASA Technical Reports Server (NTRS)

DiVito, Ben L.; Roberts, Larry W.

1996-01-01

We describe a recent NASA-sponsored pilot project intended to gauge the effectiveness of using formal methods in Space Shuttle software requirements analysis. Several Change Requests (CR's) were selected as promising targets to demonstrate the utility of formal methods in this application domain. A CR to add new navigation capabilities to the Shuttle, based on Global Positioning System (GPS) technology, is the focus of this report. Carried out in parallel with the Shuttle program's conventional requirements analysis process was a limited form of analysis based on formalized requirements. Portions of the GPS CR were modeled using the language of SRI's Prototype Verification System (PVS). During the formal methods-based analysis, numerous requirements issues were discovered and submitted as official issues through the normal requirements inspection process. Shuttle analysts felt that many of these issues were uncovered earlier than would have occurred with conventional methods. We present a summary of these encouraging results and conclusions we have drawn from the pilot project.

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.

Formal Methods of V&V of Partial Specifications: An Experience Report

NASA Technical Reports Server (NTRS)

Easterbrook, Steve; Callahan, John

1997-01-01

This paper describes our work exploring the suitability of formal specification methods for independent verification and validation (IV&V) of software specifications for large, safety critical systems. An IV&V contractor often has to perform rapid analysis on incomplete specifications, with no control over how those specifications are represented. Lightweight formal methods show significant promise in this context, as they offer a way of uncovering major errors, without the burden of full proofs of correctness. We describe an experiment in the application of the method SCR. to testing for consistency properties of a partial model of requirements for Fault Detection Isolation and Recovery on the space station. We conclude that the insights gained from formalizing a specification is valuable, and it is the process of formalization, rather than the end product that is important. It was only necessary to build enough of the formal model to test the properties in which we were interested. Maintenance of fidelity between multiple representations of the same requirements (as they evolve) is still a problem, and deserves further study.

General Formalism of Mass Scaling Approach for Replica-Exchange Molecular Dynamics and its Application

NASA Astrophysics Data System (ADS)

Nagai, Tetsuro

2017-01-01

Replica-exchange molecular dynamics (REMD) has demonstrated its efficiency by combining trajectories of a wide range of temperatures. As an extension of the method, the author formalizes the mass-manipulating replica-exchange molecular dynamics (MMREMD) method that allows for arbitrary mass scaling with respect to temperature and individual particles. The formalism enables the versatile application of mass-scaling approaches to the REMD method. The key change introduced in the novel formalism is the generalized rules for the velocity and momentum scaling after accepted replica-exchange attempts. As an application of this general formalism, the refinement of the viscosity-REMD (V-REMD) method [P. H. Nguyen, J. Chem. Phys. 132, 144109 (2010)] is presented. Numerical results are provided using a pilot system, demonstrating easier and more optimized applicability of the new version of V-REMD as well as the importance of adherence to the generalized velocity scaling rules. With the new formalism, more sound and efficient simulations will be performed.

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.

A Tool for Requirements-Based Programming

NASA Technical Reports Server (NTRS)

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

2005-01-01

Absent a general method for mathematically sound, automated transformation of customer requirements into a formal model of the desired system, developers must resort to either manual application of formal methods or to system testing (either manual or automated). While formal methods have afforded numerous successes, they present serious issues, e.g., costs to gear up to apply them (time, expensive staff), and scalability and reproducibility when standards in the field are not settled. The testing path cannot be walked to the ultimate goal, because exhaustive testing is infeasible for all but trivial systems. So system verification remains problematic. System or requirements validation is similarly problematic. The alternatives available today depend on either having a formal model or pursuing enough testing to enable the customer to be certain that system behavior meets requirements. The testing alternative for non-trivial systems always have some system behaviors unconfirmed and therefore is not the answer. To ensure that a formal model is equivalent to the customer s requirements necessitates that the customer somehow fully understands the formal model, which is not realistic. The predominant view that provably correct system development depends on having a formal model of the system leads to a desire for a mathematically sound method to automate the transformation of customer requirements into a formal model. Such a method, an augmentation of requirements-based programming, will be briefly described in this paper, and a prototype tool to support it will be described. The method and tool enable both requirements validation and system verification for the class of systems whose behavior can be described as scenarios. An application of the tool to a prototype automated ground control system for NASA mission is presented.

Reconfigurable Hardware Adapts to Changing Mission Demands

NASA Technical Reports Server (NTRS)

2003-01-01

A new class of computing architectures and processing systems, which use reconfigurable hardware, is creating a revolutionary approach to implementing future spacecraft systems. With the increasing complexity of electronic components, engineers must design next-generation spacecraft systems with new technologies in both hardware and software. Derivation Systems, Inc., of Carlsbad, California, has been working through NASA s Small Business Innovation Research (SBIR) program to develop key technologies in reconfigurable computing and Intellectual Property (IP) soft cores. Founded in 1993, Derivation Systems has received several SBIR contracts from NASA s Langley Research Center and the U.S. Department of Defense Air Force Research Laboratories in support of its mission to develop hardware and software for high-assurance systems. Through these contracts, Derivation Systems began developing leading-edge technology in formal verification, embedded Java, and reconfigurable computing for its PF3100, Derivational Reasoning System (DRS ), FormalCORE IP, FormalCORE PCI/32, FormalCORE DES, and LavaCORE Configurable Java Processor, which are designed for greater flexibility and security on all space missions.

Optical systems engineering - A tutorial

NASA Technical Reports Server (NTRS)

Wyman, C. L.

1979-01-01

The paper examines the use of the systems engineering approach in the design of optical systems, noting that the use of such an approach which involves an integrated interdisciplinary approach to the development of systems is most appropriate for optics. It is shown that the high precision character of optics leads to complex and subtle effects on optical system performance, resulting from structural, thermal dynamical, control system, and manufacturing and assembly considerations. Attention is given to communication problems that often occur among users and optical engineers due to the unique factors of optical systems. It is concluded that it is essential that the optics community provide leadership to resolve communication problems and fully formalize the field of optical systems engineering.

Discrete approach to stochastic parametrization and dimension reduction in nonlinear dynamics.

PubMed

Chorin, Alexandre J; Lu, Fei

2015-08-11

Many physical systems are described by nonlinear differential equations that are too complicated to solve in full. A natural way to proceed is to divide the variables into those that are of direct interest and those that are not, formulate solvable approximate equations for the variables of greater interest, and use data and statistical methods to account for the impact of the other variables. In the present paper we consider time-dependent problems and introduce a fully discrete solution method, which simplifies both the analysis of the data and the numerical algorithms. The resulting time series are identified by a NARMAX (nonlinear autoregression moving average with exogenous input) representation familiar from engineering practice. The connections with the Mori-Zwanzig formalism of statistical physics are discussed, as well as an application to the Lorenz 96 system.

Circuit topology of proteins and nucleic acids.

PubMed

Mashaghi, Alireza; van Wijk, Roeland J; Tans, Sander J

2014-09-02

Folded biomolecules display a bewildering structural complexity and diversity. They have therefore been analyzed in terms of generic topological features. For instance, folded proteins may be knotted, have beta-strands arranged into a Greek-key motif, or display high contact order. In this perspective, we present a method to formally describe the topology of all folded linear chains and hence provide a general classification and analysis framework for a range of biomolecules. Moreover, by identifying the fundamental rules that intrachain contacts must obey, the method establishes the topological constraints of folded linear chains. We also briefly illustrate how this circuit topology notion can be applied to study the equivalence of folded chains, the engineering of artificial RNA structures and DNA origami, the topological structure of genomes, and the role of topology in protein folding. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

META-GLARE: A meta-system for defining your own computer interpretable guideline system-Architecture and acquisition.

PubMed

Bottrighi, Alessio; Terenziani, Paolo

2016-09-01

Several different computer-assisted management systems of computer interpretable guidelines (CIGs) have been developed by the Artificial Intelligence in Medicine community. Each CIG system is characterized by a specific formalism to represent CIGs, and usually provides a manager to acquire, consult and execute them. Though there are several commonalities between most formalisms in the literature, each formalism has its own peculiarities. The goal of our work is to provide a flexible support to the extension or definition of CIGs formalisms, and of their acquisition and execution engines. Instead of defining "yet another CIG formalism and its manager", we propose META-GLARE (META Guideline Acquisition, Representation, and Execution), a "meta"-system to define new CIG systems. In this paper, META-GLARE, a meta-system to define new CIG systems, is presented. We try to capture the commonalities among current CIG approaches, by providing (i) a general manager for the acquisition, consultation and execution of hierarchical graphs (representing the control flow of actions in CIGs), parameterized over the types of nodes and of arcs constituting it, and (ii) a library of different elementary components of guidelines nodes (actions) and arcs, in which each type definition involves the specification of how objects of this type can be acquired, consulted and executed. We provide generality and flexibility, by allowing free aggregations of such elementary components to define new primitive node and arc types. We have drawn several experiments, in which we have used META-GLARE to build a CIG system (Experiment 1 in Section 8), or to extend it (Experiments 2 and 3). Such experiments show that META-GLARE provides a useful and easy-to-use support to such tasks. For instance, re-building the Guideline Acquisition, Representation, and Execution (GLARE) system using META-GLARE required less than one day (Experiment 1). META-GLARE is a meta-system for CIGs supporting fast prototyping. Since META-GLARE provides acquisition and execution engines that are parametric over the specific CIG formalism, it supports easy update and construction of CIG systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Expedition 32 Preflight

NASA Image and Video Library

2012-07-15

Expedition 32 Flight Engineer Sunita Williams, right, Soyuz Commander Yuri Malenchenko and JAXA Flight Engineer Akihiko Hoshide, left, receive a formal go for launch from Vitaly Alexandrovich Lopota, President of Energia, left, and Vladimir Popovkin, Director of Roscosmos prior to their launch onboard the Soyuz TMA-05M on Sunday, July 15, 2012 at the Baikonur Cosmodrome in Kazakhstan. The Soyuz spacecraft with Malenchenko, Williams and Hoshide onboard launched at 8:40 a.m. later that morning Kazakhstan time. Photo Credit: (NASA/Victor Zelentsov)

Meta-Analysis of Human Factors Engineering Studies Comparing Individual Differences, Practice Effects and Equipment Design Variations.

DTIC Science & Technology

1985-02-21

Approvoid foT public 90Ieleol, 2* . tJni7nited " - . - o . - ’--. * . -... . 1 UNCLASSIFIED S, E CURITY CLASSIFICATION OF THIS PAGE-" REPORT DOCUMENTATION...ACCESSION NO. 11. TITLE (Include Security Classification) . Veta -Analysis of Human Factors Engineering Studies Comparing Individual Differences, Practice...Background C Opportunity D Significance E History III. PHASE I FINAL REPORT A Literature Review B Formal Analysis C Results D Implications for Phase II IV

Applications of Formal Methods to Specification and Safety of Avionics Software

NASA Technical Reports Server (NTRS)

Hoover, D. N.; Guaspari, David; Humenn, Polar

1996-01-01

This report treats several topics in applications of formal methods to avionics software development. Most of these topics concern decision tables, an orderly, easy-to-understand format for formally specifying complex choices among alternative courses of action. The topics relating to decision tables include: generalizations fo decision tables that are more concise and support the use of decision tables in a refinement-based formal software development process; a formalism for systems of decision tables with behaviors; an exposition of Parnas tables for users of decision tables; and test coverage criteria and decision tables. We outline features of a revised version of ORA's decision table tool, Tablewise, which will support many of the new ideas described in this report. We also survey formal safety analysis of specifications and software.

The path to next generation biofuels: successes and challenges in the era of synthetic biology

PubMed Central

2010-01-01

Volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked renewed interest in the production of fuels from renewable resources. Recent advances in synthetic biology provide new tools for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels. Metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for conversion of biomass constituents to short-chain alcohols and advanced biofuels are herewith reviewed. In the foreseeable future, formal integration of functional genomics and systems biology with synthetic biology and metabolic engineering will undoubtedly support the discovery, characterization, and engineering of new metabolic routes and more efficient microbial systems for the production of biofuels. PMID:20089184

Formal methods and their role in digital systems validation for airborne systems

NASA Technical Reports Server (NTRS)

Rushby, John

1995-01-01

This report is based on one prepared as a chapter for the FAA Digital Systems Validation Handbook (a guide to assist FAA certification specialists with advanced technology issues). Its purpose is 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 in critical applications; and to suggest factors for consideration when formal methods are offered in support of certification. The presentation concentrates on the rationale for formal methods and on their contribution to assurance for critical applications within a context such as that provided by DO-178B (the guidelines for software used on board civil aircraft); it is intended as an introduction for those to whom these topics are new.

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.

Group Work

ERIC Educational Resources Information Center

Wilson, Kristy J.; Brickman, Peggy; Brame, Cynthia J.

2018-01-01

Science, technology, engineering, and mathematics faculty are increasingly incorporating both formal and informal group work in their courses. Implementing group work can be improved by an understanding of the extensive body of educational research studies on this topic. This essay describes an online, evidence-based teaching guide published by…

Bridging the gap between formal and experience-based knowledge for context-aware laparoscopy.

PubMed

Katić, Darko; Schuck, Jürgen; Wekerle, Anna-Laura; Kenngott, Hannes; Müller-Stich, Beat Peter; Dillmann, Rüdiger; Speidel, Stefanie

2016-06-01

Computer assistance is increasingly common in surgery. However, the amount of information is bound to overload processing abilities of surgeons. We propose methods to recognize the current phase of a surgery for context-aware information filtering. The purpose is to select the most suitable subset of information for surgical situations which require special assistance. We combine formal knowledge, represented by an ontology, and experience-based knowledge, represented by training samples, to recognize phases. For this purpose, we have developed two different methods. Firstly, we use formal knowledge about possible phase transitions to create a composition of random forests. Secondly, we propose a method based on cultural optimization to infer formal rules from experience to recognize phases. The proposed methods are compared with a purely formal knowledge-based approach using rules and a purely experience-based one using regular random forests. The comparative evaluation on laparoscopic pancreas resections and adrenalectomies employs a consistent set of quality criteria on clean and noisy input. The rule-based approaches proved best with noisefree data. The random forest-based ones were more robust in the presence of noise. Formal and experience-based knowledge can be successfully combined for robust phase recognition.

A Natural Language Interface Concordant with a Knowledge Base.

PubMed

Han, Yong-Jin; Park, Seong-Bae; Park, Se-Young

2016-01-01

The discordance between expressions interpretable by a natural language interface (NLI) system and those answerable by a knowledge base is a critical problem in the field of NLIs. In order to solve this discordance problem, this paper proposes a method to translate natural language questions into formal queries that can be generated from a graph-based knowledge base. The proposed method considers a subgraph of a knowledge base as a formal query. Thus, all formal queries corresponding to a concept or a predicate in the knowledge base can be generated prior to query time and all possible natural language expressions corresponding to each formal query can also be collected in advance. A natural language expression has a one-to-one mapping with a formal query. Hence, a natural language question is translated into a formal query by matching the question with the most appropriate natural language expression. If the confidence of this matching is not sufficiently high the proposed method rejects the question and does not answer it. Multipredicate queries are processed by regarding them as a set of collected expressions. The experimental results show that the proposed method thoroughly handles answerable questions from the knowledge base and rejects unanswerable ones effectively.

Verification 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

The emergent properties of swarms make swarm-based missions powerful, but at the same time more difficult to design and to assure that the proper behaviors will emerge. We are currently investigating formal methods and techniques for verification and validation of swarm-based missions. The Autonomous Nano-Technology Swarm (ANTS) mission is being used as an example and case study for swarm-based missions to experiment and test current formal methods with intelligent swarms. Using the ANTS mission, we have evaluated multiple formal methods to determine their effectiveness in modeling and assuring swarm behavior. This paper introduces how intelligent swarm technology is being proposed for NASA missions, and gives the results of a comparison of several formal methods and approaches for specifying intelligent swarm-based systems and their effectiveness for predicting emergent behavior.

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.

Abductive Equivalential Translation and its application to Natural Language Database Interfacing

NASA Astrophysics Data System (ADS)

Rayner, Manny

1994-05-01

The thesis describes a logical formalization of natural-language database interfacing. We assume the existence of a ``natural language engine'' capable of mediating between surface linguistic string and their representations as ``literal'' logical forms: the focus of interest will be the question of relating ``literal'' logical forms to representations in terms of primitives meaningful to the underlying database engine. We begin by describing the nature of the problem, and show how a variety of interface functionalities can be considered as instances of a type of formal inference task which we call ``Abductive Equivalential Translation'' (AET); functionalities which can be reduced to this form include answering questions, responding to commands, reasoning about the completeness of answers, answering meta-questions of type ``Do you know...'', and generating assertions and questions. In each case, a ``linguistic domain theory'' (LDT) Γ and an input formula F are given, and the goal is to construct a formula with certain properties which is equivalent to F, given Γ and a set of permitted assumptions. If the LDT is of a certain specified type, whose formulas are either conditional equivalences or Horn-clauses, we show that the AET problem can be reduced to a goal-directed inference method. We present an abstract description of this method, and sketch its realization in Prolog. The relationship between AET and several problems previously discussed in the literature is discussed. In particular, we show how AET can provide a simple and elegant solution to the so-called ``Doctor on Board'' problem, and in effect allows a ``relativization'' of the Closed World Assumption. The ideas in the thesis have all been implemented concretely within the SRI CLARE project, using a real projects and payments database. The LDT for the example database is described in detail, and examples of the types of functionality that can be achieved within the example domain are presented.

State-vector formalism and the Legendre polynomial solution for modelling guided waves in anisotropic plates

NASA Astrophysics Data System (ADS)

Zheng, Mingfang; He, Cunfu; Lu, Yan; Wu, Bin

2018-01-01

We presented a numerical method to solve phase dispersion curve in general anisotropic plates. This approach involves an exact solution to the problem in the form of the Legendre polynomial of multiple integrals, which we substituted into the state-vector formalism. In order to improve the efficiency of the proposed method, we made a special effort to demonstrate the analytical methodology. Furthermore, we analyzed the algebraic symmetries of the matrices in the state-vector formalism for anisotropic plates. The basic feature of the proposed method was the expansion of field quantities by Legendre polynomials. The Legendre polynomial method avoid to solve the transcendental dispersion equation, which can only be solved numerically. This state-vector formalism combined with Legendre polynomial expansion distinguished the adjacent dispersion mode clearly, even when the modes were very close. We then illustrated the theoretical solutions of the dispersion curves by this method for isotropic and anisotropic plates. Finally, we compared the proposed method with the global matrix method (GMM), which shows excellent agreement.

Propulsion and Energetics Panel Working Group 15 on the Uniform Engine Test Programme

DTIC Science & Technology

1990-02-01

earlier test of uniform aerodynamic models in wind tunnels under the auspices of the Fluid Dynamics Panel. A formal proposal was presented to the...this major new effort and members of the engine test community throughout AGARD were selected to serve on Working Group 15 along with PEP...STPA/MO 4 Mr J.R.Bednarsk; 4 Avenue de Ia Porte d’lssy PE-63 75015 Paris Naval Air Propulsion Center PO Box 7176 GERMANY Trenton. New Jersey 08628

Expedition 31 Crew Prepares For Launch

NASA Image and Video Library

2012-05-15

Expedition 31 Flight Engineer Joe Acaba, left, Soyuz Commander Gennady Padalka, and, Flight Engineer Sergei Revin, right, receive a formal go for launch from Vitaly Alexandrovich Lopota, President of Energia, left, and Vladimir Popovkin, Director of Roscosmos prior to their launch onboard the Soyuz TMA-04M on Tuesday, May 15, 2012 at the Baikonur Cosmodrome in Kazakhstan. The Soyuz spacecraft with Padalka, Revin, and Acaba onboard, launched at 9:01 a.m. Kazakhstan time on Tuesday, May 15. Photo Credit: (NASA/GCTC/Andrey Shelepin)

Statistical analysis of Turbine Engine Diagnostic (TED) field test data

NASA Astrophysics Data System (ADS)

Taylor, Malcolm S.; Monyak, John T.

1994-11-01

During the summer of 1993, a field test of turbine engine diagnostic (TED) software, developed jointly by U.S. Army Research Laboratory and the U.S. Army Ordnance Center and School, was conducted at Fort Stuart, GA. The data were collected in conformance with a cross-over design, some of whose considerations are detailed. The initial analysis of the field test data was exploratory, followed by a more formal investigation. Technical aspects of the data analysis insights that were elicited are reported.

IEEE/NASA Workshop on Leveraging Applications of Formal Methods, Verification, and Validation

NASA Technical Reports Server (NTRS)

Margaria, Tiziana (Editor); Steffen, Bernhard (Editor); Hichey, Michael G.

2005-01-01

This volume contains the Preliminary Proceedings of the 2005 IEEE ISoLA Workshop on Leveraging Applications of Formal Methods, Verification, and Validation, with a special track on the theme of Formal Methods in Human and Robotic Space Exploration. The workshop was held on 23-24 September 2005 at the Loyola College Graduate Center, Columbia, MD, USA. The idea behind the Workshop arose from the experience and feedback of ISoLA 2004, the 1st International Symposium on Leveraging Applications of Formal Methods held in Paphos (Cyprus) last October-November. ISoLA 2004 served the need of providing a forum for developers, users, and researchers to discuss issues related to the adoption and use of rigorous tools and methods for the specification, analysis, verification, certification, construction, test, and maintenance of systems from the point of view of their different application domains.

Proportional Reasoning and the Visually Impaired

ERIC Educational Resources Information Center

Hilton, Geoff; Hilton, Annette; Dole, Shelley L.; Goos, Merrilyn; O'Brien, Mia

2012-01-01

Proportional reasoning is an important aspect of formal thinking that is acquired during the developmental years that approximate the middle years of schooling. Students who fail to acquire sound proportional reasoning often experience difficulties in subjects that require quantitative thinking, such as science, technology, engineering, and…

Black Boxes in Analytical Chemistry: University Students' Misconceptions of Instrumental Analysis

ERIC Educational Resources Information Center

Carbo, Antonio Domenech; Adelantado, Jose Vicente Gimeno; Reig, Francisco Bosch

2010-01-01

Misconceptions of chemistry and chemical engineering university students concerning instrumental analysis have been established from coordinated tests, tutorial interviews and laboratory lessons. Misconceptions can be divided into: (1) formal, involving specific concepts and formulations within the general frame of chemistry; (2)…

The FoReVer Methodology: A MBSE Framework for Formal Verification

NASA Astrophysics Data System (ADS)

Baracchi, Laura; Mazzini, Silvia; Cimatti, Alessandro; Tonetta, Stefano; Garcia, Gerald

2013-08-01

The need for high level of confidence and operational integrity in critical space (software) systems is well recognized in the Space industry and has been addressed so far through rigorous System and Software Development Processes and stringent Verification and Validation regimes. The Model Based Space System Engineering process (MBSSE) derived in the System and Software Functional Requirement Techniques study (SSFRT) focused on the application of model based engineering technologies to support the space system and software development processes, from mission level requirements to software implementation through model refinements and translations. In this paper we report on our work in the ESA-funded FoReVer project where we aim at developing methodological, theoretical and technological support for a systematic approach to the space avionics system development, in phases 0/A/B/C. FoReVer enriches the MBSSE process with contract-based formal verification of properties, at different stages from system to software, through a step-wise refinement approach, with the support for a Software Reference Architecture.

A knowledge based software engineering environment testbed

NASA Technical Reports Server (NTRS)

Gill, C.; Reedy, A.; Baker, L.

1985-01-01

The Carnegie Group Incorporated and Boeing Computer Services Company are developing a testbed which will provide a framework for integrating conventional software engineering tools with Artifical Intelligence (AI) tools to promote automation and productivity. The emphasis is on the transfer of AI technology to the software development process. Experiments relate to AI issues such as scaling up, inference, and knowledge representation. In its first year, the project has created a model of software development by representing software activities; developed a module representation formalism to specify the behavior and structure of software objects; integrated the model with the formalism to identify shared representation and inheritance mechanisms; demonstrated object programming by writing procedures and applying them to software objects; used data-directed and goal-directed reasoning to, respectively, infer the cause of bugs and evaluate the appropriateness of a configuration; and demonstrated knowledge-based graphics. Future plans include introduction of knowledge-based systems for rapid prototyping or rescheduling; natural language interfaces; blackboard architecture; and distributed processing

Rasmussen's legacy: A paradigm change in engineering for safety.

PubMed

Leveson, Nancy G

2017-03-01

This paper describes three applications of Rasmussen's idea to systems engineering practice. The first is the application of the abstraction hierarchy to engineering specifications, particularly requirements specification. The second is the use of Rasmussen's ideas in safety modeling and analysis to create a new, more powerful type of accident causation model that extends traditional models to better handle human-operated, software-intensive, sociotechnical systems. Because this new model has a formal, mathematical foundation built on systems theory (as was Rasmussen's original model), new modeling and analysis tools become possible. The third application is to engineering hazard analysis. Engineers have traditionally either omitted human from consideration in system hazard analysis or have treated them rather superficially, for example, that they behave randomly. Applying Rasmussen's model of human error to a powerful new hazard analysis technique allows human behavior to be included in engineering hazard analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Engineering Changes in Product Design - A Review

NASA Astrophysics Data System (ADS)

Karthik, K.; Janardhan Reddy, K., Dr

2016-09-01

Changes are fundamental to product development. Engineering changes are unavoidable and can arise at any phase of the product life cycle. The consideration of market requirements, customer/user feedbacks, manufacturing constraints, design innovations etc., turning them into viable products can be accomplished when product change is managed properly. In the early design cycle, informal changes are accepted. However, changes become formal when its complexity and cost increases, and as product matures. To maximize the market shares, manufacturers have to effectively and efficiently manage engineering changes by means of Configuration Control. The paper gives a broad overview about ‘Engineering Change Management’ (ECM) through configuration management and its implications in product design. The aim is to give an idea and understanding about the engineering changes in product design scenario to the new researchers. This paper elaborates the significant aspect of managing the engineering changes and the importance of ECM in a product life cycle.

Systems, methods and apparatus for verification of knowledge-based systems

NASA Technical Reports Server (NTRS)

Rash, James L. (Inventor); Gracinin, Denis (Inventor); Erickson, John D. (Inventor); Rouff, Christopher A. (Inventor); Hinchey, Michael G. (Inventor)

2010-01-01

Systems, methods and apparatus are provided through which in some embodiments, domain knowledge is translated into a knowledge-based system. In some embodiments, a formal specification is derived from rules of a knowledge-based system, the formal specification is analyzed, and flaws in the formal specification are used to identify and correct errors in the domain knowledge, from which a knowledge-based system is translated.

The Development of Introductory Statistics Students' Informal Inferential Reasoning and Its Relationship to Formal Inferential Reasoning

ERIC Educational Resources Information Center

Jacob, Bridgette L.

2013-01-01

The difficulties introductory statistics students have with formal statistical inference are well known in the field of statistics education. "Informal" statistical inference has been studied as a means to introduce inferential reasoning well before and without the formalities of formal statistical inference. This mixed methods study…

Improved object optimal synthetic description, modeling, learning, and discrimination by GEOGINE computational kernel

NASA Astrophysics Data System (ADS)

Fiorini, Rodolfo A.; Dacquino, Gianfranco

2005-03-01

GEOGINE (GEOmetrical enGINE), a state-of-the-art OMG (Ontological Model Generator) based on n-D Tensor Invariants for n-Dimensional shape/texture optimal synthetic representation, description and learning, was presented in previous conferences elsewhere recently. Improved computational algorithms based on the computational invariant theory of finite groups in Euclidean space and a demo application is presented. Progressive model automatic generation is discussed. GEOGINE can be used as an efficient computational kernel for fast reliable application development and delivery in advanced biomedical engineering, biometric, intelligent computing, target recognition, content image retrieval, data mining technological areas mainly. Ontology can be regarded as a logical theory accounting for the intended meaning of a formal dictionary, i.e., its ontological commitment to a particular conceptualization of the world object. According to this approach, "n-D Tensor Calculus" can be considered a "Formal Language" to reliably compute optimized "n-Dimensional Tensor Invariants" as specific object "invariant parameter and attribute words" for automated n-Dimensional shape/texture optimal synthetic object description by incremental model generation. The class of those "invariant parameter and attribute words" can be thought as a specific "Formal Vocabulary" learned from a "Generalized Formal Dictionary" of the "Computational Tensor Invariants" language. Even object chromatic attributes can be effectively and reliably computed from object geometric parameters into robust colour shape invariant characteristics. As a matter of fact, any highly sophisticated application needing effective, robust object geometric/colour invariant attribute capture and parameterization features, for reliable automated object learning and discrimination can deeply benefit from GEOGINE progressive automated model generation computational kernel performance. Main operational advantages over previous, similar approaches are: 1) Progressive Automated Invariant Model Generation, 2) Invariant Minimal Complete Description Set for computational efficiency, 3) Arbitrary Model Precision for robust object description and identification.

Evidence Arguments for Using Formal Methods in Software Certification

NASA Technical Reports Server (NTRS)

Denney, Ewen W.; Pai, Ganesh

2013-01-01

We describe a generic approach for automatically integrating the output generated from a formal method/tool into a software safety assurance case, as an evidence argument, by (a) encoding the underlying reasoning as a safety case pattern, and (b) instantiating it using the data produced from the method/tool. We believe this approach not only improves the trustworthiness of the evidence generated from a formal method/tool, by explicitly presenting the reasoning and mechanisms underlying its genesis, but also provides a way to gauge the suitability of the evidence in the context of the wider assurance case. We illustrate our work by application to a real example-an unmanned aircraft system- where we invoke a formal code analysis tool from its autopilot software safety case, automatically transform the verification output into an evidence argument, and then integrate it into the former.

Extended abstract: Managing disjunction for practical temporal reasoning

NASA Technical Reports Server (NTRS)

Boddy, Mark; Schrag, Bob; Carciofini, Jim

1992-01-01

One of the problems that must be dealt with in either a formal or implemented temporal reasoning system is the ambiguity arising from uncertain information. Lack of precise information about when events happen leads to uncertainty regarding the effects of those events. Incomplete information and nonmonotonic inference lead to situations where there is more than one set of possible inferences, even when there is no temporal uncertainty at all. In an implemented system, this ambiguity is a computational problem as well as a semantic one. In this paper, we discuss some of the sources of this ambiguity, which we will treat as explicit disjunction, in the sense that ambiguous information can be interpreted as defining a set of possible inferences. We describe the application of three techniques for managing disjunction in an implementation of Dean's Time Map Manager. Briefly, the disjunction is either: removed by limiting the expressive power of the system, or approximated by a weaker form of representation that subsumes the disjunction. We use a combination of these methods to implement an expressive and efficient temporal reasoning engine that performs sound inference in accordance with a well-defined formal semantics.

Granular statistical mechanics - a personal perspective

NASA Astrophysics Data System (ADS)

Blumenfeld, R.; Edwards, S. F.

2014-10-01

The science of granular matter has expanded from an activity for specialised engineering applications to a fundamental field in its own right. This has been accompanied by an explosion of research and literature, which cannot be reviewed in one paper. A key to progress in this field is the formulation of a statistical mechanical formalism that could help develop equations of state and constitutive relations. This paper aims at reviewing some milestones in this direction. An essential basic step toward the development of any static and quasi-static theory of granular matter is a systematic and useful method to quantify the grain-scale structure and we start with a review of such a method. We then review and discuss the ongoing attempt to construct a statistical mechanical theory of granular systems. Along the way, we will clarify a number of misconceptions in the field, as well as highlight several outstanding problems.

Cost benefits of advanced software: A review of methodology used at Kennedy Space Center

NASA Technical Reports Server (NTRS)

Joglekar, Prafulla N.

1993-01-01

To assist rational investments in advanced software, a formal, explicit, and multi-perspective cost-benefit analysis methodology is proposed. The methodology can be implemented through a six-stage process which is described and explained. The current practice of cost-benefit analysis at KSC is reviewed in the light of this methodology. The review finds that there is a vicious circle operating. Unsound methods lead to unreliable cost-benefit estimates. Unreliable estimates convince management that cost-benefit studies should not be taken seriously. Then, given external demands for cost-benefit estimates, management encourages software enginees to somehow come up with the numbers for their projects. Lacking the expertise needed to do a proper study, courageous software engineers with vested interests use ad hoc and unsound methods to generate some estimates. In turn, these estimates are unreliable, and the cycle continues. The proposed methodology should help KSC to break out of this cycle.

Modeling patient safety incidents knowledge with the Categorial Structure method.

PubMed

Souvignet, Julien; Bousquet, Cédric; Lewalle, Pierre; Trombert-Paviot, Béatrice; Rodrigues, Jean Marie

2011-01-01

Following the WHO initiative named World Alliance for Patient Safety (PS) launched in 2004 a conceptual framework developed by PS national reporting experts has summarized the knowledge available. As a second step, the Department of Public Health of the University of Saint Etienne team elaborated a Categorial Structure (a semi formal structure not related to an upper level ontology) identifying the elements of the semantic structure underpinning the broad concepts contained in the framework for patient safety. This knowledge engineering method has been developed to enable modeling patient safety information as a prerequisite for subsequent full ontology development. The present article describes the semantic dissection of the concepts, the elicitation of the ontology requirements and the domain constraints of the conceptual framework. This ontology includes 134 concepts and 25 distinct relations and will serve as basis for an Information Model for Patient Safety.

Formal methods for dependable real-time systems

NASA Technical Reports Server (NTRS)

Rushby, John

1993-01-01

The motivation for using formal methods to specify and reason about real time properties is outlined and approaches that were proposed and used are sketched. The formal verifications of clock synchronization algorithms are concluded as showing that mechanically supported reasoning about complex real time behavior is feasible. However, there was significant increase in the effectiveness of verification systems since those verifications were performed, at it is to be expected that verifications of comparable difficulty will become fairly routine. The current challenge lies in developing perspicuous and economical approaches to the formalization and specification of real time properties.

The Engineering Design Process: Conceptions Along the Learning-to-Teach Continuum

NASA Astrophysics Data System (ADS)

Iveland, Ashley

In this study, I sought to identify differences in the views and understandings of engineering design among individuals along the learning-to-teach continuum. To do so, I conducted a comprehensive review of literature to determine the various aspects of engineering design described in the fields of professional engineering and engineering education. Additionally, I reviewed literature on the methods used in teaching engineering design at the secondary (grade 7-12) level - to describe the various models used in classrooms, even before the implementation of the Next Generation Science Standards (NGSS Lead States, 2013). Last, I defined four groups along the learning-to-teach continuum: prospective, preservice, and practicing teachers, as well as teacher educators. The context of this study centered around a California public university, including an internship program where undergraduates engaged with practicing mentor teachers in science and engineering teaching at local high schools, and a teacher education program where secondary science preservice teachers and the teacher educators who taught them participated. Interviews were conducted with all participants to gain insights into their views and understandings of engineering design. Prospective and preservice teachers were interviewed multiple times throughout the year and completed concept maps of the engineering design process multiple times as well; practicing teachers and teacher educators were interviewed once. Three levels of analyses were conducted. I identified 30 aspects of engineering discussed by participants. Through phenomenographic methods, I also constructed six conceptual categories for engineering design to organize those aspects most commonly discussed. These categories were combined to demonstrate a participant's view of engineering design (e.g., business focused, human centered, creative, etc.) as well as their complexity of understanding of engineering design overall (the more categories their ideas fit within, the more complex their understanding was thought to be). I found that the most commonly referenced aspects of engineering design were in line with the three main dimensions described in the Next Generation Science Standards (NGSS Lead States, 2013). I also found that the practicing teacher participants overall conveyed the most complex and integrated understandings of engineering design, with the undergraduate, prospective teachers not far behind. One of the most important factors related to a more integrated understanding of engineering design was having formal engineering experience, especially in the form of conducting engineering research or having been a professional engineer. Further, I found that female participants were more likely than their male counterparts to view engineering as having a human element--recognizing the need to collaborate with others throughout the process and the need to think about the potential user of the product the engineer is solving the problem for. These findings suggest that prior experience with engineering, and not experience in the classroom or with engineering education, tends to lead to a deeper, more authentic view of engineering. Finally, I close with a discussion of the overall findings, limitations of the study, potential implications, and future work.

A Second-Year Undergraduate Course in Applied Differential Equations.

ERIC Educational Resources Information Center

Fahidy, Thomas Z.

1991-01-01

Presents the framework for a chemical engineering course using ordinary differential equations to solve problems with the underlying strategy of concisely discussing the theory behind each solution technique without extensions to formal proofs. Includes typical class illustrations, student responses to this strategy, and reaction of the…

The Direction of Web-based Training: A Practitioner's View.

ERIC Educational Resources Information Center

Kilby, Tim

2001-01-01

Web-based training has had achievements and disappointments as online learning has matured. Best practices include user-centered design, knowledge object structures, usability engineering, and formal evaluation. Knowledge management, peer-to-peer learning, and personal learning appliances will continue to alter the online learning landscape. (SK)

User Participation and Participatory Design: Topics in Computing Education.

ERIC Educational Resources Information Center

Kautz, Karlheinz

1996-01-01

Discusses user participation and participatory design in the context of formal education for computing professionals. Topics include the current curriculum debate; mathematical- and engineering-based education; traditional system-development training; and an example of a course program that includes computers and society, and prototyping. (53…

Bridging Formal and Informal Learning Environments

ERIC Educational Resources Information Center

Barker, Bradley S.; Larson, Kim; Krehbiel, Michelle

2014-01-01

Out-of-school time programs that provide science, technology, engineering, and mathematics (STEM) educational content are promising approaches to develop skills and abilities in students. These programs may potentially inspire students with engaging hands-on, minds-on activities that encourages their natural curiosity around STEM content areas.…

Informal Science: Family Education, Experiences, and Initial Interest in Science

ERIC Educational Resources Information Center

Dabney, Katherine P.; Tai, Robert H.; Scott, Michael R.

2016-01-01

Recent research and public policy have indicated the need for increasing the physical science workforce through development of interest and engagement with informal and formal science, technology, engineering, and mathematics experiences. This study examines the association of family education and physical scientists' informal experiences in…

STEMMING the Gap

ERIC Educational Resources Information Center

Kahler, Jim; Valentine, Nancy

2011-01-01

America has a gap when it comes to youth pursuing science and technology careers. In an effort to improve the knowledge and application of science, technology, engineering, and math (STEM), after-school programs can work in conjunction with formal in-school curriculum to improve science education. One organization that actively addresses this…

Window to the World

ERIC Educational Resources Information Center

Cannon, Kama

2018-01-01

Although formal papers are typical, sometimes posters or other visual presentations are more useful tools for sharing visual-spatial information. By incorporating creativity and technology into the study of geographical science, STEM (the study of Science, Technology Engineering, and Mathematics) is changed to STEAM (the A stands for ART)! The…

RAFCON: A Graphical Tool for Engineering Complex, Robotic Tasks

DTIC Science & Technology

2016-10-09

Robotic tasks are becoming increasingly complex, and with this also the robotic systems. This requires new tools to manage this complexity and to...execution of robotic tasks, called RAFCON. These tasks are described in hierarchical state machines supporting concurrency. A formal notation of this concept

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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.

Characteristics of the solitary waves and rogue waves with interaction phenomena in a (2 + 1)-dimensional Breaking Soliton equation

NASA Astrophysics Data System (ADS)

Hossen, Md. Belal; Roshid, Harun-Or; Ali, M. Zulfikar

2018-05-01

Under inquisition in this paper is a (2 + 1)-dimensional Breaking Soliton equation, which can describe various nonlinear scenarios in fluid dynamics. Using the Bell polynomials, some proficient auxiliary functions are offered to apparently construct its bilinear form and corresponding soliton solutions which are different from the previous literatures. Moreover, a direct method is used to construct its rogue wave and solitary wave solutions using particular auxiliary function with the assist of bilinear formalism. Finally, the interactions between solitary waves and rogue waves are offered with a complete derivation. These results enhance the variety of the dynamics of higher dimensional nonlinear wave fields related to mathematical physics and engineering.

A short course on measure and probability theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pebay, Philippe Pierre

2004-02-01

This brief Introduction to Measure Theory, and its applications to Probabilities, corresponds to the lecture notes of a seminar series given at Sandia National Laboratories in Livermore, during the spring of 2003. The goal of these seminars was to provide a minimal background to Computational Combustion scientists interested in using more advanced stochastic concepts and methods, e.g., in the context of uncertainty quantification. Indeed, most mechanical engineering curricula do not provide students with formal training in the field of probability, and even in less in measure theory. However, stochastic methods have been used more and more extensively in the pastmore » decade, and have provided more successful computational tools. Scientists at the Combustion Research Facility of Sandia National Laboratories have been using computational stochastic methods for years. Addressing more and more complex applications, and facing difficult problems that arose in applications showed the need for a better understanding of theoretical foundations. This is why the seminar series was launched, and these notes summarize most of the concepts which have been discussed. The goal of the seminars was to bring a group of mechanical engineers and computational combustion scientists to a full understanding of N. WIENER'S polynomial chaos theory. Therefore, these lectures notes are built along those lines, and are not intended to be exhaustive. In particular, the author welcomes any comments or criticisms.« less

Verification and validation of a Work Domain Analysis with turing machine task analysis.

PubMed

Rechard, J; Bignon, A; Berruet, P; Morineau, T

2015-03-01

While the use of Work Domain Analysis as a methodological framework in cognitive engineering is increasing rapidly, verification and validation of work domain models produced by this method are becoming a significant issue. In this article, we propose the use of a method based on Turing machine formalism named "Turing Machine Task Analysis" to verify and validate work domain models. The application of this method on two work domain analyses, one of car driving which is an "intentional" domain, and the other of a ship water system which is a "causal domain" showed the possibility of highlighting improvements needed by these models. More precisely, the step by step analysis of a degraded task scenario in each work domain model pointed out unsatisfactory aspects in the first modelling, like overspecification, underspecification, omission of work domain affordances, or unsuitable inclusion of objects in the work domain model. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Characterization of Developer Application Methods Used in Fluorescent Penetrant Inspection

NASA Astrophysics Data System (ADS)

Brasche, L. J. H.; Lopez, R.; Eisenmann, D.

2006-03-01

Fluorescent penetrant inspection (FPI) is the most widely used inspection method for aviation components seeing use for production as well as an inservice inspection applications. FPI is a multiple step process requiring attention to the process parameters for each step in order to enable a successful inspection. A multiyear program is underway to evaluate the most important factors affecting the performance of FPI, to determine whether existing industry specifications adequately address control of the process parameters, and to provide the needed engineering data to the public domain. The final step prior to the inspection is the application of developer with typical aviation inspections involving the use of dry powder (form d) usually applied using either a pressure wand or dust storm chamber. Results from several typical dust storm chambers and wand applications have shown less than optimal performance. Measurements of indication brightness and recording of the UVA image, and in some cases, formal probability of detection (POD) studies were used to assess the developer application methods. Key conclusions and initial recommendations are provided.

Toward a Model-Based Approach to Flight System Fault Protection

NASA Technical Reports Server (NTRS)

Day, John; Murray, Alex; Meakin, Peter

2012-01-01

Fault Protection (FP) is a distinct and separate systems engineering sub-discipline that is concerned with the off-nominal behavior of a system. Flight system fault protection is an important part of the overall flight system systems engineering effort, with its own products and processes. As with other aspects of systems engineering, the FP domain is highly amenable to expression and management in models. However, while there are standards and guidelines for performing FP related analyses, there are not standards or guidelines for formally relating the FP analyses to each other or to the system hardware and software design. As a result, the material generated for these analyses are effectively creating separate models that are only loosely-related to the system being designed. Development of approaches that enable modeling of FP concerns in the same model as the system hardware and software design enables establishment of formal relationships that has great potential for improving the efficiency, correctness, and verification of the implementation of flight system FP. This paper begins with an overview of the FP domain, and then continues with a presentation of a SysML/UML model of the FP domain and the particular analyses that it contains, by way of showing a potential model-based approach to flight system fault protection, and an exposition of the use of the FP models in FSW engineering. The analyses are small examples, inspired by current real-project examples of FP analyses.

Simplification of the time-dependent generalized self-interaction correction method using two sets of orbitals: Application of the optimized effective potential formalism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Messud, J.; Dinh, P. M.; Suraud, Eric

2009-10-15

We propose a simplification of the time-dependent self-interaction correction (TD-SIC) method using two sets of orbitals, applying the optimized effective potential (OEP) method. The resulting scheme is called time-dependent 'generalized SIC-OEP'. A straightforward approximation, using the spatial localization of one set of orbitals, leads to the 'generalized SIC-Slater' formalism. We show that it represents a great improvement compared to the traditional SIC-Slater and Krieger-Li-Iafrate formalisms.

Simplification of the time-dependent generalized self-interaction correction method using two sets of orbitals: Application of the optimized effective potential formalism

NASA Astrophysics Data System (ADS)

Messud, J.; Dinh, P. M.; Reinhard, P.-G.; Suraud, Eric

2009-10-01

We propose a simplification of the time-dependent self-interaction correction (TD-SIC) method using two sets of orbitals, applying the optimized effective potential (OEP) method. The resulting scheme is called time-dependent “generalized SIC-OEP.” A straightforward approximation, using the spatial localization of one set of orbitals, leads to the “generalized SIC-Slater” formalism. We show that it represents a great improvement compared to the traditional SIC-Slater and Krieger-Li-Iafrate formalisms.

Systems engineering: A formal approach. Part 1: System concepts

NASA Astrophysics Data System (ADS)

Vanhee, K. M.

1993-03-01

Engineering is the scientific discipline focused on the creation of new artifacts that are supposed to be of some use to our society. Different types of artifacts require different engineering approaches. However, in all these disciplines the development of a new artifact is divided into stages. Three stages can always be recognized: Analysis, Design, and Realization. The book considers only the first two stages of the development process. It focuses on a specific type of artifacts, called discrete dynamic systems. These systems consist of active components of actors that consume and produce passive components or tokens. Three subtypes are studied in more detail: business systems (like a factory or restaurant), information systems (whether automated or not), and automated systems (systems that are controlled by an automated information system). The first subtype is studied by industrial engineers, the last by software engineers and electrical engineers, whereas the second is a battlefield for all three disciplines. The union of these disciplines is called systems engineering.

The founding of ISOTT: the Shamattawa of engineering science and medical science.

PubMed

Bruley, Duane F

2014-01-01

The founding of ISOTT was based upon the blending of Medical and Engineering sciences. This occurrence is portrayed by the Shamattawa, the joining of the Chippewa and Flambeau rivers. Beginning with Carl Scheele's discovery of oxygen, the medical sciences advanced the knowledge of its importance to physiological phenomena. Meanwhile, engineering science was evolving as a mathematical discipline used to define systems quantitatively from basic principles. In particular, Adolf Fick's employment of a gradient led to the formalization of transport phenomena. These two rivers of knowledge were blended to found ISOTT at Clemson/Charleston, South Carolina, USA, in 1973.The establishment of our society with a mission to support the collaborative work of medical scientists, clinicians and all disciplines of engineering was a supporting step in the evolution of bioengineering. Traditional engineers typically worked in areas not requiring knowledge of biology or the life sciences. By encouraging collaboration between medical science and traditional engineering, our society became one of the forerunners in establishing bioengineering as the fifth traditional discipline of engineering.

How to Boost Engineering Support Via Web 2.0 - Seeds for the Ares Project...and/or Yours?

NASA Technical Reports Server (NTRS)

Scott, David W.

2010-01-01

The Mission Operations Laboratory (MOL) at Marshall Space Flight Center (MSFC) is responsible for Engineering Support capability for NASA s Ares launch system development. In pursuit of this, MOL is building the Ares Engineering and Operations Network (AEON), a web-based portal intended to provide a seamless interface to support and simplify two critical activities: a) Access and analyze Ares manufacturing, test, and flight performance data, with access to Shuttle data for comparison. b) Provide archive storage for engineering instrumentation data to support engineering design, development, and test. A mix of NASA-written and COTS software provides engineering analysis tools. A by-product of using a data portal to access and display data is access to collaborative tools inherent in a Web 2.0 environment. This paper discusses how Web 2.0 techniques, particularly social media, might be applied to the traditionally conservative and formal engineering support arena. A related paper by the author [1] considers use

Offshore safety case approach and formal safety assessment of ships.

PubMed

Wang, J

2002-01-01

Tragic marine and offshore accidents have caused serious consequences including loss of lives, loss of property, and damage of the environment. A proactive, risk-based "goal setting" regime is introduced to the marine and offshore industries to increase the level of safety. To maximize marine and offshore safety, risks need to be modeled and safety-based decisions need to be made in a logical and confident way. Risk modeling and decision-making tools need to be developed and applied in a practical environment. This paper describes both the offshore safety case approach and formal safety assessment of ships in detail with particular reference to the design aspects. The current practices and the latest development in safety assessment in both the marine and offshore industries are described. The relationship between the offshore safety case approach and formal ship safety assessment is described and discussed. Three examples are used to demonstrate both the offshore safety case approach and formal ship safety assessment. The study of risk criteria in marine and offshore safety assessment is carried out. The recommendations on further work required are given. This paper gives safety engineers in the marine and offshore industries an overview of the offshore safety case approach and formal ship safety assessment. The significance of moving toward a risk-based "goal setting" regime is given.

Verification of NASA Emergent Systems

NASA Technical Reports Server (NTRS)

Rouff, Christopher; Vanderbilt, Amy K. C. S.; Truszkowski, Walt; Rash, James; Hinchey, Mike

2004-01-01

NASA is studying advanced technologies for a future robotic exploration mission to the asteroid belt. This mission, the prospective ANTS (Autonomous Nano Technology Swarm) mission, will comprise of 1,000 autonomous robotic agents designed to cooperate in asteroid exploration. The emergent properties of swarm type missions make them powerful, but at the same time are more difficult to design and assure that the proper behaviors will emerge. We are currently investigating formal methods and techniques for verification and validation of future swarm-based missions. The advantage of using formal methods is their ability to mathematically assure the behavior of a swarm, emergent or otherwise. The ANT mission is being used as an example and case study for swarm-based missions for which to experiment and test current formal methods with intelligent swam. Using the ANTS mission, we have evaluated multiple formal methods to determine their effectiveness in modeling and assuring swarm behavior.

Comparison of the iterated equation of motion approach and the density matrix formalism for the quantum Rabi model

NASA Astrophysics Data System (ADS)

Kalthoff, Mona; Keim, Frederik; Krull, Holger; Uhrig, Götz S.

2017-05-01

The density matrix formalism and the equation of motion approach are two semi-analytical methods that can be used to compute the non-equilibrium dynamics of correlated systems. While for a bilinear Hamiltonian both formalisms yield the exact result, for any non-bilinear Hamiltonian a truncation is necessary. Due to the fact that the commonly used truncation schemes differ for these two methods, the accuracy of the obtained results depends significantly on the chosen approach. In this paper, both formalisms are applied to the quantum Rabi model. This allows us to compare the approximate results and the exact dynamics of the system and enables us to discuss the accuracy of the approximations as well as the advantages and the disadvantages of both methods. It is shown to which extent the results fulfill physical requirements for the observables and which properties of the methods lead to unphysical results.

Graph Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanfilippo, Antonio P.

2005-12-27

Graph theory is a branch of discrete combinatorial mathematics that studies the properties of graphs. The theory was pioneered by the Swiss mathematician Leonhard Euler in the 18th century, commenced its formal development during the second half of the 19th century, and has witnessed substantial growth during the last seventy years, with applications in areas as diverse as engineering, computer science, physics, sociology, chemistry and biology. Graph theory has also had a strong impact in computational linguistics by providing the foundations for the theory of features structures that has emerged as one of the most widely used frameworks for themore » representation of grammar formalisms.« less

REQUIREMENTS PATTERNS FOR FORMAL CONTRACTS IN ARCHITECTURAL ANALYSIS AND DESIGN LANGUAGE (AADL) MODELS

DTIC Science & Technology

2017-04-17

Cyberphysical Systems, Formal Methods , Requirements Patterns, AADL, Assume Guarantee Reasoning Environment 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...5 3. Methods , Assumptions, and Procedures...Rockwell Collins has been addressing these challenges by developing compositional reasoning methods that permit the verification of systems that exceed

Program Developments: Formal Explanations of Implementations.

DTIC Science & Technology

1982-08-01

January 1982. [Cheatham 791 Cheatham, T. E., G. H. Holloway, and J. A. Townley . "Symbolic evaluation and the analysis of programs," IEEE Transactions on...Software Engineering 5, (4), July 1979, 402-417. [Cheatham 81] Cheatham, T. E., G. H. Holloway, and J. A. Townley , "Program refinement by

Investigations in Computer-Aided Instruction and Computer-Aided Controls. Final Report.

ERIC Educational Resources Information Center

Rosenberg, R.C.; And Others

These research projects, designed to delve into certain relationships between humans and computers, are focused on computer-assisted instruction and on man-computer interaction. One study demonstrates that within the limits of formal engineering theory, a computer simulated laboratory (Dynamic Systems Laboratory) can be built in which freshmen…

Improving Function Allocation for Integrated Systems Design

DTIC Science & Technology

1996-06-01

in the movie Star Trek—The Next Generation, the android DATA is both perceived and treated as a member of the crew. That type of perceptual change...time-consuming, formal contract change. LABORATORY VIEW OF FUNCTION ALLOCATION In 1951, Paul M. Fitts, the founder of the Human Engineering Divi

A Semi-Automatic Approach to Construct Vietnamese Ontology from Online Text

ERIC Educational Resources Information Center

Nguyen, Bao-An; Yang, Don-Lin

2012-01-01

An ontology is an effective formal representation of knowledge used commonly in artificial intelligence, semantic web, software engineering, and information retrieval. In open and distance learning, ontologies are used as knowledge bases for e-learning supplements, educational recommenders, and question answering systems that support students with…

Appreciating Formal Similarities in the Kinetics of Homogeneous, Heterogeneous, and Enzyme Catalysis

ERIC Educational Resources Information Center

Ashby, Michael T.

2007-01-01

Because interest in catalysts is widespread, the kinetics of catalytic reactions have been investigated by widely diverse groups of individuals, including chemists, engineers, and biologists. This has lead to redundancy in theories, particularly with regard to the topics of homogeneous, heterogeneous, and enzyme catalysis. From a pedagogical…

Abstract Numeric Relations and the Visual Structure of Algebra

ERIC Educational Resources Information Center

Landy, David; Brookes, David; Smout, Ryan

2014-01-01

Formal algebras are among the most powerful and general mechanisms for expressing quantitative relational statements; yet, even university engineering students, who are relatively proficient with algebraic manipulation, struggle with and often fail to correctly deploy basic aspects of algebraic notation (Clement, 1982). In the cognitive tradition,…

Community Partnerships for Fostering Student Interest and Engagement in STEM

ERIC Educational Resources Information Center

Watters, James J.; Diezmann, Carmel M.

2013-01-01

The foundations of Science, Technology, Engineering and Mathematics (STEM) education begins in the early years of schooling when students encounter formal learning experiences primarily in mathematics and science. Politicians, economists and industrialists recognise the importance of STEM in society, and therefore a number of strategies have been…

FY 1997 Scientific and Technical Reports, Articles, Papers, and Presentations

NASA Technical Reports Server (NTRS)

Waits, J. E. Turner (Compiler)

1998-01-01

This document presents formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY97. The information in this report may be of value to the scientific and engineering community in determining what information has been published and what is available.

The Atlanta University Center: A Consortium-Based Dual Degree Engineering Program

ERIC Educational Resources Information Center

Jackson, Marilyn T.

2007-01-01

The Atlanta University Center (AUC) comprises five historically black colleges and a centralized library. All are separate institutions, each having its own board of directors, president, infrastructure, students, faculty, staff, and traditions. To encourage coordination of effort and resources, the AUC was formed and the first formal cooperative…

META II: Formal Co-Verification of Correctness of Large-Scale Cyber-Physical Systems during Design. Volume 1

DTIC Science & Technology

2011-08-01

design space is large. His research contributions are to the field of Decision-based Design, specifically in linking consumer preferences and...Integrating Consumer Preferences into Engineering Design, to be published in 2012. He received his PhD from Northwestern University in Mechanical

Balancing Stakeholders' Interests in Evolving Teacher Education Accreditation Contexts

ERIC Educational Resources Information Center

Elliott, Alison

2008-01-01

While Australian teacher education programs have long had rigorous accreditation pathways at the University level they have not been subject to the same formal public or professional scrutiny typical of professions such as medicine, nursing or engineering. Professional accreditation for teacher preparation programs is relatively new and is linked…

Euler Teaches a Class in Structural Steel Design

ERIC Educational Resources Information Center

Boyajian, David M.

2009-01-01

Even before steel was a topic of formal study for structural engineers, the brilliant eighteenth century Swiss mathematician and physicist, Leonhard Euler (1707-1783), investigated the theory governing the elastic behaviour of columns, the results of which are incorporated into the American Institute of Steel Construction's (AISC's) Bible: the…

IB Offering Certificate for Careers

ERIC Educational Resources Information Center

Robelen, Erik W.

2012-01-01

The International Baccalaureate (IB) organization, best known in the United States for its prestigious two-year diploma program for juniors and seniors, will enter new terrain this fall as it formally rolls out an initiative centered on a variety of career pathways that includes engineering, culinary arts, and automotive technology. The move comes…

Describing the What and Why of Students' Difficulties in Boolean Logic

ERIC Educational Resources Information Center

Herman, Geoffrey L.; Loui, Michael C.; Kaczmarczyk, Lisa; Zilles, Craig

2012-01-01

The ability to reason with formal logic is a foundational skill for computer scientists and computer engineers that scaffolds the abilities to design, debug, and optimize. By interviewing students about their understanding of propositional logic and their ability to translate from English specifications to Boolean expressions, we characterized…

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.

Joint electrical engineering/physics course sequence for optics fundamentals and design

NASA Astrophysics Data System (ADS)

Magnusson, Robert; Maldonado, Theresa A.; Black, Truman D.

2000-06-01

Optics is a key technology in a broad range of engineering and science applications of high national priority. Engineers and scientists with a sound background in this field are needed to preserve technical leadership and to establish new directions of research and development. To meet this educational need, a joint Electrical Engineering/Physics optics course sequence was created as PHYS 3445 Fundamentals of Optics and EE 4444 Optical Systems Design, both with a laboratory component. The objectives are to educate EE and Physics undergraduate students in the fundamentals of optics; in interdisciplinary problem solving; in design and analysis; in handling optical components; and in skills such as communications and team cooperation. Written technical reports in professional format are required, formal presentations are given, and participation in paper design contests is encouraged.

Clinical Immersion and Biomedical Engineering Design Education: "Engineering Grand Rounds".

PubMed

Walker, Matthew; Churchwell, André L

2016-03-01

Grand Rounds is a ritual of medical education and inpatient care comprised of presenting the medical problems and treatment of a patient to an audience of physicians, residents, and medical students. Traditionally, the patient would be in attendance for the presentation and would answer questions. Grand Rounds has evolved considerably over the years with most sessions being didactic-rarely having a patient present (although, in some instances, an actor will portray the patient). Other members of the team, such as nurses, nurse practitioners, and biomedical engineers, are not traditionally involved in the formal teaching process. In this study we examine the rapid ideation in a clinical setting to forge a system of cross talk between engineers and physicians as a steady state at the praxis of ideation and implementation.

Thermodynamical analysis of a quantum heat engine based on harmonic oscillators.

PubMed

Insinga, Andrea; Andresen, Bjarne; Salamon, Peter

2016-07-01

Many models of heat engines have been studied with the tools of finite-time thermodynamics and an ensemble of independent quantum systems as the working fluid. Because of their convenient analytical properties, harmonic oscillators are the most frequently used example of a quantum system. We analyze different thermodynamical aspects with the final aim of the optimization of the performance of the engine in terms of the mechanical power provided during a finite-time Otto cycle. The heat exchange mechanism between the working fluid and the thermal reservoirs is provided by the Lindblad formalism. We describe an analytical method to find the limit cycle and give conditions for a stable limit cycle to exist. We explore the power production landscape as the duration of the four branches of the cycle are varied for short times, intermediate times, and special frictionless times. For short times we find a periodic structure with atolls of purely dissipative operation surrounding islands of divergent behavior where, rather than tending to a limit cycle, the working fluid accumulates more and more energy. For frictionless times the periodic structure is gone and we come very close to the global optimal operation. The global optimum is found and interestingly comes with a particular value of the cycle time.

Flood design recipes vs. reality: can predictions for ungauged basins be trusted?

NASA Astrophysics Data System (ADS)

Efstratiadis, A.; Koussis, A. D.; Koutsoyiannis, D.; Mamassis, N.

2013-12-01

Despite the great scientific and technological advances in flood hydrology, everyday engineering practices still follow simplistic approaches, such as the rational formula and the SCS-CN method combined with the unit hydrograph theory that are easy to formally implement in ungauged areas. In general, these "recipes" have been developed many decades ago, based on field data from few experimental catchments. However, many of them have been neither updated nor validated across all hydroclimatic and geomorphological conditions. This has an obvious impact on the quality and reliability of hydrological studies, and, consequently, on the safety and cost of the related flood protection works. Preliminary results, based on historical flood data from Cyprus and Greece, indicate that a substantial revision of many aspects of flood engineering procedures is required, including the regionalization formulas as well as the modelling concepts themselves. In order to provide a consistent design framework and to ensure realistic predictions of the flood risk (a key issue of the 2007/60/EU Directive) in ungauged basins, it is necessary to rethink the current engineering practices. In this vein, the collection of reliable hydrological data would be essential for re-evaluating the existing "recipes", taking into account local peculiarities, and for updating the modelling methodologies as needed.

Machine Learning Technologies and Their Applications for Science and Engineering Domains Workshop -- Summary Report

NASA Technical Reports Server (NTRS)

Ambur, Manjula; Schwartz, Katherine G.; Mavris, Dimitri N.

2016-01-01

The fields of machine learning and big data analytics have made significant advances in recent years, which has created an environment where cross-fertilization of methods and collaborations can achieve previously unattainable outcomes. The Comprehensive Digital Transformation (CDT) Machine Learning and Big Data Analytics team planned a workshop at NASA Langley in August 2016 to unite leading experts the field of machine learning and NASA scientists and engineers. The primary goal for this workshop was to assess the state-of-the-art in this field, introduce these leading experts to the aerospace and science subject matter experts, and develop opportunities for collaboration. The workshop was held over a three day-period with lectures from 15 leading experts followed by significant interactive discussions. This report provides an overview of the 15 invited lectures and a summary of the key discussion topics that arose during both formal and informal discussion sections. Four key workshop themes were identified after the closure of the workshop and are also highlighted in the report. Furthermore, several workshop attendees provided their feedback on how they are already utilizing machine learning algorithms to advance their research, new methods they learned about during the workshop, and collaboration opportunities they identified during the workshop.

Spin filter for arbitrary spins by substrate engineering

NASA Astrophysics Data System (ADS)

Pal, Biplab; Römer, Rudolf A.; Chakrabarti, Arunava

2016-08-01

We design spin filters for particles with potentially arbitrary spin S≤ft(=1/2,1,3/2,\\ldots \\right) using a one-dimensional periodic chain of magnetic atoms as a quantum device. Describing the system within a tight-binding formalism we present an analytical method to unravel the analogy between a one-dimensional magnetic chain and a multi-strand ladder network. This analogy is crucial, and is subsequently exploited to engineer gaps in the energy spectrum by an appropriate choice of the magnetic substrate. We obtain an exact correlation between the magnitude of the spin of the incoming beam of particles and the magnetic moment of the substrate atoms in the chain desired for opening up of a spectral gap. Results of spin polarized transport, calculated within a transfer matrix formalism, are presented for particles having half-integer as well as higher spin states. We find that the chain can be made to act as a quantum device which opens a transmission window only for selected spin components over certain ranges of the Fermi energy, blocking them in the remaining part of the spectrum. The results appear to be robust even when the choice of the substrate atoms deviates substantially from the ideal situation, as verified by extending the ideas to the case of a ‘spin spiral’. Interestingly, the spin spiral geometry, apart from exhibiting the filtering effect, is also seen to act as a device flipping spins—an effect that can be monitored by an interplay of the system size and the period of the spiral. Our scheme is applicable to ultracold quantum gases, and might inspire future experiments in this direction.

Systems, methods and apparatus for pattern matching in procedure development and verification

NASA Technical Reports Server (NTRS)

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

2011-01-01

Systems, methods and apparatus are provided through which, in some embodiments, a formal specification is pattern-matched from scenarios, the formal specification is analyzed, and flaws in the formal specification are corrected. The systems, methods and apparatus may include pattern-matching an equivalent formal model from an informal specification. Such a model can be analyzed for contradictions, conflicts, use of resources before the resources are available, competition for resources, and so forth. From such a formal model, an implementation can be automatically generated in a variety of notations. The approach can improve the resulting implementation, which, in some embodiments, is provably equivalent to the procedures described at the outset, which in turn can improve confidence that the system reflects the requirements, and in turn reduces system development time and reduces the amount of testing required of a new system. Moreover, in some embodiments, two or more implementations can be "reversed" to appropriate formal models, the models can be combined, and the resulting combination checked for conflicts. Then, the combined, error-free model can be used to generate a new (single) implementation that combines the functionality of the original separate implementations, and may be more likely to be correct.

Impact of distributed virtual reality on engineering knowledge retention and student engagement

NASA Astrophysics Data System (ADS)

Sulbaran, Tulio Alberto

Engineering Education is facing many problems, one of which is poor knowledge retention among engineering students. This problem affects the Architecture, Engineering, and Construction (A/E/C) industry, because students are unprepared for many necessary job skills. This problem of poor knowledge retention is caused by many factors, one of which is the mismatch between student learning preferences and the media used to teach engineering. The purpose of this research is to assess the impact of Distributed Virtual Reality (DVR) as an engineering teaching tool. The implementation of DVR addresses the issue of poor knowledge retention by impacting the mismatch between learning and teaching style in the visual versus verbal spectrum. Using as a point of departure three knowledge domain areas (Learning and Instruction, Distributed Virtual Reality and Crane Selection as Part of Crane Lift Planning), a DVR engineering teaching tool is developed, deployed and assessed in engineering classrooms. The statistical analysis of the data indicates that: (1) most engineering students are visual learners; (2) most students would like more classes using DVR; (3) engineering students find DVR more engaging than traditional learning methods; (4) most students find the responsiveness of the DVR environments to be either good or very good; (5) all students are able to interact with DVR and most of the students found it easy or very easy to navigate (without previous formal training in how to use DVR); (6) students' knowledge regarding the subject (crane selection) is higher after the experiment; and, (7) students' using different instructional media do not demonstrate statistical difference in knowledge retained after the experiment. This inter-disciplinary research offers opportunities for direct and immediate application in education, research, and industry, due to the fact that the instructional module developed (on crane selection as part of construction crane lift planning) can be used to convey knowledge to engineers beyond the classrooms. This instructional module can also be used as a workbench to assess parameters on engineering education such as time on task, assessment media, and long-term retention among others.

Fusing Quantitative Requirements Analysis with Model-based Systems Engineering

NASA Technical Reports Server (NTRS)

Cornford, Steven L.; Feather, Martin S.; Heron, Vance A.; Jenkins, J. Steven

2006-01-01

A vision is presented for fusing quantitative requirements analysis with model-based systems engineering. This vision draws upon and combines emergent themes in the engineering milieu. "Requirements engineering" provides means to explicitly represent requirements (both functional and non-functional) as constraints and preferences on acceptable solutions, and emphasizes early-lifecycle review, analysis and verification of design and development plans. "Design by shopping" emphasizes revealing the space of options available from which to choose (without presuming that all selection criteria have previously been elicited), and provides means to make understandable the range of choices and their ramifications. "Model-based engineering" emphasizes the goal of utilizing a formal representation of all aspects of system design, from development through operations, and provides powerful tool suites that support the practical application of these principles. A first step prototype towards this vision is described, embodying the key capabilities. Illustrations, implications, further challenges and opportunities are outlined.

Assessing the Higher National Diploma Chemical Engineering programme in Ghana: students' perspective

NASA Astrophysics Data System (ADS)

Boateng, Cyril D.; Cudjoe Bensah, Edem; Ahiekpor, Julius C.

2012-05-01

Chemical engineers have played key roles in the growth of the chemical and allied industries in Ghana but indigenous industries that have traditionally been the domain of the informal sector need to be migrated to the formal sector through the entrepreneurship and innovation of chemical engineers. The Higher National Diploma Chemical Engineering programme is being migrated from a subject-based to a competency-based curriculum. This paper evaluates the programme from the point of view of students. Data were drawn from a survey conducted in the department and were analysed using SPSS. The survey involved administering questionnaires to students at all levels in the department. Analysis of the responses indicated that the majority of the students had decided to pursue chemical engineering due to the career opportunities available. Their knowledge of the programme learning outcomes was, however, poor. The study revealed that none of the students was interested in developing indigenous industries.

NASA Langley's Formal Methods Research in Support of the Next Generation Air Transportation System

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Munoz, Cesar A.

2008-01-01

This talk will provide a brief introduction to the formal methods developed at NASA Langley and the National Institute for Aerospace (NIA) for air traffic management applications. NASA Langley's formal methods research supports the Interagency Joint Planning and Development Office (JPDO) effort to define and develop the 2025 Next Generation Air Transportation System (NGATS). The JPDO was created by the passage of the Vision 100 Century of Aviation Reauthorization Act in Dec 2003. The NGATS vision calls for a major transformation of the nation s air transportation system that will enable growth to 3 times the traffic of the current system. The transformation will require an unprecedented level of safety-critical automation used in complex procedural operations based on 4-dimensional (4D) trajectories that enable dynamic reconfiguration of airspace scalable to geographic and temporal demand. The goal of our formal methods research is to provide verification methods that can be used to insure the safety of the NGATS system. Our work has focused on the safety assessment of concepts of operation and fundamental algorithms for conflict detection and resolution (CD&R) and self- spacing in the terminal area. Formal analysis of a concept of operations is a novel area of application of formal methods. Here one must establish that a system concept involving aircraft, pilots, and ground resources is safe. The formal analysis of algorithms is a more traditional endeavor. However, the formal analysis of ATM algorithms involves reasoning about the interaction of algorithmic logic and aircraft trajectories defined over an airspace. These trajectories are described using 2D and 3D vectors and are often constrained by trigonometric relations. Thus, in many cases it has been necessary to unload the full power of an advanced theorem prover. The verification challenge is to establish that the safety-critical algorithms produce valid solutions that are guaranteed to maintain separation under all possible scenarios. Current research has assumed perfect knowledge of the location of other aircraft in the vicinity so absolute guarantees are possible, but increasingly we are relaxing the assumptions to allow incomplete, inaccurate, and/or faulty information from communication sources.

Model-based engineering for medical-device software.

PubMed

Ray, Arnab; Jetley, Raoul; Jones, Paul L; Zhang, Yi

2010-01-01

This paper demonstrates the benefits of adopting model-based design techniques for engineering medical device software. By using a patient-controlled analgesic (PCA) infusion pump as a candidate medical device, the authors show how using models to capture design information allows for i) fast and efficient construction of executable device prototypes ii) creation of a standard, reusable baseline software architecture for a particular device family, iii) formal verification of the design against safety requirements, and iv) creation of a safety framework that reduces verification costs for future versions of the device software. 1.

Management Of Optical Projects

NASA Astrophysics Data System (ADS)

Young, Peter S.; Olson, David R.

1981-03-01

This paper discusses the management of optical projects from the concept stage, beginning with system specifications, through design, optical fabrication and test tasks. Special emphasis is placed on effective coupling of design engineering with fabrication development and utilization of available technology. Contrasts are drawn between accepted formalized management techniques, the realities of dealing with fragile components and the necessity of an effective project team which integrates the special characteristics of highly skilled optical specialists including lens designers, optical engineers, opticians, and metrologists. Examples are drawn from the HEAO-2 X-Ray Telescope and Space Telescope projects.

Prefreshman and Cooperative Education Program. [PREFACE training

NASA Technical Reports Server (NTRS)

1976-01-01

Of the 93 students enrolled in the PREFACE program over its four-year history, 70 are still in engineering school. Tables show profiles of student placement and participation from 1973 to 1977 (first semester completed). During the 1977 summer, 10 students were placed at NASA Goddard, 8 at DOE-Brookhaven, and 2 at American Can. Eleven students with less high school math preparation remained on campus for formal precalculus classes. Majors of the students in the program include civil, chemical, electrical, and mechanical engineering. Student satisfaction with their training experiences is summarized.

The application of SSADM to modelling the logical structure of proteins.

PubMed

Saldanha, J; Eccles, J

1991-10-01

A logical design that describes the overall structure of proteins, together with a more detailed design describing secondary and some supersecondary structures, has been constructed using the computer-aided software engineering (CASE) tool, Auto-mate. Auto-mate embodies the philosophy of the Structured Systems Analysis and Design Method (SSADM) which enables the logical design of computer systems. Our design will facilitate the building of large information systems, such as databases and knowledgebases in the field of protein structure, by the derivation of system requirements from our logical model prior to producing the final physical system. In addition, the study has highlighted the ease of employing SSADM as a formalism in which to conduct the transferral of concepts from an expert into a design for a knowledge-based system that can be implemented on a computer (the knowledge-engineering exercise). It has been demonstrated how SSADM techniques may be extended for the purpose of modelling the constituent Prolog rules. This facilitates the integration of the logical system design model with the derived knowledge-based system.

Dynamical Energy Gap Engineering in Graphene via Oscillating Out-of-Plane Deformations

NASA Astrophysics Data System (ADS)

Sandler, Nancy; Zhai, Dawei

The close relation between electronic properties and mechanical deformations in graphene has been the topic of active research in recent years. Interestingly, the effect of deformations on electronic properties can be understood in terms of pseudo-magnetic fields, whose spatial distribution and intensity are controllable via the deformation geometry. Previous results showed that electromagnetic fields (light) have the potential to induce dynamical gaps in graphene's energy bands, transforming graphene from a semimetal to a semiconductor. However, laser frequencies required to achieve these regimes are in the THz regime, which imposes challenges for practical purposes. In this talk we report a novel method to create dynamical gaps using oscillating mechanical deformations, i.e., via time-dependent pseudo-magnetic fields. Using the Floquet formalism we show the existence of a dynamical gap in the band structure at energies set by the frequency of the oscillation, and with a magnitude tuned by the geometry of the deformation. This dynamical-mechanical manipulation strategy appears as a promising venue to engineer electronic properties of suspended graphene devices. Work supported by NSF-DMR 1508325.

A comparison between state-specific and linear-response formalisms for the calculation of vertical electronic transition energy in solution with the CCSD-PCM method.

PubMed

Caricato, Marco

2013-07-28

The calculation of vertical electronic transition energies of molecular systems in solution with accurate quantum mechanical methods requires the use of approximate and yet reliable models to describe the effect of the solvent on the electronic structure of the solute. The polarizable continuum model (PCM) of solvation represents a computationally efficient way to describe this effect, especially when combined with coupled cluster (CC) methods. Two formalisms are available to compute transition energies within the PCM framework: State-Specific (SS) and Linear-Response (LR). The former provides a more complete account of the solute-solvent polarization in the excited states, while the latter is computationally very efficient (i.e., comparable to gas phase) and transition properties are well defined. In this work, I review the theory for the two formalisms within CC theory with a focus on their computational requirements, and present the first implementation of the LR-PCM formalism with the coupled cluster singles and doubles method (CCSD). Transition energies computed with LR- and SS-CCSD-PCM are presented, as well as a comparison between solvation models in the LR approach. The numerical results show that the two formalisms provide different absolute values of transition energy, but similar relative solvatochromic shifts (from nonpolar to polar solvents). The LR formalism may then be used to explore the solvent effect on multiple states and evaluate transition probabilities, while the SS formalism may be used to refine the description of specific states and for the exploration of excited state potential energy surfaces of solvated systems.

Lfm2000: Fifth NASA Langley Formal Methods Workshop

NASA Technical Reports Server (NTRS)

Holloway, C. Michael (Compiler)

2000-01-01

This is the proceedings of Lfm2000: Fifth NASA Langley Formal Methods Workshop. The workshop was held June 13-15, 2000, in Williamsburg, Virginia. See the web site for complete information about the event.

The Hierarchical Structure of Formal Operational Tasks.

ERIC Educational Resources Information Center

Bart, William M.; Mertens, Donna M.

1979-01-01

The hierarchical structure of the formal operational period of Piaget's theory of cognitive development was explored through the application of ordering theoretical methods to a set of data that systematically utilized the various formal operational schemes. Results suggested a common structure underlying task performance. (Author/BH)

Experimental validation of structural optimization methods

NASA Technical Reports Server (NTRS)

Adelman, Howard M.

1992-01-01

The topic of validating structural optimization methods by use of experimental results is addressed. The need for validating the methods as a way of effecting a greater and an accelerated acceptance of formal optimization methods by practicing engineering designers is described. The range of validation strategies is defined which includes comparison of optimization results with more traditional design approaches, establishing the accuracy of analyses used, and finally experimental validation of the optimization results. Examples of the use of experimental results to validate optimization techniques are described. The examples include experimental validation of the following: optimum design of a trussed beam; combined control-structure design of a cable-supported beam simulating an actively controlled space structure; minimum weight design of a beam with frequency constraints; minimization of the vibration response of helicopter rotor blade; minimum weight design of a turbine blade disk; aeroelastic optimization of an aircraft vertical fin; airfoil shape optimization for drag minimization; optimization of the shape of a hole in a plate for stress minimization; optimization to minimize beam dynamic response; and structural optimization of a low vibration helicopter rotor.

Improving Student Writing: Methods You Can Use in Science and Engineering Classrooms

NASA Astrophysics Data System (ADS)

Hitt, S. J.; Bright, K.

2013-12-01

Many educators in the fields of science and engineering assure their students that writing is an important and necessary part of their work. According to David Lindsay, in Scientific Writing=Thinking in Words, 99% of scientists agree that writing is an integral part of their jobs. However, only 5% of those same scientists have ever had formal instruction in scientific writing, and those who are also educators may then feel unconfident in teaching this skill to their students (2). Additionally, making time for writing instruction in courses that are already full of technical content can cause it to be hastily and/or peremptorily included. These situations may be some of the contributing factors to the prevailing attitude of frustration that pervades the conversation about writing in science and engineering classrooms. This presentation provides a summary of past, present, and ongoing Writing Center research on effective writing tutoring in order to give science and engineering educators integrated approaches for working with student writers in their disciplines. From creating assignments, providing instruction, guiding revisions, facilitating peer review, and using assessments, we offer a comprehensive approach to getting your students motivated to improve their writing. Our new research study focuses on developing student writing resources and support in science and engineering institutions, with the goal of utilizing cross-disciplinary knowledge that can be used by the various constituencies responsible for improving the effectiveness of writing among student engineers and scientists. We will will draw upon recent findings in the study of the rhetoric and compositional pedagogy and apply them to the specific needs of the science and engineering classroom. The fields of communication, journalism, social sciences, rhetoric, technical writing, and philosophy of science have begun to integrate these findings into classroom practice, and we will show how these can also benefit educators in science and engineering, with the goal of producing more effective student writing.

A Formal Semantics for the WS-BPEL Recovery Framework

NASA Astrophysics Data System (ADS)

Dragoni, Nicola; Mazzara, Manuel

While current studies on Web services composition are mostly focused - from the technical viewpoint - on standards and protocols, this work investigates the adoption of formal methods for dependable composition. The Web Services Business Process Execution Language (WS-BPEL) - an OASIS standard widely adopted both in academic and industrial environments - is considered as a touchstone for concrete composition languages and an analysis of its ambiguous Recovery Framework specification is offered. In order to show the use of formal methods, a precise and unambiguous description of its (simplified) mechanisms is provided by means of a conservative extension of the π-calculus. This has to be intended as a well known case study providing methodological arguments for the adoption of formal methods in software specification. The aspect of verification is not the main topic of the paper but some hints are given.

Neurotoxic effects of ivermectin administration in genetically engineered mice with targeted insertion of the mutated canine ABCB1 gene.

PubMed

Orzechowski, Krystyna L; Swain, Marla D; Robl, Martin G; Tinaza, Constante A; Swaim, Heidi L; Jones, Yolanda L; Myers, Michael J; Yancy, Haile F

2012-09-01

To develop in genetically engineered mice an alternative screening method for evaluation of P-glycoprotein substrate toxicosis in ivermectin-sensitive Collies. 14 wild-type C57BL/6J mice (controls) and 21 genetically engineered mice in which the abcb1a and abcb1b genes were disrupted and the mutated canine ABCB1 gene was inserted. Mice were allocated to receive 10 mg of ivermectin/kg via SC injection (n = 30) or a vehicle-only formulation of propylene glycol and glycerol formal (5). Each was observed for clinical signs of toxic effects from 0 to 7 hours following drug administration. After ivermectin administration, considerable differences were observed in drug sensitivity between the 2 types of mice. The genetically engineered mice with the mutated canine ABCB1 gene had signs of severe sensitivity to ivermectin, characterized by progressive lethargy, ataxia, and tremors, whereas the wild-type control mice developed no remarkable effects related to the ivermectin. The ivermectin sensitivity modeled in the transgenic mice closely resembled the lethargy, stupor, disorientation, and loss of coordination observed in ivermectin-sensitive Collies with the ABCB1-1Δ mutation. As such, the model has the potential to facilitate toxicity assessments of certain drugs for dogs that are P-glycoprotein substrates, and it may serve to reduce the use of dogs in avermectin derivative safety studies that are part of the new animal drug approval process.

The historical evolution of engineering degrees: competing stakeholders, contestation over ideas, and coherence across national borders

NASA Astrophysics Data System (ADS)

Case, Jennifer M.

2017-11-01

Recent times have seen significant realignment of engineering degrees globally, most notably in the Washington Accord, a system of mutual recognition of accreditation across much of the Anglophone world and beyond, and the Bologna Process, impacting significantly on the form of engineering degrees in Europe. This article, tracing the historical evolution of engineering degrees, argues that recent events can be seen to be part of an ongoing process of reworking the arrangements for formal engineering education, based on a long-standing contradiction between the different stakeholders that have an interest in curriculum: the state, engineering employers, and academics. This is reflected in a contestation over what was historically termed the 'shop culture' of the employers versus the 'school culture' of the academy. Furthermore, contemporary developments of mutual accreditation beyond national borders can be seen to have an earlier echo in the relative measure of global coherence that was achieved in the 1870s.

Automatically Grading Customer Confidence in a Formal Specification.

ERIC Educational Resources Information Center

Shukur, Zarina; Burke, Edmund; Foxley, Eric

1999-01-01

Describes an automatic grading system for a formal methods computer science course that is able to evaluate a formal specification written in the Z language. Quality is measured by considering first, specification correctness (syntax, semantics, and satisfaction of customer requirements), and second, specification maintainability (comparison of…

Formal Solutions for Polarized Radiative Transfer. II. High-order Methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janett, Gioele; Steiner, Oskar; Belluzzi, Luca, E-mail: gioele.janett@irsol.ch

When integrating the radiative transfer equation for polarized light, the necessity of high-order numerical methods is well known. In fact, well-performing high-order formal solvers enable higher accuracy and the use of coarser spatial grids. Aiming to provide a clear comparison between formal solvers, this work presents different high-order numerical schemes and applies the systematic analysis proposed by Janett et al., emphasizing their advantages and drawbacks in terms of order of accuracy, stability, and computational cost.

Formalizing New Navigation Requirements for NASA's Space Shuttle

NASA Technical Reports Server (NTRS)

DiVito, Ben L.

1996-01-01

We describe a recent NASA-sponsored pilot project intended to gauge the effectiveness of using formal methods in Space Shuttle software requirements analysis. Several Change Requests (CRs) were selected as promising targets to demonstrate the utility of formal methods in this demanding application domain. A CR to add new navigation capabilities to the Shuttle, based on Global Positioning System (GPS) technology, is the focus of this industrial usage report. Portions of the GPS CR were modeled using the language of SRI's Prototype Verification System (PVS). During a limited analysis conducted on the formal specifications, numerous requirements issues were discovered. We present a summary of these encouraging results and conclusions we have drawn from the pilot project.

NASA propagation information center

NASA Technical Reports Server (NTRS)

Smith, Ernest K.; Flock, Warren L.

1990-01-01

The NASA Propagation Information Center became formally operational in July 1988. It is located in the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. The center is several things: a communications medium for the propagation with the outside world, a mechanism for internal communication within the program, and an aid to management.

B-2 Systems Engineering Case Study

DTIC Science & Technology

2007-01-01

formal configuration freeze , an immediate refocus of the Task Teams was required. Within several days, the air vehicle task teams were conducting...39 3.3.3 Configuration Freeze ...1983 PDR 1 Oct 1982 Reconfiguration Feb 1983-Aug 1983 (LP3, LP4) Configuration Freeze July 1983 PDR 2 Mar-April 1984 CDR Dec 1986

Towards Model-Driven End-User Development in CALL

ERIC Educational Resources Information Center

Farmer, Rod; Gruba, Paul

2006-01-01

The purpose of this article is to introduce end-user development (EUD) processes to the CALL software development community. EUD refers to the active participation of end-users, as non-professional developers, in the software development life cycle. Unlike formal software engineering approaches, the focus in EUD on means/ends development is…

FY 1991 scientific and technical reports, articles, papers, and presentations

NASA Technical Reports Server (NTRS)

Turner, Joyce E. (Compiler)

1991-01-01

Formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY 1991 are presented. Papers of MSFC contractors are also included. The information in this report may be of value to the scientific and engineering community in determining what information has been published and what is available.

NASA Propagation Information Center

NASA Technical Reports Server (NTRS)

Smith, Ernest K.; Flock, Warren L.

1989-01-01

The NASA Propagation Information Center became formally operational in July 1988. It is located in the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. The Center is several things: a communications medium for the propagation with the outside world, a mechanism for internal communication within the program, and an aid to management.

Sawlog weights for Appalachian hardwoods

Treesearch

Floyd G. Timson; Floyd G. Timson

1972-01-01

The tables are presented in this paper as reference material needed as a foundation for further work in the field of hardwood log weights. Such work may be undertaken by researchers, engineers, and equipment designers in the form of formal and informal studies, or by timbermen in the normal course of action to improve their operations.

Reengineering Framework for Systems in Education

ERIC Educational Resources Information Center

Choquet, Christophe; Corbiere, Alain

2006-01-01

Specifications recently proposed as standards in the domain of Technology Enhanced Learning (TEL), question the designers of TEL systems on how to put them into practice. Recent studies in Model Driven Engineering have highlighted the need for a framework which could formalize the use of these specifications as well as enhance the quality of the…

STEM Learning through Engineering Design: Impact on Middle Secondary Students' Interest towards STEM

ERIC Educational Resources Information Center

Shahali, Edy Hafizan Mohd; Halim, Lilia; Rasul, Mohamad Sattar; Osman, Kamisah; Zulkifeli, Mohd Afendi

2017-01-01

The purpose of this study was to identify students' changes of (i) interest toward STEM subjects and (ii) interest to pursuing STEM career after participating in non-formal integrated STEM education programme. The programme exposed students with integrated STEM education through project based learning involving the application of five phases…

Lesson Learning at JPL

NASA Technical Reports Server (NTRS)

Oberhettinger, David

2011-01-01

A lessons learned system is a hallmark of a mature engineering organization A formal lessons learned process can help assure that valuable lessons get written and published, that they are well-written, and that the essential information is "infused" into institutional practice. Requires high-level institutional commitment, and everyone's participation in gathering, disseminating, and using the lessons

Evaluating the Learning Process of Mechanical CAD Students

ERIC Educational Resources Information Center

Hamade, R. F.; Artail, H. A.; Jaber, M. Y.

2007-01-01

There is little theoretical or experimental research on how beginner-level trainees learn CAD skills in formal training sessions. This work presents findings on how trainees develop their skills in utilizing a solid mechanical CAD tool (Pro/Engineer version 2000i[squared] and later version Wildfire). Exercises at the beginner and intermediate…

A Formal Application of Safety and Risk Assessment in Software Systems

DTIC Science & Technology

2004-09-01

characteristics of Software Engineering, Development, and Safety...against a comparison of planned and actual schedules, costs, and characteristics . Software Safety is focused on the reduction of unsafe incidents...they merely carry out the role for which they were anatomically designed.55 Software is characteristically like an anatomical cell as it merely

Architecting the Human Space Flight Program with Systems Modeling Language (SysML)

NASA Technical Reports Server (NTRS)

Jackson, Maddalena M.; Fernandez, Michela Munoz; McVittie, Thomas I.; Sindiy, Oleg V.

2012-01-01

The next generation of missions in NASA's Human Space Flight program focuses on the development and deployment of highly complex systems (e.g., Orion Multi-Purpose Crew Vehicle, Space Launch System, 21st Century Ground System) that will enable astronauts to venture beyond low Earth orbit and explore the moon, near-Earth asteroids, and beyond. Architecting these highly complex system-of-systems requires formal systems engineering techniques for managing the evolution of the technical features in the information exchange domain (e.g., data exchanges, communication networks, ground software) and also, formal correlation of the technical architecture to stakeholders' programmatic concerns (e.g., budget, schedule, risk) and design development (e.g., assumptions, constraints, trades, tracking of unknowns). This paper will describe how the authors have applied System Modeling Language (SysML) to implement model-based systems engineering for managing the description of the End-to-End Information System (EEIS) architecture and associated development activities and ultimately enables stakeholders to understand, reason, and answer questions about the EEIS under design for proposed lunar Exploration Missions 1 and 2 (EM-1 and EM-2).

Job Search Methods: Consequences for Gender-based Earnings Inequality.

ERIC Educational Resources Information Center

Huffman, Matt L.; Torres, Lisa

2001-01-01

Data from adults in Atlanta, Boston, and Los Angeles (n=1,942) who searched for work using formal (ads, agencies) or informal (networks) methods indicated that type of method used did not contribute to the gender gap in earnings. Results do not support formal job search as a way to reduce gender inequality. (Contains 55 references.) (SK)

A Systematic Review of Mixed Methods Research on Human Factors and Ergonomics in Health Care

PubMed Central

Carayon, Pascale; Kianfar, Sarah; Li, Yaqiong; Xie, Anping; Alyousef, Bashar; Wooldridge, Abigail

2016-01-01

This systematic literature review provides information on the use of mixed methods research in human factors and ergonomics (HFE) research in health care. Using the PRISMA methodology, we searched four databases (PubMed, PsycInfo, Web of Science, and Engineering Village) for studies that met the following inclusion criteria: (1) field study in health care, (2) mixing of qualitative and quantitative data, (3) HFE issues, and (4) empirical evidence. Using an iterative and collaborative process supported by a structured data collection form, the six authors identified a total of 58 studies that primarily address HFE issues in health information technology (e.g., usability) and in the work of healthcare workers. About two-thirds of the mixed methods studies used the convergent parallel study design where quantitative and qualitative data were collected simultaneously. A variety of methods were used for collecting data, including interview, survey and observation. The most frequent combination involved interview for qualitative data and survey for quantitative data. The use of mixed methods in healthcare HFE research has increased over time. However, increasing attention should be paid to the formal literature on mixed methods research to enhance the depth and breadth of this research. PMID:26154228

Utilisation d'analyse de concepts formels pour la gestion de variabilite d'un logiciel configure dynamiquement

NASA Astrophysics Data System (ADS)

Menguy, Theotime

Because of its critical nature, avionic industry is bound with numerous constraints such as security standards and certifications while having to fulfill the clients' desires for personalization. In this context, variability management is a very important issue for re-engineering projects of avionic softwares. In this thesis, we propose a new approach, based on formal concept analysis and semantic web, to support variability management. The first goal of this research is to identify characteristic behaviors and interactions of configuration variables in a dynamically configured system. To identify such elements, we used formal concept analysis on different levels of abstractions in the system and defined new metrics. Then, we built a classification for the configuration variables and their relations in order to enable a quick identification of a variable's behavior in the system. This classification could help finding a systematic approach to process variables during a re-engineering operation, depending on their category. To have a better understanding of the system, we also studied the shared controls of code between configuration variables. A second objective of this research is to build a knowledge platform to gather the results of all the analysis performed, and to store any additional element relevant in the variability management context, for instance new results helping define re-engineering process for each of the categories. To address this goal, we built a solution based on a semantic web, defining a new ontology, very extensive and enabling to build inferences related to the evolution processes. The approach presented here is, to the best of our knowledge, the first classification of configuration variables of a dynamically configured software and an original use of documentation and variability management techniques using semantic web in the aeronautic field. The analysis performed and the final results show that formal concept analysis is a way to identify specific properties and behaviors and that semantic web is a good solution to store and explore the results. However, the use of formal concept analysis with new boolean relations, such as the link between configuration variables and files, and the definition of new inferences may be a way to draw better conclusions. The use of the same methodology with other systems would enable to validate the approach in other contexts.

Perspectives on knowledge in engineering design

NASA Technical Reports Server (NTRS)

Rasdorf, W. J.

1985-01-01

Various perspectives are given of the knowledge currently used in engineering design, specifically dealing with knowledge-based expert systems (KBES). Constructing an expert system often reveals inconsistencies in domain knowledge while formalizing it. The types of domain knowledge (facts, procedures, judgments, and control) differ from the classes of that knowledge (creative, innovative, and routine). The feasible tasks for expert systems can be determined based on these types and classes of knowledge. Interpretive tasks require reasoning about a task in light of the knowledge available, where generative tasks create potential solutions to be tested against constraints. Only after classifying the domain by type and level can the engineer select a knowledge-engineering tool for the domain being considered. The critical features to be weighed after classification are knowledge representation techniques, control strategies, interface requirements, compatibility with traditional systems, and economic considerations.

Deep first formal concept search.

PubMed

Zhang, Tao; Li, Hui; Hong, Wenxue; Yuan, Xiamei; Wei, Xinyu

2014-01-01

The calculation of formal concepts is a very important part in the theory of formal concept analysis (FCA); however, within the framework of FCA, computing all formal concepts is the main challenge because of its exponential complexity and difficulty in visualizing the calculating process. With the basic idea of Depth First Search, this paper presents a visualization algorithm by the attribute topology of formal context. Limited by the constraints and calculation rules, all concepts are achieved by the visualization global formal concepts searching, based on the topology degenerated with the fixed start and end points, without repetition and omission. This method makes the calculation of formal concepts precise and easy to operate and reflects the integrity of the algorithm, which enables it to be suitable for visualization analysis.

Software Tools for Formal Specification and Verification of Distributed Real-Time Systems.

DTIC Science & Technology

1997-09-30

set of software tools for specification and verification of distributed real time systems using formal methods. The task of this SBIR Phase II effort...to be used by designers of real - time systems for early detection of errors. The mathematical complexity of formal specification and verification has

A STUDY OF FORMALLY ADVERTISED PROCUREMENT

DTIC Science & Technology

As a method of procuring goods and services, formally advertised procurement offers a number of advantages. These include the prevention of fraud and...two-thirds of all contracts are let in these cases. This is done by examining over 2,300 contracts let under formal advertising procedures. A measure of

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…

Study of sampling systems for comets and Mars

NASA Technical Reports Server (NTRS)

Amundsen, R. J.; Clark, B. C.

1987-01-01

Several aspects of the techniques that can be applied to acquisition and preservation of samples from Mars and a cometary nucleus were examined. Scientific approaches to sampling, grounded in proven engineering methods are the key to achieving the maximum science value from the sample return mission. If development of these approaches for collecting and preserving does not preceed mission definition, it is likely that only suboptimal techniques will be available because of the constraints of formal schedule timelines and the normal pressure to select only the most conservative and least sophisticated approaches when development has lagged the mission milestones. With a reasonable investment now, before the final mission definition, the sampling approach can become highly developed, ready for implementation, and mature enough to help set the requirements for the mission hardware and its performance.

Effective Tools and Resources from the MAVEN Education and Public Outreach Program

NASA Astrophysics Data System (ADS)

Mason, T.

2015-12-01

Since 2010, NASA's Mars Atmosphere and Volatile Evolution (MAVEN) Education and Public Outreach (E/PO) team has developed and implemented a robust and varied suite of projects, serving audiences of all ages and diverse backgrounds from across the country. With a program designed to reach formal K-12 educators and students, afterschool and summertime communities, museum docents, journalists, and online audiences, we have incorporated an equally varied approach to developing tools, resources, and evaluation methods to specifically reach each target population and to determine the effectiveness of our efforts. This poster will highlight some of the tools and resources we have developed to share the complex science and engineering of the MAVEN mission, as well as initial evaluation results and lessons-learned from each of our E/PO projects.

Prediction of Petermann I and II Spot Sizes for Single-mode Dispersion-shifted and Dispersion-flattened Fibers by a Simple Technique

NASA Astrophysics Data System (ADS)

Kamila, Kiranmay; Panda, Anup Kumar; Gangopadhyay, Sankar

2013-09-01

Employing the series expression for the fundamental modal field of dispersion-shifted trapezoidal and dispersion-flattened graded and step W fibers, we present simple but accurate analytical expressions for Petermann I and II spot sizes of such kind of fibers. Choosing some typical dispersion-shifted trapezoidal and dispersion-flattened graded and step W fibers as examples, we show that our estimations match excellently with the exact numerical results. The evaluation of the concerned propagation parameters by our formalism needs very little computations. This accurate but simple formalism will benefit the system engineers working in the field of all optical technology.

Providing solid angle formalism for skyshine calculations.

PubMed

Gossman, Michael S; Pahikkala, A Jussi; Rising, Mary B; McGinley, Patton H

2010-08-17

We detail, derive and correct the technical use of the solid angle variable identified in formal guidance that relates skyshine calculations to dose-equivalent rate. We further recommend it for use with all National Council on Radiation Protection and Measurements (NCRP), Institute of Physics and Engineering in Medicine (IPEM) and similar reports documented. In general, for beams of identical width which have different resulting areas, within ± 1.0 % maximum deviation the analytical pyramidal solution is 1.27 times greater than a misapplied analytical conical solution through all field sizes up to 40 × 40 cm². Therefore, we recommend determining the exact results with the analytical pyramidal solution for square beams and the analytical conical solution for circular beams.

Better Broader Impacts through National Science Foundation Centers

NASA Astrophysics Data System (ADS)

Campbell, K. M.

2010-12-01

National Science Foundation Science and Technology Centers (STCs) play a leading role in developing and evaluating “Better Broader Impacts”; best practices for recruiting a broad spectrum of American students into STEM fields and for educating these future professionals, as well as their families, teachers and the general public. With staff devoted full time to Broader Impacts activities, over the ten year life of a Center, STCs are able to address both a broad range of audiences and a broad range of topics. Along with other NSF funded centers, such as Centers for Ocean Sciences Education Excellence, Engineering Research Centers and Materials Research Science and Engineering Centers, STCs develop both models and materials that individual researchers can adopt, as well as, in some cases, direct opportunities for individual researchers to offer their disciplinary research expertise to existing center Broader Impacts Programs. The National Center for Earth-surface Dynamics is an STC headquartered at the University of Minnesota. NCED’s disciplinary research spans the physical, biological and engineering issues associated with developing an integrative, quantitative and predictive understanding of rivers and river basins. Funded in 2002, we have had the opportunity to partner with individuals and institutions ranging from formal to informal education and from science museums to Tribal and women’s colleges. We have developed simple table top physical models, complete museum exhibitions, 3D paper maps and interactive computer based visualizations, all of which have helped us communicate with this wide variety of learners. Many of these materials themselves or plans to construct them are available online; in many cases they have also been formally evaluated. We have also listened to the formal and informal educators with whom we partner, from whom we have learned a great deal about how to design Broader Impacts activities and programs. Using NCED as a case study, this session showcases NCED’s materials, approaches and lessons learned. We will also introduce the work of our sister STCs, whose disciplines span the STEM fields.

Implementing Elementary School Next Generation Science Standards

NASA Astrophysics Data System (ADS)

Kennedy, Katheryn B.

Implementation of the Next Generation Science Standards requires developing elementary teacher content and pedagogical content knowledge of science and engineering concepts. Teacher preparation for this undertaking appears inadequate with little known about how in-service Mid-Atlantic urban elementary science teachers approach this task. The purpose of this basic qualitative interview study was to explore the research questions related to perceived learning needs of 8 elementary science teachers and 5 of their administrators serving as instructional leaders. Strategies needed for professional growth to support learning and barriers that hamper it at both building and district levels were included. These questions were considered through the lens of Schon's reflective learning and Weick's sensemaking theories. Analysis with provisional and open coding strategies identified informal and formal supports and barriers to teachers' learning. Results indicated that informal supports, primarily internet usage, emerged as most valuable to the teachers' learning. Formal structures, including professional learning communities and grade level meetings, arose as both supportive and restrictive at the building and district levels. Existing formal supports emerged as the least useful because of the dominance of other priorities competing for time and resources. Addressing weaknesses within formal supports through more effective planning in professional development can promote positive change. Improvement to professional development approaches using the internet and increased hands on activities can be integrated into formal supports. Explicit attention to these strategies can strengthen teacher effectiveness bringing positive social change.

Stopping power of dense plasmas: The collisional method and limitations of the dielectric formalism.

PubMed

Clauser, C F; Arista, N R

2018-02-01

We present a study of the stopping power of plasmas using two main approaches: the collisional (scattering theory) and the dielectric formalisms. In the former case, we use a semiclassical method based on quantum scattering theory. In the latter case, we use the full description given by the extension of the Lindhard dielectric function for plasmas of all degeneracies. We compare these two theories and show that the dielectric formalism has limitations when it is used for slow heavy ions or atoms in dense plasmas. We present a study of these limitations and show the regimes where the dielectric formalism can be used, with appropriate corrections to include the usual quantum and classical limits. On the other hand, the semiclassical method shows the correct behavior for all plasma conditions and projectile velocity and charge. We consider different models for the ion charge distributions, including bare and dressed ions as well as neutral atoms.

Mathematical, Logical, and Formal Methods in Information Retrieval: An Introduction to the Special Issue.

ERIC Educational Resources Information Center

Crestani, Fabio; Dominich, Sandor; Lalmas, Mounia; van Rijsbergen, Cornelis Joost

2003-01-01

Discusses the importance of research on the use of mathematical, logical, and formal methods in information retrieval to help enhance retrieval effectiveness and clarify underlying concepts of information retrieval. Highlights include logic; probability; spaces; and future research needs. (Author/LRW)

From quantum heat engines to laser cooling: Floquet theory beyond the Born–Markov approximation

NASA Astrophysics Data System (ADS)

Restrepo, Sebastian; Cerrillo, Javier; Strasberg, Philipp; Schaller, Gernot

2018-05-01

We combine the formalisms of Floquet theory and full counting statistics with a Markovian embedding strategy to access the dynamics and thermodynamics of a periodically driven thermal machine beyond the conventional Born–Markov approximation. The working medium is a two-level system and we drive the tunneling as well as the coupling to one bath with the same period. We identify four different operating regimes of our machine which include a heat engine and a refrigerator. As the coupling strength with one bath is increased, the refrigerator regime disappears, the heat engine regime narrows and their efficiency and coefficient of performance decrease. Furthermore, our model can reproduce the setup of laser cooling of trapped ions in a specific parameter limit.

The Sizing and Optimization Language (SOL): A computer language to improve the user/optimizer interface

NASA Technical Reports Server (NTRS)

Lucas, S. H.; Scotti, S. J.

1989-01-01

The nonlinear mathematical programming method (formal optimization) has had many applications in engineering design. A figure illustrates the use of optimization techniques in the design process. The design process begins with the design problem, such as the classic example of the two-bar truss designed for minimum weight as seen in the leftmost part of the figure. If formal optimization is to be applied, the design problem must be recast in the form of an optimization problem consisting of an objective function, design variables, and constraint function relations. The middle part of the figure shows the two-bar truss design posed as an optimization problem. The total truss weight is the objective function, the tube diameter and truss height are design variables, with stress and Euler buckling considered as constraint function relations. Lastly, the designer develops or obtains analysis software containing a mathematical model of the object being optimized, and then interfaces the analysis routine with existing optimization software such as CONMIN, ADS, or NPSOL. This final state of software development can be both tedious and error-prone. The Sizing and Optimization Language (SOL), a special-purpose computer language whose goal is to make the software implementation phase of optimum design easier and less error-prone, is presented.

Big questions, big science: meeting the challenges of global ecology.

PubMed

Schimel, David; Keller, Michael

2015-04-01

Ecologists are increasingly tackling questions that require significant infrastucture, large experiments, networks of observations, and complex data and computation. Key hypotheses in ecology increasingly require more investment, and larger data sets to be tested than can be collected by a single investigator's or s group of investigator's labs, sustained for longer than a typical grant. Large-scale projects are expensive, so their scientific return on the investment has to justify the opportunity cost-the science foregone because resources were expended on a large project rather than supporting a number of individual projects. In addition, their management must be accountable and efficient in the use of significant resources, requiring the use of formal systems engineering and project management to mitigate risk of failure. Mapping the scientific method into formal project management requires both scientists able to work in the context, and a project implementation team sensitive to the unique requirements of ecology. Sponsoring agencies, under pressure from external and internal forces, experience many pressures that push them towards counterproductive project management but a scientific community aware and experienced in large project science can mitigate these tendencies. For big ecology to result in great science, ecologists must become informed, aware and engaged in the advocacy and governance of large ecological projects.

AOPs and Biomarkers: Bridging High Throughput Screening ...

EPA Pesticide Factsheets

As high throughput screening (HTS) plays a larger role in toxicity testing, camputational toxicology has emerged as a critical component in interpreting the large volume of data produced. Computational models designed to quantify potential adverse effects based on HTS data will benefit from additional data sources that connect the magnitude of perturbation from the in vitro system to a level of concern at the organism or population level. The adverse outcome pathway (AOP) concept provides an ideal framework for combining these complementary data. Recent international efforts under the auspices of the Organization for Economic Co-operation and Development (OECD) have resulted in an AOP wiki designed to house formal descriptions of AOPs suitable for use in regulatory decision making. Recent efforts have built upon this to include an ontology describing the AOP with linkages to biological pathways, physiological terminology, and taxonomic applicability domains. Incorporation of an AOP network tool developed by the U.S. Army Corps of Engineers also allows consideration of cumulative risk from chemical and non-chemical stressors. Biomarkers are an important complement to formal AOP descriptions, particularly when dealing with susceptible subpopulations or lifestages in human health risk assessment. To address the issue of nonchemical stressors than may modify effects of criteria air pollutants, a novel method was used to integrate blood gene expression data with hema

Quantum dynamics of light-driven chiral molecular motors.

PubMed

Yamaki, Masahiro; Nakayama, Shin-ichiro; Hoki, Kunihito; Kono, Hirohiko; Fujimura, Yuichi

2009-03-21

The results of theoretical studies on quantum dynamics of light-driven molecular motors with internal rotation are presented. Characteristic features of chiral motors driven by a non-helical, linearly polarized electric field of light are explained on the basis of symmetry argument. The rotational potential of the chiral motor is characterized by a ratchet form. The asymmetric potential determines the directional motion: the rotational direction is toward the gentle slope of the asymmetric potential. This direction is called the intuitive direction. To confirm the unidirectional rotational motion, results of quantum dynamical calculations of randomly-oriented molecular motors are presented. A theoretical design of the smallest light-driven molecular machine is presented. The smallest chiral molecular machine has an optically driven engine and a running propeller on its body. The mechanisms of transmission of driving forces from the engine to the propeller are elucidated by using a quantum dynamical treatment. The results provide a principle for control of optically-driven molecular bevel gears. Temperature effects are discussed using the density operator formalism. An effective method for ultrafast control of rotational motions in any desired direction is presented with the help of a quantum control theory. In this method, visible or UV light pulses are applied to drive the motor via an electronic excited state. A method for driving a large molecular motor consisting of an aromatic hydrocarbon is presented. The molecular motor is operated by interactions between the induced dipole of the molecular motor and the electric field of light pulses.

Formal Methods in Air Traffic Management: The Case of Unmanned Aircraft Systems

NASA Technical Reports Server (NTRS)

Munoz, Cesar A.

2015-01-01

As the technological and operational capabilities of unmanned aircraft systems (UAS) continue to grow, so too does the need to introduce these systems into civil airspace. Unmanned Aircraft Systems Integration in the National Airspace System is a NASA research project that addresses the integration of civil UAS into non-segregated airspace operations. One of the major challenges of this integration is the lack of an onboard pilot to comply with the legal requirement that pilots see and avoid other aircraft. The need to provide an equivalent to this requirement for UAS has motivated the development of a detect and avoid (DAA) capability to provide the appropriate situational awareness and maneuver guidance in avoiding and remaining well clear of traffic aircraft. Formal methods has played a fundamental role in the development of this capability. This talk reports on the formal methods work conducted under NASA's Safe Autonomous System Operations project in support of the development of DAA for UAS. This work includes specification of low-level and high-level functional requirements, formal verification of algorithms, and rigorous validation of software implementations. The talk also discusses technical challenges in formal methods research in the context of the development and safety analysis of advanced air traffic management concepts.

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 models and analyses can be used to help eliminate mode confusion from flight deck designs and at the same time increase our confidence in the safety of the implementation. The paper is based upon interim results from a new project involving NASA Langley and Rockwell Collins in applying formal methods to a realistic business jet Flight Guidance System (FGS).

Working the College System: Six Strategies for Building a Personal Powerbase

ERIC Educational Resources Information Center

Simplicio, Joseph S. C.

2008-01-01

Within each college system there are prescribed formalized methods for accomplishing tasks and achieving established goals. To truly understand how a college, or any large organization functions, it is vital to understand the basis of the formal structure. Those individuals who understand formal systems within a college can use this knowledge to…

An Educational Development Tool Based on Principles of Formal Ontology

ERIC Educational Resources Information Center

Guzzi, Rodolfo; Scarpanti, Stefano; Ballista, Giovanni; Di Nicolantonio, Walter

2005-01-01

Computer science provides with virtual laboratories, places where one can merge real experiments with the formalism of algorithms and mathematics and where, with the advent of multimedia, sounds and movies can also be added. In this paper we present a method, based on principles of formal ontology, allowing one to develop interactive educational…

Rewriting Logic Semantics of a Plan Execution Language

NASA Technical Reports Server (NTRS)

Dowek, Gilles; Munoz, Cesar A.; Rocha, Camilo

2009-01-01

The Plan Execution Interchange Language (PLEXIL) is a synchronous language developed by NASA to support autonomous spacecraft operations. In this paper, we propose a rewriting logic semantics of PLEXIL in Maude, a high-performance logical engine. The rewriting logic semantics is by itself a formal interpreter of the language and can be used as a semantic benchmark for the implementation of PLEXIL executives. The implementation in Maude has the additional benefit of making available to PLEXIL designers and developers all the formal analysis and verification tools provided by Maude. The formalization of the PLEXIL semantics in rewriting logic poses an interesting challenge due to the synchronous nature of the language and the prioritized rules defining its semantics. To overcome this difficulty, we propose a general procedure for simulating synchronous set relations in rewriting logic that is sound and, for deterministic relations, complete. We also report on the finding of two issues at the design level of the original PLEXIL semantics that were identified with the help of the executable specification in Maude.

Teaching Basic Quantum Mechanics in Secondary School Using Concepts of Feynman Path Integrals Method

ERIC Educational Resources Information Center

Fanaro, Maria de los Angeles; Otero, Maria Rita; Arlego, Marcelo

2012-01-01

This paper discusses the teaching of basic quantum mechanics in high school. Rather than following the usual formalism, our approach is based on Feynman's path integral method. Our presentation makes use of simulation software and avoids sophisticated mathematical formalism. (Contains 3 figures.)

A Vector Representation for Thermodynamic Relationships

ERIC Educational Resources Information Center

Pogliani, Lionello

2006-01-01

The existing vector formalism method for thermodynamic relationship maintains tractability and uses accessible mathematics, which can be seen as a diverting and entertaining step into the mathematical formalism of thermodynamics and as an elementary application of matrix algebra. The method is based on ideas and operations apt to improve the…

On decentralized design: Rationale, dynamics, and effects on decision-making

NASA Astrophysics Data System (ADS)

Chanron, Vincent

The focus of this dissertation is the design of complex systems, including engineering systems such as cars, airplanes, and satellites. Companies who design these systems are under constant pressure to design better products that meet customer expectations, and competition forces them to develop them faster. One of the responses of the industry to these conflicting challenges has been the decentralization of the design responsibilities. The current lack of understanding of the dynamics of decentralized design processes is the main motivation for this research, and places value on the descriptive base. It identifies the main reasons and the true benefits for companies to decentralize the design of their products. It also demonstrates the limitations of this approach by listing the relevant issues and problems created by the decentralization of decisions. Based on these observations, a game-theoretic approach to decentralized design is proposed to model the decisions made during the design process. The dynamics are modeled using mathematical formulations inspired from control theory. Building upon this formalism, the issue of convergence in decentralized design is analyzed: the equilibrium points of the design space are identified and convergent and divergent patterns are recognized. This rigorous investigation of the design process provides motivation and support for proposing new approaches to decentralized design problems. Two methods are developed, which aim at improving the design process in two ways: decreasing the product development time, and increasing the optimality of the final design. The frame of these methods are inspired by eigenstructure decomposition and set-based design, respectively. The value of the research detailed within this dissertation is in the proposed methods which are built upon the sound mathematical formalism developed. The contribution of this work is two fold: rigorous investigation of the design process, and practical support to decision-making in decentralized environments.

Genetic Design Automation: engineering fantasy or scientific renewal?

PubMed Central

Lux, Matthew W.; Bramlett, Brian W.; Ball, David A.; Peccoud, Jean

2013-01-01

Synthetic biology aims to make genetic systems more amenable to engineering, which has naturally led to the development of Computer-Aided Design (CAD) tools. Experimentalists still primarily rely on project-specific ad-hoc workflows instead of domain-specific tools, suggesting that CAD tools are lagging behind the front line of the field. Here, we discuss the scientific hurdles that have limited the productivity gains anticipated from existing tools. We argue that the real value of efforts to develop CAD tools is the formalization of genetic design rules that determine the complex relationships between genotype and phenotype. PMID:22001068

NSF Director to resign

NASA Astrophysics Data System (ADS)

Richman, Barbara T.

Edward A. Knapp, director of the National Science Foundation (NSF) since late 1982, will resign his post later this year to return to research at the Los Alamos National Laboratory. President Ronald Reagan has announced his intention to nominate Erich Bloch, vice president for technical personnel development at the IBM Corp., as Knapp's successor.Following formal nomination by President Reagan, the Senate must confirm Bloch as NSF director. If Bloch is confirmed, he is likely to bring to NSF the greater emphasis on engineering that the agency has sought in response to requests from Congress and the engineering community during the last year.

The Study on Collaborative Manufacturing Platform Based on Agent

NASA Astrophysics Data System (ADS)

Zhang, Xiao-yan; Qu, Zheng-geng

To fulfill the trends of knowledge-intensive in collaborative manufacturing development, we have described multi agent architecture supporting knowledge-based platform of collaborative manufacturing development platform. In virtue of wrapper service and communication capacity agents provided, the proposed architecture facilitates organization and collaboration of multi-disciplinary individuals and tools. By effectively supporting the formal representation, capture, retrieval and reuse of manufacturing knowledge, the generalized knowledge repository based on ontology library enable engineers to meaningfully exchange information and pass knowledge across boundaries. Intelligent agent technology increases traditional KBE systems efficiency and interoperability and provides comprehensive design environments for engineers.

Teaching Logistics without Formal Classes: A Case Study

ERIC Educational Resources Information Center

Carravilla, Maria Antonia; Oliveira, Jose Fernando

2004-01-01

This paper describes a case study concerning the teaching of logistics in the Computers and Electrical Engineering degree at FEUP. The logistics course is taken in the last semester of the degree and there are no lectures given by the teachers. All the learning strategy is based upon the autonomous learning capacity of the students, following the…

Transitional to Formal Operational: Using Authentic Research Experiences to Get Non-Science Students to Think More Like Scientists

ERIC Educational Resources Information Center

Moore, J. Christopher

2012-01-01

University and high school students not pursuing a science, technology, engineering, and/or mathematics (STEM) course of study demonstrate less developed scientific reasoning than their STEM-based peers. Previous studies show that the majority of non-STEM students can be classified as either concrete operational or transitional reasoners in…

One Mission-Centered, Market-Smart Globalization Response: A Case Study of the Georgia Tech-Emory University Biomedical Engineering Curricular Joint Venture

ERIC Educational Resources Information Center

Burriss, Annie Hunt

2010-01-01

One innovative, higher-education response to globalization and changing fiscal realities is the curricular joint venture (CJV), a formal collaboration between academic institutions that leverages missions through new joint degrees and research not previously offered by collaborating institutions (Eckel, 2003). In 1997, a pioneering biomedical…

Technical and Symbolic Knowledge in CNC Machining: A Study of Technical Workers of Different Backgrounds.

ERIC Educational Resources Information Center

Martin, Laura M. W.; Beach, King

Performances of 45 individuals with varying degrees of formal and informal training in machining and programming were compared on tasks designed to tap intellectual changes that may occur with the introduction of computer numerical control (CNC). Participants--30 machinists, 8 machine operators, and 7 engineers--were asked background questions and…

Automated Knowledge Generation with Persistent Surveillance Video

DTIC Science & Technology

2008-03-26

5 2.1 Artificial Intelligence . . . . . . . . . . . . . . . . . . . . 5 2.1.1 Formal Logic . . . . . . . . . . . . . . . . . . . 6 2.1.2...background of Artificial Intelligence and the reasoning engines that will be applied to generate knowledge from data. Section 2.2 discusses background on...generation from persistent video. 4 II. Background In this chapter, we will discuss the background of Artificial Intelligence, Semantic Web, image

FY 1995 Scientific and Technical Reports, Articles, Papers, and Presentations, Volume 1

NASA Technical Reports Server (NTRS)

Turner, Joyce E. (Compiler)

1995-01-01

This document presents formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY95. It also includes papers of MSFC contractors. The information in this report may be of value to the scientific and engineering community in determining what information has been published and what is available.

FY 2002 Scientific and Technical Reports, Articles, Papers, and Presentations

NASA Technical Reports Server (NTRS)

Fowler, B. A. (Compiler)

2003-01-01

This Technical Memorandum (TM) presents formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY 2002. It also includes papers of MSFC contractors. The information in this TM may be of value to the scientific and engineering community in determining what information has been published and what is available.

DoD Science and Engineering Apprenticeship Program for High School Minorities and Women Summer 1990 Activities

DTIC Science & Technology

1991-01-01

lectures, laboratory demon- strations, scientific films, a formal course and a weekly discussion session on the history of science using the book Coming...lectures and discussions with Dr. Pfeffer on Coming of Age in the Milky Way, an exciting book on the history of science by Timothy Ferris. A series of

Using Continuous Assessment to Promote Student Engagement in a Large Class

ERIC Educational Resources Information Center

Cole, Jonathan S.; Spence, Stephen W. T.

2012-01-01

The authors have developed a first-year fluids course for a class of around 230 aerospace, civil and mechanical engineering students. This paper aims to show how the teaching and assessment methodology was applied to the challenge of a large class. The lectures featured formal teaching interspersed with active learning elements. Smaller group…

The 18 mm[superscript 2] Laboratory: Teaching MEMS Development with the SUMMiT Foundry Process

ERIC Educational Resources Information Center

Dallas, T.; Berg, J. M.; Gale, R. O.

2012-01-01

This paper describes the goals, pedagogical system, and educational outcomes of a three-semester curriculum in microelectromechanical systems (MEMS). The sequence takes engineering students with no formal MEMS training and gives them the skills to participate in cutting-edge MEMS research and development. The evolution of the curriculum from…

Technology Transfer Summary Report (FY92), Naval Surface Warfare Center Dahlgren Division

DTIC Science & Technology

1994-04-20

communications; no formal records are kept of these. Community Technical Outreach NSWCDD participates in the "Science and Engineering Apprentice" and the " Bay ...ADMINISTRATOR’S OFFICE NAVAL UNDERSEA WARFARE CENTER PO BOX 545 DIVISION NEWPORT SEQUIM WA 98382 NEWPORI’ RI 02841-5047 ATTN GIFT AND EXCHANGE DIV 4 ATTN CODE 00

Problem-Solving Rubrics Revisited: Attending to the Blending of Informal Conceptual and Formal Mathematical Reasoning

ERIC Educational Resources Information Center

Hull, Michael M.; Kuo, Eric; Gupta, Ayush; Elby, Andrew

2013-01-01

Much research in engineering and physics education has focused on improving students' problem-solving skills. This research has led to the development of step-by-step problem-solving strategies and grading rubrics to assess a student's expertise in solving problems using these strategies. These rubrics value "communication" between the…

Integrated model development for liquid fueled rocket propulsion systems

NASA Technical Reports Server (NTRS)

Santi, L. Michael

1993-01-01

As detailed in the original statement of work, the objective of phase two of this research effort was to develop a general framework for rocket engine performance prediction that integrates physical principles, a rigorous mathematical formalism, component level test data, system level test data, and theory-observation reconciliation. Specific phase two development tasks are defined.

The Role of Engineering Skills in Development

ERIC Educational Resources Information Center

DeBoer, Jennifer Jean

2012-01-01

A young child dreams of being an astronaut. She dreams of piloting a complex rocket full of buttons and gadgets through the sky and discovering new planets in the unknown, unchartered universe of scientific frontiers. As the child grows, she makes her way through the sacred halls of formal schooling. She takes classes, goes to college, and starts…

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.

Reduced-Order Blade Mistuning Analysis Techniques Developed for the Robust Design of Engine Rotors

NASA Technical Reports Server (NTRS)

Min, James B.

2004-01-01

The primary objective of this research program is to develop vibration analysis tools, design tools, and design strategies to significantly improve the safety and robustness of turbine engine rotors. Bladed disks in turbine engines always feature small, random blade-to-blade differences, or mistuning. Mistuning can lead to a dramatic increase in blade forced-response amplitudes and stresses. Ultimately, this results in high-cycle fatigue, which is a major safety and cost concern. In this research program, the necessary steps will be taken to transform a state-of-the-art vibration analysis tool, the Turbo-Reduce forced-response prediction code, into an effective design tool by enhancing and extending the underlying modeling and analysis methods. Furthermore, novel techniques will be developed to assess the safety of a given design. In particular, a procedure will be established for using eigenfrequency curve veerings to identify "danger zones" in the operating conditions--ranges of rotational speeds and engine orders in which there is a great risk that the rotor blades will suffer high stresses. This work also will aid statistical studies of the forced response by reducing the necessary number of simulations. Finally, new strategies for improving the design of rotors will be pursued. Several methods will be investigated, including the use of intentional mistuning patterns to mitigate the harmful effects of random mistuning, and the modification of disk stiffness to avoid reaching critical values of interblade coupling in the desired operating range. Recent research progress is summarized in the following paragraphs. First, significant progress was made in the development of the component mode mistuning (CMM) and static mode compensation (SMC) methods for reduced-order modeling of mistuned bladed disks (see the following figure). The CMM method has been formalized and extended to allow a general treatment of mistuning. In addition, CMM allows individual mode mistuning, which accounts for the realistic effects of local variations in blade properties that lead to different mistuning values for different mode types (e.g., mistuning of the first torsion mode versus the second flexural mode). The accuracy and efficiency of the CMM method and the corresponding Turbo-Reduce code were validated for an example finite element model of a bladed disk.

Systematic Model-in-the-Loop Test of Embedded Control Systems

NASA Astrophysics Data System (ADS)

Krupp, Alexander; Müller, Wolfgang

Current model-based development processes offer new opportunities for verification automation, e.g., in automotive development. The duty of functional verification is the detection of design flaws. Current functional verification approaches exhibit a major gap between requirement definition and formal property definition, especially when analog signals are involved. Besides lack of methodical support for natural language formalization, there does not exist a standardized and accepted means for formal property definition as a target for verification planning. This article addresses several shortcomings of embedded system verification. An Enhanced Classification Tree Method is developed based on the established Classification Tree Method for Embeded Systems CTM/ES which applies a hardware verification language to define a verification environment.

Assessment of the Orion-SLS Interface Management Process in Achieving the EIA 731.1 Systems Engineering Capability Model Generic Practices Level 3 Criteria

NASA Technical Reports Server (NTRS)

Jellicorse, John J.; Rahman, Shamin A.

2016-01-01

NASA is currently developing the next generation crewed spacecraft and launch vehicle for exploration beyond earth orbit including returning to the Moon and making the transit to Mars. Managing the design integration of major hardware elements of a space transportation system is critical for overcoming both the technical and programmatic challenges in taking a complex system from concept to space operations. An established method of accomplishing this is formal interface management. In this paper we set forth an argument that the interface management process implemented by NASA between the Orion Multi-Purpose Crew Vehicle (MPCV) and the Space Launch System (SLS) achieves the Level 3 tier of the EIA 731.1 System Engineering Capability Model (SECM) for Generic Practices. We describe the relevant NASA systems and associated organizations, and define the EIA SECM Level 3 Generic Practices. We then provide evidence for our compliance with those practices. This evidence includes discussions of: NASA Systems Engineering Interface (SE) Management standard process and best practices; the tailoring of that process for implementation on the Orion to SLS interface; changes made over time to improve the tailored process, and; the opportunities to take the resulting lessons learned and propose improvements to our institutional processes and best practices. We compare this evidence against the practices to form the rationale for the declared SECM maturity level.

A knowledge engineering framework towards clinical support for adverse drug event prevention: the PSIP approach.

PubMed

Koutkias, Vassilis; Stalidis, George; Chouvarda, Ioanna; Lazou, Katerina; Kilintzis, Vassilis; Maglaveras, Nicos

2009-01-01

Adverse Drug Events (ADEs) are currently considered as a major public health issue, endangering patients' safety and causing significant healthcare costs. Several research efforts are currently concentrating on the reduction of preventable ADEs by employing Information Technology (IT) solutions, which aim to provide healthcare professionals and patients with relevant knowledge and decision support tools. In this context, we present a knowledge engineering approach towards the construction of a Knowledge-based System (KBS) regarded as the core part of a CDSS (Clinical Decision Support System) for ADE prevention, all developed in the context of the EU-funded research project PSIP (Patient Safety through Intelligent Procedures in Medication). In the current paper, we present the knowledge sources considered in PSIP and the implications they pose to knowledge engineering, the methodological approach followed, as well as the components defining the knowledge engineering framework based on relevant state-of-the-art technologies and representation formalisms.

The power of a critical heat engine

PubMed Central

Campisi, Michele; Fazio, Rosario

2016-01-01

Since its inception about two centuries ago thermodynamics has sparkled continuous interest and fundamental questions. According to the second law no heat engine can have an efficiency larger than Carnot's efficiency. The latter can be achieved by the Carnot engine, which however ideally operates in infinite time, hence delivers null power. A currently open question is whether the Carnot efficiency can be achieved at finite power. Most of the previous works addressed this question within the Onsager matrix formalism of linear response theory. Here we pursue a different route based on finite-size-scaling theory. We focus on quantum Otto engines and show that when the working substance is at the verge of a second order phase transition diverging energy fluctuations can enable approaching the Carnot point without sacrificing power. The rate of such approach is dictated by the critical indices, thus showing the universal character of our analysis. PMID:27320127

The MetSkill Program — Rapidly Developing Effective Young Engineers in the Workplace

NASA Astrophysics Data System (ADS)

Drinkwater, Diana; Bianco, Nina

MetSkill is a professional development program for metallurgical engineers that integrates with normal duties in their first one or two years of service. Graduates work together on a structured technical project, facilitated by specialists and supported by formal learning, and ultimately reported to their technical managers. The program enables graduates to "fill the gaps" in their undergraduate education, which is increasingly pertinent as engineering degrees become more general. Participants report that they enjoy the focus on more challenging (rewarding) aspects of their jobs and feel more confident about problem solving. Sponsor companies add that the relationships developed with external technical specialists enhances opportunities for innovation and development. MetSkill was delivered to two major resource companies in Australia in 2012. This paper provides an outline of the program and the reasons for its success, and demonstrates how the learning model could be applied to groups of graduates in other engineering disciplines.

Location priority for non-formal early childhood education school based on promethee method and map visualization

NASA Astrophysics Data System (ADS)

Ayu Nurul Handayani, Hemas; Waspada, Indra

2018-05-01

Non-formal Early Childhood Education (non-formal ECE) is an education that is held for children under 4 years old. The implementation in District of Banyumas, Non-formal ECE is monitored by The District Government of Banyumas and helped by Sanggar Kegiatan Belajar (SKB) Purwokerto as one of the organizer of Non-formal Education. The government itself has a program for distributing ECE to all villages in Indonesia. However, The location to construct the ECE school in several years ahead is not arranged yet. Therefore, for supporting that program, a decision support system is made to give some recommendation villages for constructing The ECE building. The data are projected based on Brown’s Double Exponential Smoothing Method and utilizing Preference Ranking Organization Method for Enrichment Evaluation (Promethee) to generate priority order. As the recommendations system, it generates map visualization which is colored according to the priority level of sub-district and village area. The system was tested with black box testing, Promethee testing, and usability testing. The results showed that the system functionality and Promethee algorithm were working properly, and the user was satisfied.

Generalizability of the Ordering among Five Formal Reasoning Tasks by an Ordering-Theoretic Method.

ERIC Educational Resources Information Center

Bart, William M.; And Others

1979-01-01

Five Inhelder-Piaget formal operations tasks were analyzed to determine the extent that the formal operational skills they assess were ordered into a stable hierarchy generalizable across samples of subjects. Subjects were 34 collegiate gymnasts (19 males, 15 females), and 22 students (1 male, 21 females) from a university nursing program.…

The Values-Based Infrastructure of Non-Formal Education: A Case Study of Personal Education in Israeli Schools

ERIC Educational Resources Information Center

Goldratt, Miri; Cohen, Eric H.

2016-01-01

This article explores encounters between formal, informal, and non-formal education and the role of mentor-educators in creating values education in which such encounters take place. Mixed-methods research was conducted in Israeli public schools participating in the Personal Education Model, which combines educational modes. Ethnographic and…

Formal Method of Description Supporting Portfolio Assessment

ERIC Educational Resources Information Center

Morimoto, Yasuhiko; Ueno, Maomi; Kikukawa, Isao; Yokoyama, Setsuo; Miyadera, Youzou

2006-01-01

Teachers need to assess learner portfolios in the field of education. However, they need support in the process of designing and practicing what kind of portfolios are to be assessed. To solve the problem, a formal method of describing the relations between the lesson forms and portfolios that need to be collected and the relations between…

Contour-time approach to the Bose-Hubbard model in the strong coupling regime: Studying two-point spatio-temporal correlations at the Hartree-Fock-Bogoliubov level

NASA Astrophysics Data System (ADS)

Fitzpatrick, Matthew R. C.; Kennett, Malcolm P.

2018-05-01

We develop a formalism that allows the study of correlations in space and time in both the superfluid and Mott insulating phases of the Bose-Hubbard Model. Specifically, we obtain a two particle irreducible effective action within the contour-time formalism that allows for both equilibrium and out of equilibrium phenomena. We derive equations of motion for both the superfluid order parameter and two-point correlation functions. To assess the accuracy of this formalism, we study the equilibrium solution of the equations of motion and compare our results to existing strong coupling methods as well as exact methods where possible. We discuss applications of this formalism to out of equilibrium situations.

75 FR 69165 - Conductor Certification

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-10

...FRA proposes to prescribe regulations for certification of conductors, as required by the Rail Safety Improvement Act of 2008. The proposed rule would require railroads to have a formal program for certifying conductors. As part of that program, railroads would be required to have a formal process for training prospective conductors and determining that all persons are competent before permitting them to serve as a conductor. FRA is proposing this regulation to ensure that only those persons who meet minimum Federal safety standards serve as conductors, to reduce the rate and number of accidents and incidents, and to improve railroad safety. Although this NPRM does not propose any specific amendments to the regulation governing locomotive engineer certification, it does highlight areas in that regulation that may require conforming changes.

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 activities of this task.

The TAME Project: Towards improvement-oriented software environments

NASA Technical Reports Server (NTRS)

Basili, Victor R.; Rombach, H. Dieter

1988-01-01

Experience from a dozen years of analyzing software engineering processes and products is summarized as a set of software engineering and measurement principles that argue for software engineering process models that integrate sound planning and analysis into the construction process. In the TAME (Tailoring A Measurement Environment) project at the University of Maryland, such an improvement-oriented software engineering process model was developed that uses the goal/question/metric paradigm to integrate the constructive and analytic aspects of software development. The model provides a mechanism for formalizing the characterization and planning tasks, controlling and improving projects based on quantitative analysis, learning in a deeper and more systematic way about the software process and product, and feeding the appropriate experience back into the current and future projects. The TAME system is an instantiation of the TAME software engineering process model as an ISEE (integrated software engineering environment). The first in a series of TAME system prototypes has been developed. An assessment of experience with this first limited prototype is presented including a reassessment of its initial architecture.

Unmanned Aircraft Systems in the National Airspace System: A Formal Methods Perspective

NASA Technical Reports Server (NTRS)

Munoz, Cesar A.; Dutle, Aaron; Narkawicz, Anthony; Upchurch, Jason

2016-01-01

As the technological and operational capabilities of unmanned aircraft systems (UAS) have grown, so too have international efforts to integrate UAS into civil airspace. However, one of the major concerns that must be addressed in realizing this integration is that of safety. For example, UAS lack an on-board pilot to comply with the legal requirement that pilots see and avoid other aircraft. This requirement has motivated the development of a detect and avoid (DAA) capability for UAS that provides situational awareness and maneuver guidance to UAS operators to aid them in avoiding and remaining well clear of other aircraft in the airspace. The NASA Langley Research Center Formal Methods group has played a fundamental role in the development of this capability. This article gives a selected survey of the formal methods work conducted in support of the development of a DAA concept for UAS. This work includes specification of low-level and high-level functional requirements, formal verification of algorithms, and rigorous validation of software implementations.

Memory sparing, fast scattering formalism for rigorous diffraction modeling

NASA Astrophysics Data System (ADS)

Iff, W.; Kämpfe, T.; Jourlin, Y.; Tishchenko, A. V.

2017-07-01

The basics and algorithmic steps of a novel scattering formalism suited for memory sparing and fast electromagnetic calculations are presented. The formalism, called ‘S-vector algorithm’ (by analogy with the known scattering-matrix algorithm), allows the calculation of the collective scattering spectra of individual layered micro-structured scattering objects. A rigorous method of linear complexity is applied to model the scattering at individual layers; here the generalized source method (GSM) resorting to Fourier harmonics as basis functions is used as one possible method of linear complexity. The concatenation of the individual scattering events can be achieved sequentially or in parallel, both having pros and cons. The present development will largely concentrate on a consecutive approach based on the multiple reflection series. The latter will be reformulated into an implicit formalism which will be associated with an iterative solver, resulting in improved convergence. The examples will first refer to 1D grating diffraction for the sake of simplicity and intelligibility, with a final 2D application example.

Two-Component Noncollinear Time-Dependent Spin Density Functional Theory for Excited State Calculations.

PubMed

Egidi, Franco; Sun, Shichao; Goings, Joshua J; Scalmani, Giovanni; Frisch, Michael J; Li, Xiaosong

2017-06-13

We present a linear response formalism for the description of the electronic excitations of a noncollinear reference defined via Kohn-Sham spin density functional methods. A set of auxiliary variables, defined using the density and noncollinear magnetization density vector, allows the generalization of spin density functional kernels commonly used in collinear DFT to noncollinear cases, including local density, GGA, meta-GGA and hybrid functionals. Working equations and derivations of functional second derivatives with respect to the noncollinear density, required in the linear response noncollinear TDDFT formalism, are presented in this work. This formalism takes all components of the spin magnetization into account independent of the type of reference state (open or closed shell). As a result, the method introduced here is able to afford a nonzero local xc torque on the spin magnetization while still satisfying the zero-torque theorem globally. The formalism is applied to a few test cases using the variational exact-two-component reference including spin-orbit coupling to illustrate the capabilities of the method.

A Linguistic Truth-Valued Temporal Reasoning Formalism and Its Implementation

NASA Astrophysics Data System (ADS)

Lu, Zhirui; Liu, Jun; Augusto, Juan C.; Wang, Hui

Temporality and uncertainty are important features of many real world systems. Solving problems in such systems requires the use of formal mechanism such as logic systems, statistical methods or other reasoning and decision-making methods. In this paper, we propose a linguistic truth-valued temporal reasoning formalism to enable the management of both features concurrently using a linguistic truth valued logic and a temporal logic. We also provide a backward reasoning algorithm which allows the answering of user queries. A simple but realistic scenario in a smart home application is used to illustrate our work.

Expressive map design: OGC SLD/SE++ extension for expressive map styles

NASA Astrophysics Data System (ADS)

Christophe, Sidonie; Duménieu, Bertrand; Masse, Antoine; Hoarau, Charlotte; Ory, Jérémie; Brédif, Mathieu; Lecordix, François; Mellado, Nicolas; Turbet, Jérémie; Loi, Hugo; Hurtut, Thomas; Vanderhaeghe, David; Vergne, Romain; Thollot, Joëlle

2018-05-01

In the context of custom map design, handling more artistic and expressive tools has been identified as a carto-graphic need, in order to design stylized and expressive maps. Based on previous works on style formalization, an approach for specifying the map style has been proposed and experimented for particular use cases. A first step deals with the analysis of inspiration sources, in order to extract `what does make the style of the source', i.e. the salient visual characteristics to be automatically reproduced (textures, spatial arrangements, linear stylization, etc.). In a second step, in order to mimic and generate those visual characteristics, existing and innovative rendering techniques have been implemented in our GIS engine, thus extending the capabilities to generate expressive renderings. Therefore, an extension of the existing cartographic pipeline has been proposed based on the following aspects: 1- extension of the symbolization specifications OGC SLD/SE in order to provide a formalism to specify and reference expressive rendering methods; 2- separate the specification of each rendering method and its parameterization, as metadata. The main contribution has been described in (Christophe et al. 2016). In this paper, we focus firstly on the extension of the cartographic pipeline (SLD++ and metadata) and secondly on map design capabilities which have been experimented on various topographic styles: old cartographic styles (Cassini), artistic styles (watercolor, impressionism, Japanese print), hybrid topographic styles (ortho-imagery & vector data) and finally abstract and photo-realist styles for the geovisualization of costal area. The genericity and interoperability of our approach are promising and have already been tested for 3D visualization.

A study to evaluate primary dressings for the application of cultured keratinocytes.

PubMed

Price, R D; Das-Gupta, V; Frame, J D; Navsaria, H A

2001-12-01

Despite the recent improvements in cell culture and dermal regeneration methods, tissue engineering of skin has yet to receive widespread acceptance in the management of burn injuries. The reasons for this are complex and include not only the inherent costs of (particularly) setting up and running such a system but also the continuing difficulties in achieving successful engraftment of the neoepidermis. The latter has previously been addressed in a number of ways, including improving the recipient bed and using pre-confluent delivery systems to allow earlier application of cells to that wound bed. One area that has received little attention is that of the optimal wound dressing to use with this technology; the cells are very poorly attached at early time points, and, in this context, the traditional dressing of paraffin gauze has never been formally assessed in comparison with newer materials. Using a porcine acute wound chamber model, we performed a prospective randomised trial to assess four different wound dressings with reference to the amount of epidermal cover gained and the histological quality of the regenerated skin after 3 weeks. Out of the four materials tested, polyurethane foam (Allevyn) was superior histologically (although equal in take rate with paraffin gauze), whilst polythene sheet (Opsite) and silicone sheet were substantially inferior. We conclude that the traditional dressing used with this technology should be compared with polyurethane foam in a clinical trial. In the future, novel dressings should be formally tested against traditional methods before being adopted. Copyright 2001 The British Association of Plastic Surgeons.

NASA's New Science Education and Public Outreach Forums: Bringing Communities and Resources Together to Increase Effectiveness and Sustainability

NASA Astrophysics Data System (ADS)

Smith, Denise A.; Mendez, B.; Shipp, S.; Schwerin, T.; Stockman, S.; Cooper, L. P.; Sharma, M.

2010-01-01

Scientists, engineers, educators, and public outreach professionals have a rich history of creatively using NASA's pioneering scientific discoveries and technology to engage and educate youth and adults nationwide in core science, technology, engineering, and mathematics topics. We introduce four new Science Education and Public Outreach Forums that will work in partnership with the community and NASA's Science Mission Directorate (SMD) to ensure that current and future SMD-funded education and public outreach (E/PO) activities form a seamless whole, with easy entry points for general public, students, K-12 formal and informal science educators, faculty, scientists, engineers, and E/PO professionals alike. The new Science Education and Public Outreach Forums support the astrophysics, heliophysics, planetary and Earth science divisions of NASA SMD in three core areas: 1) E/PO community engagement and development activities will provide clear paths of involvement for scientists and engineers interested - or potentially interested - in participating in SMD-funded E/PO activities. Collaborations with scientists and engineers are vital for infusing current, accurate SMD mission and research findings into educational products and activities. Forum activities will also yield readily accessible information on effective E/PO strategies, resources, and expertise; context for individual E/PO activities; and opportunities for collaboration. 2) A rigorous analysis of SMD-funded K-12 formal, informal, and higher education products and activities will help the community and SMD to understand how the existing collection supports education standards and audience needs, and to strategically identify areas of opportunity for new materials and activities. 3) Finally, a newly convened Coordinating Committee will work across the four SMD science divisions to address systemic issues and integrate related activities. By supporting the NASA E/PO community and facilitating coordination of E/PO activities, the NASA-SEPOF partnerships will lead to more effective, sustainable, and efficient utilization of NASA science discoveries and learning experiences.

Evolution and Revolutions of Adult Learning: Capacity Building in Adult and Non-Formal Education in Nigeria

ERIC Educational Resources Information Center

Ugwu, Chinwe U.

2015-01-01

The National Commission for Mass Literacy, Adult and Non-Formal Education (NMEC) is the Federal Statutory Agency set up to co-ordinate all aspects of Non-Formal Education in Nigeria whether offered by government agencies or non-governmental organisations. This study looked at the existing Capacity Building Programme, the delivery methods, impact…

Hydra Revisited: Substituting Formal for Self- and Informal In-Home Care among Older Adults with Disabilities

ERIC Educational Resources Information Center

Penning, Margaret J.

2002-01-01

Purpose: In response to concerns among policymakers and others that increases in the availability of publicly funded formal services will lead to reductions in self- and informal care, this study examines the relationship between the extent of formal in-home care received and levels of self- and informal care. Design and Methods: Two-stage least…

The Influence of Rural Location on Utilization of Formal Home Care: The Role of Medicaid

ERIC Educational Resources Information Center

McAuley, William J.; Spector, William D.; Van Nostrand, Joan; Shaffer, Tom

2004-01-01

Purpose: This research examines the impact of rural-urban residence on formal home-care utilization among older people and determines whether and how Medicaid coverage influences the association between, rural-urban location and risk of formal home-care use. Design and Methods: We combined data from the 1998 consolidated file of the Medical…

A Bayesian Framework for Analysis of Pseudo-Spatial Models of Comparable Engineered Systems with Application to Spacecraft Anomaly Prediction Based on Precedent Data

NASA Astrophysics Data System (ADS)

Ndu, Obibobi Kamtochukwu

To ensure that estimates of risk and reliability inform design and resource allocation decisions in the development of complex engineering systems, early engagement in the design life cycle is necessary. An unfortunate constraint on the accuracy of such estimates at this stage of concept development is the limited amount of high fidelity design and failure information available on the actual system under development. Applying the human ability to learn from experience and augment our state of knowledge to evolve better solutions mitigates this limitation. However, the challenge lies in formalizing a methodology that takes this highly abstract, but fundamentally human cognitive, ability and extending it to the field of risk analysis while maintaining the tenets of generalization, Bayesian inference, and probabilistic risk analysis. We introduce an integrated framework for inferring the reliability, or other probabilistic measures of interest, of a new system or a conceptual variant of an existing system. Abstractly, our framework is based on learning from the performance of precedent designs and then applying the acquired knowledge, appropriately adjusted based on degree of relevance, to the inference process. This dissertation presents a method for inferring properties of the conceptual variant using a pseudo-spatial model that describes the spatial configuration of the family of systems to which the concept belongs. Through non-metric multidimensional scaling, we formulate the pseudo-spatial model based on rank-ordered subjective expert perception of design similarity between systems that elucidate the psychological space of the family. By a novel extension of Kriging methods for analysis of geospatial data to our "pseudo-space of comparable engineered systems", we develop a Bayesian inference model that allows prediction of the probabilistic measure of interest.

Engineering the Business of Defense Acquisition: An Analysis of Program Office Processes

DTIC Science & Technology

2015-05-01

Information Technology and Business Process Redesign | MIT Sloan Management Review . MIT Sloan Management Review . Retrieved from http://sloanreview.mit.edu...links systems management to process execution Three Phases/ Multi-Year Effort (This Phase) Literature review Model development— Formal and...estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining

FY 2005 Scientific and Technical Reports, Articles, Papers, and Presentations

NASA Technical Reports Server (NTRS)

Narmore, K. A. (Compiler)

2007-01-01

This Technical Memorandum (TM) presents formal NASA technical reports, papers published in technical journals, and presentations by Marshall Space Flight Center (MSFC) personnel in FY 2005. It also includes papers of MSFC contractors. The information in this TM may be of value to the scientific and engineering community in determining what information has been published and what is available.

Year-Long Peer Mentoring Activity to Enhance the Retention of Freshmen STEM Students in a NSF Scholarship Program

ERIC Educational Resources Information Center

Cutright, Teresa J.; Evans, Edward

2016-01-01

The last year of a National Science Foundation (NSF) funded scholarship program was used to provide pseudo-formal peer mentoring activities to engineering, mathematics, and science undergraduates. A one-credit class was used to afford time for peer mentors and mentees to interact. During the fall semester, seniors augmented each week's topics with…

FY 1994 scientific and technical reports, articles, papers, and presentations

NASA Technical Reports Server (NTRS)

Turner, Joyce E. (Compiler)

1994-01-01

This document presents formal NASA technical reports, papers published in technical journals, and presentations by Marshall Space Flight Center personnel in FY94. It also includes papers of MSFC contractors and author indexes. The information in this report may be of value to the scientific and engineering community in determining what information has been published and what is available.

Funding Building Projects in a Tough Economy: Hidden Money Will Help You Construct and Maintain Your Buildings

ERIC Educational Resources Information Center

Love, Paula

2012-01-01

The federal government last formally assessed the state of the nation's schools in the 1999 report "Condition of America's Public School," which estimated that it would take $127 billion to bring the nation's schools to "good condition." The American Society of Civil Engineers (ASCE) issued its own report card the same year. In…

Haptic Paddle Enhancements and a Formal Assessment of Student Learning in System Dynamics

ERIC Educational Resources Information Center

Gorlewicz, Jenna L.; Kratchman, Louis B.; Webster, Robert J., III

2014-01-01

The haptic paddle is a force-feedback joystick used at several universities in teaching System Dynamics, a core mechanical engineering undergraduate course where students learn to model dynamic systems in several domains. A second goal of the haptic paddle is to increase the accessibility of robotics and haptics by providing a low-cost device for…

Bibliography of Supersonic Cruise Research (SCR) program from 1980 to 1983

NASA Technical Reports Server (NTRS)

Hoffman, S.

1984-01-01

A bibliography for the Supersonic Cruise Research (SCR) and Variable Cycle Engine (VCE) Programs is presented. An annotated bibliography for the last 123 formal reports and a listing of titles for 44 articles and presentations is included. The studies identifies technologies for producing efficient supersonic commercial jet transports for cruise Mach numbers from 2.0 to 2.7.

Information visualisation based on graph models

NASA Astrophysics Data System (ADS)

Kasyanov, V. N.; Kasyanova, E. V.

2013-05-01

Information visualisation is a key component of support tools for many applications in science and engineering. A graph is an abstract structure that is widely used to model information for its visualisation. In this paper, we consider practical and general graph formalism called hierarchical graphs and present the Higres and Visual Graph systems aimed at supporting information visualisation on the base of hierarchical graph models.

Retaining Army Engineer Officers

DTIC Science & Technology

2010-04-01

withdrawal behavior: organization-wide factors (e.g. pay and promotion), immediate work environment factors (e.g. supervisory style), job -content... embeddedness construct. It is a departure from the traditional model focus on employee attitudes and alternatives. Job embeddedness is a web of influence...more embedded than one who perceives less links. Job embeddedness is highly individualized and classified as links, fit, and sacrifice. Links are formal

Formal ontology for natural language processing and the integration of biomedical databases.

PubMed

Simon, Jonathan; Dos Santos, Mariana; Fielding, James; Smith, Barry

2006-01-01

The central hypothesis underlying this communication is that the methodology and conceptual rigor of a philosophically inspired formal ontology can bring significant benefits in the development and maintenance of application ontologies [A. Flett, M. Dos Santos, W. Ceusters, Some Ontology Engineering Procedures and their Supporting Technologies, EKAW2002, 2003]. This hypothesis has been tested in the collaboration between Language and Computing (L&C), a company specializing in software for supporting natural language processing especially in the medical field, and the Institute for Formal Ontology and Medical Information Science (IFOMIS), an academic research institution concerned with the theoretical foundations of ontology. In the course of this collaboration L&C's ontology, LinKBase, which is designed to integrate and support reasoning across a plurality of external databases, has been subjected to a thorough auditing on the basis of the principles underlying IFOMIS's Basic Formal Ontology (BFO) [B. Smith, Basic Formal Ontology, 2002. http://ontology.buffalo.edu/bfo]. The goal is to transform a large terminology-based ontology into one with the ability to support reasoning applications. Our general procedure has been the implementation of a meta-ontological definition space in which the definitions of all the concepts and relations in LinKBase are standardized in the framework of first-order logic. In this paper we describe how this principles-based standardization has led to a greater degree of internal coherence of the LinKBase structure, and how it has facilitated the construction of mappings between external databases using LinKBase as translation hub. We argue that the collaboration here described represents a new phase in the quest to solve the so-called "Tower of Babel" problem of ontology integration [F. Montayne, J. Flanagan, Formal Ontology: The Foundation for Natural Language Processing, 2003. http://www.landcglobal.com/].

Literate Specification: Using Design Rationale To Support Formal Methods in the Development of Human-Machine Interfaces.

ERIC Educational Resources Information Center

Johnson, Christopher W.

1996-01-01

The development of safety-critical systems (aircraft cockpits and reactor control rooms) is qualitatively different from that of other interactive systems. These differences impose burdens on design teams that must ensure the development of human-machine interfaces. Analyzes strengths and weaknesses of formal methods for the design of user…

Enabling Requirements-Based Programming for Highly-Dependable Complex Parallel and Distributed Systems

NASA Technical Reports Server (NTRS)

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

2005-01-01

The manual application of formal methods in system specification has produced successes, but in the end, despite any claims and assertions by practitioners, there is no provable relationship between a manually derived system specification or formal model and the customer's original requirements. Complex parallel and distributed system present the worst case implications for today s dearth of viable approaches for achieving system dependability. No avenue other than formal methods constitutes a serious contender for resolving the problem, and so recognition of requirements-based programming has come at a critical juncture. We describe a new, NASA-developed automated requirement-based programming method that can be applied to certain classes of systems, including complex parallel and distributed systems, to achieve a high degree of dependability.

A phenomenographic study of students' experiences with transition from pre-college engineering programs to first-year engineering

NASA Astrophysics Data System (ADS)

Salzman, Noah

Recent national dialogues on the importance of preparing more students for careers in Science, Technology, Engineering, and Mathematics has driven the development of formal and informal learning opportunities for children and adolescents to explore engineering. Despite the growth of these programs, relatively little research exists on how participation in these programs affects students who choose to pursue further study in engineering. The present study addressed this gap through an exploration of the different ways that First-Year Engineering students experience the transition from pre-college engineering to undergraduate engineering studies. Given the focus of this research on students' experiences, phenomenography was chosen to explore the phenomenon of transition from pre-college to first-year engineering at a large, public Midwestern university. This facilitated understanding the range of variation in the ways that students experienced this transition. Twenty-two students with different amounts of participation in a variety of different engineering programs were selected to be interviewed using a purposeful maximum variation sampling strategy. The interviews were guided by a semi-structured interview protocol that encouraged the participants to reflect on their pre-college engineering experiences, their experiences in First-Year Engineering, and the transition between the two domains. The interviews were analyzed using phenomenographic methods to develop an outcome space consisting of five qualitatively different but related ways of experiencing the transition from pre-college to First-Year Engineering. These categories of description included Foreclosure, Frustration, Tedium, Connection, and Engaging Others. With the exception of the first category which was characterized by a lack of passion and commitment to engineering, the remaining four categories formed a hierarchical relationship representing increasing integration in First-Year Engineering. The outcome space that emerged from this study captured a variety of positive and negative ways that the participants experienced their transitions to First-Year Engineering. Positive outcomes included increased familiarity and confidence with the material being taught in First-Year Engineering, a stronger commitment and drive to be successful in engineering, and the ability to encourage and incorporate input from others in the design process. Negative outcomes included less interest in First-Year Engineering projects, disappointment at the lack of alignment with pre-college engineering, and a struggle to connect with their peers. While not initially guided by Self-Determination Theory, the results of this study align with aspects of Self-Determination Theory, and the relationships between the results of this study and the motivational factors of competence, autonomy, and relatedness are explored. Finally, implications for First-Year and pre-college engineering instructional practices are presented, along with a plan for future work.

Solving ordinary differential equations by electrical analogy: a multidisciplinary teaching tool

NASA Astrophysics Data System (ADS)

Sanchez Perez, J. F.; Conesa, M.; Alhama, I.

2016-11-01

Ordinary differential equations are the mathematical formulation for a great variety of problems in science and engineering, and frequently, two different problems are equivalent from a mathematical point of view when they are formulated by the same equations. Students acquire the knowledge of how to solve these equations (at least some types of them) using protocols and strict algorithms of mathematical calculation without thinking about the meaning of the equation. The aim of this work is that students learn to design network models or circuits in this way; with simple knowledge of them, students can establish the association of electric circuits and differential equations and their equivalences, from a formal point of view, that allows them to associate knowledge of two disciplines and promote the use of this interdisciplinary approach to address complex problems. Therefore, they learn to use a multidisciplinary tool that allows them to solve these kinds of equations, even students of first course of engineering, whatever the order, grade or type of non-linearity. This methodology has been implemented in numerous final degree projects in engineering and science, e.g., chemical engineering, building engineering, industrial engineering, mechanical engineering, architecture, etc. Applications are presented to illustrate the subject of this manuscript.

A systematic review of mixed methods research on human factors and ergonomics in health care.

PubMed

Carayon, Pascale; Kianfar, Sarah; Li, Yaqiong; Xie, Anping; Alyousef, Bashar; Wooldridge, Abigail

2015-11-01

This systematic literature review provides information on the use of mixed methods research in human factors and ergonomics (HFE) research in health care. Using the PRISMA methodology, we searched four databases (PubMed, PsycInfo, Web of Science, and Engineering Village) for studies that met the following inclusion criteria: (1) field study in health care, (2) mixing of qualitative and quantitative data, (3) HFE issues, and (4) empirical evidence. Using an iterative and collaborative process supported by a structured data collection form, the six authors identified a total of 58 studies that primarily address HFE issues in health information technology (e.g., usability) and in the work of healthcare workers. About two-thirds of the mixed methods studies used the convergent parallel study design where quantitative and qualitative data were collected simultaneously. A variety of methods were used for collecting data, including interview, survey and observation. The most frequent combination involved interview for qualitative data and survey for quantitative data. The use of mixed methods in healthcare HFE research has increased over time. However, increasing attention should be paid to the formal literature on mixed methods research to enhance the depth and breadth of this research. Copyright © 2015. Published by Elsevier Ltd.

Genetic design automation: engineering fantasy or scientific renewal?

PubMed

Lux, Matthew W; Bramlett, Brian W; Ball, David A; Peccoud, Jean

2012-02-01

The aim of synthetic biology is to make genetic systems more amenable to engineering, which has naturally led to the development of computer-aided design (CAD) tools. Experimentalists still primarily rely on project-specific ad hoc workflows instead of domain-specific tools, which suggests that CAD tools are lagging behind the front line of the field. Here, we discuss the scientific hurdles that have limited the productivity gains anticipated from existing tools. We argue that the real value of efforts to develop CAD tools is the formalization of genetic design rules that determine the complex relationships between genotype and phenotype. Copyright © 2011 Elsevier Ltd. All rights reserved.

SU-E-T-477: An Efficient Dose Correction Algorithm Accounting for Tissue Heterogeneities in LDR Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mashouf, S; Lai, P; Karotki, A

2014-06-01

Purpose: Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose surrounding the brachytherapy seeds is based on American Association of Physicist in Medicine Task Group No. 43 (TG-43 formalism) which generates the dose in homogeneous water medium. Recently, AAPM Task Group No. 186 emphasized the importance of accounting for tissue heterogeneities. This can be done using Monte Carlo (MC) methods, but it requires knowing the source structure and tissue atomic composition accurately. In this work we describe an efficient analytical dose inhomogeneity correction algorithm implemented usingmore » MIM Symphony treatment planning platform to calculate dose distributions in heterogeneous media. Methods: An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of source structure. The ICF is extracted using CT images and the absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG-43 formalism times ICF. To evaluate the methodology, we compared our results with Monte Carlo simulations as well as experiments in phantoms with known density and atomic compositions. Results: The dose distributions obtained through applying ICF to TG-43 protocol agreed very well with those of Monte Carlo simulations as well as experiments in all phantoms. In all cases, the mean relative error was reduced by at least 50% when ICF correction factor was applied to the TG-43 protocol. Conclusion: We have developed a new analytical dose calculation method which enables personalized dose calculations in heterogeneous media. The advantages over stochastic methods are computational efficiency and the ease of integration into clinical setting as detailed source structure and tissue segmentation are not needed. University of Toronto, Natural Sciences and Engineering Research Council of Canada.« less

Changes in formal sex education: 1995-2002.

PubMed

Lindberg, Laura Duberstein; Santelli, John S; Singh, Susheela

2006-12-01

Although comprehensive sex education is broadly supported by health professionals, funding for abstinence-only education has increased. Using data from the 1995 National Survey of Adolescent Males, the 1995 National Survey of Family Growth (NSFG) and the 2002 NSFG, changes in male and female adolescents' reports of the sex education they have received from formal sources were examined. Life-table methods were used to measure the timing of instruction, and t tests were used for changes over time. From 1995 to 2002, reports of formal instruction about birth control methods declined among both genders (males, from 81% to 66%; females, from 87% to 70%). This, combined with increases in reports of abstinence education among males (from 74% to 83%), resulted in a lower proportion of teenagers' overall receiving formal instruction about both abstinence and birth control methods (males, 65% to 59%; females, 84% to 65%), and a higher proportion of teenagers' receiving instruction only about abstinence (males, 9% to 24%; females, 8% to 21%). Teenagers in 2002 had received abstinence education about two years earlier (median age, 11.4 for males, 11.8 for females) than they had received birth control instruction (median age, 13.5 for both males and females). Among sexually experienced adolescents, 62% of females and 54% of males had received instruction about birth control methods prior to first sex. A substantial retreat from formal instruction about birth control methods has left increasing proportions of adolescents receiving only abstinence education. Efforts are needed to expand teenagers' access to medically accurate and comprehensive reproductive health information.

Building a pipeline of talent for operating radio observatories

NASA Astrophysics Data System (ADS)

Wingate, Lory M.

2016-07-01

The National Radio Astronomy Observatory's (NRAO) National and International Non-Traditional Exchange (NINE) Program teaches concepts of project management and systems engineering in a focused, nine-week, continuous effort that includes a hands-on build project with the objective of constructing and verifying the performance of a student-level basic radio instrument. The combination of using a project management (PM)/systems engineering (SE) methodical approach based on internationally recognized standards in completing this build is to demonstrate clearly to the learner the positive net effects of following methodical approaches to achieving optimal results. It also exposes the learner to basic radio science theory. An additional simple research project is used to impress upon the learner both the methodical approach, and to provide a basic understanding of the functional area of interest to the learner. This program is designed to teach sustainable skills throughout the full spectrum of activities associated with constructing, operating and maintaining radio astronomy observatories. NINE Program learners thereby return to their host sites and implement the program in their own location as a NINE Hub. This requires forming a committed relationship (through a formal Letter of Agreement), establishing a site location, and developing a program that takes into consideration the needs of the community they represent. The anticipated outcome of this program is worldwide partnerships with fast growing radio astronomy communities designed to facilitate the exchange of staff and the mentoring of under-represented1 groups of learners, thereby developing a strong pipeline of global talent to construct, operate and maintain radio astronomy observatories.

Unpacking (In)formal Learning in an Academic Development Programme: A Mixed-Method Social Network Perspective

ERIC Educational Resources Information Center

Rienties, Bart; Hosein, Anesa

2015-01-01

How and with whom academics develop and maintain formal and informal networks for reflecting on their teaching practice has received limited attention even though academic development (AD) programmes have become an almost ubiquitous feature of higher education. The primary goal of this mixed-method study is to unpack how 114 academics in an AD…

An ORCID based synchronization framework for a national CRIS ecosystem.

PubMed

Mendes Moreira, João; Cunha, Alcino; Macedo, Nuno

2015-01-01

PTCRIS (Portuguese Current Research Information System) is a program aiming at the creation and sustained development of a national integrated information ecosystem, to support research management according to the best international standards and practices. This paper reports on the experience of designing and prototyping a synchronization framework for PTCRIS based on ORCID (Open Researcher and Contributor ID). This framework embraces the "input once, re-use often" principle, and will enable a substantial reduction of the research output management burden by allowing automatic information exchange between the various national systems. The design of the framework followed best practices in rigorous software engineering, namely well-established principles in the research field of consistency management, and relied on formal analysis techniques and tools for its validation and verification. The notion of consistency between the services was formally specified and discussed with the stakeholders before the technical aspects on how to preserve said consistency were explored. Formal specification languages and automated verification tools were used to analyze the specifications and generate usage scenarios, useful for validation with the stakeholder and essential to certificate compliant services.

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.

Timing of Formal Phase Safety Reviews for Large-Scale Integrated Hazard Analysis

NASA Technical Reports Server (NTRS)

Massie, Michael J.; Morris, A. Terry

2010-01-01

Integrated hazard analysis (IHA) is a process used to identify and control unacceptable risk. As such, it does not occur in a vacuum. IHA approaches must be tailored to fit the system being analyzed. Physical, resource, organizational and temporal constraints on large-scale integrated systems impose additional direct or derived requirements on the IHA. The timing and interaction between engineering and safety organizations can provide either benefits or hindrances to the overall end product. The traditional approach for formal phase safety review timing and content, which generally works well for small- to moderate-scale systems, does not work well for very large-scale integrated systems. This paper proposes a modified approach to timing and content of formal phase safety reviews for IHA. Details of the tailoring process for IHA will describe how to avoid temporary disconnects in major milestone reviews and how to maintain a cohesive end-to-end integration story particularly for systems where the integrator inherently has little to no insight into lower level systems. The proposal has the advantage of allowing the hazard analysis development process to occur as technical data normally matures.

Composing, Analyzing and Validating Software Models

NASA Astrophysics Data System (ADS)

Sheldon, Frederick T.

1998-10-01

This research has been conducted at the Computational Sciences Division of the Information Sciences Directorate at Ames Research Center (Automated Software Engineering Grp). The principle work this summer has been to review and refine the agenda that were carried forward from last summer. Formal specifications provide good support for designing a functionally correct system, however they are weak at incorporating non-functional performance requirements (like reliability). Techniques which utilize stochastic Petri nets (SPNs) are good for evaluating the performance and reliability for a system, but they may be too abstract and cumbersome from the stand point of specifying and evaluating functional behavior. Therefore, one major objective of this research is to provide an integrated approach to assist the user in specifying both functionality (qualitative: mutual exclusion and synchronization) and performance requirements (quantitative: reliability and execution deadlines). In this way, the merits of a powerful modeling technique for performability analysis (using SPNs) can be combined with a well-defined formal specification language. In doing so, we can come closer to providing a formal approach to designing a functionally correct system that meets reliability and performance goals.

Composing, Analyzing and Validating Software Models

NASA Technical Reports Server (NTRS)

Sheldon, Frederick T.

1998-01-01

This research has been conducted at the Computational Sciences Division of the Information Sciences Directorate at Ames Research Center (Automated Software Engineering Grp). The principle work this summer has been to review and refine the agenda that were carried forward from last summer. Formal specifications provide good support for designing a functionally correct system, however they are weak at incorporating non-functional performance requirements (like reliability). Techniques which utilize stochastic Petri nets (SPNs) are good for evaluating the performance and reliability for a system, but they may be too abstract and cumbersome from the stand point of specifying and evaluating functional behavior. Therefore, one major objective of this research is to provide an integrated approach to assist the user in specifying both functionality (qualitative: mutual exclusion and synchronization) and performance requirements (quantitative: reliability and execution deadlines). In this way, the merits of a powerful modeling technique for performability analysis (using SPNs) can be combined with a well-defined formal specification language. In doing so, we can come closer to providing a formal approach to designing a functionally correct system that meets reliability and performance goals.

Latina high school students figured world of STEM: Identity formation in formal and informal communities of practice

NASA Astrophysics Data System (ADS)

Alcantara, Minosca Victoria

In the United States, the education and skill levels of the American population are not measuring up to the growing demands of the STEM workplace. The Bureau of Labor Statistics (BLS) (2007) projects that over the next 20 years, there will be an estimated shortage of 21 million skilled workers. STEM professions (those in Science, Technology, Engineering, and Mathematics), will continue to lead this workforce growth. However, fewer students are majoring in these areas of critical need, particularly women and minorities. Only a small fraction of U.S.-born scientists and engineers training to fill these positions are members of underrepresented minorities (Latino, Black, and American Indian/Native Alaskan students), yet this same population is expected to experience the greatest growth over the next several decades. Using qualitative methods, I explore the role formal and informal communities of practice play in either motivating or hindering Latinas' interest in STEM career. I use the narratives of 16 low-income, urban Latina high school seniors to provide a counternarrative as to the reasons for these underrepresentation. Teachers in the U.S. play a significant role in the reproduction of the culturally prototypical conception of math and science students; the best and brightest in the school. Teachers' role in positioning Latina students in honors/gifted programs based on their perceptions of students' characteristics and their recommendations for placement in honors classes/ programs, STEM extracurricular activities and summer programs are critical to Latina's "good student" identity formation which has a significant role in their motivation or erasure of STEM identities. Latinas in this study strongly identified with their school and were very concerned in maintaining their good student identities. They defined academic success based on the grades they obtained and the colleges they were accepted into. I propose an identity model, L-STEM which highlight the power of sociohistorical meanings in motivating or hindering Latina students' interests in STEM fields.

Itô-SDE MCMC method for Bayesian characterization of errors associated with data limitations in stochastic expansion methods for uncertainty quantification

NASA Astrophysics Data System (ADS)

Arnst, M.; Abello Álvarez, B.; Ponthot, J.-P.; Boman, R.

2017-11-01

This paper is concerned with the characterization and the propagation of errors associated with data limitations in polynomial-chaos-based stochastic methods for uncertainty quantification. Such an issue can arise in uncertainty quantification when only a limited amount of data is available. When the available information does not suffice to accurately determine the probability distributions that must be assigned to the uncertain variables, the Bayesian method for assigning these probability distributions becomes attractive because it allows the stochastic model to account explicitly for insufficiency of the available information. In previous work, such applications of the Bayesian method had already been implemented by using the Metropolis-Hastings and Gibbs Markov Chain Monte Carlo (MCMC) methods. In this paper, we present an alternative implementation, which uses an alternative MCMC method built around an Itô stochastic differential equation (SDE) that is ergodic for the Bayesian posterior. We draw together from the mathematics literature a number of formal properties of this Itô SDE that lend support to its use in the implementation of the Bayesian method, and we describe its discretization, including the choice of the free parameters, by using the implicit Euler method. We demonstrate the proposed methodology on a problem of uncertainty quantification in a complex nonlinear engineering application relevant to metal forming.

On the simulation of indistinguishable fermions in the many-body Wigner formalism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sellier, J.M., E-mail: jeanmichel.sellier@gmail.com; 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.more » 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.« less

Energy/dissipation-preserving Birkhoffian multi-symplectic methods for Maxwell's equations with dissipation terms

DOE PAGES

Su, Hongling; Li, Shengtai

2016-02-03

In this study, we propose two new energy/dissipation-preserving Birkhoffian multi-symplectic methods (Birkhoffian and Birkhoffian box) for Maxwell's equations with dissipation terms. After investigating the non-autonomous and autonomous Birkhoffian formalism for Maxwell's equations with dissipation terms, we first apply a novel generating functional theory to the non-autonomous Birkhoffian formalism to propose our Birkhoffian scheme, and then implement a central box method to the autonomous Birkhoffian formalism to derive the Birkhoffian box scheme. We have obtained four formal local conservation laws and three formal energy global conservation laws. We have also proved that both of our derived schemes preserve the discrete versionmore » of the global/local conservation laws. Furthermore, the stability, dissipation and dispersion relations are also investigated for the schemes. Theoretical analysis shows that the schemes are unconditionally stable, dissipation-preserving for Maxwell's equations in a perfectly matched layer (PML) medium and have second order accuracy in both time and space. Numerical experiments for problems with exact theoretical results are given to demonstrate that the Birkhoffian multi-symplectic schemes are much more accurate in preserving energy than both the exponential finite-difference time-domain (FDTD) method and traditional Hamiltonian scheme. Finally, we also solve the electromagnetic pulse (EMP) propagation problem and the numerical results show that the Birkhoffian scheme recovers the magnitude of the current source and reaction history very well even after long time propagation.« less

Energy/dissipation-preserving Birkhoffian multi-symplectic methods for Maxwell's equations with dissipation terms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Hongling; Li, Shengtai

In this study, we propose two new energy/dissipation-preserving Birkhoffian multi-symplectic methods (Birkhoffian and Birkhoffian box) for Maxwell's equations with dissipation terms. After investigating the non-autonomous and autonomous Birkhoffian formalism for Maxwell's equations with dissipation terms, we first apply a novel generating functional theory to the non-autonomous Birkhoffian formalism to propose our Birkhoffian scheme, and then implement a central box method to the autonomous Birkhoffian formalism to derive the Birkhoffian box scheme. We have obtained four formal local conservation laws and three formal energy global conservation laws. We have also proved that both of our derived schemes preserve the discrete versionmore » of the global/local conservation laws. Furthermore, the stability, dissipation and dispersion relations are also investigated for the schemes. Theoretical analysis shows that the schemes are unconditionally stable, dissipation-preserving for Maxwell's equations in a perfectly matched layer (PML) medium and have second order accuracy in both time and space. Numerical experiments for problems with exact theoretical results are given to demonstrate that the Birkhoffian multi-symplectic schemes are much more accurate in preserving energy than both the exponential finite-difference time-domain (FDTD) method and traditional Hamiltonian scheme. Finally, we also solve the electromagnetic pulse (EMP) propagation problem and the numerical results show that the Birkhoffian scheme recovers the magnitude of the current source and reaction history very well even after long time propagation.« less

A Benchmark for Comparing Different Approaches for Specifying and Verifying Real-Time Systems

DTIC Science & Technology

1993-01-01

To be considered correct or useful, real - time systems must deliver results within specified time intervals, either without exception or with high...probability. Recently, a large number of formal methods have been invented for specifying and verifying real - time systems . It has been suggested that...these formal methods need to be tested out on actual real - time systems . Such testing will allow the scalability of the methods to be assessed and also

Semi-classical approach to transitionless quantum driving: Explicitness and Locality

NASA Astrophysics Data System (ADS)

Loewe, Benjamin; Hipolito, Rafael; Goldbart, Paul M.

Berry has shown that, via a reverse engineering strategy, non-adiabatic transitions in time-dependent quantum systems can be stifled through the introduction of a specific auxiliary hamiltonian. This hamiltonian comes, however, expressed as a formal sum of outer products of the original instantaneous eigenstates and their time-derivatives. Generically, how to create such an operator in the laboratory is thus not evident. Furthermore, the operator may be non- local. By following a semi-classical approach, we obtain a recipe that yields the auxiliary hamiltonian explicitly in terms of the fundamental operators of the system (e.g., position and momentum). By using this formalism, we are able to ascertain criteria for the locality of the auxiliary hamiltonian, and also to determine its exact form in certain special cases.