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Accuracy of CDC 6600/7600 Fortran library functions

Description: This report documents the results of tests of accuracy performed on Fortran library functions corresponding to version 3.0 (PSR 326) of the Fortran Extended Library and version V327 of the CDC 6600 SCOPE 3.3 operating system; version 4.6 (PSR 439) of the Fortran Extended Library and the NOS operating system; and version 4.6 (level 420) of the Fortran extended Library and level 221C of the 7000 SCOPE 2.1 operating system. It is emphasized that corresponding routines of the same name in different libraries may--and often do--yield different results, so that those reported apply only to the particular system on which they were obtained. They are not intended as endorsements or criticisms of the CDC routines tested, but as information for users of Sandia Laboratories 6600/7600 computer systems. 1 figure, 11 tables.
Date: October 1, 1977
Creator: Bailey, C.B. & Jones, R.E.
Partner: UNT Libraries Government Documents Department

A Novel Three-Dimensional Contact Finite Element Based on Smooth Pressure Interpolations

Description: This article proposes a new three-dimensional contact finite element which employs continuous and weakly coupled pressure interpolations on each of the interacting boundaries. The resulting formulation circumvents the geometric bias of one-pass methods, as well as the surface locking of traditional two-pass node-on-surf ace methods. A Lagrange multiplier implementation of the proposed element is validated for frictionless quasi-static contact by a series of numerical simulations.
Date: October 1, 2000
Creator: Jones, R.E. & Papadopoulos, P.
Partner: UNT Libraries Government Documents Department

A Preliminary Investigation of the Performance of a Short Length Turbojet Combustor Using Vaporized Hydrocarbon Fuels

Description: Two short turbojet combustors designed for use with vaporized hydrocarbon fuels were tested in a one-quarter annular duct. The experimental combustors consisted of many small "swirl-can" combustor elements manifolded together. This design approach allowed the secondary mixing zone to be considerably reduced over that of conventional combustors. The over-all combustion lengths, for the two configurations were 13.5 and 11.0 inches, approximately one-half the length of the shortest conventional combustors. These short combustors did not provide combustion efficiencies as high as those for conventional combustors at low pressures. However, over the range of combustor-inlet total-pressures expected in aircraft capable of flight at Mach numbers of 2.5 and above, these short combustors gave very high efficiencies. A combustion efficiency of 97 percent was obtained at a combustor-inlet total-pressure of 25.0 inches of mercury absolute, reference velocity of 120 feet per second, and inlet-air total temperature of 1160 deg R. By proportioning the fuel flow between the manifold rows of can combustor elements, control of the combustor-outlet radial total-temperature profile was demonstrated. Combustor totalpressure loss varied from 0.75 percent of the inlet total pressure at isothermal conditions and a reference velocity of 75 feet per second to 5.5 percent at a total-temperature ratio of 1.8 and a reference velocity of 180 feet per second.
Date: January 7, 1958
Creator: Jones, R. E. & Pawlik, E. V.
Partner: UNT Libraries Government Documents Department

Automatic assembly planning and its role in agile manufacturing: A Sandia perspective

Description: Sandia has been studying automatic assembly planning of electromechanical devices for some years, based on an implemented system called Archimedes. Work done to date has focussed on automatic generation of high-level plans, and translation of these plans into robotic control code and workcell layout. More recently, the importance of an assembly planning capability as a design aid has been emphasized, as it could potentially provide early feedback to a designer on the manufacturability of the design. This paper describes the work done on assembly planning to date, plans for extending it, and its applications to agile manufacturing. In particular, we describe an agile manufacturing demonstration project underway at Sandia, and the role the Archimedes assembly planning system will play in it.
Date: November 1, 1993
Creator: Jones, R. E. & Kaufman, S. G.
Partner: UNT Libraries Government Documents Department

Constraint-based interactive assembly planning

Description: The constraints on assembly plans vary depending on the product, assembly facility, assembly volume, and many other factors. This paper describes the principles and implementation of a framework that supports a wide variety of user-specified constraints for interactive assembly planning. Constraints from many sources can be expressed on a sequencing level, specifying orders and conditions on part mating operations in a number of ways. All constraints are implemented as filters that either accept or reject assembly operations proposed by the planner. For efficiency, some constraints are supplemented with special-purpose modifications to the planner`s algorithms. Replanning is fast enough to enable a natural plan-view-constrain-replan cycle that aids in constraint discovery and documentation. We describe an implementation of the framework in a computer-aided assembly planning system and experiments applying the system to several complex assemblies. 12 refs., 2 figs., 3 tabs.
Date: March 1, 1997
Creator: Jones, R.E.; Wilson, R.H. & Calton, T.L.
Partner: UNT Libraries Government Documents Department

Estimating the impacts of federal efforts to improve energy efficiency: The case of building

Description: The US Department of Energy`s Office of Energy Efficiency and Renewable Energy [EE] has for more than a decade focused its efforts on research to develop new technologies for improving the efficiency of energy use and increasing the role of renewable energy; success has usually been measured in terms of energy saved or displaced. Estimates of future energy savings remain an important factor in program planning and prioritization. A variety of internal and external factors are now radically changing the planning process, and in turn the composition and thrust of the EE program. The Energy Policy Act of 1992, the Framework Convention on Climate Change (and the Administration`s Climate Change Action Plan), and concerns for the future of the economy (especially employment and international competitiveness) are increasing emphasis on technology deployment and near-term results. The Reinventing Government Initiative, the Government Performance and Results Act, and the Executive Order on Environmental Justice are all forcing Federal programs to demonstrate that they are producing desired results in a cost-effective manner. The application of Total Quality Management principles has increased the scope and importance of producing quantified measures of benefit. EE has established a process for estimating the benefits of DOE`s energy efficiency and renewable energy programs called `Quality Metrics` (QM). The ``metrics`` are: Energy; Environment; Employment; Risk; Equity; Economics. This paper describes the approach taken by EE`s Office of Building Technologies to prepare estimates of program benefits in terms of these metrics, presents the estimates, discusses their implications, and explores possible improvements to the QM process as it is currently configured.
Date: November 1, 1994
Creator: Nicolls, A.K.; Shankle, S.A.; LaMontagne, J. & Jones, R.E.
Partner: UNT Libraries Government Documents Department

On Constraints in Assembly Planning

Description: Constraints on assembly plans vary depending on product, assembly facility, assembly volume, and many other factors. Assembly costs and other measures to optimize vary just as widely. To be effective, computer-aided assembly planning systems must allow users to express the plan selection criteria that appIy to their products and production environments. We begin this article by surveying the types of user criteria, both constraints and quality measures, that have been accepted by assembly planning systems to date. The survey is organized along several dimensions, including strategic vs. tactical criteria; manufacturing requirements VS. requirements of the automated planning process itself and the information needed to assess compliance with each criterion. The latter strongly influences the efficiency of planning. We then focus on constraints. We describe a framework to support a wide variety of user constraints for intuitive and efficient assembly planning. Our framework expresses all constraints on a sequencing level, specifying orders and conditions on part mating operations in a number of ways. Constraints are implemented as simple procedures that either accept or reject assembly operations proposed by the planner. For efficiency, some constraints are supplemented with special-purpose modifications to the planner's algorithms. Fast replanning enables an interactive plan-view-constrain-replan cycle that aids in constraint discovery and documentation. We describe an implementation of the framework in a computer-aided assembly planning system and experiments applying the system to a number of complex assemblies, including one with 472 parts.
Date: December 17, 1998
Creator: Calton, T.L.; Jones, R.E. & Wilson, R.H.
Partner: UNT Libraries Government Documents Department

The Automated Assembly Team contributions to the APRIMED Agile Manufacturing Project

Description: The Automated Assembly Team of the APRIMED Project (abbreviated as A{prime}) consists of two parts: the Archimedes Project, which is an ongoing project developing automated assembly technology, and the A{prime} Robot Team. Archimedes is a second generation assembly planning system that both provides a general high-level assembly sequencing capability and, for a smaller class of products, facilitates automatic programming of a robotic workcell to assemble them. The A{prime} robot team designed, developed, and implemented a flexible robot workcell which served as the automated factory of the A{prime} project. In this document we briefly describe the role of automated assembly planning in agile manufacturing, and specifically describe the contributions of the Archimedes project and the A{prime} robot team to the A{prime} project. We introduce the concepts of the Archimedes automated assembly planning project, and discuss the enhancements to Archimedes which were developed in response to the needs of the A{prime} project. We also present the work of the A{prime} robot team in designing and developing the A{prime} robot workcell, including all tooling and programming to support assembly of the A{prime} discriminator devices. Finally, we discuss the process changes which these technologies have enabled in the A{prime} project.
Date: June 1, 1995
Creator: Jones, R.E.; Ames, A.L. & Calton, T.L.
Partner: UNT Libraries Government Documents Department

LDRD final report: Automated planning and programming of assembly of fully 3D mechanisms

Description: This report describes the results of assembly planning research under the LDRD. The assembly planning problem is that of finding a sequence of assembly operations, starting from individual parts, that will result in complete assembly of a device specified as a CAD model. The automated assembly programming problem is that of automatically producing a robot program that will carry out a given assembly sequence. Given solutions to both of these problems, it is possible to automatically program a robot to assemble a mechanical device given as a CAD data file. This report describes the current state of our solutions to both of these problems, and a software system called Archimedes 2 we have constructed to automate these solutions. Because Archimedes 2 can input CAD data in several standard formats, we have been able to test it on a number of industrial assembly models more complex than any before attempted by automated assembly planning systems, some having over 100 parts. A complete path from a CAD model to an automatically generated robot program for assembling the device represented by the CAD model has also been demonstrated.
Date: November 1, 1996
Creator: Kaufman, S. G.; Wilson, R. H.; Jones, R. E.; Calton, T. L. & Ames, A. L.
Partner: UNT Libraries Government Documents Department

The Archimedes 2 mechanical assembly planning system

Description: We describe the implementation and performance of Archimedes 2, an integrated mechanical assembly planning system. Archimedes 2 includes two planners, two assembly sequence animation facilities, and an associated robotic workcell. Both planners use full 3 dimensional data. A rudimentary translator from high level assembly plans to control code for the robotic workcell has also been implemented. We can translate data from a commercial CAD system into input data for the system, which has allowed us to plan assembly sequences for many industrial assemblies. Archimedes 2 has been used to plan sequences for assemblies consisting of 5 to 109 parts. We have also successfully taken a CAD model of an assembly, produced an optimized assembly sequence for it, and translated the plan into robot code, which successfully assembles the device specified in the model.
Date: March 1, 1996
Creator: Kaufman, S.G.; Wilson, R.H.; Jones, R.E.; Calton, T.L. & Ames, A.L.
Partner: UNT Libraries Government Documents Department

A process for the agile product realization of electromechanical devices (A-primed)

Description: This paper describes a product realization process developed at Sandia National Laboratories by the A-PRIMED project that integrates many of the key components of ``agile manufacturing`` (Nagel & Dove, 1992) into a complete, step-by-step, design-to-production process. For two separate product realization efforts, each geared to a different set of requirements, A-PRIMED demonstrated product realization of a custom device in less than a month. A-PRIMED used a discriminator (a precision electro mechanical device) as the demonstration device, but the process is readily adaptable to other electro mechanical products. The process begins with a qualified design parameter space (Diegert et al, 1995). From that point, the product realization process encompasses all facets of requirements development, analysis and testing, design, manufacturing, robot assembly and quality assurance, as well as product data management and concurrent engineering. In developing the product realization process, A-PRIMED employed an iterative approach whereby after each build, the process was reviewed and refinements were made on the basis of lessons learned. This paper describes the integration of project functions and product realization technologies to develop a product realization process that on repeated iterations, was proven successful.
Date: February 1, 1996
Creator: Forsythe, C.; Ashby, M.R.; Benavides, G.L.; Diegert, K.V.; Jones, R.E.; Longcope, D.B. et al.
Partner: UNT Libraries Government Documents Department

A process for the agile product realization of electro-mechanical devices

Description: This paper describes a product realization process developed and demonstrated at Sandia by the A-PRIMED (Agile Product Realization for Innovative Electro MEchanical Devices) project that integrates many of the key components of ``agile manufacturing`` into a complete, design-to-production process. Evidence indicates that the process has reduced the product realization cycle and assured product quality. Products included discriminators for a robotic quick change adapter and for an electronic defense system. These discriminators, built using A-PRIMED, met random vibration requirements and had life cycles that far surpass the performance obtained from earlier efforts.
Date: September 1, 1995
Creator: Forsythe, C.; Ashby, M.R.; Benavides, G.L.; Diegert, K.V.; Jones, R.E.; Longcope, D.B. et al.
Partner: UNT Libraries Government Documents Department

Defect Doping of InN

Description: InN films grown by molecular beam epitaxy have been subjected to 2 MeV He{sup +} irradiation followed by thermal annealing. Theoretical analysis of the electron mobilities shows that thermal annealing removes triply charged donor defects, creating films with electron mobilities approaching those predicted for uncompensated, singly charged donors. Optimum thermal annealing of irradiated InN can be used to produce samples with electron mobilities higher than those of as grown films.
Date: July 22, 2007
Creator: Jones, R.E.; van Genuchten, H.C.M.; Yu, K.M.; Walukiewicz, W.; Li, S.X.; A ger III, J.W. et al.
Partner: UNT Libraries Government Documents Department

Exceptional Electron Transport Properties of In-rich InGaN

Description: Recent years have seen an explosion of interest in the narrow band gap end of the InGaN alloy system, particularly in InN. The existence of surface electron accumulation and a tendency for n-type conductivity have been well-established and are explained by an extremely large electron affinity and the location of the Fermi level stabilization energy (E{sub FS}) high in the conduction band [1]. These characteristics pose significant challenges to the integration of In-rich InGaN into devices and demonstrate the need for a better understanding of the relationship between native defects and electronic transport in the alloy system. It has been previously shown that high-energy particle irradiation can predictably control the electronic properties of In-rich InGaN [1]. With increasing irradiation dose, the electron concentration (n) increases and the electron mobility ({mu}) decreases until the Fermi level reaches E{sub FS}, which is the saturation point. The value of n at saturation decreases with decreasing In fraction, due to the raising of the conduction band edge with respect to E{sub FS}.
Date: October 22, 2006
Creator: Jones, R.E.; van Genuchten, H.C.M.; Yu, K.M.; Walukiewicz, W.; Li, S.X.; Liliental-Weber, Z. et al.
Partner: UNT Libraries Government Documents Department

Photoluminescence of Energetic Particle-Irradiated InxGa1-xNAlloys

Description: A study of the photoluminescence (PL) characteristics of In{sub x}Ga{sub 1-x}N alloys in which the Fermi level is controlled by energetic particle irradiation is reported. In In-rich In{sub x}Ga{sub 1-x}N the intensity of the PL emission initially increases with irradiation dose before falling rapidly at high doses. This unusual trend is attributed to the location of the average energy of the dangling-bond type native defects (the Fermi level stabilization energy, or E{sub FS}), which lies about 0.9 eV above the conduction band edge of InN. As a result of this atypically high position of E{sub FS}, irradiation-induced defects formed at low doses are donors, and do not act as efficient recombination centers. Thus, low dose irradiation increases the electron concentration and leads to an increase of the photoluminescence intensity. However, at higher irradiation doses, the Fermi level approaches E{sub FS}, and the defects formed become increasingly effective as a non-radiative recombination centers and the PL quenches quickly. Our calculations of the PL intensity based on the effect of the electron concentration and the minority carrier lifetime, show good agreement with the experimental data. Finally, the blue shift of PL signal with increasing electron concentration is explained by the breakdown of momentum conservation due to the irradiation damage.
Date: December 14, 2005
Creator: Li, S.X.; Jones, R.E.; Haller, E.E.; Yu, K.M.; Walukiewicz, W.; Ager III, J.W. et al.
Partner: UNT Libraries Government Documents Department

Dopants and Defects in InN and InGaN Alloys

Description: We have performed systematic studies of the effects of high-energy particle irradiation on the properties of InGaN alloys. In agreement with the amphoteric defect model, irradiation of InN produces donor-like defects. The electron concentration increases with increasing radiation dose and saturates at 4 x 10{sup 20} cm{sup -3} at very high doses. We find that the increase of the electron concentration causes a large blue-shift of the absorption edge, which is well-explained by the Burstein-Moss effect. The maximum electron concentration decreases with increasing Ga fraction in irradiated In{sub 1-x}Ga{sub x}N alloys as the conduction band edge approaches the Fermi level stabilization energy (E{sub FS}). For x > 0.66 the conduction band edge moves above E{sub FS} and the irradiation of n-type films produces acceptor-like defects, resulting in a reduced free electron concentration. An analysis of the concentration dependence of the electron mobility in InN indicates that the dominant defects in irradiated InN are triply-charged donors. Finally, we show that InN films doped with Mg acceptors behave like undoped films above a threshold radiation dose.
Date: April 1, 2005
Creator: Walukiewicz, W.; Jones, R.E.; Li, S.X.; Yu, K.M.; Ager III, J.W.; Haller, E.E. et al.
Partner: UNT Libraries Government Documents Department

On the crystalline structure, stoichiometry and band gap of InN thin films

Description: Detailed transmission electron microscopy (TEM), x-ray diffraction (XRD), and optical characterization of a variety of InN thin films grown by molecular beam epitaxy under both optimized and non-optimized conditions is reported. Optical characterization by absorption and photoluminescence confirms that the band gap of single crystalline and polycrystalline wurtzite InN is 0.70 {+-} 0.05 eV. Films grown under optimized conditions with a AlN nucleation layer and a GaN buffer layer are stoichiometric, single crystalline wurtzite structure with dislocation densities not exceeding mid-10{sup 10} cm{sup -2}. Non-optimal films can be poly-crystalline and display an XRD diffraction feature at 2{theta} {approx} 33{sup o}; this feature has been attributed by others to the presence of metallic In clusters. Careful indexing of wide angle XRD scans and selected area diffraction patterns shows that this peak is in fact due to the presence of polycrystalline InN grains; no evidence of metallic In clusters was found in any of the studied samples.
Date: September 23, 2004
Creator: Yu, K.M.; Liliental-Weber, Z.; Walukiewicz, W.; Li, S.X.; Jones, R.E.; Shan, W. et al.
Partner: UNT Libraries Government Documents Department

Fermi level stabilization energy in group III-nitrides

Description: Energetic particle irradiation is used to systematically introduce point defects into In{sub 1-x}Ga{sub x}N alloys over the entire composition range. Three types of energetic particles (electrons, protons, and {sup 4}He{sup +}) are used to produce a displacement damage dose spanning five decades. In InN and In-rich InGaN the free electron concentration increases with increasing irradiation dose but saturates at a sufficiently high dose. The saturation is due to Fermi level pinning at the Fermi Stabilization Energy (E{sub FS}), which is located at 4.9 eV below the vacuum level. Electrochemical capacitance-voltage (ECV) measurements show that the pinning of the surface Fermi energy at E{sub FS} is also responsible for the surface electron accumulation in as-grown InN and In-rich InGaN alloys. The results are in agreement with the amphoteric defect model that predicts that the same type of native defects are responsible for the Fermi level pinning in both cases.
Date: January 7, 2005
Creator: Li, S. X.; Yu, K. M.; Wu, J.; Jones, R. E.; Walukiewicz, W.; AgerIII, J. W. et al.
Partner: UNT Libraries Government Documents Department

Electronic and Optical Properties of Energetic Particle-IrradiatedIn-rich InGaN

Description: We have carried out a systematic study of the effects of irradiation on the electronic and optical properties of InGaN alloys over the entire composition range. High energy electrons, protons, and {sup 4}He{sup +} were used to produce displacement damage doses (D{sub d}) spanning over five orders of magnitude. The free electron concentrations in InN and In-rich InGaN increase with D{sub d} and finally saturate after a sufficiently high D{sub d}. The saturation of carrier density is attributed to the formation of native donors and the Fermi level pinning at the Fermi Stabilization Energy (E{sub FS}), as predicted by the amphoteric native defect model. Electrochemical capacitance-voltage (ECV) measurements reveal a surface electron accumulation whose concentration is determined by pinning at E{sub FS}.
Date: April 13, 2005
Creator: Li, S. X.; Yu, K. M.; Jones, R. E.; Wu, J.; Walukiewicz, W.; AgerIII, J. W. et al.
Partner: UNT Libraries Government Documents Department