Showing papers by "General Electric published in 1999"

Bundle Adjustment - A Modern Synthesis

Abstract: This paper is a survey of the theory and methods of photogrammetric bundle adjustment, aimed at potential implementors in the computer vision community. Bundle adjustment is the problem of refining a visual reconstruction to produce jointly optimal structure and viewing parameter estimates. Topics covered include: the choice of cost function and robustness; numerical optimization including sparse Newton methods, linearly convergent approximations, updating and recursive methods; gauge (datum) invariance; and quality control. The theory is developed for general robust cost functions rather than restricting attention to traditional nonlinear least squares.

Multi-slice helical CT: Scan and reconstruction

Abstract: The multi-slice CT scanner refers to a special CT system equipped with a multiple-row detector array to simultaneously collect data at different slice locations. The multi-slice CT scanner has the capability of rapidly scanning large longitudinal (z) volume with high z-axis resolution. It also presents new challenges and new characteristics. In this paper, we study the scan and reconstruction principles of the multi-slice helical CT in general and the 4-slice helical CT in particular. The multi-slice helical computed tomography consists of the following three key components: the preferred helical pitches for efficient z sampling in data collection and better artifact control; the new helical interpolation algorithms to correct for fast simultaneous patient translation; and the z-filtering reconstruction for providing multiple tradeoffs of the slice thickness, image noise and artifacts to suit for different application requirements. The concept of the preferred helical pitch is discussed with a newly proposed z sampling analysis. New helical reconstruction algorithms and z-filtering reconstruction are developed for multi-slice CT in general. Furthermore, the theoretical models of slice profile and image noise are established for multi-slice helical CT. For 4-slice helical CT in particular, preferred helical pitches are discussed. Special reconstruction algorithms are developed. Slice profiles, image noises, and artifacts of 4-slice helical CT are studied and compared with single slice helical CT. The results show that the slice profile, image artifacts, and noise exhibit performance peaks or valleys at certain helical pitches in the multi-slice CT, whereas in the single-slice CT the image noise remains unchanged and the slice profile and image artifacts steadily deteriorate with helical pitch. The study indicates that the 4-slice helical CT can provide equivalent image quality at 2 to 3 times the volume coverage speed of the single slice helical CT.

Light emitting device with phosphor composition

Abstract: The invention relates to a light source comprising a phosphor composition and a light emitting device such as an LED or a laser diode. The phosphor composition absorbs radiation having a first spectrum and emits radiation having a second spectrum and comprises at least one of: YBO3:Ce3+,Tb3+; BaMgAl?10?O17:Eu?2+, Mn2+?; (Sr,Ca,Ba)(Al,Ga)?2?S4:Eu?2+?; and Y?3?Al5O12-Ce?3+?; and at least one of: Y?2?O2S:Eu?3+,Bi3+; YVO?4:Eu3+,Bi3+; SrS:Eu2+; SrY2S4:Eu2+; CaLa?2?S4:Ce?3+?; and (Ca,Sr)S:Eu2+. The phosphor composition and the light source together can produce white light with pleasing characteristics, such as a color temperature of 3000-6500° K, a color rendering index of about 83-87, and a device luminous efficacy of about 10-20 lumens per watt.

Inventory management system and method

Abstract: An inventory management system and method provide information concerning inventory amounts and inventory ordering to at least one of a manufacturing site and inventory vendor. The system comprises at least one storage receptacle that stores inventory; at least one amount indicator that determines an inventory amount in each receptacle, each amount indicator generating inventory amount signals representative of inventory amounts in the receptacle; at least one inventory price source that provides inventory price information; and a control unit that receives the inventory amount signals from the amount indicator and inventory price information from the inventory price source. The control unit analyzes the inventory amount signals to determine inventory amounts in the receptacle. The control unit also analyzes the inventory amounts and inventory price information, and determines if an inventory order should be placed.

Large-Eddy Simulation of a Gas Turbine Combustor Flow

Abstract: Large-eddy simulation (LES) of turbulent premixed reacting flows in a gas turbine combustor (General Electric's lean premixed dry low-NOx LM6000) has been carried out to evaluate the potential of LES for design studies of realistic hardware. A flamelet model for the premixed flame is combined with a dynamic model for the subgrid kinetic energy to simulate the propagation of the turbulent flame in this high swirl and high Reynolds number flow. Comparison of the computed results with experimental data indicate good agreement in spite of relatively coarse grid resolution employed in the LES. These results provide significant confidence that LES capability for design studies of practical interest is feasible in the near future.

An adaptive statistical time-frequency method for detection of broken bars and bearing faults in motors using stator current

Abstract: It is well known that motor current is a nonstationary signal, the properties of which vary with respect to the time-varying normal operating conditions of the motor. As a result, Fourier analysis makes it difficult to recognize fault conditions from the normal operating conditions of the motor. Time-frequency analysis, on the other hand, unambiguously represents the motor current which makes signal properties related to fault detection more evident in the transform domain. In this paper, the authors present an adaptive, statistical, time-frequency method for the detection of broken bars and bearing faults. Due to the time-varying normal operating conditions of the motor and the effect of motor geometry on the current, they employ a training-based approach in which the algorithm is trained to recognize the normal operating modes of the motor before the actual testing starts. During the training stage, features which are relevant to fault detection are estimated using the torque and mechanical speed estimation. These features are then statistically analyzed and segmented into normal operating modes of the motor. For each mode, a representative and a threshold are computed and stored in a database to be used as a baseline during the testing stage. In the testing stage, the distance of the test features to the mode representatives are computed and compared with the thresholds. If it is larger than all the thresholds, the measurement is tagged as a potential fault signal. In the postprocessing stage, the testing is repeated for multiple measurements to improve the accuracy of the detection. The experimental results from their study suggest that the proposed method provides a powerful and a general approach to the motor-current-based fault detection.

Color tunable light source

Abstract: A color tunable light source ( 10 ) includes multiple light emitting components ( 32, 34, 36 ), such as light emitting diodes (LEDs) or laser diodes (LDs) with different emission wavelengths, and multiple phosphors ( 24 ) with different excitation and emission wavelengths. The emission wavelengths of the different light emitting components are chosen to match the excitation wavelengths of the different phosphors. The light emitting components are powered by an electrical circuit ( 42, 44, 46 ), which allows separate control of the optical power output of the different wavelength LEDs/LDs. The light from the light emitting components is arranged to impinge on the combination of phosphors such that the phosphors are excited and emit light at their characteristic wavelengths. By separately adjusting the power to each LED/LD, the amount of light emitted by each phosphor, and hence, through color mixing, the color of the light emitted, is varied.

Vehicle maintenance management system and method

Abstract: An apparatus and method of predicting vehicle breakdown and operability includes monitoring at a monitoring station on-board systems parameter data transmitted from a vehicle from a remote location; determining whether any of the monitored data is out of a predetermined range; calculating trends for monitored data determined to be out of range; identifying any system fault; and predicting what vehicle system(s) must be corrected to avoid vehicle failure and when such system(s) are likely to fail unless corrected.

Brain: Gadolinium-enhanced Fast Fluid-attenuated Inversion-Recovery MR Imaging

Abstract: PURPOSE: To determine the clinical utility of gadolinium-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging of the brain by comparing results with those at gadolinium-enhanced T1-weighted MR imaging with magnetization transfer (MT) saturation. MATERIALS AND METHODS: In 105 consecutive patients referred for gadolinium-enhanced brain imaging, FLAIR and T1-weighted MR imaging with MT saturation were performed before and after administration of gadopentetate dimeglumine (0.1 mmol per kilogram of body weight). Pre- and postcontrast images were evaluated to determine the presence of abnormal contrast enhancement and whether enhancement was more conspicuous with the FLAIR or T1-weighted sequences. RESULTS: Thirty-nine studies showed intracranial contrast enhancement. Postcontrast T1-weighted images with MT saturation showed superior enhancement in 14 studies, whereas postcontrast fast FLAIR images showed superior enhancement in 15 studies. Four cases demonstrated approximately e...

Methods and systems for defining targeted marketing campaigns using embedded models and historical data

Abstract: Methods and systems for increasing the efficiency of marketing campaigns are disclosed. A targeting engine is used for analyzing data input and generating data output. The method includes the steps of using historical data to determine a target group based upon a plurality of embedded models and directing the marketing campaign towards the target groups flagged by the models.

Comparative analysis of NMR and NIRS measurements of intracellular PO2 in human skeletal muscle

Abstract: 1H NMR has detected both the deoxygenated proximal histidyl NδH signals of myoglobin (deoxyMb) and deoxygenated Hb (deoxyHb) from human gastrocnemius muscle. Exercising the muscle or pressure cuffi...

Multilayer article and method of making by ARC plasma deposition

Abstract: According to an exemplary embodiment of the invention, a method of forming a plurality of layers on an article comprises steps of generating a plasma by forming an arc between a cathode and an anode; injecting a first material comprising an organic compound into the plasma to deposit a first layer on the article; injecting a second material comprising an organometallic material into the plasma to form a second layer on the first layer; and injecting a third material comprising a silicon containing organic compound into the plasma to deposit a third layer on the second layer The invention also relates to an article of manufacture comprising a substrate; an interlayer disposed on the substrate; a second layer disposed on the interlayer, the second layer comprising an inorganic ultraviolet absorbing material; and a third layer disposed on the second layer, the third layer comprising an abrasion resistant material The interlayer may comprise a polymerized organosilicon material or a polymerized hydrocarbon material, for example The second layer may comprise a metal oxide or zinc sulfide, for example The third layer may comprise an oxidized organosilicon material, for example

Myoglobin desaturation with exercise intensity in human gastrocnemius muscle

Abstract: The present study evaluated whether intracellular partial pressure of O2 ( P O 2 ) modulates the muscle O2 uptake (V˙o 2) as exercise intensity increased. Indirect calorimetry followedV˙o 2, wherea...

Premixing dry low NOx emissions combustor with lean direct injection of gas fuel

Abstract: Lean premixed combustion of a hydrocarbon fuel and air is combined with lean direct injection of hydrocarbon fuel and carrier fluid such as air or inert gas or a mixture of air and inert gas into a combustor downstream of the premixed reaction zone in order to achieve extremely low levels of emissions of oxides of nitrogen at the high combustor exit temperatures required by advanced heavy duty industrial gas turbines. One or more premixing fuel nozzles are used to supply a lean mixture of hydrocarbon fuel and air to the main or primary reaction zone of a gas turbine combustor. This lean fuel/air mixture has an adiabatic flame temperature below the temperature that would result in substantial thermal NOx formation. After this low temperature reaction has been completed, additional fuel and carrier fluid are injected into the products of combustion downstream of the main reaction zone in order to raise the temperature of the mixture to the level required to operate an advanced, high efficiency, heavy duty industrial gas turbine at high load. Formation of nitrogen oxides in the region after this secondary fuel and carrier fluid injection is minimized by partial premixing of fuel and carrier fluid prior to ignition and by minimizing the residence time between the secondary fuel injection and the turbine first stage inlet.

Method and apparatus for remotely configuring and servicing a field replaceable unit in a medical diagnostic system

Abstract: A method for remotely configuring and servicing a field replaceable unit associated with a medical diagnostic system includes establishing a communication connection between the medical diagnostic system and a remote facility, communicating identification information from an electronic device coupled to the field replaceable unit to the remote facility, communicating configuration information from the remote facility to the medical diagnostic system, and configuring the medical diagnostic system in accordance with the configuration information from the remote facility. A corresponding apparatus includes a memory unit configured to store identification indicia associated with the field replaceable unit and a communication interface configured to communicate identification information from the identification indicia to a remote facility via a network.

Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine: Part 1 — Experimental Results

Abstract: A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the design and execution of the experimental portion of the study, which represents the first reported investigation to obtain nearly full surface information on heat transfer coefficients within an environment that develops an appropriate pressure distribution about an airfoil blade tip and shroud model. A stationary blade cascade experiment has been run consisting of three airfoils, the center airfoil having a variable tip gap clearance. The airfoil models the aerodynamic tip section of a high-pressure turbine blade with inlet Mach number of 0.30, exit Mach number of 0.75, pressure ratio of 1.45, exit Reynolds number based on axial chord of 2.57 x 10{sup 6}, and total turning of about 110 degrees. A hue detection based liquid crystal method is used to obtain the detailed heat transfer coefficient distribution on the blade tip surface for flat, smooth tip surfaces with both sharp and rounded edges. The cascade inlet turbulence intensity level took on values of either 5 or 9%.more » The cascade also models the casing recess in the shroud surface ahead of the blade. Experimental results are shown for the pressure distribution measurements on the airfoil near the tip gap, on the blade tip surface, and on the opposite shroud surface. Tip surface heat transfer coefficient distributions are shown for sharp edge and rounded edge tip geometries at each of the inlet turbulence intensity levels.« less

Polyester molding composition

Abstract: A thermoplastic resin composition with enhanced elongation and good appearance comprising a compatible resin blend of a polyester sulfonate salt ionomer and a polyamide and an effective amount of at least one difunctional epoxy compound wherein the difunctional epoxy compound has at least one cyclohexane ring moiety and having two terminal epoxy functional groups, wherein at least one of the two terminal epoxy functional groups is a substituent on the at least one cyclohexane ring moiety; and optionally an effective amount of a catalyst compound or rubbery impact modifier.

Electrical motor monitoring system and method

Abstract: An integrated motor monitoring system collects, analyzes, and stores to database(s) on-line and off-line coordinated real-time motor data for industrial AC and DC motors. On-line coordinated real-time motor data from both on-motor sensors and remote sensors at a motor control center are collected simultaneously and processed. Off-line measurements are performed with integrated stimulus and measurement apparatus. Monitoring units at the motor and motor control center each collect specific data on the motor. The database provides current and historical data on the motor for analyses conducted at the motor or at the motor control center. Additionally the motor monitoring system has the capability of relating motor system or process events with motor performance.

Power overlay chip scale packages for discrete power devices

Abstract: A power semiconductor device package includes at least one power semiconductor device mounted onto at least one electrically and thermally conductive spacer having an upper end surface bonded to a back surface of the device; a substrate of hardened substrate molding material surrounding the semiconductor device and the spacer except for an active major surface of the device and an lower end surface of the spacer, a dielectric film overlying the device active major surface and a top side of the substrate, the dielectric layer having a plurality of holes aligned with predetermined ones of the contact pads; a top side patterned metal layer on the dielectric film including portions extending into the holes electrically and thermally connected to contact pads of the device; and a backside metal layer on a substrate bottom side electrically and thermally connected to the spacer lower end surface. Optional through-post structures can be employed to bring all electrical connections either to the top side of the device package or the bottom side. Optional heat sinks can be mounted to the top side, the bottom side, or both sides.

A Comparative Evaluation of New Silicon Carbide Diodes and State-of-the-Art Silicon Diodes for Power Electronic Applications

Abstract: Recent progress in silicon carbide (SiC) material has made it feasible to build power devices of reasonable current density This paper presents recent results including a comparison with state-of-the-art silicon diodes Switching losses for two silicon diodes (a fast diode, 600 V, 50 A, 60 ns Trr), an ultra-fast silicon diode (600 V, 50 A, 23 ns Trr) and a 4H-SiC diode (600 V, 50 A) are compared The effect of diode reverse recovery on the turn-on losses of a fast WARP/sup TM/ IGBT are studied both at room temperature and at 150/spl deg/C At room temperature, SiC diodes allow a reduction of IGBT turn-on losses by 25% compared to ultra-fast silicon diodes and by 70% compared to fast silicon diodes At 150/spl deg/C junction temperature, SiC diodes allow a turn-on loss reduction of 35% and 85% compared to ultra-fast and fast silicon diodes respectively The silicon and SiC diodes are used in a boost power converter with the WARP/sup TM/ IGBT to assess the overall effect of SiC diodes on the power converter characteristics Efficiency measurements at light load (100 W) and full load (500 W) are reported Although SiC diodes exhibit very low switching losses, their high conduction losses due to the high forward drop dominate the overall losses, hence reducing the overall efficiency Since this is an ongoing development, it is expected that future prototypes will have improved forward characteristics

Methods and systems for analyzing marketing campaigns

Abstract: Methods and systems for analyzing the success of a marketing campaign by using campaign results and an original campaign database are disclosed The method includes the steps of profiling results of the marketing campaign against a list of user defined dimensions (analytic models may be used to derive dimensions) and assigning a score to the results of the marketing campaign

Method and system for identifying critical faults in machines

Abstract: A method and system for identifying a plurality of critical faults in machines is provided. The method allows for collecting from a predetermined plurality of the machines respective machine data indicative of each fault logged over a predetermined period of time. Respective identifying steps allow for identifying in the collected machine data respective faults most frequently occurring relative to one another and for identifying in the most frequently occurring faults, respective faults that, relative to one another, affect a higher number of machines. A classifying step allows for classifying the faults identified in the last-recited identifying step based on an expected level of machine degradation associated with the identified faults, and a storing step allows for storing any faults classified as likely to result in an imminent machine mission failure in a predetermined database of critical faults.

System and method for generating alerts through multi-variate data assessment

Abstract: This invention provides a system and method for generating alerts through multi-variate assessment. A normalizer normalizes data obtained from a process. A classifier classifies the correlated data in a multi-dimensional space defined for the variables in the process. The normalized data are classified into a normal cluster indicative of normal operating conditions and at least one alert cluster each indicative of alert conditions. An alert verifier verifies correlated data classified as an alert condition. In another embodiment of this invention, a tracker is used for addressing drifting data sets that arise in the process over time which allows the adaptation of classifiers to the shifted state. In a third embodiment, the multi-variate generator is used in parallel with a trend performance analysis tool to validate alerts generated therefrom.

Amide modified polyesters

Abstract: A thermoplastic resin composition comprises units represented by the amide formula (I) and the ester formula (II) wherein said amide units are present as a physical mixture in said resin or as a polymer with the repeating ester units to impart an enhanced crystallization rate as compared to said resin without said amide units of formula (I), said amide units being present in an effective amount to decrease the difference between the temperature of melting and the temperature of crystallization of said resin to an amount less than 5 mole percent of amide units of formula (I) based on the moles of ester units of formula (II).

Processing high-temperature refractory-metal silicide in-situ composites

Abstract: High-temperature, refractory-metal, intermetallic, in-situ composites consist of high-strength, niobium-based silicides with a niobium-based metallic toughening phase. A variety of processing schemes have been used to generate these in-situ composites, including solidification and vapor phase processes. Secondary processing, such as forging and extrusion, has also been employed. These composites offer an excellent balance of high-and low-temperature mechanical properties with promising environmental resistance at temperatures above 1,100°C.

Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine: Part 2 — Simulation Results

Abstract: A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (>100 MW). This paper is concerned with the numerical prediction of the tip surface heat transfer. Good comparison with the experimental measured distribution was achieved through accurate modeling of the most important features of the blade passage and heating arrangement as well as the details of experimental rig likely to affect the tip heat transfer. A sharp edge and a radiused edge tip was considered. The results using the radiused edge tip agreed better with the experimental data. This improved agreement was attributed to the absence of edge separation on the tip of the radiused edge blade.

Method and system for analyzing fault log data for diagnostics

Abstract: The present invention discloses a system and method for analyzing fault log data from a malfunctioning machine. The system comprises a processor for receiving new fault log data comprising a plurality of faults from the malfunctioning machine and selecting a plurality of distinct faults from the new fault log data. The processor generates at least one distinct fault cluster from the selected plurality of distinct faults. Thereafter, the processor predicts at least one repair for at least one distinct fault cluster using a plurality of predetermined weighted repair and distinct fault cluster combinations.