John Broddus Deaton

GE Asset Management, Genworth Financial, and GE Insurance Use a Sequential-Linear-Programming Algorithm to Optimize Portfolios

GE Asset Management Incorporated (GEAM), a wholly owned subsidiary of General Electric Company (GE), manages investment portfolios on behalf of various GE units and over 200 unaffiliated clients worldwide, including Genworth Financial (Genworth) and GE Insurance (GEI) portfolios worth billions of dollars. GEAM invests portfolios of assets—derived from cash flows for various insurance, reinsurance, and financial products—primarily in corporate and government bonds in accordance with risk and regulatory constraints. In asset-liability management (ALM) applications, portfolio managers try to maximize return or minimize risk and match the characteristics of asset portfolios with corresponding liabilities. While risk is widely represented by variance or volatility, it is usually a nonlinear measure; ALM portfolio managers traditionally need to use linear risk sensitivities for computational tractability. We developed a novel, sequential-linear-programming algorithm that handles the nonlinearity iteratively but efficiently. Patented and implemented on a limited basis since 2003, GE used it to optimize more than 30 portfolios valued at over

Development of transfer functions for controlling fabrication of components by laser net shape deposition (LNSM)

30 billion. It is now in broader use at GEAM, GEI, and Genworth. Hypothetically, based on

Porosity evaluation in aircraft composite parts using laser-ultrasound

100 billion of assets, the present value of potential benefits could approximate

Simultaneous Determination of Orientation and Thickness in Anisotropic Media

75 million over five years.

System and method of determining porosity in composite materials using ultrasound

Although laser cladding was developed thirty years ago, it has only been in the last ten years that research groups and companies have begun to exploit this technology to produce fully dense, near-net shape components with metals through techniques such as Direct Metal Deposition (DMD), Directed Light Fabrication (DLF), Laser Consolidation (LC), or Laser Engineered Net Shape (LENS). In order to produce components with fine features, it is necessary to provide proper thermal management of the weld pool during deposition. This is achieved by two means. First, proper choice of process parameters must be made to generate uniform deposits. Second, external sensor and control strategies must be employed to insure that the weld pool size is stable during the course of deposition. In this paper, the process for developing the transfer functions for laser net shape manufacturing (LNSM) is discussed. Finally, the strategy for how these transfer functions can be combined with sensors to control deposition is outlined.Although laser cladding was developed thirty years ago, it has only been in the last ten years that research groups and companies have begun to exploit this technology to produce fully dense, near-net shape components with metals through techniques such as Direct Metal Deposition (DMD), Directed Light Fabrication (DLF), Laser Consolidation (LC), or Laser Engineered Net Shape (LENS). In order to produce components with fine features, it is necessary to provide proper thermal management of the weld pool during deposition. This is achieved by two means. First, proper choice of process parameters must be made to generate uniform deposits. Second, external sensor and control strategies must be employed to insure that the weld pool size is stable during the course of deposition. In this paper, the process for developing the transfer functions for laser net shape manufacturing (LNSM) is discussed. Finally, the strategy for how these transfer functions can be combined with sensors to control deposition is outlined.

Two dimensional phased arrays for volumetric ultrasonic inspection and methods of use

In polymer-matrix composites, porosity must be evaluated and ultrasonic inspection is a proven technique to assess this parameter. To standardize reject criteria among different ultrasonic systems, ultrasonic systems must be quantitatively compared. Samples with different levels of porosity fabricated especially for a round robin were scanned using the laser-ultrasound facility built at Lockheed Martin Aerospace Fort Worth. The results obtained agree qualitatively and quantitatively with the results obtained on the same samples using conventional ultrasonic systems. Overall, the laser-ultrasound accuracy is equivalent to the average conventional system but with an inspection speed more than ten times faster.

Method and apparatus for thickness determination in multilayer articles

Ultrasonic travel-time techniques are commonly utilized for thickness determination in parts where the properties of the material are well characterized. Typically, this use has been limited to isotropic materials ( where the ultrasonic velocity used to determine the thickness is independent of the direction of propagation in the material ). For anisotropic materials, the situation is considerably more complicated due to the directional dependence of the ultrasonic velocity. If the orientation of the material is known, then the same approach used for isotropic samples can be used for thickness determination, providing one properly accounts for the known anisotropy in velocity. When the orientation and thickness are both unknown, a new approach must be utilized to avoid errors arising from the intrinsic variation in the ultrasonic velocity due to anisotropy.