General Electric

About: General Electric is a company organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Turbine & Signal. The organization has 76365 authors who have published 110557 publications receiving 1885108 citations. The organization is also known as: General Electric Company & GE.

The transformational leader

Abstract: The Themes, The Protagonists, The Transformational Drama. RECOGNIZING THE NEED FOR REVITALIZATION. The Gathering Storm. Overcoming the Resistance to Change. CREATING A NEW VISION. Diagnosing the Problem. Creating a Motivating Vision. Mobilizing Commitment: Getting People Signed on to the Mission. INSTITUTIONALIZING CHANGE. Creative Destruction: Reweaving the Social Fabric. The Leader as Social Architect I: Making Bureaucracy Behave. The Leader as Social Architect II: Motivating People. EPILOGUE. History Repeats Itself. Notes. References. Index.

Recognition and parsing of context-free languages in time n3*

Abstract: A recognition algorithm is exhibited whereby an arbitrary string over a given vocabulary can be tested for containment in a given context-free language. A special merit of this algorithm is that it is completed in a number of steps proportional to the “cube” of the number of symbols in the tested string. As a byproduct of the grammatical analysis, required by the recognition algorithm, one can obtain, by some additional processing not exceeding the “cube” factor of computational complexity, a parsing matrix—a complete summary of the grammatical structure of the sentence. It is also shown how, by means of a minor modification of the recognition algorithm, one can obtain an integer representing the ambiguity of the sentence, i.e., the number of distinct ways in which that sentence can be generated by the grammar. The recognition algorithm is then simulated on a Turing Machine. It is shown that this simulation likewise requires a number of steps proportional to only the “cube” of the test string length.

Free‐Volume Model of the Amorphous Phase: Glass Transition

Abstract: Free volume vf is defined as that part of the thermal expansion, or excess volume Δv which can be redistributed without energy change. Assuming a Lennard‐Jones potential function for a molecule within its cage in the condensed phase, it can be shown that at small Δv considerable energy is required to redistribute the excess volume; however, at Δv considerably greater than some value δvg (corresponding to potentials within the linear region), most of the volume added can be redistributed freely. The transition from glass to liquid may be associated with the introduction of appreciable free volume into the system. Free volume will be distributed at random within the amorphous phase and there is a contribution to the entropy from this randomness which is not present in the entropy of the crystalline phase. According to our model all liquids would become glasses at sufficiently low temperature if crystallization did not intervene. Therefore whether or not a glass forms is determined by the crystallization kinetic constants and the cooling rate of the liquid. The experience on the glass formation is consistent with the generalization: at a given level of cohesive energy the glass‐forming tendency of a substance in a particular class is greater the less is the ratio of the energy to the entropy of crystallization.

Damage propagation modeling for aircraft engine run-to-failure simulation

Abstract: This paper describes how damage propagation can be modeled within the modules of aircraft gas turbine engines. To that end, response surfaces of all sensors are generated via a thermo-dynamical simulation model for the engine as a function of variations of flow and efficiency of the modules of interest. An exponential rate of change for flow and efficiency loss was imposed for each data set, starting at a randomly chosen initial deterioration set point. The rate of change of the flow and efficiency denotes an otherwise unspecified fault with increasingly worsening effect. The rates of change of the faults were constrained to an upper threshold but were otherwise chosen randomly. Damage propagation was allowed to continue until a failure criterion was reached. A health index was defined as the minimum of several superimposed operational margins at any given time instant and the failure criterion is reached when health index reaches zero. Output of the model was the time series (cycles) of sensed measurements typically available from aircraft gas turbine engines. The data generated were used as challenge data for the prognostics and health management (PHM) data competition at PHMpsila08.