This article is concerned with the determination of kinetic parameters of the Calvin photosynthes... more This article is concerned with the determination of kinetic parameters of the Calvin photosynthesis cycle which is described by seventeen non-linear ordinary differential equations, It is shown that the task requires dynamic data for several sets of initial conditions. The numerical technique is based upon an algorithm for non-linear optimization and Gear's numerical integration scheme for stiff systems of differential equations. The sensitivity of the parameters to noise in the data is tested with a method adapted from Rosen-brook ahd Storey. A preliminary set of parameters has been obtained from a preliminary set of experimental data. The numerical methods are then tested with synthetic data derived from these parameters. The mathematical model and the results obtained in the simulation are used as an aid in designing new experiments.
General algebraic structures are introduced and used to develop representations for discrete syst... more General algebraic structures are introduced and used to develop representations for discrete systems. Properties of the structures and mappings between the structures are derived. The first general structure presented is based on a free monoid of m-tuples of mappings. A second general structure is presented that is based on a commutative ring of functions with finite support. These structures are specialized to obtain representations for three models of discrete systems: finite-state machines. Petri nets, and inhibitor nets. Uniqueness of the representations is established, and examples of representations for each type of svstem are given. 0 1998 Elseviclr Science Inc.
This article is concerned with the determination of kinetic parameters of the Calvin photosynthes... more This article is concerned with the determination of kinetic parameters of the Calvin photosynthesis cycle which is described by seventeen nonlinear ordinary differential equations. It is shown that the task requires dynamic data for several sets of initial conditions. The numerical technique is based upon an algorithm for non-linear optimization and Gear's numerical integration scheme for stiff systems of differential equations. The sensitivity of the parameters to noise in the data is tested with a method adapted from Rosenbrook and Storey. A preliminary set of parameters has been obtained from a preliminary set of experimental data. The numerical methods are then tested with synthetic data derived from these parameters. The mathematical model and the results obtained in the simulation are used as an aid in designing new experiments.
The resolution of satellite imagery is often traded-off to satisfy transmission time and bandwidt... more The resolution of satellite imagery is often traded-off to satisfy transmission time and bandwidth, memory, and display limitations. Although there are many ways to achieve the same reduction in resolution, algorithms vary in their ability to preserve the visual quality of the original imagery. These issues are investigated in the context of the Landsat browse system, which permits the user
A method of nonlinear optimization is presented. The method is based on searches along weighted r... more A method of nonlinear optimization is presented. The method is based on searches along weighted random directions together with spline and Lagrangian approximations. We define the concept of mutually dual vectors with respect to the product of two diagonal matrices. These vectors are search directions with orthogonality properties. The properties of the method are analysed for the quadratic case, and an estimate of the minimum from an iterative improvement factor is given. The algorithm has been extensively tested on standard test functions.
General algebraic structures are introduced and used to develop representations for discrete syst... more General algebraic structures are introduced and used to develop representations for discrete systems. Properties of the structures and mappings between the structures are derived. The first general structure presented is based on a free monoid of m-tuples of mappings. A second general structure is presented that is based on a commutative ring of functions with finite support. These structures are specialized to obtain representations for three models of discrete systems: finite-state machines. Petri nets, and inhibitor nets. Uniqueness of the representations is established, and examples of representations for each type of svstem are given. 0 1998 Elseviclr Science Inc.
We show that finite-state machines can be represented as unique elements of special modules of fu... more We show that finite-state machines can be represented as unique elements of special modules of functions. We obtain a module representation for the machine with the least number of states over a class of equivalent machines. We present a unique factorization of this representation.
Space satellite enterprises are complex systems that often involve the application of leading-edg... more Space satellite enterprises are complex systems that often involve the application of leading-edge technologies in order to achieve the requirements and best performance feasible. A space program can take as long as decades from initial concept to full system deployment. Considerable technical and programmatic risks must be properly managed during the program lifetime in order to achieve success. This paper discusses these engineering challenges with a particular emphasis on the ground enterprise (segment) that operates and performs the mission of the satellite system (space segment). We pay particular attention to the software development challenges for the ground segment. These development projects engage sizable contractor teams that can acquire and build the ground system, the space segment, or both. This paper discusses future acquisition options based on experience gained from lessons learned on a number of space programs. The key finding of this paper is that, in our experience, the ground system carries the highest software development risks. These risks must be evaluated early on in the life of a program, since their accurate assessment must drive the acquisition strategy. A number of acquisition options must be considered and carefully evaluated. Decisions made in the embryonic phase of early program concept definition, have significant effects on the program later on. Appropriate acquisition strategy, architectural philosophy, and design tools are necessary in order to launch a successful program, as well as during proper follow through during the lifetime of the program. 0-7803-9087
Architectural Assessment of Embedded Systems Using Aspect-Oriented Programming Principles
Page 1. Architectural Assessment of Embedded Systems Using Aspect-Oriented Programming Principles... more Page 1. Architectural Assessment of Embedded Systems Using Aspect-Oriented Programming Principles Phillip Schmidt The Aerospace Corporation [email protected] Jaime Milstein The Aerospace Corporation [email protected] ...
A Systems Engineering Perspective of Aspect-oriented Software Architectural Analysis using UML
Literature on Unified Modeling Language (UML) and aspect-orientation often focus on improving the... more Literature on Unified Modeling Language (UML) and aspect-orientation often focus on improving the software development process [2]. This paper presents a systems engineering perspective that motivates an aspect-oriented software architectural analysis approach using ...
This article is concerned with the determination of kinetic parameters of the Calvin photosynthes... more This article is concerned with the determination of kinetic parameters of the Calvin photosynthesis cycle which is described by seventeen non-linear ordinary differential equations, It is shown that the task requires dynamic data for several sets of initial conditions. The numerical technique is based upon an algorithm for non-linear optimization and Gear's numerical integration scheme for stiff systems of differential equations. The sensitivity of the parameters to noise in the data is tested with a method adapted from Rosen-brook ahd Storey. A preliminary set of parameters has been obtained from a preliminary set of experimental data. The numerical methods are then tested with synthetic data derived from these parameters. The mathematical model and the results obtained in the simulation are used as an aid in designing new experiments.
General algebraic structures are introduced and used to develop representations for discrete syst... more General algebraic structures are introduced and used to develop representations for discrete systems. Properties of the structures and mappings between the structures are derived. The first general structure presented is based on a free monoid of m-tuples of mappings. A second general structure is presented that is based on a commutative ring of functions with finite support. These structures are specialized to obtain representations for three models of discrete systems: finite-state machines. Petri nets, and inhibitor nets. Uniqueness of the representations is established, and examples of representations for each type of svstem are given. 0 1998 Elseviclr Science Inc.
This article is concerned with the determination of kinetic parameters of the Calvin photosynthes... more This article is concerned with the determination of kinetic parameters of the Calvin photosynthesis cycle which is described by seventeen nonlinear ordinary differential equations. It is shown that the task requires dynamic data for several sets of initial conditions. The numerical technique is based upon an algorithm for non-linear optimization and Gear's numerical integration scheme for stiff systems of differential equations. The sensitivity of the parameters to noise in the data is tested with a method adapted from Rosenbrook and Storey. A preliminary set of parameters has been obtained from a preliminary set of experimental data. The numerical methods are then tested with synthetic data derived from these parameters. The mathematical model and the results obtained in the simulation are used as an aid in designing new experiments.
The resolution of satellite imagery is often traded-off to satisfy transmission time and bandwidt... more The resolution of satellite imagery is often traded-off to satisfy transmission time and bandwidth, memory, and display limitations. Although there are many ways to achieve the same reduction in resolution, algorithms vary in their ability to preserve the visual quality of the original imagery. These issues are investigated in the context of the Landsat browse system, which permits the user
A method of nonlinear optimization is presented. The method is based on searches along weighted r... more A method of nonlinear optimization is presented. The method is based on searches along weighted random directions together with spline and Lagrangian approximations. We define the concept of mutually dual vectors with respect to the product of two diagonal matrices. These vectors are search directions with orthogonality properties. The properties of the method are analysed for the quadratic case, and an estimate of the minimum from an iterative improvement factor is given. The algorithm has been extensively tested on standard test functions.
General algebraic structures are introduced and used to develop representations for discrete syst... more General algebraic structures are introduced and used to develop representations for discrete systems. Properties of the structures and mappings between the structures are derived. The first general structure presented is based on a free monoid of m-tuples of mappings. A second general structure is presented that is based on a commutative ring of functions with finite support. These structures are specialized to obtain representations for three models of discrete systems: finite-state machines. Petri nets, and inhibitor nets. Uniqueness of the representations is established, and examples of representations for each type of svstem are given. 0 1998 Elseviclr Science Inc.
We show that finite-state machines can be represented as unique elements of special modules of fu... more We show that finite-state machines can be represented as unique elements of special modules of functions. We obtain a module representation for the machine with the least number of states over a class of equivalent machines. We present a unique factorization of this representation.
Space satellite enterprises are complex systems that often involve the application of leading-edg... more Space satellite enterprises are complex systems that often involve the application of leading-edge technologies in order to achieve the requirements and best performance feasible. A space program can take as long as decades from initial concept to full system deployment. Considerable technical and programmatic risks must be properly managed during the program lifetime in order to achieve success. This paper discusses these engineering challenges with a particular emphasis on the ground enterprise (segment) that operates and performs the mission of the satellite system (space segment). We pay particular attention to the software development challenges for the ground segment. These development projects engage sizable contractor teams that can acquire and build the ground system, the space segment, or both. This paper discusses future acquisition options based on experience gained from lessons learned on a number of space programs. The key finding of this paper is that, in our experience, the ground system carries the highest software development risks. These risks must be evaluated early on in the life of a program, since their accurate assessment must drive the acquisition strategy. A number of acquisition options must be considered and carefully evaluated. Decisions made in the embryonic phase of early program concept definition, have significant effects on the program later on. Appropriate acquisition strategy, architectural philosophy, and design tools are necessary in order to launch a successful program, as well as during proper follow through during the lifetime of the program. 0-7803-9087
Architectural Assessment of Embedded Systems Using Aspect-Oriented Programming Principles
Page 1. Architectural Assessment of Embedded Systems Using Aspect-Oriented Programming Principles... more Page 1. Architectural Assessment of Embedded Systems Using Aspect-Oriented Programming Principles Phillip Schmidt The Aerospace Corporation [email protected] Jaime Milstein The Aerospace Corporation [email protected] ...
A Systems Engineering Perspective of Aspect-oriented Software Architectural Analysis using UML
Literature on Unified Modeling Language (UML) and aspect-orientation often focus on improving the... more Literature on Unified Modeling Language (UML) and aspect-orientation often focus on improving the software development process [2]. This paper presents a systems engineering perspective that motivates an aspect-oriented software architectural analysis approach using ...
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