Showing papers on "Component (UML) published in 1993"

Composing specifications

Abstract: A rigorous modular specification method requires a proof rule asserting that if each component behaves correctly in isolation, then it behaves correctly in concert with other components. Such a rule is subtle because a component need behave correctly only when its environment does, and each component is part of the others' environments. We examine the precise distinction between a system and its environment, and provide the requisite proof rule when modules are specified with safety and liveness properties.

The concept assignment problem in program understanding

Abstract: Concept assignment is a process of recognizing concepts within a computer program and building up an understanding of the program by relating the recognized concepts to portions of the program, its operational context and to one another. The problem of discovering individual human oriented concepts and assigning them to their implementation oriented counterparts for a given program is the concept assignment problem. The authors argue that the solution to this problem requires methods that have a strong plausible reasoning component. They illustrate these ideas through example scenarios using an existing design recovery system called DESIRE. DESIRE is evaluated based on its usage on real-world problems over the years. >

The concept assignment problem in program understanding

Abstract: The problem of discovering individual human oriented concepts and assigning them to their implementation-oriented counterparts for a given program is the concept assignment problem. It is argued that the solution to this problem requires methods that have a strong plausible reasoning component. These ideas are illustrated through recovery system called DESIRE. DESIRE is evaluated based on its use on real-world problems over the years. >

Microcell design principles

Abstract: The ways in which microcell systems can help cellular operators face a number of challenges to achieve continued growth, including the need for increased system capacity, enhanced coverage, lower network cost per subscriber, improved performance, delivery of innovative value-added services, and well-planned equipment and service migration strategies, are discussed. It is argued that microcells must work with conventional cellular systems with lower equipment costs per subscriber, and should require only minimal preinstallation RF design and engineering. Keys to cost-effective microcell deployment are high-performance RF component and digital signal processing technology, efficient radio resource management, optimized distributed network design, and effective switch and network integration. >

A unified texture model based on a 2-D Wold-like decomposition

Abstract: A unified texture model that is applicable to a wide variety of texture types found in natural images is presented. This model leads to the derivation of texture analysis and synthesis algorithms designed to estimate the texture parameters and to reconstruct the original texture field from these parameters. The texture field is assumed to be a realization of a regular homogeneous random field, which is characterized in general by a mixed spectral distribution. The texture field is orthogonally decomposed into a purely indeterministic component and a deterministic component. The deterministic component is further orthogonally decomposed into a harmonic component, and a generalized-evanescent component. Both analytical and experimental results show that the deterministic components should be parameterized separately from the purely indeterministic component. The model is very efficient in terms of the number of parameters required to faithfully represent textures. Reconstructed textures are practically indistinguishable from the originals. >

Nacelle and mounting arrangement for an aircraft engine

Abstract: A nacelle and mounting arrangement for a high bypass ratio ducted fan aircraft engine mounted external to the aircraft main structure is disclosed. The nacelle and mounting arrangement isolate the engine from the adverse effects of certain aerodynamic forces acting on the nacelle by transferring substantially all of those forces directly from the nacelle to the aircraft and transferring substantially none of those forces to the engine. Various arrangements of the nacelle components which facilitate engine removal while avoiding the placement of nacelle component interfaces in highly stressed regions of the nacelle are also disclosed.

Generating explanations of device behavior using compositional modeling and causal ordering

Abstract: Generating explanations of device behavior is a long-standmg goal of AI research in reasoning about physical systems. Much of the relevant work has concentrated on new methods for modeling and simulation, such as qualitative physics, or on sophisticated natural language generation, in which the device models are specially crafted for explanatory purposes. We show how two techniques from the modeling research--compositional modeling and causal ordering-- can be effectively combined to generate natural language explanations of device behavior from engineering models. The explanations offer three advances over the data displays produced by conventional simulation software: (1) causal interpretations of the data, (2) summaries at appropriate levels of abstraction (physical mechanisms and component operating modes), and (3) query-driven, natural language summaries. Furthermore, combining the compositional modeling and causal ordering techniques allows models that are more scalable and less brittle than models designed solely for explanation. However, these techniques produce models with detail that can be distracting in explanations and would be removed in hand-crafted models (e.g., intermediate variables). We present domain-independent filtering and aggregation techniques that overcome these problems.

Engineering system for modeling computer programs

Abstract: A human oriented object programming system provides an interactive and dynamic modeling system to assist in the incremental building of computer programs which facilitates the development of complex computer programs such as operating systems and large applications with graphic user interfaces (GUIs). A program is modeled as a collection of units called components. A component represents a single compilable language element such as a class or a function. The three major functionality are the database, the compiler and the build mechanism. The database stores the components and properties. The compiler, along with compiling the source code of a property, is responsible for calculating the dependencies associated with a component. The build mechanism uses properties of components along with the compiler generated dependencies to correctly and efficiently sequence the compilation of components during a build process.

The interface between phrasal and functional constraints

Abstract: Many modern grammatical formalisms divide the task of linguistic specification into a context=free component of phrasal constraints and a separate component of attribute-value or functional constraints. Conventional methods for recognizing the strings of a language also divide into two parts so that they can exploit the different computational properties of these components. This paper focuses on the interface between these components as a source of computational complexity distinct from the complexity internal to each. We first analyze the common hybrid strategy in which a polynomial context-free parser is modified to interleave functional constraint solving with context-free constituent analysis. This strategy depends on the property of monotonicity in order to prune unnecessary computation. We describe a number of other properties that can be exploited for computational advantage, and we analyze some alternative interface strategies based on them. We present the results of preliminary experiments that generally support our intuitive analyses. A surprising outcome is that under certain circumstances an algorithm that does no pruning in the interface may perform significantly better than one that does.

Scalable software libraries

Abstract: Many software libraries (e.g., the Booch C++ Components, libg++, NIHCL, COOL) provide components (classes) that implement data structures. Each component is written by hand and represents a unique combination of features (e.g. concurrency, data structure, memory allocation algorithms) that distinguishes it from other components.We argue that this way of building data structure component libraries is inherently unscalable. Libraries should not enumerate complex components with numerous features; rather, libraries should take a minimalist approach: they should provide only primitive building blocks and be accompanied by generators that can combine these blocks to yield complex custom data structures.In this paper, we describe a prototype data structure generator and the building blocks that populate its library. We also present preliminary experimental results which suggest that this approach does not compromise programmer productivity nor the run-time performance of generated data structures.

Cryptographic key management method and apparatus

Abstract: A system for the secure communication of a message from a transmitting user to a receiving user using a split key scheme. Each user generates a key component using a cryptographic engine. The key component is a pseudorandom sequence of bits with an appended error detection field which is mathematically calculated based on the pseudorandom sequence. This key component is then sent out on a communications channel from the transmitting user to the receiving user. The receiving user also sends its key component to the transmitting user. Each location performs a mathematical check on the key component received from the other location. If the key component checks pass at both locations, the transmit key component and the receive key component, including the error detection fields, are combined at both locations, forming identical complete keys at both locations. The identical complete keys are then used to initiate the cryptographic engines at both locations for subsequent encryption and decryption of messages between the two locations.

Identification of pin-open faults by capacitive coupling through the integrated circuit package

Abstract: Disclosed is a system that determines whether input and output pins of semiconductor components are present and properly soldered to a printed circuit board. The system uses an oscillator which supplies a signal, typically ten kilohertz (10 kHz) at 0.2 volts, to the pin under test. A conductive electrode is placed on top of the component package. The electrode is connected to a current measuring device. Another pin of the component is connected to the common signal return. Typically the other pin is chosen to be a power or ground pin of the component.

Thermal component models for electro-thermal network simulations

Abstract: A procedure is given for developing thermal component models for electrothermal network simulation. In the new electrothermal network simulation methodology, the simulator solves for the temperature distribution within the semiconductor devices, packages, and heat sinks (thermal network) as well as the currents and voltages within the electrical network. The thermal network is represented as an interconnection of compact thermal component models so that the system designer can readily interchange different thermal components and examine different configurations of the thermal network. To facilitate electrothermal network design, the interconnection of the thermal component models is specified by the user in the same way that the interconnection of the electrical network components is specified. The thermal component models are also parameterized in terms of structural and material parameters so that the details of the heat transport physics are transparent to the user. Examples of electrothermal network simulations are given, and the temperature measurement methods used to validate the thermal component models are described. >

Method and apparatus of incrementally linking components of a modeled computer program

Abstract: A human oriented object programming system provides an interactive and dynamic process for the incremental building of computer programs which facilitates the development of complex computer programs such as operating systems and large applications with graphic user interfaces (GUIs). The program is modeled as a collection of units called components. A component represents a single compilable language element such as a class or a function. The major functionalities are the database, the compiler, build and link mechanism. The database stores the components and properties. The compiler, along with compiling the source code of a property, and generating object code is responsible for calculating the dependencies associated with a component. The build mechanism uses properties of components along with the compiler generated dependencies to correctly and efficiently sequence the compilation of components during a build process. The link mechanism links all object code as the component stores it in the component database. Only updated components require linking operations.

Planning and certifying software system reliability

Abstract: An approach to software reliability and certification is presented that is based on the use of three mathematical models: the sampling, component, and certification models. The approach helps reduce reliability analysis to a problem that can be evaluated and manipulated through a series of spreadsheets. This approach was motivated by interest in applying the cleanroom software-engineering method in environments that require extensive code reuse. >

Separable multi-account safety credit card

Abstract: A separable safety credit card which contains multiple account numbers and is mechanically detachable into two component parts whereby that part upon which is embossed the credit account numbers may be separately carried from the individual identification part thereof for purposes of safety and security so that if either component is lost or stolen the card may not be used by another in the making of unauthorized transactions.

ActorSpace: an open distributed programming paradigm

Abstract: We present a new programming paradigm called ActorSpace. ActorSpace provides a new communication model based on destination patterns. An actorSpace is a computationally passive container of actors which acts as a context for matching patterns. Patterns are matched against listed attributes of actors and actorSpaces that are visible in the actorSpace. Both visibility and attributes are dynamic. Messages may be sent to one or all members of a group defined by a pattern. The paradigm provides powerful support for component-based construction of massively parallel and distributed applications. In particular, it supports open interfaces to servers and pattern-directed access to software repositories.

Program and interface slicing for reverse engineering

Abstract: A case is presented for the use of conventional and interface slicing as enabling mechanisms for numerous reverse engineering and reengineering tasks. The authors first discuss the applicability of conventional slicing to algorithm extraction and design recovery at statement-level granularity. They then present interface slicing and show how it provides similar capabilities at module-level granularity. Module is a general term for a collection of subprograms, possibly with information hiding mechanisms: It includes but is not limited to Ada packages. Component refers to a module in a reuse repository. A component is thus a code asset of a repository, possibly also incorporated into a program. Ada is used for the example, as Ada's features facilitate the types of transformations which are invoked. >

Signature matching: a key to reuse

Abstract: Software reuse is only effective if it is easier to locate (and appropriately modify) a reusable component than to write it from scratch. We present signature matching as a method for achieving this goal by using signature information easily derived from the component. We consider two kinds of software components, functions and modules, and hence two kinds of matching, function mathcing and module matching. The signature of a function is simply its type; the signature of a module is a multiset of user-defined types and a multiset of function signatures. For both functions and modules, we consider not just exact match, but also various flavors of relaxed match. We briefly describe an experimental facility written in Standard ML for performing signature matching over a library of ML functions.

Method and system for interfacing components via aggregate components formed by aggregating the components each with an instance of a component manager

Abstract: A method and system for managing the connection of client components to an interface implemented by a server component. In a preferred embodiment, a user component provides an implementation of an interface and a description of the interface. A component manager aggregates the user component into itself to form a server component. When a client requests a connection to the interface, the component manager retrieves a reference to the interface from the user component and sends the reference to the client components. In a preferred embodiment, the component manager tracks the client components connected through an interface. A user component may also provide multiple interfaces to client components which the component manager also tracks.

System Failure: An Analysis of 2000 Incident Reports:

Abstract: Although 70–80% of problems have some component of human error, its overall contribution to many problems may be small; studies of complex systems have revealed that up to 85% are primarily due to ...

On the geometric component of charge-pumping current in MOSFETs

Abstract: A simple method of unambiguously determining the presence of any geometric component in a charge-pumping measurement by collecting this component at another node via a nearby junction is presented. With the method it has been possible to study the dependence of geometric components on device dimensions and various experimental conditions with unprecedented sensitivity. By effectively separating the two current contributions, this method can at the same time be used to reduce geometric components in the regular charge-pumping signal, thereby increasing the accuracy of the various implementations of the charge pumping (CP) technique. >

A Parametric Approach to Cost Estimating at the Conceptual Stage of Design

Abstract: A methodology has been developed that enables designers to estimate the cost of a product at the conceptual stage of design with minimal component information and little or no experience of the intended production process. The methodology is based on a parametric approach in which the information available at the conceptual design stage is directed through a set of data converters to give values of parameters which have been identified as the cost drivers. Parametric equations, derived from a large database of component information, are then used to calculate a cost estimate. This methodology has been used to develop a computer-based cost estimating system for a range of injection-moulded components. It is capable of estimating costs to within 20% and is the first stage in the development of a conceptual cost comparison system.

Towards an Adaptive Hypermedia Component for an Intelligent Learning Environment

Abstract: This paper discusses the problem of integration of hypermedia and Intelligent Learning Environments (ILEs) technologies and the problem of creating an adaptive hypermedia component for ILEs Our experience of creating an adaptive on-line help facilities for ITEM/IP system is described This experience forms a background for our hypermedia work and provides some good ideas for it We also present our approach to integration of a hypermedia component into internal structure of ILE and illustrate it with two examples of adaptive hypermedia components for the most recent versions of our ILEs ISIS-Tutor and ITEM/PG Finally, we summarize main features of this approach, provide some references to related works, and consider some issues of adaptive hypermedia in general

Supervisory control in a dynamic and uncertain environment: a process model of skilled human-environment interaction

Abstract: An understanding of how both psychological and environmental factors mutually constrain skilled behavior is required to effectively support human activity. As a step toward meeting this need, a process model of skilled human interaction with a dynamic and uncertain environment is presented. The model was able to mimic human behavior in a laboratory task requiring one- and two-person crews to direct the activities of a fleet of agents to locate and process valued objects in a simulated world. The process model is a pair of highly interactive components that together mimic the behavior of the human-environment system. One component is a representation of the external environment as a dynamically changing set of opportunities for action. The second component is a dynamic representation of skilled human decision making and planning behavior within the environment so described. The process model is an expression of a general theory of skilled interaction assuming that perception and action mechanisms sensitive to environmental constraints are responsible for generating much of behavior, and where the need for additional cognitive processing of internal representations may result from environmental designs that do not adequately support the perceptual guidance of activity. >

Method and apparatus for building a software program using dependencies derived from software component interfaces

Abstract: A human oriented object programming system provides an interactive and dynamic process for the incremental building of computer programs which facilitates the development of complex computer programs such as operating systems and large applications with graphic user interfaces (GUIs). The program is modeled as a collection of units called components. A component represents a single compilable language element such as a class or a function. The three major functionality are the database, the compiler and the build mechanism. The database stores the components and properties. The compiler, along with compiling the source code of a property, is responsible for calculating the dependencies associated with a component. The build mechanism uses properties of components along with the compiler generated dependencies to correctly and efficiently sequence the compilation of components during a build process.

System and method for verifying a hierarchical circuit design

Abstract: A computer-based system and method is provided for building a representation of a hierarchical circuit design and component intrusions for the components making up the circuit design, as well as for verifying a design so-represented. For a subject hierarchical circuit design, a VLSI circuit design component representing a leaf design entity is isolated. A set of locations in the design where the component appears is determined. These locations represent unique instances of the leaf design entity. A set of links is associated with the VLSI circuit design component and the locations. The links connect various ones of the locations to one another to denote placement of the component within the hierarchical circuit design. To complete the representation, a set of instance counts is computed, one instance count for each location in the design where the component is represented. Each instance count denotes the number of instances of the component represented at the location with which the instance count is associated. Additional features of the invention include applicability to numerous types of design components (e.g., devices, nets, microprocessors, resistors), correspondence between each node of the inverse layout graph and a unique placement in the hierarchical circuit design, and the ability to determine intrusions according to any measure of proximity.

An integration of neural network and rule-based systems for design and planning of mechanical assemblies

Abstract: A case associative assembly planning system (CAAPS), which integrates neural computing techniques and rule-based systems has been developed. The neural network computing captures the designer's design concept and self-organizes similar experienced designs. The CBAPM (CLIPS-based assembly planning module), a component of CAAPS, generates a task-level assembly plan automatically. The design concept is expressed by a standard pattern format representing components' 3D geometry. A feature-based model translates the conceptual design into a preliminary boundary representation (B-rep). Based on a refinement of the B-rep assembly representation, assembly plans are generated for practical use in a single-robot assembly workcell. A feasible assembly plan that minimizes tool changes and subassembly reorientations is generated from the system. The CBCAPM presented draws input relationships directly from the conceptual design and the geometry of the assembly. At all stages of the design process the designer can consult the design cluster memory and plan cluster memory to see what "experience" knows of similar assemblies. Efficient use of prior experiences is emphasized. >