Steven R. Ray

Bio: Steven R. Ray is an academic researcher from National Institute of Standards and Technology. The author has contributed to research in topics: Process development execution system & Process Specification Language. The author has an hindex of 14, co-authored 34 publications receiving 804 citations. Previous affiliations of Steven R. Ray include Princeton University.

Flame spread in an opposed forced flow: the effect of ambient oxygen concentration

Abstract: The velocity of flame propagation over the surface of thick PMMA and thin paper sheets has been measured as a function of the velocity and oxygen concentration of a forced gas flow opposing the direction of flame propagation. It is shown that although for thin fuels the flame spread rate always decreases as the opposed flow velocity increases, for thick fuels the dependence of the spread rate on the gas velocity is also a function of the ambient oxygen concentration. For low oxygen concentrations the flame spread rate decreases as the velocity of the gas flow increases. For high oxygen concentrations, however, the spread rate increases with the flow velocity, reaches a maximum and then decreases as the gas velocity increases. The velocity of the opposed flow at which the maximum occurs is a function of the oxygen concentration, decreasing as the concentration decreases. Following phenomenological considerations and simplified descriptions of the primary mechanisms occurring during the flame spread process, the experimental results are correlated by two non-dimensional parameters, one describing the gas phase kinetic effects and the other describing the process of heat transfer from the flame to the fuel. Such a correlation provides a powerful means of predicting the flame spread prcess as well as physical insight into the mechanisms controlling the propagation of the flame.

ALPS: A Language for Process Specification

Abstract: This paper describes research identifying information models to facilitate process specification and to transfer this information to process control A conceptual schema is introduced as a means to bridge the gap between process planning requirements and production control requirements The result is a process specification language based on directed graph notation which allows full specification of parallel activities, event synchronization, alternative processes, resource management, and task decomposition

Unified Process Specification Language: Requirements for Modeling Process

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Process Specification Language: An Analysis of Existing Representations

Abstract: The goal of the NIST Process Specification Language (PSL) project is to investigate and arrive at a neutral, unifying representation of process information to enable sharing of process data among manufacturing engineering and business applications. This paper focuses on the second phase of the project, the analysis of existing process representations to determine how well existing process representation methodologies support the requirements for specifying processes found in Phase One. This analysis will provide an objective basis from which to develop a comprehensive language and will promote the leveraging of existing work. Process Specification Language: An Analysis of Existing Representations

Interoperability Standards in the Semantic Web

Abstract: The growth in the use of the Internet brings with it an increase in the number of interconnections among information systems supporting the manufacturing supply chain as well as other businesses. Each of these interconnections must be carefully prescribed to ensure interoperability. However, the sheer number of interconnections and the resulting complexity threaten to overwhelm the ability of the standards community or industry to provide the necessary specifications—a way out of this impasse must be found. This paper outlines the elements of an approach and the technology to move toward self-integrating systems, wherein the systems negotiate meaningful interfaces as needed in a dynamic environment. DOI: 10.1115/1.1480024

Reference architecture for holonic manufacturing systems: PROSA

Abstract: Future manufacturing systems need to cope with frequent changes and disturbances. As such, their control requires constant adaptation and high flexibility. Holonic manufacturing is a highly distributed control paradigm that promises to handle these problems successfully. It is based on the concept of autonomous co-operating agents, called `holons'. This paper gives an overview of the holonic reference architecture for manufacturing systems as developed at PMA-KULeuven. This architecture, called PROSA, consists of three types of basic holons: order holons, product holons, and resource holons. They are structured using the object-oriented concepts of aggregation and specialisation. Staff holons can be added to assist the basic holons with expert knowledge. The resulting architecture has a high degree of self-similarity, which reduces the complexity to integrate new components and enables easy reconfiguration of the system. PROSA shows to cover aspects of both hierarchical as well as heterarchical control approaches. As such, it can be regarded as a generalisation of the two former approaches. More importantly, PROSA introduces significant innovations: the system structure is decoupled from the control algorithm, logistical aspects can be decoupled from technical ones, and PROSA opens opportunities to achieve more advanced hybrid control algorithms.

A review of product–service systems design methodologies

Abstract: Product–service systems (PSS), motivated to fulfil customers’ needs, are seen as good strategies to face today's competitive business environment. The field of PSS research is however not fully mature and many different methodologies are proposed for the PSS design. This paper seeks to understand the directions taken in eight state-of-the-art methodologies so as to identify common needs in future research. The methodologies are studied across their authors’ views and definitions of services, PSS and their objectives and challenges, along with the tools that have been developed. A maturity model is built to access the current PSS design across 20 dimensions. The model highlights that only three dimensions are strongly treated: design processes for integrating products and services, definitions of new terminologies and considerations concerning planning and designing life-cycle phases. To enhance the industrial application, collaboration between researchers and practitioners can be spurred through two chall...

Concurrent engineering design tool and method

Abstract: A computer-based engineering design system to design a part, a tool to make the part, and the process to make the part. The design system has a processor and a memory. The memory stores feature templates, each feature template being a representation of a primitive object having a form and a function. Each feature template is indexed by the function of the primitive object and includes a representation of a primitive geometric entity having the form of the primitive object. Each feature template can include information relating to a tool to make the primitive object and a process to make the primitive object. The design system also includes an input device for receiving a request to design the part. This request includes one or more predetermined functions that the part performs. A core design module, executable by the processor, designs the part, the tool to make the part and process to make the part by accessing the plurality of feature templates in the memory to locate one or more primitive objects that perform the one or more predetermined functions.

A Survey of Design Rationale Systems: Approaches, Representation, Capture and Retrieval

Abstract: This paper provides a survey on recent research in the area of design rationale. The study of design rationale spans a number of diverse disciplines, touching on concepts from research communities in mechanical design, software engineering, artificial intelligence, civil engineering, computer-supported cooperative work, and human-factors and human-computer interaction research. We focus this survey on prototype design rationale systems for these application domains, and put forward several major criteria with which to describe and classify design rationale systems, including argumentation-based, descriptive, process-based approaches. Further, we attempt to abstract the place of systems and tools for design rationale capture and retrieval in the context of contemporary knowledge-based engineering and Computer-Aided Design (CAD) tools. This survey is structured around classes of fundamentally different approaches, their representation schema, their capture methods and retrieval techniques. A number of recent design rationale systems, including JANUS, COMET, ADD. REMAP, HOS, PHIDIAS, DRIVE and IBIS are analysed. We conclude with an assessment of current state-of-the-art and a discussion of critical open research issues.

Business Process Analysis and Optimization: Beyond Reengineering

Abstract: There is an abundance of business process modeling techniques that capture and address different aspects of a business process. A limited number of these process models allow further quantitative analysis, and only a few enable structured process improvement. This paper reviews and classifies the main techniques for business process modeling with regard to their analysis and optimization capabilities. Three primary groups are identified, and a selection of representative business process modeling techniques is classified based on these. Similar classification is also presented for the analysis and optimization approaches for business processes that were identified in relevant literature. The main contribution of the paper is that it identifies which types of business process models are suitable for analysis and optimization, and also highlights the lack of such approaches. This paper offers a state-of-the-art review in the areas of business process modeling, analysis, and optimization-underlining that the latter two have not received enough coverage and support in the literature.