Policy of Safety Assurance (Design Constraints and Additional Functional Requirements)

2017 ◽  
pp. 65-102
Author(s):  
Yoshio Kani
Keyword(s):  
Functional Requirements ◽  
Design Constraints ◽  
Safety Assurance

Identifying reformulations of mechanical parametric design constraints

1991 ◽  
Vol 5 (3) ◽  
pp. 173-188 ◽  
Author(s):  
John D. Watton ◽  
James R. Rinderle
Keyword(s):  
Parametric Design ◽  
Mechanical Design ◽  
Design Parameters ◽  
Critical Ratio ◽  
Functional Requirements ◽  
Dimensional Parameter ◽  
Design Constraints ◽  
Alternative Design ◽  
Functional Behavior ◽  
Highly Nonlinear

The complexity of mechanical design is reflected in the complexity of the design constraints which relate functional requirements to design parameters. Reformulations of the design constraints can significantly reduce this complexity. This is accomplished by a transformation to alternative design parameters, such as a critical ratio, a non-dimensional parameter, or a simple difference; e.g. the ratio of surface area to volume for heat transfer loss, the Reynold's number in fluid mechanics, or the velocity difference across a fluid coupling. We have developed a method by which the alternative parameters are chosen for physical significance and for the ability to create a more direct correspondence to functional behavior as determined by measures of serial and block decomposability of the constraints. Rules have been developed for the creation of physically significant new parameters from the algebraic combination of the original parameters. The rules are based on engineering principles and rely on knowledge about what a parameter physically represents rather than other qualities such as dimensions. A computer based system, called EUDOXUS, has been developed to automate this procedure. The system operates on a set of design constraints to produce sets of transformed constraints in terms of alternative design parameters. The method and its implementation have demonstrated successful results for many highly nonlinear and highly coupled parameterized designs from many mechanical engineering domains.

scholarly journals Machine safety - determination safety integrity level

2018 ◽  
Vol 19 (7-8) ◽  
pp. 53-57
Author(s):  
Wojciech Danilczuk
Keyword(s):  
International Standards ◽  
Legal Regulations ◽  
Functional Requirements ◽  
Safety Assurance ◽  
Safety Integrity Level ◽  
Machine Safety ◽  
Basic Concepts

The article presents a method for determining machine safety by calculating the safety integrity level (SIL). Problems of machine safety were presented in the context of applicable legal regulations and international standards. On the basis of the literature and standards, methods for determining the safety integrity level, quantitative measures used within the PN EN 62061 standard and basic concepts related to functional requirements have been presented. In addition, the author compares the method of determining the SIL level from the PL level of safety assurance. The article is a continuation of the author's previous publication on machine safety.

scholarly journals A Methodology for Conceptual Design of Mechanisms by Parsing Design Specifications

2005 ◽  
Vol 127 (6) ◽  
pp. 1039-1044 ◽  
Author(s):  
Dar-Zen Chen ◽  
Wei-Ming Pai
Keyword(s):  
Conceptual Design ◽  
Design Process ◽  
Combustion Engine ◽  
Kinematic Chain ◽  
Kinematic Structure ◽  
Functional Requirements ◽  
Design Constraints ◽  
Structural Requirements ◽  
Design Specifications ◽  
Stroke Engine

In this paper, design specifications for the conceptual design of mechanisms are parsed into three coherent categories: functional requirements, structural requirements, and design constraints. Based on functional requirements, the functioning kinematic chain of a mechanism can be constructed by connecting the functioning links accordingly. From structural requirements, admissible kinematic structures are searched from the existing atlases of kinematic structures. Those admissible kinematic structures, which comprise at least one segment with the same characteristics of the functioning kinematic chain, are identified as compatible kinematic structures. Thus, feasible mechanisms that fulfill design specifications can be yielded by labeling joints in the compatible kinematic structures subject to design constraints. With this methodology, classified design specifications are used to guide designer through various stages of the conceptual design process in a systematic manner. The creation of the variable-stroke engine mechanism [Freudenstein, F., Maki, E. R., 1983, “Development of an Optimum Variable-Stroke Internal-Combustion Engine Mechanism From the Viewpoint of Kinematic Structure,” ASME J. Mech., Trans., Automat., Des., Vol. 105, pp. 259–267] is used as an illustrative example.

An Integrated Approach for a Knowledge-based Clinical Workstation: Architecture and Experience

1998 ◽  
Vol 37 (01) ◽  
pp. 16-25 ◽  
Author(s):  
P. Ringleb ◽  
T. Steiner ◽  
P. Knaup ◽  
W. Hacke ◽  
R. Haux ◽  
...  
Keyword(s):  
Decision Support ◽  
Information Systems ◽  
Patient Care ◽  
Hospital Information Systems ◽  
Medical Decision ◽  
Daily Routine ◽  
Functional Requirements ◽  
Support Functions ◽  
Knowledge Based ◽  
Clinical Workstation

Abstract:Today, the demand for medical decision support to improve the quality of patient care and to reduce costs in health services is generally recognized. Nevertheless, decision support is not yet established in daily routine within hospital information systems which often show a heterogeneous architecture but offer possibilities of interoperability. Currently, the integration of decision support functions into clinical workstations is the most promising way. Therefore, we first discuss aspects of integrating decision support into clinical workstations including clinical needs, integration of database and knowledge base, knowledge sharing and reuse and the role of standardized terminology. In addition, we draw up functional requirements to support the physician dealing with patient care, medical research and administrative tasks. As a consequence, we propose a general architecture of an integrated knowledge-based clinical workstation. Based on an example application we discuss our experiences concerning clinical applicability and relevance. We show that, although our approach promotes the integration of decision support into hospital information systems, the success of decision support depends above all on an adequate transformation of clinical needs.

Urban Development Strategies of City Centers: The Case of Rafah City, Palestinian Territories

2014 ◽  
Vol 8 (3) ◽  
pp. 195
Author(s):  
Omar S. Asfour ◽  
Samar Abu Ghali
Keyword(s):  
Urban Development ◽  
Gaza Strip ◽  
Geographic Location ◽  
Development Strategies ◽  
Functional Requirements ◽  
City Center ◽  
Palestinian Territories ◽  
The Gaza Strip ◽  
The City ◽  
Commercial Center

City centers worldwide are perceived as essential parts of the city, where city memories are preserved and its identity is expressed. They are planned to satisfy the functional requirements and pleasurable qualities of the city. Under the accelerating urbanization of the modern city, several challenges face these centers including demographic, economic, and environmental challenges. This requires a continuous and incremental urban development process based on clear strategy and action plans. Thus, this study focuses on urban development strategies of city centers, with a focus on Rafah city located in the Gaza Strip, Palestinian Territories. The geographic location of this city near the Palestinian-Egyptian borders makes it a promising commercial city at local and regional levels. Thus, the current situation of Rafah city center has been analyzed, and several development strategies have been proposed. This has been done through a field survey based on observation and a questionnaire directed to city center users. It has been found that there is a great potential of Rafah city center to be developed as a commercial center. In this regard, several strategies and required actions have been proposed in the fields of transportation, environmental quality, shopping activities, investment opportunities, and visual perception.

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