scholarly journals Three-frequency models for determining the orientation of a solid body taking into account the vibration environment

2021 ◽  
pp. 29-36
Author(s):  
Irina Homozkova
Keyword(s):  
Inertial Navigation System ◽  
Reference Model ◽  
Broadband Noise ◽  
Traffic Modeling ◽  
Angular Velocity Vector ◽  
Third Order ◽  
Frequency Reference ◽  
Definition Of ◽  
Solid Motion ◽  
Engine Rotor

Two new three-frequency reference models of solid motion taking into account the vibrational environment are proposed. They are based on a four-frequency reference model of rotation [1], which implements rotations according to Krylov angles. For the developed models the analytical dependences for quasi-coordinates, projections of the angular velocity vector and components of the quaternion of orientation corresponding to such rotational motion are obtained. The urgency of taking into account the influence of vibration in traffic modeling on the basis of domestic and foreign literature in the field of navigation, including for the last 10 years. The main sources of vibration are described in detail and what types of oscillations they correspond to - harmonic oscillations occur in moving elements of onboard systems, such as the engine rotor, and in the engine unit and its units there are oscillations that have the character of random broadband noise. Methods of correction of such influence for increase of accuracy of definition of orientation of object are analyzed. The location of the components of the platformless inertial navigation system relative to the vibration sources is considered to be related to the strength of the influence of the vibration environment on the accuracy of the obtained data. Numerical implementations of the models are obtained and the drift error for the third-order orientation algorithm is estimated for several sets of specified parameters in a certain way. The parameters are chosen arbitrarily, but taking into account the existing restrictions on angular motion. The corresponding figures show the result for one of these sets of numerical values (which shows the result of the research in the most detail). The obtained results are compared with the corresponding results for the four-frequency rotation model [1]. The expediency of using new three-frequency models under certain conditions is shown.

Development and Evaluation of Fuzzy Criteria for the Diagnosis of Rheumatoid Arthritis

1996 ◽  
Vol 35 (04/05) ◽  
pp. 334-342 ◽  
Author(s):  
K.-P. Adlassnig ◽  
G. Kolarz ◽  
H. Leitich
Keyword(s):  
Rheumatoid Arthritis ◽  
Reference Model ◽  
American Rheumatism Association ◽  
Uniform Definition ◽  
Sensitivity Rate ◽  
Fuzzy Techniques ◽  
Definition Of ◽  
Different Levels ◽  
Specificity Rate

Abstract:In 1987, the American Rheumatism Association issued a set of criteria for the classification of rheumatoid arthritis (RA) to provide a uniform definition of RA patients. Fuzzy set theory and fuzzy logic were used to transform this set of criteria into a diagnostic tool that offers diagnoses at different levels of confidence: a definite level, which was consistent with the original criteria definition, as well as several possible and superdefinite levels. Two fuzzy models and a reference model which provided results at a definite level only were applied to 292 clinical cases from a hospital for rheumatic diseases. At the definite level, all models yielded a sensitivity rate of 72.6% and a specificity rate of 87.0%. Sensitivity and specificity rates at the possible levels ranged from 73.3% to 85.6% and from 83.6% to 87.0%. At the superdefinite levels, sensitivity rates ranged from 39.0% to 63.7% and specificity rates from 90.4% to 95.2%. Fuzzy techniques were helpful to add flexibility to preexisting diagnostic criteria in order to obtain diagnoses at the desired level of confidence.

Identification of principal screws of two- and three-screw systems

2007 ◽  
Vol 221 (12) ◽  
pp. 1701-1715 ◽  
Author(s):  
J-S Zhao ◽  
F Chu ◽  
Z-J Feng
Keyword(s):  
Screw Theory ◽  
Coordinate Systems ◽  
Third Order ◽  
Analytical Methodology ◽  
Partial Derivatives ◽  
Spatial Mechanisms ◽  
Analysis Theory ◽  
Definition Of ◽  
Derivatives Of ◽  
Homogeneous Linear

The current paper proposes a unified analytical methodology to identify the principal screws of two- and three-screw systems. Based on the definition of the pitch of a screw, it first obtains an identical homogeneous quadric equation. According to functional analysis theory, it is known that the partial derivatives of an identical quadric equation with respect to its variables must be zero. Therefore, the paper deduces a set of linear homogeneous equations that are made up of the partial derivatives of the quadric equation. With the existing criteria of non-zero solutions for homogeneous linear algebra equations, it ultimately obtains the formulas of the principal pitches and the associated principal screws of the system. The most outstanding contribution of this methodology is that it proposes a unified analytical approach to identify the principal pitches and the principal coordinate systems of the second-order and the third-order screw systems. This should be a new contribution to the screw theory and will boost its applications to the kinematics analysis of robots and spatial mechanisms.

Semantics Enhancing Knowledge Discovery and Ontology Engineering Using Mining Techniques

2011 ◽  
pp. 163-188
Author(s):  
Elena Irina Neaga
Keyword(s):  
Knowledge Discovery ◽  
Knowledge Engineering ◽  
Reference Model ◽  
Distributed Processing ◽  
Ontology Engineering ◽  
Software Architectures ◽  
Model Driven ◽  
Architectural Models ◽  
Definition Of ◽  
Comprehensive Framework

This chapter deals with a roadmap on the bidirectional interaction and support between knowledge discovery (Kd) processes and ontology engineering (Onto) mainly directed to provide refined models using common methodologies. This approach provides a holistic literature review required for the further definition of a comprehensive framework and an associated meta-methodology (Kd4onto4dm) based on the existing theories, paradigms, and practices regarding knowledge discovery and ontology engineering as well as closely related areas such as knowledge engineering, machine/ontology learning, standardization issues and architectural models. The suggested framework may adhere to the Iso-reference model for open distributed processing and Omg-model-driven architecture, and associated dedicated software architectures should be defined.

Designing a M-Health Framework for Conceptualizing Mobile Health Systems

2011 ◽  
pp. 1-24 ◽  
Author(s):  
Phillip Olla ◽  
Joseph Tan
Keyword(s):  
Health System ◽  
Health Systems ◽  
Mobile Networks ◽  
High Speed ◽  
Reference Model ◽  
Mobile Telecommunication ◽  
Technological Infrastructure ◽  
Key Dimensions ◽  
Definition Of ◽  
Health Field

The reference model presented in this chapter encourages the breakdown of m-health systems into the following five key dimensions: communication infrastructure: this is a description of the mobile telecommunication technologies and networks; device type: this relates to the type of device being used such as PDA, sensor, or tablet PC; data display: describes how the data will be displayed to the user and transmitted such as images, e-mail and textual data; application purpose: identification of the objective for the m-health system; application domain: definition of the area that the system will be implemented. Healthcare stakeholders and system implementer can use the reference model presented in this chapter to understand the security implications of the proposed system, identify the technological infrastructure, business requirements and operational needs of the m-health systems being implemented. A reference model to encapsulate the emerging m-health field is needed for cumulative progress in this field. Currently, the m-health field is disjointed and it is often unclear what constitutes an m-health system. In the future, m-health applications will take advantage of technological advances such as device miniaturizations, device convergence, high-speed mobile networks, and improved medical sensors. This will lead to the increased diffusion of clinical m-health systems requiring better understanding of the components, which constitute the m-health system.

The M-Health Reference Model

2011 ◽  
pp. 455-473
Author(s):  
Phillip Olla ◽  
Joseph Tan
Keyword(s):  
Health System ◽  
Health Systems ◽  
Mobile Networks ◽  
High Speed ◽  
Reference Model ◽  
Mobile Telecommunication ◽  
Technological Infrastructure ◽  
Key Dimensions ◽  
Definition Of ◽  
Health Field

The reference model presented in this article encourages the breakdown of M-Health systems into the following five key dimensions: (1) Communication Infrastructure: a description of mobile telecommunication technologies and networks; (2) Device Type: the type of device being used, such as PDA, sensor, or tablet PC; (3) Data Display: describes how the data will be displayed to the user and transmitted, such as images, email, and textual data; (4) Application Purpose: identification of the objective for the M-Health system; (5) Application Domain: definition of the area in which the system will be implemented. Healthcare stakeholders and system implementer can use the reference model presented in this article to understand the security implications of the proposed system and to identify the technological infrastructure, business requirements, and operational needs of the M-Health systems being implemented. A reference model that encapsulates the emerging M-Health field is needed for cumulative progress in this field. Currently, the M-Health field is disjointed, and it is often unclear what constitutes an M-Health system. In the future, M-Health applications will take advantage of technological advances such as device miniaturizations, device convergence, high-speed mobile networks, and improved medical sensors. This will lead to the increased diffusion of clinical M-Health systems, which will require better understanding of the components that constitute the M-Health system.

How much drinking water can be saved by using rainwater harvesting on a large urban area? Application to Paris agglomeration

2014 ◽  
Vol 70 (11) ◽  
pp. 1782-1788 ◽  
Author(s):  
Ali Belmeziti ◽  
Olivier Coutard ◽  
Bernard de Gouvello
Keyword(s):  
Drinking Water ◽  
Urban Area ◽  
Potable Water ◽  
Rainwater Harvesting ◽  
Reference Model ◽  
Total Current ◽  
Large Urban Area ◽  
Residential Sector ◽  
Definition Of ◽  
Building Level

This paper is based on a prospective scenario of development of rainwater harvesting (RWH) on a given large urban area (such as metropolitan area or region). In such a perspective, a new method is proposed to quantify the related potential of potable water savings (PPWS) indicator on this type of area by adapting the reference model usually used on the building level. The method is based on four setting-up principles: gathering (definition of buildings-types and municipalities-types), progressing (use of an intermediate level), increasing (choice of an upper estimation) and prioritizing (ranking the stakes of RWH). Its application to the Paris agglomeration shows that is possible to save up to 11% of the total current potable water through the use of RWH. It also shows that the residential sector offers the most important part because it holds two-thirds of the agglomeration PPWS.

Issues in the definition of a project support environment reference model

1993 ◽  
Vol 15 (5) ◽  
pp. 431-443
Author(s):  
A.W Brown ◽  
D.J Carney ◽  
P.H Feiler ◽  
P.A Oberndorf ◽  
M.V Zelkowitz
Keyword(s):  
Reference Model ◽  
Definition Of
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