3,929 research outputs found
A framework for effective management of condition based maintenance programs in the context of industrial development of E-Maintenance strategies
CBM (Condition Based Maintenance) solutions are increasingly present in industrial systems due to two
main circumstances: rapid evolution, without precedents, in the capture and analysis of data and
significant cost reduction of supporting technologies. CBM programs in industrial systems can become
extremely complex, especially when considering the effective introduction of new capabilities provided
by PHM (Prognostics and Health Management) and E-maintenance disciplines. In this scenario, any CBM
solution involves the management of numerous technical aspects, that the maintenance manager needs
to understand, in order to be implemented properly and effectively, according to the company’s strategy.
This paper provides a comprehensive representation of the key components of a generic CBM solution,
this is presented using a framework or supporting structure for an effective management of the CBM
programs. The concept “symptom of failure”, its corresponding analysis techniques (introduced by ISO
13379-1 and linked with RCM/FMEA analysis), and other international standard for CBM open-software
application development (for instance, ISO 13374 and OSA-CBM), are used in the paper for the
development of the framework. An original template has been developed, adopting the formal structure
of RCM analysis templates, to integrate the information of the PHM techniques used to capture the failure
mode behaviour and to manage maintenance. Finally, a case study describes the framework using the
referred template.Gobierno de Andalucía P11-TEP-7303 M
High Linearity Millimeter Wave Power Amplifiers with Novel Linearizer Techniques
Millimeter-wave communications have experienced phenomenal growth in recent
years when limited frequency spectrum is occupied by the ever-developing communication
services. The power amplifier, as the key component in the transmitter/receiver module
of communication systems, affects performance of the whole system directly and receives
much attention.
For minimized distortion and optimum system performance, the non-constant en-
velope modulation schemes used in communication systems have challenging requirements
on linearity. As linearity is related to communication quality directly, several linearization
techniques, such as predistortion and feedforward, are applied to power amplifier design.
Predistortion method has the advantages over other techniques in relatively simple struc-
ture and reasonable linearity improvement. But current predistortion circuits have quite
limited performance improvement and relatively large insertion loss, which indicate the
need for further research. In most of millimeter-wave amplifier design, great effort has
been spent on output power or gain, while linearity is often ignored. As almost all the
predistortion circuits operate at the RF frequencies, the linearized millimeter-wave com-
munication circuit is still relatively immature and very challenging.
This project is dedicated to solve the linearity problem faced by millimeter-wave
power amplifier in communication systems, which lacks of e®ective techniques in this field.
Linearity improvement with the predistortion method will be the key issue in this project
and some original ideas for predistortion circuit design will be applied to millimeter-wave
amplifiers.
In this thesis, several predistortion circuits with novel structure were proposed,
which provide a new approach for linearity improvement for millimeter-wave power am-
plifier. A millimeter-wave power ampli¯er for LMDS applications built on GaAs pHEMT
technology was developed to a high engineering standard, which works as the test bench
for linearization. Actual operation and parasitic elements at tens of gigahertz have been
taken into consideration during the design.
Firstly, two novel predistorter structures based on the amplifier were proposed, one
is based on an amplifier with a fixed bias circuit and the other is based on an amplifier with
a nonlinear signal dependant bias circuit. These novel structures can improve the linearity
while improving other metrics simultaneously, which can effectively solve the problem of
insertion loss faced by the conventional structures. Besides this, an original predistortion
circuit design methodology derived from frequency to signal amplitude transformation was
proposed. Based on this methodology, several transfer functions were proposed and related
predistortion circuits were built to linearize the power amplifier. As this methodology is
quite different from the traditional approach, it can improve the linearity signifficantly
while other metrics are affected slightly and has a broad prospect for application
High Linearity Millimeter Wave Power Amplifiers with Novel Linearizer Techniques
Millimeter-wave communications have experienced phenomenal growth in recent
years when limited frequency spectrum is occupied by the ever-developing communication
services. The power amplifier, as the key component in the transmitter/receiver module
of communication systems, affects performance of the whole system directly and receives
much attention.
For minimized distortion and optimum system performance, the non-constant en-
velope modulation schemes used in communication systems have challenging requirements
on linearity. As linearity is related to communication quality directly, several linearization
techniques, such as predistortion and feedforward, are applied to power amplifier design.
Predistortion method has the advantages over other techniques in relatively simple struc-
ture and reasonable linearity improvement. But current predistortion circuits have quite
limited performance improvement and relatively large insertion loss, which indicate the
need for further research. In most of millimeter-wave amplifier design, great effort has
been spent on output power or gain, while linearity is often ignored. As almost all the
predistortion circuits operate at the RF frequencies, the linearized millimeter-wave com-
munication circuit is still relatively immature and very challenging.
This project is dedicated to solve the linearity problem faced by millimeter-wave
power amplifier in communication systems, which lacks of e®ective techniques in this field.
Linearity improvement with the predistortion method will be the key issue in this project
and some original ideas for predistortion circuit design will be applied to millimeter-wave
amplifiers.
In this thesis, several predistortion circuits with novel structure were proposed,
which provide a new approach for linearity improvement for millimeter-wave power am-
plifier. A millimeter-wave power ampli¯er for LMDS applications built on GaAs pHEMT
technology was developed to a high engineering standard, which works as the test bench
for linearization. Actual operation and parasitic elements at tens of gigahertz have been
taken into consideration during the design.
Firstly, two novel predistorter structures based on the amplifier were proposed, one
is based on an amplifier with a fixed bias circuit and the other is based on an amplifier with
a nonlinear signal dependant bias circuit. These novel structures can improve the linearity
while improving other metrics simultaneously, which can effectively solve the problem of
insertion loss faced by the conventional structures. Besides this, an original predistortion
circuit design methodology derived from frequency to signal amplitude transformation was
proposed. Based on this methodology, several transfer functions were proposed and related
predistortion circuits were built to linearize the power amplifier. As this methodology is
quite different from the traditional approach, it can improve the linearity signifficantly
while other metrics are affected slightly and has a broad prospect for application
Model-Driven Design and Development of Flexible Automated Production Control Configurations for Industry 4.0
The continuous changes of the market and customer demands have forced modern automation systems to provide stricter Quality of service (QoS) requirements. This work is centered in automation production system flexibility, understood as the ability to shift from one controller configuration to a different one, in the most quick and cost-effective way, without disrupting its normal operation. In the manufacturing field, this allows to deal with non-functional requirements such as assuring control system availability or workload balancing, even in the case of failure of a machine, components, network or controllers. Concretely, this work focuses on flexible applications at production level, using Programmable Logic Controllers (PLCs) as primary controllers. The reconfiguration of the control system is not always possible as it depends on the process state. Thus, an analysis of the system state is necessary to make a decision. In this sense, architectures based on industrial Multi Agent Systems (MAS) have been used to provide this support at runtime. Additionally, the introduction of these mechanisms makes the design and the implementation of the control system more complex. This work aims at supporting the design and development of such flexible automation production systems, through the proposed model-based framework. The framework consists of a set of tools that, based on models, automate the generation of control code extensions that add flexibility to the automation production system, according to industry 4.0 paradigm.This work was financed by MCIU/AEI/FEDER, UE (grant number RTI2018-096116-B-I00) and by GV/EJ (grant number IT1324-19)
Study of the Business Model of three Earth Observation (EO) companies already present in the Very Low Earth Orbit market (VLEO)
The emergence of a new private spaceflight industry has taken the Earth Observation (EO) sector by surprise. NewSpace companies are challenging the traditional satellite sector by addressing their services to mass market requirements of high-quality and low-cost EO. As part of the DISCOVERER project, this study aims to determine the Key Success Factors to consider by a new EO company at Low Earth Orbit (LEO). Hence, three businesses fitting the description were analyzed with the Case Study Methodology to establish their Business Model Canvas (BMC), associated Patterns, and Key Success Factors. The investigation consolidated the newly proposed Democratizing Business Model Pattern and added new characteristics. Successful EO NewSpace firms are getting divided between integrated operators, integrated manufacturers, and end-user specialists. A new EO company should consider the Democratizing Pattern success factors and the Vertically Integrated Strategies (VIS), depending on its disruptive idea and resource capabilities. Further research is needed to identify new factors, strengthen the validity of the Pattern, and VIS tendencies
Spartan Daily, September 21, 1989
Volume 93, Issue 14https://scholarworks.sjsu.edu/spartandaily/7874/thumbnail.jp
Methodologies for CIM systems integration in small batch manufacturing
This thesis is concerned with identifying the problems and constraints faced by
small batch manufacturing companies during the implementation of Computer
Integrated Manufacturing (CIM). The main aim of this work is to recommend
generic solutions to these problems with particular regard to those constraints
arising because of the need for ClM systems integration involving both new and
existing systems and procedures. The work has involved the application of
modern computer technologies, including suitable hardware and software tools, in
an industrial environment.
Since the research has been undertaken with particular emphasis on the industrial
implementor's viewpoint, it is supported by the results of a two phased
implementation of computer based control systems within the machine shop of a
manufacturing company. This involved the specific implementation of a
Distributed Numerical Control system on a single machine in a group technology
cell of machines followed by the evolution of this system into Cell and Machine
Management Systems to provide a comprehensive decision support and
information distribution facility for the foremen and uperators within the cell. The
work also required the integration of these systems with existing Factory level
manufacturing control and CADCAM functions. Alternative approaches have
been investigated which may have been applicable under differing conditions and
the implications that this specific work has for CIM systems integration in small
batch manufacturing companies evaluated with regard not only to the users within
an industrial company but also the systems suppliers external to the company.
The work has resulted in certain generic contributions to knowledge by
complementing ClM systems integration research with regard to problems
encountered; cost implications; the use of appropriate methodologies including
the role of emerging international standard methods, tools and technologies and
also the importance of 'human integration' when implementing CIM systems in a
real industrial situation
The Rockefeller Foundation Program NYC Cultural Innovation Fund: Evaluation
The Rockefeller Foundation launched the NYC Cultural Innovation Fund (CIF) in2007. Since then, it has supported six rounds of annual grantmaking, resulting in99 grants to 86 nonprofit cultural and community organizations in New York City.Grants across the six years 2007–2012 totaled $16.3 million.An Evaluation Team headed by Helicon Collaborative assessed CIF for the periodDecember 2012 to May 2013 based on Terms of Reference issued by the RockefellerFoundation in September 2012
Effectiveness of OPC for systems integration in the process control information architecture
A Process is defined as the progression to some particular end or objective through a logical and orderly sequence of events. Various devices (e.g., actuators, limit switches, motors, sensors, etc.) play a significant role in making sure that the process attains its objective (e.g., maintaining the furnace temperature within an acceptable limit). To do these things effectively, manufacturers need to access data from the plant floor or devices and integrate those into their control applications, which maybe one of the off the shelf tools such as Supervisory Control and Data Acquisition (SCADA), Distributed Control System (DCS), or Programmable Logic Controllers (PLC). A number of vendors have devised their own Data Acquisition Networks or Process Control Architectures (e.g., PROFIBUS, DEVICENET, INTERBUS, ETHERNET I/P, etc.) that claim to be open to or interoperable with a number of third party devices or products that make process data available to the Process or Business Management level. In reality this is far from what it is claimed to be. Due to the problem of interoperability, a manufacturer is forced to be bound, either with the solutions provided by a single vendor or with the writing of a driver for each hardware device that is accessed by a process application. Today\u27s manufacturers are looking for advanced distributed object technologies that allow for seamless exchange of information across plant networks as a means of integrating the islands of automation that exist in their manufacturing operations. OLE for Process Control (OPC) works to significantly reduce the time, cost, and effort required in writing custom interfaces for hundreds of different intelligent devices and networks in use today. The objective of this thesis is to explore the OLE for Process Control (OPC) technology in depth by highlighting its need in industry and by using the OPC technology in an application in which data from a process controlled by Siemens Simatic S7 PLC are shared with a client application running in LabVTEW6i
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