757,998 research outputs found
Electrode Potential Evaluation of Effect of Inhibitors on the Electrochemical Corrosion Behaviour of Mild Steel Reinforcement in Concrete in H2SO4
The electrochemical corrosion behaviour of mild steel embedded in concrete, and partially immersed in 0.2M
H2SO4, was studied in this investigation at ambient temperature by potential monitoring technique. The
experimental work was performed with a digital multimeter and a Cu/CuSO4 electrode (CSE) as the reference
electrode. Extracts of carica papaya leaves and sodium nitrite (NaNO2) in different concentrations were
separately and in combination, used as inhibitors. This paper reports the observed electrochemical response
from the electrode potential monitoring of the embedded steel rebar during the experiments. The results
obtained, showed a reduction in the active corrosion reactions behaviour of the embedded mild steel in
concrete with added different concentrations of sodium nitrite and the pawpaw leaves extracts in the acidic
test environment. This reduced active corrosion reaction was an indication of corrosion inhibition / protection
characteristic. The observed inhibition was associated with the protective film provided on the embedded
steel’s surface in the concrete by the complex chemical compounds of the plant leaves’ extracts and of the
sodium nitrite with the alkaline composition/environment of the concrete constituents. The protective film
prevented and/or reduced the chloride ions penetration to the steel surface. The combination of c. papaya
extracts and the NaNO2 solution also provided effective corrosion inhibition of the embedded steel by
synergism. The 100% concentration of each of the inhibitors and when in combinations, exhibited the most
effective corrosion inhibition performance in the sulphuric acid test environment
Assessment of a human computer interface prototyping environment
A Human Computer Interface (HCI) prototyping environment with embedded evaluation capability has been successfully assessed which will be valuable in developing and refining HCI standards and evaluating program/project interface development, especially Space Station Freedom on-board displays for payload operations. The HCI prototyping environment is designed to include four components: (1) a HCI format development tool, (2) a test and evaluation simulator development tool, (3) a dynamic, interactive interface between the HCI prototype and simulator, and (4) an embedded evaluation capability to evaluate the adequacy of an HCI based on a user's performance
Integrated Design and Implementation of Embedded Control Systems with Scilab
Embedded systems are playing an increasingly important role in control
engineering. Despite their popularity, embedded systems are generally subject
to resource constraints and it is therefore difficult to build complex control
systems on embedded platforms. Traditionally, the design and implementation of
control systems are often separated, which causes the development of embedded
control systems to be highly time-consuming and costly. To address these
problems, this paper presents a low-cost, reusable, reconfigurable platform
that enables integrated design and implementation of embedded control systems.
To minimize the cost, free and open source software packages such as Linux and
Scilab are used. Scilab is ported to the embedded ARM-Linux system. The drivers
for interfacing Scilab with several communication protocols including serial,
Ethernet, and Modbus are developed. Experiments are conducted to test the
developed embedded platform. The use of Scilab enables implementation of
complex control algorithms on embedded platforms. With the developed platform,
it is possible to perform all phases of the development cycle of embedded
control systems in a unified environment, thus facilitating the reduction of
development time and cost.Comment: 15 pages, 14 figures; Open Access at
http://www.mdpi.org/sensors/papers/s8095501.pd
Ada(R) Test and Verification System (ATVS)
The Ada Test and Verification System (ATVS) functional description and high level design are completed and summarized. The ATVS will provide a comprehensive set of test and verification capabilities specifically addressing the features of the Ada language, support for embedded system development, distributed environments, and advanced user interface capabilities. Its design emphasis was on effective software development environment integration and flexibility to ensure its long-term use in the Ada software development community
Spacecraft attitude control using a smart control system
Traditionally, spacecraft attitude control has been implemented using control loops written in native code for a space hardened processor. The Naval Research Lab has taken this approach during the development of the Attitude Control Electronics (ACE) package. After the system was developed and delivered, NRL decided to explore alternate technologies to accomplish this same task more efficiently. The approach taken by NRL was to implement the ACE control loops using systems technologies. The purpose of this effort was to: (1) research capabilities required of an expert system in processing a classic closed-loop control algorithm; (2) research the development environment required to design and test an embedded expert systems environment; (3) research the complexity of design and development of expert systems versus a conventional approach; and (4) test the resulting systems against the flight acceptance test software for both response and accuracy. Two expert systems were selected to implement the control loops. Criteria used for the selection of the expert systems included that they had to run in both embedded systems and ground based environments. Using two different expert systems allowed a comparison of the real-time capabilities, inferencing capabilities, and the ground-based development environment. The two expert systems chosen for the evaluation were Spacecraft Command Language (SCL), and NEXTPERT Object. SCL is a smart control system produced for the NRL by Interface and Control Systems (ICS). SCL was developed to be used for real-time command, control, and monitoring of a new generation of spacecraft. NEXPERT Object is a commercially available product developed by Neuron Data. Results of the effort were evaluated using the ACE test bed. The ACE test bed had been developed and used to test the original flight hardware and software using simulators and flight-like interfaces. The test bed was used for testing the expert systems in a 'near-flight' environment. The technical approach, the system architecture, the development environments, knowledge base development, and results of this effort are detailed
More on molecular excitations: Dark matter detection in ice
In this paper we investigate di-atomic molecules embedded in ice crystals
under strain. In this environment coherent vibrations of many OH-bonds may be
generated by one WIMP collision. The detection of such multiple-photon signals
may provide a signature of a 100~GeV/c WIMP. To do a proper lab test of
WIMP-induced multi-photon emission is very difficult. We suggest that Ice Cube
make a search for multi-photon events, and investigate whether the rate of such
events exhibits yearly modulation
An Adaptive Design Methodology for Reduction of Product Development Risk
Embedded systems interaction with environment inherently complicates
understanding of requirements and their correct implementation. However,
product uncertainty is highest during early stages of development. Design
verification is an essential step in the development of any system, especially
for Embedded System. This paper introduces a novel adaptive design methodology,
which incorporates step-wise prototyping and verification. With each adaptive
step product-realization level is enhanced while decreasing the level of
product uncertainty, thereby reducing the overall costs. The back-bone of this
frame-work is the development of Domain Specific Operational (DOP) Model and
the associated Verification Instrumentation for Test and Evaluation, developed
based on the DOP model. Together they generate functionally valid test-sequence
for carrying out prototype evaluation. With the help of a case study 'Multimode
Detection Subsystem' the application of this method is sketched. The design
methodologies can be compared by defining and computing a generic performance
criterion like Average design-cycle Risk. For the case study, by computing
Average design-cycle Risk, it is shown that the adaptive method reduces the
product development risk for a small increase in the total design cycle time.Comment: 21 pages, 9 figure
Test Automation Framework for Embedded Systems
Embedded systems are everywhere! Electronic systems in just about every engineering
market segment are classified as embedded systems, consumer electronics, medical, automotive,
avionics, etc. Embedded systems differ from more conventional systems, such as
computers, because they are limited to the embedded hardware, are designed to perform
a dedicated function and have high quality and reliability requirements.
Due to these characteristics, this type of system is strongly related to critical systems.
Critical systems are systems that in the event of a failure can cause damage to living
beings or the environment. Thus, it is necessary to ensure a high level of correctness
in this type of systems. One way to increase the correctness of a system is through the
process of testing. However, testing embedded systems presents a degree of difficulty
because they are typically closed systems and work with real-time data that is difficult to
reproduce and are non-deterministic.
In this way, and with the collaboration of Altran Portugal, we intend to solve this
problem by developing a framework that allows test automation for embedded systems.
Automating the test data creation and execution of test case increases the quality of these
systems by identifying defects to be fixed in a more efficient way.
To this end, a survey of automation tools is done and each tool evaluated according
to a set of criteria defined when designing the solution. The selected tool is Robot Framework,
which is a widely used tool in the web and desktop application. Thus, integrating
such a proficient tool in the embedded environment elevates the test automation in the
embedded systems context.
Then, we test the concept developed in this dissertation by executing functional tests
in embedded systems that follow a model-driven development approach
Spike Processing on an Embedded Multi-task Computer: Image Reconstruction
There is an emerging philosophy, called Neuro-informatics, contained
in the Artificial Intelligence field, that aims to emulate how living beings do tasks
such as taking a decision based on the interpretation of an image by emulating spiking
neurons into VLSI designs and, therefore, trying to re-create the human brain at
its highest level. Address-Event-Representation (AER) is a communication protocol
that has embedded part of the processing. It is intended to transfer spikes between
bioinspired chips. An AER based system may consist of a hierarchical structure with
several chips that transmit spikes among them in real-time, while performing some
processing. There are several AER tools to help to develop and test AER based systems.
These tools require the use of a computer to allow the higher level processing of
the event information, reaching very high bandwidth at the AER communication level.
We propose the use of an embedded platform based on a multi-task operating system
to allow both, the AER communication and processing without the requirement of either
a laptop or a computer. In this paper, we present and study the performance of a
new philosophy of a frame-grabber AER tool based on a multi-task environment. This
embedded platform is based on the Intel XScale processor which is governed by an
embedded GNU/Linux system. We have connected and programmed it for processing
Address-Event information from a spiking generator.Ministerio de Educación y Ciencia TEC2006-11730-C03-0
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