Abstract: In this paper we intend to ascertain the state of the art on multifingered end-effectors, also known as robotic hands or dexterous robot hands, and propose an experimental setup for an innovative task based design approach, involving cutting edge technologies in motion capture. After an initial description of the capabilities and complexity of a human hand when grasping objects, in order to point out the importance of replicating it, we analyze the mechanical and kinematical structure of some important works carried out all around the world in the last three decades and also review the actuators and sensing technologies used. Finally we describe a new design philosophy proposing an experimental setup for the first stage using recent developments in human body motion capture systems that might lead to lighter and always more dexterous robotic hands.
Abstract: This experiment discusses the effects of fracture
parameters such as depth, length, width, angle and the number of the
fracture to the conductance properties of laterite using the DUK-2B
digital electrical measurement system combined with the method of
simulating the fractures. The results of experiment show that the
changes of fracture parameters produce effects to the conductance
properties of laterite. There is a clear degressive period of the
conductivity of laterite during increasing the depth, length, width, or
the angle and the quantity of fracture gradually. When the depth of
fracture exceeds the half thickness of the soil body, the conductivity of
laterite shows evidently non-linear diminishing pattern and the
amplitude of decrease tends to increase. The length of fracture has
fewer effects than the depth to the conductivity. When the width of
fracture reaches some fixed values, the change of the conductivity is
less sensitive to the change of the width, and at this time, the
conductivity of laterite maintains at a stable level. When the angle of
fracture is less than 45°, the decrease of the conductivity is more
clearly as the angle increases. But when angle is more than 45°,
change of the conductivity is relatively gentle as the angle increases.
The increasing quantity of the fracture causes the other fracture
parameters having great impact on the change of conductivity. When
moisture content and temperature were unchanged, depth and angle of
fractures are the major factors affecting the conductivity of laterite
soil; quantity, length, and width are minor influencing factors. The
sensitivity of fracture parameters affect conductivity of laterite soil is:
depth >angles >quantity >length >width.
Abstract: With the approaching of digital era, various interactive
service platforms and systems support human beings- needs in lives by
different contents and measures. Design strategies have gradually
turned from function-based to user-oriented, and are often customized.
In other words, how designers include users- value reaction in creation
becomes the goal. Creative design service of interior design requires
positive interaction and communication to allow users to obtain full
design information, recognize the style and process of personal needs,
develop creative service design, lower communication time and cost
and satisfy users- sense of achievement. Thus, by constructing a
co-design method, based on the communication between interior
designers and users, this study recognizes users- real needs and
provides the measure of co-design for designers and users.
Abstract: Benefits to the organisation are just as important as technical ability when it comes to software success. The challenge is to provide industry with professionals who understand this. In other words: How to teach computer engineering students to look beyond technology, and at the benefits of software to organizations? This paper reports on the conceptual design of a section of the computer networks module aimed to sensitize the students to the organisational context.
Checkland focuses on different worldviews represented by various role players in the organisation. He developed the Soft Systems Methodology that guides purposeful action in organisations, while incorporating different worldviews in the modeling process. If we can sensitize students to these methods, they are likely to appreciate the wider context of application of system software. This paper will provide literature on these concepts as well as detail on how the students will be guided to adopt these concepts.
Abstract: The purpose of this study is to research on thoughts transmitted from virtual fitting-room and to deduce discussion in an auxiliary narrative way. The research structure is based on 3D virtual fitting-room as the research subject. Initially, we will discuss the principles of narrate study, User Demand and so on by using a narrative design pattern to transmit their objective indications of “people-situation-reason-object", etc, and then to analyze the virtual fitting-room examples that are able to provide a new thinking for designers who engaged in clothing related industry – which comes in “story telling" and “user-centered design" forms. Clothing designs are not just to cover up the body to keep warm but to draw closer to people-s demand physiologically and psychologically through interactive designs so as to achieve cognition between people and environment. In the “outside" goal of clothing-s functional designs, we use tribal group-s behavior characteristics to “transform" the existing personal cultural stories, and “reform" them to design appropriate interactive products. Synthesizing the above matters, apart from being able to regard “narrate" as a kind of functional thinking process, we are also able to regard it as a kind of choice, arrangement and an activity of story expression, allowing interactive design-s spirit, product characteristics and experience ideas be transmitted to target tribal group in a visual image performance method. It is a far more confident and innovative attempt, and meanwhile, able to achieve entertainment, joyful and so forth fundamental interactive transmissions. Therefore, this study takes “user-centered design" thinking as a basis to establish a set of clothing designs with interactive experience patterns and to assist designers to examine the five sensual feeling of interactive demands in order to initiate a new value in textile industry.
Abstract: The aim of this study was to evaluate the sensitivity
of a range of EEG indices to time-on-task effects and to a workload
manipulation (cueing), during performance of a resource-limited
vigilance task. Effects of task period and cueing on performance and
subjective state response were consistent with previous vigilance
studies and with resource theory. Two EEG indices – the Task Load
Index (TLI) and global lower frequency (LF) alpha power – showed
effects of task period and cueing similar to those seen with correct
detections. Across four successive task periods, the TLI declined and
LF alpha power increased. Cueing increased TLI and decreased LF
alpha. Other indices – the Engagement Index (EI), frontal theta and
upper frequency (UF) alpha failed to show these effects. However, EI
and frontal theta were sensitive to interactive effects of task period
and cueing, which may correspond to a stronger anxiety response to
the uncued task.
Abstract: The Institute of Product Development is dealing
with the development, design and dimensioning of micro components
and systems as a member of the Collaborative Research
Centre 499 “Design, Production and Quality Assurance of
Molded micro components made of Metallic and Ceramic Materials".
Because of technological restrictions in the miniaturization
of conventional manufacturing techniques, shape and
material deviations cannot be scaled down in the same proportion
as the micro parts, rendering components with relatively
wide tolerance fields. Systems that include such components
should be designed with this particularity in mind, often requiring
large clearance. On the end, the output of such systems
results variable and prone to dynamical instability. To save
production time and resources, every study of these effects
should happen early in the product development process and
base on computer simulation to avoid costly prototypes. A
suitable method is proposed here and exemplary applied to a
micro technology demonstrator developed by the CRC499. It
consists of a one stage planetary gear train in a sun-planet-ring
configuration, with input through the sun gear and output
through the carrier. The simulation procedure relies on ordinary
Multi Body Simulation methods and subsequently adds
other techniques to further investigate details of the system-s
behavior and to predict its response. The selection of the relevant
parameters and output functions followed the engineering
standards for regular sized gear trains. The first step is to
quantify the variability and to reveal the most critical points of
the system, performed through a whole-mechanism Sensitivity
Analysis. Due to the lack of previous knowledge about the system-s
behavior, different DOE methods involving small and
large amount of experiments were selected to perform the SA.
In this particular case the parameter space can be divided into
two well defined groups, one of them containing the gear-s profile
information and the other the components- spatial location.
This has been exploited to explore the different DOE techniques
more promptly. A reduced set of parameters is derived for
further investigation and to feed the final optimization process,
whether as optimization parameters or as external perturbation
collective. The 10 most relevant perturbation factors and 4 to 6
prospective variable parameters are considered in a new, simplified
model. All of the parameters are affected by the mentioned
production variability. The objective functions of interest
are based on scalar output-s variability measures, so the
problem becomes an optimization under robustness and reliability constrains. The study shows an initial step on the development
path of a method to design and optimize complex micro
mechanisms composed of wide tolerated elements accounting
for the robustness and reliability of the systems- output.
Abstract: Utilization of various sensors has made it possible to
extend capabilities of industrial robots. Among these are vision
sensors that are used for providing visual information to assist robot
controllers. This paper presents a method of integrating a vision
system and a simulation program with an industrial robot. The vision
system is employed to detect a target object and compute its location
in the robot environment. Then, the target object-s information is sent
to the robot controller via parallel communication port. The robot
controller uses the extracted object information and the simulation
program to control the robot arm for approaching, grasping and
relocating the object. This paper presents technical details of system
components and describes the methodology used for this integration.
It also provides a case study to prove the validity of the methodology
developed.
Abstract: This paper focuses on reducing the power consumption
of wireless sensor networks. Therefore, a communication protocol
named LEACH (Low-Energy Adaptive Clustering Hierarchy) is modified.
We extend LEACHs stochastic cluster-head selection algorithm
by a modifying the probability of each node to become cluster-head
based on its required energy to transmit to the sink. We present
an efficient energy aware routing algorithm for the wireless sensor
networks. Our contribution consists in rotation selection of clusterheads
considering the remoteness of the nodes to the sink, and then,
the network nodes residual energy. This choice allows a best distribution
of the transmission energy in the network. The cluster-heads
selection algorithm is completely decentralized. Simulation results
show that the energy is significantly reduced compared with the
previous clustering based routing algorithm for the sensor networks.
Abstract: This paper features the proposed modeling and design
of a Robust Decentralized Periodic Output Feedback (RDPOF)
control technique for the active vibration control of smart flexible
multimodel Euler-Bernoulli cantilever beams for a multivariable
(MIMO) case by retaining the first 6 vibratory modes. The beam
structure is modeled in state space form using the concept of
piezoelectric theory, the Euler-Bernoulli beam theory and the Finite
Element Method (FEM) technique by dividing the beam into 4 finite
elements and placing the piezoelectric sensor / actuator at two finite
element locations (positions 2 and 4) as collocated pairs, i.e., as
surface mounted sensor / actuator, thus giving rise to a multivariable
model of the smart structure plant with two inputs and two outputs.
Five such multivariable models are obtained by varying the
dimensions (aspect ratios) of the aluminum beam, thus giving rise to
a multimodel of the smart structure system. Using model order
reduction technique, the reduced order model of the higher order
system is obtained based on dominant eigen value retention and the
method of Davison. RDPOF controllers are designed for the above 5
multivariable-multimodel plant. The closed loop responses with the
RDPOF feedback gain and the magnitudes of the control input are
observed and the performance of the proposed multimodel smart
structure system with the controller is evaluated for vibration control.
Abstract: Non-uniform current distribution in polymer
electrolyte membrane fuel cells results in local over-heating,
accelerated ageing, and lower power output than expected. This
issue is very critical when fuel cell experiences water flooding. In
this work, the performance of a PEM fuel cell is investigated under
cathode flooding conditions. Two-dimensional partially flooded
GDL models based on the conservation laws and electrochemical
relations are proposed to study local current density distributions
along flow fields over a wide range of cell operating conditions.
The model results show a direct association between cathode inlet
humidity increases and that of average current density but the
system becomes more sensitive to flooding. The anode inlet
relative humidity shows a similar effect. Operating the cell at
higher temperatures would lead to higher average current densities
and the chance of system being flooded is reduced. In addition,
higher cathode stoichiometries prevent system flooding but the
average current density remains almost constant. The higher anode
stoichiometry leads to higher average current density and higher
sensitivity to cathode flooding.
Abstract: Proprietary sensor network systems are typically expensive, rigid and difficult to incorporate technologies from other vendors. When using competing and incompatible technologies, a non-proprietary system is complex to create because it requires significant technical expertise and effort, which can be more expensive than a proprietary product. This paper presents the Sensor Abstraction Layer (SAL) that provides middleware architectures with a consistent and uniform view of heterogeneous sensor networks, regardless of the technologies involved. SAL abstracts and hides the hardware disparities and specificities related to accessing, controlling, probing and piloting heterogeneous sensors. SAL is a single software library containing a stable hardware-independent interface with consistent access and control functions to remotely manage the network. The end-user has near-real-time access to the collected data via the network, which results in a cost-effective, flexible and simplified system suitable for novice users. SAL has been used for successfully implementing several low-cost sensor network systems.
Abstract: Due to heavy energy constraints in WSNs clustering is
an efficient way to manage the energy in sensors. There are many
methods already proposed in the area of clustering and research is
still going on to make clustering more energy efficient. In our paper
we are proposing a minimum spanning tree based clustering using
divide and conquer approach. The MST based clustering was first
proposed in 1970’s for large databases. Here we are taking divide and
conquer approach and implementing it for wireless sensor networks
with the constraints attached to the sensor networks. This Divide and
conquer approach is implemented in a way that we don’t have to
construct the whole MST before clustering but we just find the edge
which will be the part of the MST to a corresponding graph and
divide the graph in clusters there itself if that edge from the graph can
be removed judging on certain constraints and hence saving lot of
computation.
Abstract: Wireless Sensor Networks (WSNs) have attracted the attention of many researchers. This has resulted in their rapid integration in very different areas such as precision agriculture,environmental monitoring, object and event detection and military surveillance. Due to the current WSN characteristics this technology is specifically useful in industrial areas where security, reliability and autonomy are basic, such as nuclear power plants, chemical plants, and others. In this paper we present a system based on WSNs to monitor environmental conditions around and inside a nuclear power plant, specifically, radiation levels. Sensor nodes, equipped with radiation sensors, are deployed in fixed positions throughout the plant. In addition, plant staff are also equipped with mobile devices with higher capabilities than sensors such as for example PDAs able to monitor radiation levels and other conditions around them. The system enables communication between PDAs, which form a Mobile Ad-hoc Wireless Network (MANET), and allows workers to monitor remote conditions in the plant. It is particularly useful during stoppage periods for inspection or in the event of an accident to prevent risk situations.
Abstract: The major challenge faced by wireless sensor networks is security. Because of dynamic and collaborative nature of sensor networks the connected sensor devices makes the network unusable. To solve this issue, a trust model is required to find malicious, selfish and compromised insiders by evaluating trust worthiness sensors from the network. It supports the decision making processes in wireless sensor networks such as pre key-distribution, cluster head selection, data aggregation, routing and self reconfiguration of sensor nodes. This paper discussed the kinds of trust model, trust metrics used to address attacks by monitoring certain behavior of network. It describes the major design issues and their countermeasures of building trust model. It also discusses existing trust models used in various decision making process of wireless sensor networks.
Abstract: Tanzania secondary schools in rural areas are geographically and socially isolated, hence face a number of problems in getting learning materials resulting in poor performance in National examinations. E-learning as defined to be the use of information and communication technology (ICT) for supporting the educational processes has motivated Tanzania to apply ICT in its education system. There has been effort to improve secondary school education using ICT through several projects. ICT for e-learning to Tanzania rural secondary school is one of the research projects conceived by the University of Dar-es-Salaam through its College of Engineering and Technology. The main objective of the project is to develop a tool to enable ICT support rural secondary school. The project is comprehensive with a number of components, one being development of e-learning management system (e-LMS) for Tanzania secondary schools. This paper presents strategies of developing e-LMS. It shows the importance of integrating action research methodology with the modeling methods as presented by model driven architecture (MDA) and the usefulness of Unified Modeling Language (UML) on the issue of modeling. The benefit of MDA will go along with the development based on software development life cycle (SDLC) process, from analysis and requirement phase through design and implementation stages as employed by object oriented system analysis and design approach. The paper also explains the employment of open source code reuse from open source learning platforms for the context sensitive development of the e-LMS for Tanzania secondary schools.
Abstract: To develop a process of extracting pixel values over the using of satellite remote sensing image data in Thailand. It is a very important and effective method of forecasting rainfall. This paper presents an approach for forecasting a possible rainfall area based on pixel values from remote sensing satellite images. First, a method uses an automatic extraction process of the pixel value data from the satellite image sequence. Then, a data process is designed to enable the inference of correlations between pixel value and possible rainfall occurrences. The result, when we have a high averaged pixel value of daily water vapor data, we will also have a high amount of daily rainfall. This suggests that the amount of averaged pixel values can be used as an indicator of raining events. There are some positive associations between pixel values of daily water vapor images and the amount of daily rainfall at each rain-gauge station throughout Thailand. The proposed approach was proven to be a helpful manual for rainfall forecasting from meteorologists by which using automated analyzing and interpreting process of meteorological remote sensing data.
Abstract: A compact 1x3 power splitter based on Photonic
Crystal Waveguides (PCW) with flexible power splitting ratio is
presented in this paper. Multimode interference coupler (MMI) is
integrated with PCW. The device size reduction compared with the
conventional MMI power splitter is attributed to the large dispersion
of the PCW. Band Solve tool is used to calculate the band structure of
PCW. Finite Difference Time Domain (FDTD) method is adopted to
simulate the relevant structure at 1550nm wavelength. The device is
polarization insensitive and allows the control of output (o/p) powers
within certain percentage points for both polarizations.
Abstract: Fuzzy controllers are potential candidates for the
control of nonlinear, time variant and also complicated systems. Anti
lock brake system (ABS) which is a nonlinear system, may not be
easily controlled by classical control methods. An intelligent Fuzzy
control method is very useful for this kind of nonlinear system. A
typical antilock brake system (ABS) by sensing the wheel lockup,
releases the brakes for a short period of time, and then reapplies again
the brakes when the wheel spins up. In this paper, an intelligent fuzzy
ABS controller is designed to adjust slipping performance for variety
of roads. There are tow major sections in the proposing control
system. First section consists of tow Fuzzy-Logic Controllers (FLC)
providing optimal brake torque for both front and rear wheels.
Second section which is also a FLC provides required amount of slip
and torque references properties for different kind of roads.
Simulation results of our proposed intelligent ABS for three different
kinds of road show more reliable and better performance in compare
with two other break systems.
Abstract: With the advancement of wireless sensor network technology,
its practical utilization is becoming an important challange.
This paper overviews my past environmental monitoring project,
and discusses the process of starting the monitoring by classifying
it into four steps. The steps to start environmental monitoring can
be complicated, but not well discussed by researchers of wireless
sensor network technology. This paper demonstrates our activity and
challenges in each of the four steps to ease the process, and argues
future challenges to enable quick start of environmental monitoring.