Abstract: The excellent suitability of the externally excited synchronous
machine (EESM) in automotive traction drive applications
is justified by its high efficiency over the whole operation range and
the high availability of materials. Usually, maximum efficiency is
obtained by modelling each single loss and minimizing the sum of all
losses. As a result, the quality of the optimization highly depends on
the precision of the model. Moreover, it requires accurate knowledge
of the saturation dependent machine inductances. Therefore, the
present contribution proposes a method to minimize the overall losses
of a salient pole EESM and its inverter in steady state operation based
on measurement data only. Since this method does not require any
manufacturer data, it is well suited for an automated measurement
data evaluation and inverter parametrization. The field oriented control
(FOC) of an EESM provides three current components resp. three
degrees of freedom (DOF). An analytic minimization of the copper
losses in the stator and the rotor (assuming constant inductances) is
performed and serves as a first approximation of how to choose the
optimal current reference values. After a numeric offline minimization
of the overall losses based on measurement data the results are
compared to a control strategy that satisfies cos (ϕ) = 1.
Abstract: Green propellants used for satellite-level propulsion
system become attractive in recent years because the non-toxicity and
lower requirements of safety protection. One of the green propellants,
high-concentration hydrogen peroxide H2O2 solution (≥70% w/w,
weight concentration percentage), often known as high-test peroxide
(HTP), is considered because it is ITAR-free, easy to manufacture and
the operating temperature is lower than traditional monopropellant
propulsion. To establish satellite propulsion technology, the National
Space Organization (NSPO) in Taiwan has initialized a long-term
cooperation project with the National Cheng Kung University to
develop compatible tank and thruster. An experimental propulsion
payload has been allocated for the future self-reliant satellite to
perform orbit transfer and maintenance operations. In the present
research, an 1-Newton thruster prototype is designed and the thrusting
force is measured by a pendulum-type platform. The preliminary
hot-firing test at ambient environment showed the generated thrust and
the specific impulse are about 0.7 Newton and 102 seconds,
respectively.
Abstract: The right information at the right time influences the
enterprise and technical success. Sharing knowledge among members
of a big organization may be a complex activity. And as long as the
knowledge is not shared, can not be exploited by the organization.
There are some mechanisms which can originate knowledge sharing.
It is intended, in this paper, to trigger these mechanisms by using
semantic nets. Moreover, the intersection and overlapping of terms
and sub-terms, as well as their relationships will be described through
the mereology science for the whole knowledge sharing system. It is
proposed a knowledge system to supply to operators with the right
information about a specific process and possible risks, e.g. at the
assembly process, at the right time in an automated manufacturing
environment, such as at the automotive industry.
Abstract: The concept of flexible manufacturing is highly
appealing in gaining a competitive edge in the market by quickly
adapting to the changing customer needs. Scheduling jobs on flexible
manufacturing systems (FMSs) is a challenging task of managing the
available flexibility on the shop floor to react to the dynamics of the
environment in real-time. In this paper, an agent-oriented scheduling
framework that can be integrated with a real or a simulated FMS is
proposed. This framework works in stochastic environments with a
dynamic model of job arrival. It supports a hierarchical cooperative
scheduling that builds on the available flexibility of the shop floor.
Testing the framework on a model of a real FMS showed the
capability of the proposed approach to overcome the drawbacks of
the conventional approaches and maintain a near optimal solution
despite the dynamics of the operational environment.
Abstract: The fact that traditional food safety system in the
absence of food safety culture is inadequate has recently become a
cause of concern for food safety professionals and other stakeholders.
Focusing on implementation of traditional food safety system i.e
HACCP prerequisite program and HACCP without the presence of
food safety culture in the food industry has led to the processing,
marketing and distribution of contaminated foods. The results of this
are regular out breaks of food borne illnesses and recalls of foods
from retail outlets with serious consequences to the consumers and
manufacturers alike. This article will consider the importance of food
safety culture, the cases of outbreaks and recalls that occurred when
companies did not make food safety culture a priority. Most
importantly, the food safety cultures of some food industries in South
Africa were assessed from responses to questionnaires from food
safety/food industry professionals in Durban South Africa. The
article was concluded by recommending that both food
industry employees and employers alike take food safety culture
seriously.
Abstract: Abstraction of water from the dry river sand-beds is
well-known as an alternative source of water during dry seasons.
Internally, because of the form of sand particles, voids are created
which can store water in the riverbeds. Large rivers are rare in South
Africa. Many rivers are sand river types and without water during the
prolonged dry periods. South Africa has not taken full advantage of
water storage in sand as a solution to the growing water scarcity both
in urban and rural areas. The paper reviews the benefits of run-off
storage in sand reservoirs gained from other arid areas and need for
adoption in rural areas of South Africa as an alternative water supply
where it is probable.
Abstract: Rotating stages in semiconductor, display industry and many other fields require challenging accuracy to perform their functions properly. Especially, Axis of rotation error on rotary system is significant; such as the spindle error motion of the aligner, wire bonder and inspector machine which result in the poor state of manufactured goods. To evaluate and improve the performance of such precision rotary stage, unessential movements on the other 5 degrees of freedom of the rotary stage must be measured and analyzed. In this paper, we have measured the three translations and two tilt motions of a rotating stage with high precision capacitive sensors. To obtain the radial error motion from T.I.R (Total Indicated Reading) of radial direction, we have used Donaldson's reversal technique. And the axial components of the spindle tilt error motion can be obtained accurately from the axial direction outputs of sensors by Estler face motion reversal technique. Further more we have defined and measured the sensitivity of positioning error to the five error motions.
Abstract: Modern manufacturing facilities are large scale,
highly complex, and operate with large number of variables under
closed loop control. Early and accurate fault detection and diagnosis
for these plants can minimise down time, increase the safety of plant
operations, and reduce manufacturing costs. Fault detection and
isolation is more complex particularly in the case of the faulty analog
control systems. Analog control systems are not equipped with
monitoring function where the process parameters are continually
visualised. In this situation, It is very difficult to find the relationship
between the fault importance and its consequences on the product
failure. We consider in this paper an approach to fault detection and
analysis of its effect on the production quality using an adaptive
centring and scaling in the pickling process in cold rolling. The fault
appeared on one of the power unit driving a rotary machine, this
machine can not track a reference speed given by another machine.
The length of metal loop is then in continuous oscillation, this affects
the product quality. Using a computerised data acquisition system,
the main machine parameters have been monitored. The fault has
been detected and isolated on basis of analysis of monitored data.
Normal and faulty situation have been obtained by an artificial neural
network (ANN) model which is implemented to simulate the normal
and faulty status of rotary machine. Correlation between the product
quality defined by an index and the residual is used to quality
classification.
Abstract: This is an applied research to propose the method for
price quotation for a contract electronics manufacturer. It has had a
precise price quoting method but such method could not quickly
provide a result as the customer required. This reduces the ability of
company to compete in this kind of business. In this case, the cause
of long time quotation process was analyzed. A lot of product
features have been demanded by customer. By checking routine
processes, it was found that high fraction of quoting time was used
for production time estimating which has effected to the
manufacturing or production cost. Then the historical data of
products including types, number of components, assembling
method, and their assembling time were used to analyze the key
components affecting to production time. The price quoting model
then was proposed. The implementation of proposed model was able
to remarkably reduce quoting time with an acceptable required
precision.
Abstract: The paper provides a literature review of the STEPNC
compliant research around the world. The first part of this paper
focuses on projects based on STEP compliance followed by research
and development in this area based on machining operations. Review
the literature relating to relevant STEP standards and application in
the area of turning centers. This research will review the various
research work, carried out from the evolution of STEP-NC of the
CNC manufacturing activities. The paper concludes with discussion
of the applications in this particular area.
Abstract: Organizational culture fosters innovation, and
innovation is the main engine to be sustained within the uncertainty
market. Like other countries, the construction industry significantly
contributes to the economy, society and technology of Malaysia, yet,
innovation is still considered slow compared to other industries such
as manufacturing. Given the important role of an architect as the key
player and the contributor of new ideas in the construction industry,
there is a call to identify the issue and improve the current situation
by focusing on the architectural firms. In addition, the existing
studies tend to focus only on a few dimensions of organizational
culture and very few studies consider whether innovation is being
generated or adopted. Hence, the present research tends to fill in the
gap by identifying the organizational cultures that foster or hinder
innovation generation and/or innovation adoption, and propose a
model of organizational culture and innovation generation and/or
adoption.
Abstract: This work presents the results of a study carried out to
determine the sliding wear behavior and its effect on the process
parameters of components manufactured by direct metal laser
sintering (DMLS). A standard procedure and specimen had been used
in the present study to find the wear behavior. Using Taguchi-s
experimental technique, an orthogonal array of modified L8 had been
developed. Sliding wear testing using pin-on-disk machine was
carried out and analysis of variance (ANOVA) technique was used to
investigate the effect of process parameters and to identify the main
process parameter that influences the properties of wear behavior on
the DMLS components. It has been found that part orientation, one
of the selected process parameter had more influence on wear as
compared to other selected process parameters.
Abstract: Knowing consumers' preferences and perceptions of
the sensory evaluation of drink products are very significant to
manufacturers and retailers alike. With no appropriate sensory
analysis, there is a high risk of market disappointment. This paper
aims to rank the selected coffee products and also to determine the
best of quality attribute through sensory evaluation using fuzzy
decision making model. Three products of coffee drinks were used
for sensory evaluation. Data were collected from thirty judges at a
hypermarket in Kuala Terengganu, Malaysia. The judges were asked
to specify their sensory evaluation in linguistic terms of the quality
attributes of colour, smell, taste and mouth feel for each product and
also the weight of each quality attribute. Five fuzzy linguistic terms
represent the quality attributes were introduced prior analysing. The
judgment membership function and the weights were compared to
rank the products and also to determine the best quality attribute. The
product of Indoc was judged as the first in ranking and 'taste' as the
best quality attribute. These implicate the importance of sensory
evaluation in identifying consumers- preferences and also the
competency of fuzzy approach in decision making.
Abstract: This paper mathematically analyses the varying
magnitude of production loss, which may occur due to idle time (inprocess
waiting time and traveling time) on a linear walking worker
assembly line. Within this flexible and reconfigurable assembly
system, each worker travels down the line carrying out each
assembly task at each station; and each worker accomplishes the
assembly of a unit from start to finish and then travels back to the
first station to start the assembly of a new product. This strategy of
system design attempts to combine the flexibility of the U-shaped
moving worker assembly cell with the efficiency of the conventional
fixed worker assembly line. The paper aims to evaluate the effect of
idle time that may offset the labor efficiency of each walking worker
providing an insight into the mechanism of such a flexible and
reconfigurable assembly system.
Abstract: In Iran, due to abundance of energy resources, energy consumption is extraordinarily higher than international standards and transportation sector is considered to be one of the major consumers of energy. Moreover, air pollution in urban areas as a result of high dependence on private vehicle and lower standards of vehicles, high subsidies spent on fuel and time waste due to traffic congestion in urban areas all have led to speculations on new strategies and policies in order to control energy consumption in transportation sector. These strategies and policies will be introduced in this paper and their consequences will be analyzed with consideration to socio-economic factors affecting the urban society of Iran. Besides, the intention is to suggest and analyze new approaches such as broader application of public transportation system, demand management in transport sector, replacement of deteriorated vehicles, quality improvement in car manufacture and introduction of substitute fuels.
Abstract: Thermochemcial characteristics of powder fabricated
using oxidation treatment of spent PWR fuel and SIMFUEL were
evaluated for recycling of spent fuel such as DUPIC process.
Especially, the influence of spent fuel burn-ups on the powder
fabrication characteristics was experimentally evaluated, ranging from
27,300 to 65,000 MWd/tU. Densities of powder manufactured from an
oxidation, OREOX and the milling processes at the same process
conditions were compared as a function of the fuel burn-ups
respectively. Also, based on chemical analysis results, homogeneity of
fissile elements in oxidized powder was confirmed.
Abstract: This paper presents the determination of the proper
quality costs parameters which provide the optimum return. The
system dynamics simulation was applied. The simulation model was
constructed by the real data from a case of the electronic devices
manufacturer in Thailand. The Steepest Descent algorithm was
employed to optimise. The experimental results show that the
company should spend on prevention and appraisal activities for 850
and 10 Baht/day respectively. It provides minimum cumulative total
quality cost, which is 258,000 Baht in twelve months. The effect of
the step size in the stage of improving the variables to the optimum
was also investigated. It can be stated that the smaller step size
provided a better result with more experimental runs. However, the
different yield in this case is not significant in practice. Therefore, the
greater step size is recommended because the region of optima could
be reached more easily and rapidly.
Abstract: It is necessary to incorporate technological advances
achieved in the field of engineering into dentistry in order to enhance
the process of diagnosis, treatment planning and enable the doctors to
render better treatment to their patients. To achieve this ultimate goal
long distance collaborations are often necessary. This paper discusses
the various collaborative tools and their applications to solve a few
burning problems confronted by the dentists. Customization is often
the solution to most of the problems. But rapid designing,
development and cost effective manufacturing is a difficult task to
achieve. This problem can be solved using the technique of digital
manufacturing. Cases from 6 major branches of dentistry have been
discussed and possible solutions with the help of state of art
technology using rapid digital manufacturing have been proposed in
the present paper. The paper also entails the usage of existing tools in
collaborative and digital manufacturing area.
Abstract: Automated material handling is given prime
importance in the semi automated and automated facilities since it
provides solution to the gigantic problems related to inventory and
also support the latest philosophies like just in time production JIT
and lean production. Automated storage and retrieval system is an
antidote (if designed properly) to the facility sufferings like getting
the right material , materials getting perished, long cycle times or
many other similar kind of problems. A working model of automated
storage and retrieval system (AS/RS) is designed and developed
under the design parameters specified by Material Handling Industry
of America (MHIA). Later on analysis was carried out to calculate
the throughput and size of the machine. The possible implementation
of this technology in local scenario is also discussed in this paper.
Abstract: A lot of research made during these last 15 years
showed that the quantification of the springback has a significant role
in the industry of sheet metal forming. These studies were made with
the objective of finding techniques and methods to minimize or
completely avoid this permanent physical variation. Moreover, the
use of steel and aluminum alloys in the car industry and aviation
poses every day the problem of the springback. The determination in
advance of the quantity of the springback allows consequently the
design and manufacture of the tool. The aim of this paper is to study
experimentally the influence of the blank holder force BHF and the
radius of curvature of the die on the springback and their influence on
the strain in various zone of specimen.
The original of our purpose consist on tests which are ensured by
adapting a U-type stretching-bending device on a tensile testing
machine, where we studied and quantified the variation of the
springback according to displacement.