Abstract: This paper is based on a study conducted in 2006 to assess the impact of computer usage on health of National Institute for Medical Research (NIMR) staff. NIMR being a research Institute, most of its staff spend substantial part of their working time on computers. There was notion among NIMR staff on possible prolonged computer usage health hazards. Hence, a study was conducted to establish facts and possible mitigation measures. A total of 144 NIMR staff were involved in the study of whom 63.2% were males and 36.8% females aged between 20 and 59 years. All staff cadres were included in the sample. The functions performed by Institute staff using computers includes; data management, proposal development and report writing, research activities, secretarial duties, accounting and administrative duties, on-line information retrieval and online communication through e-mail services. The interviewed staff had been using computers for 1-8 hours a day and for a period ranging from 1 to 20 years. The study has indicated ergonomic hazards for a significant proportion of interviewees (63%) of various kinds ranging from backache to eyesight related problems. The authors highlighted major issues which are substantially applicable in preventing occurrences of computer related problems and they urged NIMR Management and/or the government of Tanzania opts to adapt their practicability.
Abstract: The continued interest in the use of distributed generation in recent years is leading to the growth in number of distributed generators connected to distribution networks. Steady state voltage rise resulting from the connection of these generators can be a major obstacle to their connection at lower voltage levels. The present electric distribution network is designed to keep the customer voltage within tolerance limit. This may require a reduction in connectable generation capacity, under utilization of appropriate generation sites. Thus distribution network operators need a proper voltage regulation method to allow the significant integration of distributed generation systems to existing network. In this work a voltage rise problem in a typical distribution system has been studied. A method for voltage regulation of distribution system with multiple DG system by coordinated operation distributed generator, capacitor and OLTC has been developed. A sensitivity based analysis has been carried out to determine the priority for individual generators in multiple DG environment. The effectiveness of the developed method has been evaluated under various cases through simulation results.
Abstract: The study describes chitosan membrane platform
modified with nanostructure pattern which using nanotechnology to
fabricate. The cell-substrate interaction between neuro-2a neuroblasts
cell lines and chitosan membrane (flat, nanostructure and
nanostructure pattern types) was investigated. The adhered
morphology of neuro-2a cells depends on the topography of chitosan
surface. We have found that neuro-2a showed different morphogenesis
when cells adhered on flat and nanostructure chitosan membrane. The
cell projected area of neuro-2a on flat chitosan membrane is larger
than on nanostructure chitosan membrane. In addition, neuro-2a cells
preferred to adhere on flat chitosan surface region than on
nanostructure chitosan membrane to immobilize and differentiation.
The experiment suggests surface topography can be used as a critical
mechanism to isolate group of neuro-2a to a particular rectangle area
on chitosan membrane. Our finding will provide a platform to take
patch clamp to record electrophysiological behavior about neurons in
vitro in the future.
Abstract: Standard packaging and interconnection technologies
of power devices have difficulties meeting the increasing thermal
demands of new application fields of power electronics devices.
Main restrictions are the decreasing reliability of bond-wires and
solder layers with increasing junction temperature. In the last few
years intensive efforts have been invested in developing new
packaging and interconnection solutions which may open a path to
future application of power devices. In this paper, the main failure
mechanisms of power devices are described and principle of new
packaging and interconnection concepts and their power cycling
reliability are presented.
Abstract: In this paper we present two novel 1-bit full adder
cells in dynamic logic style. NP-CMOS (Zipper) and Multi-Output
structures are used to design the adder blocks. Characteristic of
dynamic logic leads to higher speeds than the other standard static
full adder cells. Using HSpice and 0.18┬Ám CMOS technology
exhibits a significant decrease in the cell delay which can result in a
considerable reduction in the power-delay product (PDP). The PDP
of Multi-Output design at 1.8v power supply is around 0.15 femto
joule that is 5% lower than conventional dynamic full adder cell and
at least 21% lower than other static full adders.
Abstract: Technology changes have been acknowledged as a
critical factor in determining competitiveness of organization. Under
such environment, the right anticipation of technology change has
been of huge importance in strategic planning. To monitor technology
change, technology forecasting (TF) is frequently utilized. In
academic perspective, TF has received great attention for a long time.
However, few researches have been conducted to provide overview of
the TF literature. Even though some studies deals with review of TF
research, they generally focused on type and characteristics of various
TF, so hardly provides information about patterns of TF research and
which TF method is used in certain technology industry. Accordingly,
this study profile developments in and patterns of scholarly research in
TF over time. Also, this study investigates which technology
industries have used certain TF method and identifies their
relationships. This study will help in understanding TF research trend
and their application area.
Abstract: In order to calculate the flexural strength of
normal-strength concrete (NSC) beams, the nonlinear actual concrete
stress distribution within the compression zone is normally replaced
by an equivalent rectangular stress block, with two coefficients of α
and β to regulate the intensity and depth of the equivalent stress
respectively. For NSC beams design, α and β are usually assumed
constant as 0.85 and 0.80 in reinforced concrete (RC) codes. From an
earlier investigation of the authors, α is not a constant but significantly
affected by flexural strain gradient, and increases with the increasing
of strain gradient till a maximum value. It indicates that larger
concrete stress can be developed in flexure than that stipulated by
design codes. As an extension and application of the authors- previous
study, the modified equivalent concrete stress block is used here to
produce a series of design charts showing the maximum design limits
of flexural strength and ductility of singly- and doubly- NSC beams,
through which both strength and ductility design limits are improved
by taking into account strain gradient effect.
Abstract: Public administration institutions in cooperation with
politicians are not the sole policy decision makers in full meaning
any longer. Meanwhile, a special role, namely steering the decision
making process, could be delegated to them.
Despite the wide scientific discussion on different aspects what
has direct impact on policy creation, there is a lack of holistic
practical managerial advice, which could integrate infrastructure of
policy decision making with intellectual capital and with
interconnection of partnership. The proposed harmonized decision
making model of process, people and partnership entitled by
acronym HM-3P is analyzed as a framework for implementation of
public administration steering role seeking the coherent social
involvement in policy decision making.
Abstract: This paper identifies five key design characteristics of
production scheduling software systems in printed circuit board (PCB) manufacturing. The authors consider that, in addition to an effective scheduling engine, a scheduling system should be able to
process a preventative maintenance calendar, to give the user the
flexibility to handle data using a variety of electronic sources, to run
simulations to support decision-making, and to have simple and
customisable graphical user interfaces. These design considerations
were the result of a review of academic literature, the evaluation of
commercial applications and a compilation of requirements of a PCB manufacturer. It was found that, from those systems that were evaluated, those that effectively addressed all five characteristics
outlined in this paper were the most robust of all and could be used in
PCB manufacturing.
Abstract: This paper focuses on the 3D reconstruction of
the architectural design of Darul Ridzuan Museum. It has
concentrated on designing exterior part of the building according
to colored digital photo of the real museum. Besides viewing the
architecture, walkthroughs are generated for the user to control
it in an easier way. User can travel through the museum to get
the feel of the environment and to explore the design of the
museum as a whole; both exterior and interior. The result has
shown positive result in terms of realism, navigation, collision
detection, suitability, usability and user-s acceptance. In brief,
the 3D virtual museum has provided an alternative to present a
real museum.
Abstract: There has been a growing interest in the field of
bio-mimetic robots that resemble the shape of an insect or an aquatic
animal, among many others. One bio-mimetic robot serves the
purpose of exploring pipelines, spotting any troubled areas or
malfunctions and reporting its data. Moreover, the robot is able to
prepare for and react to any abnormal routes in the pipeline. In order
to move effectively inside a pipeline, the robot-s movement will
resemble that of a lizard. When situated in massive pipelines with
complex routes, the robot places fixed sensors in several important
spots in order to complete its monitoring. This monitoring task is to
prevent a major system failure by preemptively recognizing any minor
or partial malfunctions. Areas uncovered by fixed sensors are usually
impossible to provide real-time observation and examination, and thus
are dependant on periodical offline monitoring. This paper provides
the Monitoring System that is able to monitor the entire area of
pipelines–with and without fixed sensors–by using the bio-mimetic
robot.
Abstract: Application of wood in rural construction is diffused
all around the world since remote times. However, its inclusion in
structural design deserves strong support from broad knowledge of
material properties. The pertinent literature reveals the application of
optical methods in determining the complete field displacement on
bodies exhibiting regular as well as irregular surfaces. The use of
moiré techniques in experimental mechanics consists in analyzing the
patterns generated on the body surface before and after deformation.
The objective of this research work is to study the qualitative
deformation behavior of wooden testing specimens under specific
loading situations. The experiment setup follows the literature
description of shadow moiré methods. Results indicate strong
anisotropy influence of the generated displacement field. Important
qualitative as well as quantitative stress and strain distribution were
obtained wooden members which are applicable to rural
constructions.
Abstract: Construction of tunnels is connected with high
uncertainty in the field of costs, construction period, safety and
impact on surroundings. Risk management became therefore a
common part of tunnel projects, especially after a set of fatal
collapses occurred in 1990's. Such collapses are caused usually by
combination of factors that can be divided into three main groups, i.e.
unfavourable geological conditions, failures in the design and
planning or failures in the execution.
This paper suggests a procedure enabling quantification of the
excavation risk related to extraordinary accidents using FTA and
ETA tools. It will elaborate on a common process of risk analysis and
enable the transfer of information and experience between particular
tunnel construction projects. Further, it gives a guide for designers,
management and other participants, how to deal with risk of such
accidents and how to make qualified decisions based on a
probabilistic approach.
Abstract: Rapid enlargement and physical development of cities
have facilitated the emergence of a number of city life crises and
decrease of environment quality. Subsequently, the need for noticing
the concept of quality and its improvement in urban environments,
besides quantitative issues, is obviously recognized. In the domain of
urban ideas the importance of taking these issues into consideration
is obvious not only in accordance to sustainable development
concepts and improvement of public environment quality, but also in
the enhancement of social and behavioral models.
The major concern of present article is to study the nature of urban
environment quality in urban development plans, which is important
not only in the concept and the aim of projects but also in their
execution procedure. As a result, this paper is going to utilize
planning capacities caused by environmental virtues in the planning
procedure of Moft Abad neighborhood. Thus, at the first step,
applying the Analytical Hierarchy Process (AHP), it has assessed
quantitative environmental issues. The present conditions of Moft
Abad state that “the neighborhood is generally suffering from the
lack of qualitative parameters, and the previously formed planning
procedures could not take the sustainable and developmental paths
which are aimed at environment quality virtues." The diminution of
economical and environmental virtues has resulted in the diminution
of residential and social virtues. Therefore, in order to enhance the
environment quality in Moft Abad, the present paper has tried to
supply the subject plans in order to make a safe, healthy, and lively
neighborhood.
Abstract: Short circuit currents plays a vital role in influencing the design and operation of equipment and power system and could not be avoided despite careful planning and design, good maintenance and thorough operation of the system. This paper discusses the short circuit analysis conducted in KSO briefly comprising of its significances, methods and results. A result sample of the analysis based on a single transformer is detailed in this paper. Furthermore, the results of the analysis and its significances were also discussed and commented.
Abstract: Phase locked loops for data links operating at 10 Gb/s
or faster are low phase noise devices designed to operate with a low
jitter reference clock. Characterization of their jitter transfer function
is difficult because the intrinsic noise of the device is comparable to
the random noise level in the reference clock signal. A linear model
is proposed to account for the intrinsic noise of a PLL. The intrinsic
noise data of a PLL for 10 Gb/s links is presented. The jitter transfer
function of a PLL in a test chip for 12.8 Gb/s data links was
determined in experiments using the 400 MHz reference clock as the
source of simultaneous excitations over a wide range of frequency.
The result shows that the PLL jitter transfer function can be
approximated by a second order linear model.
Abstract: With the advantage of wireless network technology,
there are a variety of mobile applications which make the issue of
wireless sensor networks as a popular research area in recent years.
As the wireless sensor network nodes move arbitrarily with the
topology fast change feature, mobile nodes are often confronted with
the void issue which will initiate packet losing, retransmitting,
rerouting, additional transmission cost and power consumption.
When transmitting packets, we would not predict void problem
occurring in advance. Thus, how to improve geographic routing with
void avoidance in wireless networks becomes an important issue. In
this paper, we proposed a greedy geographical void routing algorithm
to solve the void problem for wireless sensor networks. We use the
information of source node and void area to draw two tangents to
form a fan range of the existence void which can announce voidavoiding
message. Then we use source and destination nodes to draw
a line with an angle of the fan range to select the next forwarding
neighbor node for routing. In a dynamic wireless sensor network
environment, the proposed greedy void avoiding algorithm can be
more time-saving and more efficient to forward packets, and improve
current geographical void problem of wireless sensor networks.
Abstract: In the past years a lot of effort has been made in the
field of face detection. The human face contains important features
that can be used by vision-based automated systems in order to
identify and recognize individuals. Face location, the primary step of
the vision-based automated systems, finds the face area in the input
image. An accurate location of the face is still a challenging task.
Viola-Jones framework has been widely used by researchers in order
to detect the location of faces and objects in a given image. Face
detection classifiers are shared by public communities, such as
OpenCV. An evaluation of these classifiers will help researchers to
choose the best classifier for their particular need. This work focuses
of the evaluation of face detection classifiers minding facial
landmarks.
Abstract: Power-line networks are widely used today for broadband data transmission. However, due to multipaths within the broadband power line communication (BPLC) systems owing to stochastic changes in the network load impedances, branches, etc., network or channel capacity performances are affected. This paper attempts to investigate the performance of typical medium voltage channels that uses Orthogonal Frequency Division Multiplexing (OFDM) techniques with Quadrature Amplitude Modulation (QAM) sub carriers. It has been observed that when the load impedances are different from line characteristic impedance channel performance decreases. Also as the number of branches in the link between the transmitter and receiver increases a loss of 4dB/branch is found in the signal to noise ratio (SNR). The information presented in the paper could be useful for an appropriate design of the BPLC systems.
Abstract: This paper undertakes the problem of optimal
capacitor placement in a distribution system. The problem is how to
optimally determine the locations to install capacitors, the types and
sizes of capacitors to he installed and, during each load level,the
control settings of these capacitors in order that a desired objective
function is minimized while the load constraints,network constraints
and operational constraints (e.g. voltage profile) at different load
levels are satisfied. The problem is formulated as a combinatorial
optimization problem with a nondifferentiable objective function.
Four solution mythologies based on algorithms (GA),tabu search
(TS), and hybrid GA-SA algorithms are presented.The solution
methodologies are preceded by a sensitivity analysis to select the
candidate capacitor installation locations.