Abstract: The study of the fouling deposition of pink guava
juice (PGJ) is relatively new research compared to milk fouling
deposit. In this work, a new experimental set-up was developed to
imitate the fouling formation in heat exchanger, namely a continuous
flow experimental set-up heat exchanger. The new experimental setup
was operated under industrial pasteurization temperature of PGJ,
which was at 93°C. While the flow rate and pasteurization period
were based on the experimental capacity, which were 0.5 and 1
liter/min for the flow rate and the pasteurization period was set for 1
hour. Characterization of the fouling deposit was determined by
using various methods. Microstructure of the deposits was carried
out using ESEM. Proximate analyses were performed to determine
the composition of moisture, fat, protein, fiber, ash and carbohydrate
content. A study on the hardness and stickiness of the fouling deposit
was done using a texture analyzer. The presence of seedstone in pink
guava juice was also analyzed using a particle analyzer. The findings
shown that seedstone from pink guava juice ranging from 168 to
200μm and carbohydrate was found to be a major composition
(47.7% of fouling deposit consists of carbohydrate). Comparison
between the hardness and stickiness of the deposits at two different
flow rates showed that fouling deposits were harder and denser at
higher flow rate. Findings from this work provide basis knowledge
for further study on fouling and cleaning of PGJ.
Abstract: 98% of the energy needed in Taiwan has been
imported. The prices of petroleum and electricity have been
increasing. In addition, facility capacity, amount of electricity
generation, amount of electricity consumption and number of Taiwan
Power Company customers have continued to increase. For these
reasons energy conservation has become an important topic. In the
past linear regression was used to establish the power consumption
models for chillers. In this study, grey prediction is used to evaluate
the power consumption of a chiller so as to lower the total power
consumption at peak-load (so that the relevant power providers do not
need to keep on increasing their power generation capacity and facility
capacity).
In grey prediction, only several numerical values (at least four
numerical values) are needed to establish the power consumption
models for chillers. If PLR, the temperatures of supply chilled-water
and return chilled-water, and the temperatures of supply cooling-water
and return cooling-water are taken into consideration, quite accurate
results (with the accuracy close to 99% for short-term predictions)
may be obtained. Through such methods, we can predict whether the
power consumption at peak-load will exceed the contract power
capacity signed by the corresponding entity and Taiwan Power
Company. If the power consumption at peak-load exceeds the power
demand, the temperature of the supply chilled-water may be adjusted
so as to reduce the PLR and hence lower the power consumption.
Abstract: The use and management of projects has risen to
a new prominence, with projects seen as critical to economic in
both the private and public sectors due challenging and dynamic
business environment. However, failure in managing project is
encountered regularly, which cause the waste of company
resources. The impacts of projects that failed to meet
stakeholders expectations have left behind long lasting negative
consequences in organization. Therefore, this research aims to
investigate on key success factors of project management in an
organization. It is believed that recognizing important factors
that contribute to successful project will help companies to
increase the overall profitability. 150 questionnaires were
distributed to respondents and 110 questionnaires were collected
and used in performing the data analysis. The result has strongly
supported the relationship between independent variables and
project performance.
Abstract: Vector quantization is a powerful tool for speech
coding applications. This paper deals with LPC Coding of speech
signals which uses a new technique called Multi Switched Split
Vector Quantization, This is a hybrid of two product code vector
quantization techniques namely the Multi stage vector quantization
technique, and Switched split vector quantization technique,. Multi
Switched Split Vector Quantization technique quantizes the linear
predictive coefficients in terms of line spectral frequencies. From
results it is proved that Multi Switched Split Vector Quantization
provides better trade off between bitrate and spectral distortion
performance, computational complexity and memory requirements
when compared to Switched Split Vector Quantization, Multi stage
vector quantization, and Split Vector Quantization techniques. By
employing the switching technique at each stage of the vector
quantizer the spectral distortion, computational complexity and
memory requirements were greatly reduced. Spectral distortion was
measured in dB, Computational complexity was measured in
floating point operations (flops), and memory requirements was
measured in (floats).
Abstract: This paper presents a hybrid electric scooter model developed and simulated using Matlab/Simulink. This hybrid scooter modeled has a parallel hybrid structure. The main propulsion units consist of a two stroke internal combustion engine and a hub motor attached to the front wheel of the scooter. The methodology used to optimize the energy and fuel consumption of the hybrid electric scooter is the multi-mode approach. Various case studies were presented to check the model and were compared to the literatures. Results shown that the model developed was feasible and valuable.
Abstract: We report in this paper the model adopted by our
system of continuous speech recognition in Arab language SySRA
and the results obtained until now. This system uses the database
Arabdic-10 which is a corpus of word for the Arab language and
which was manually segmented. Phonetic decoding is represented
by an expert system where the knowledge base is translated in the
form of production rules. This expert system transforms a vocal
signal into a phonetic lattice. The higher level of the system takes
care of the recognition of the lattice thus obtained by deferring it in
the form of written sentences (orthographical Form). This level
contains initially the lexical analyzer which is not other than the
module of recognition. We subjected this analyzer to a set of
spectrograms obtained by dictating a score of sentences in Arab
language. The rate of recognition of these sentences is about 70%
which is, to our knowledge, the best result for the recognition of the
Arab language. The test set consists of twenty sentences from four
speakers not having taken part in the training.
Abstract: In this research, we study a control method of a multivehicle
system while considering the limitation of communication
range for each vehicles. When we control networked vehicles with
limitation of communication range, it is important to control the
communication network structure of a multi-vehicle system in order
to keep the network-s connectivity. From this, we especially aim to
control the network structure to the target structure. We formulate
the networked multi-vehicle system with some disturbance and the
communication constraints as a hybrid dynamical system, and then
we study the optimal control problems of the system. It is shown
that the system converge to the objective network structure in finite
time when the system is controlled by the receding horizon method.
Additionally, the optimal control probrems are convertible into the
mixed integer problems and these problems are solvable by some
branch and bound algorithm.
Abstract: Using Dynamic Bayesian Networks (DBN) to model genetic regulatory networks from gene expression data is one of the major paradigms for inferring the interactions among genes. Averaging a collection of models for predicting network is desired, rather than relying on a single high scoring model. In this paper, two kinds of model searching approaches are compared, which are Greedy hill-climbing Search with Restarts (GSR) and Markov Chain Monte Carlo (MCMC) methods. The GSR is preferred in many papers, but there is no such comparison study about which one is better for DBN models. Different types of experiments have been carried out to try to give a benchmark test to these approaches. Our experimental results demonstrated that on average the MCMC methods outperform the GSR in accuracy of predicted network, and having the comparable performance in time efficiency. By proposing the different variations of MCMC and employing simulated annealing strategy, the MCMC methods become more efficient and stable. Apart from comparisons between these approaches, another objective of this study is to investigate the feasibility of using DBN modeling approaches for inferring gene networks from few snapshots of high dimensional gene profiles. Through synthetic data experiments as well as systematic data experiments, the experimental results revealed how the performances of these approaches can be influenced as the target gene network varies in the network size, data size, as well as system complexity.
Abstract: In rail vehicles, air springs are very important isolating component, which guarantee good ride comfort for passengers during their trip. In the most new rail–vehicle models, developed by researchers, the thermo–dynamical effects of air springs are ignored and secondary suspension is modeled by simple springs and dampers. As the performance of suspension components have significant effects on rail–vehicle dynamics and ride comfort of passengers, a complete nonlinear thermo–dynamical air spring model, which is a combination of two different models, is introduced. Result from field test shows remarkable agreement between proposed model and experimental data. Effects of air suspension parameters on the system performances are investigated here and then these parameters are tuned to minimize Sperling ride comfort index during the trip. Results showed that by modification of air suspension parameters, passengers comfort is improved and ride comfort index is reduced about 10%.
Abstract: All over the world, including the Middle and East
European countries, sustainable tillage and sowing technologies are
applied increasingly broadly with a view to optimising soil resources,
mitigating soil degradation processes, saving energy resources,
preserving biological diversity, etc. As a result, altered conditions of
tillage and sowing technological processes are faced inevitably. The
purpose of this study is to determine the seedbed topsoil hardness
when using a combined sowing coulter in different sustainable tillage
technologies. The research involved a combined coulter consisting
of two dissected blade discs and a shoe coulter. In order to determine
soil hardness at the seedbed area, a multipenetrometer was used. It
was found by experimental studies that in loosened soil, a combined
sowing coulter equally suppresses the furrow bottom, walls and soil
near the furrow; therefore, here, soil hardness was similar at all
researched depths and no significant differences were established. In
loosened and compacted (double-rolled) soil, the impact of a
combined coulter on the hardness of seedbed soil surface was more
considerable at a depth of 2 mm. Soil hardness at the furrow bottom
and walls to a distance of up to 26 mm was 1.1 MPa. At a depth of 10
mm, the greatest hardness was established at the furrow bottom. In
loosened and heavily compacted (rolled for 6 times) soil, at a depth
of 2 and 10 mm a combined coulter most of all compacted the furrow
bottom, which has a hardness of 1.8 MPa. At a depth of 20 mm, soil
hardness within the whole investigated area varied insignificantly and
fluctuated by around 2.0 MPa. The hardness of furrow walls and soil
near the furrow was by approximately 1.0 MPa lower than that at the
furrow bottom
Abstract: The compression-absorption heat pump (C-A HP), one
of the promising heat recovery equipments that make process hot
water using low temperature heat of wastewater, was evaluated by
computer simulation. A simulation program was developed based on
the continuity and the first and second laws of thermodynamics. Both
the absorber and desorber were modeled using UA-LMTD method. In
order to prevent an unfeasible temperature profile and to reduce
calculation errors from the curved temperature profile of a mixture,
heat loads were divided into lots of segments. A single-stage
compressor was considered. A compressor cooling load was also
taken into account. An isentropic efficiency was computed from the
map data. Simulation conditions were given based on the system
consisting of ordinarily designed components. The simulation results
show that most of the total entropy generation occurs during the
compression and cooling process, thus suggesting the possibility that
system performance can be enhanced if a rectifier is introduced.
Abstract: This paper presents modeling and analysis of 12-phase distribution static compensator (DSTATCOM), which is capable of balancing the source currents in spite of unbalanced loading and phase outages. In addition to balance the supply current, the power factor can be set to a desired value. The theory of instantaneous symmetrical components is used to generate the twelve-phase reference currents. These reference currents are then tracked using current controlled voltage source inverter, operated in a hysteresis band control scheme. An ideal compensator in place of physical realization of the compensator is used. The performance of the proposed DTATCOM is validated through MATLAB simulation and detailed simulation results are given.
Abstract: The increasing demand for sufficient and clean
energy forces industrial and service companies to align their strategies towards efficient consumption. This trend refers also to the
residential building sector. There, large amounts of energy consumption are caused by house and facility heating. Many of the
operated hot water heating systems lack hydraulic balanced working
conditions for heat distribution and –transmission and lead to
inefficient heating. Through hydraulic balancing of heating systems,
significant energy savings for primary and secondary energy can be
achieved. This paper addresses the use of KNX-technology (Smart
Buildings) in residential buildings to ensure a dynamic adaption of
hydraulic system's performance, in order to increase the heating
system's efficiency. In this paper, the procedure of heating system
segmentation into hydraulically independent units (meshes) is
presented. Within these meshes, the heating valve are addressed and
controlled by a central facility server. Feasibility criteria towards
such drivers will be named. The dynamic hydraulic balance is
achieved by positioning these valves according to heating loads, that
are generated from the temperature settings in the corresponding
rooms. The energetic advantages of single room heating control
procedures, based on the application FacilityManager, is presented.
Abstract: The aim of this study is to investigate the effect of
perceived social support and stress on the coping capability and level
of depression of foreign and local students in Malaysia. Using
convenience sampling, 200 students from three universities in
Selangor, Malaysia participated in the study. The results of this study
revealed that there was a significant relationship between perceived
social support and coping capability. It is also found that there is a
negative relationship between coping capability and depression.
Further, stress and depression are positively related whereas stress
and coping capability are negatively related. Lastly, there is no
significant difference for the stress level and coping capability
amongst local and foreign students.
Abstract: In the present investigation, H13 tool steel has been
deposited on copper alloy substrate using both CO2 and diode laser.
A detailed parametric analysis has been carried out in order to find
out optimum processing zone for coating defect free H13 tool steel
on copper alloy substrate. Followed by parametric optimization, the
microstructure and microhardness of the deposited clads have been
evaluated. SEM micrographs revealed dendritic microstructure in
both clads. However, the microhardness of CO2 laser deposited clad
was much higher compared to diode laser deposited clad.
Abstract: Perceptions of quality from both designers and users
perspective have now stretched beyond the traditional usability,
incorporating abstract and subjective concepts. This has led to a shift
in human computer interaction research communities- focus; a shift
that focuses on achieving user experience (UX) by not only fulfilling
conventional usability needs but also those that go beyond them. The
term UX, although widely spread and given significant importance,
lacks consensus in its unified definition. In this paper, we survey
various UX definitions and modeling frameworks and examine them
as the foundation for proposing a UX evolution lifecycle framework
for understanding UX in detail. In the proposed framework we identify
the building blocks of UX and discuss how UX evolves in various
phases. The framework can be used as a tool to understand experience
requirements and evaluate them, resulting in better UX design and
hence improved user satisfaction.
Abstract: With the intention of screening for heavy metal
tolerance, a number of bacteria were isolated and characterized from
a pristine soil. Two Gram positive isolates were identified as
Paenibacillus sp. and Bacillus thuringeinsis. Tolerance of Cd2+, Cu2+
and Zn2+ by these bacteria was studied and found that both bacteria
were highly sensitive to Cu2+ compared to other two metals. Both
bacteria showed the same pattern of metal tolerance in the order Zn+
> Cd2+ > Cu2+. When the metal tolerance in both bacteria was
compared, Paenibacillus sp. showed the highest sensitivity to Cu2+
where as B. thuringiensis showed highest sensitivity to Cd2+ and Zn2+
.These findings revealed the potential of Paenibacillus sp. in
developing a biosensor to detect Cu2+ in environmental samples.
Abstract: Little research has examined working memory
capacity (WMC) in signed language interpreters and deaf signers.
This paper presents the findings of a study that investigated WMC in
professional Australian Sign Language (Auslan)/English interpreters
and deaf signers. Thirty-one professional Auslan/English interpreters
(14 hearing native signers and 17 hearing non-native signers)
completed an English listening span task and then an Auslan working
memory span task, which tested their English WMC and their Auslan
WMC, respectively. Moreover, 26 deaf signers (6 deaf native signers
and 20 deaf non-native signers) completed the Auslan working
memory span task. The results revealed a non-significant difference
between the hearing native signers and the hearing non-native signers
in their English WMC, and a non-significant difference between the
hearing native signers and the hearing non-native signers in their
Auslan WMC. Moreover, the results yielded a non-significant
difference between the hearing native signers- English WMC and
their Auslan WMC, and a non-significant difference between the
hearing non-native signers- English WMC and their Auslan WMC.
Furthermore, a non-significant difference was found between the deaf
native signers and the deaf non-native signers in their Auslan WMC.
Abstract: In this paper, we address the problem of reducing the
switching activity (SA) in on-chip buses through the use of a bus
binding technique in high-level synthesis. While many binding
techniques to reduce the SA exist, we present yet another technique for
further reducing the switching activity. Our proposed method
combines bus binding and data sequence reordering to explore a wider
solution space. The problem is formulated as a multiple traveling
salesman problem and solved using simulated annealing technique.
The experimental results revealed that a binding solution obtained
with the proposed method reduces 5.6-27.2% (18.0% on average) and
2.6-12.7% (6.8% on average) of the switching activity when compared
with conventional binding-only and hybrid binding-encoding
methods, respectively.
Abstract: To determine the length of engagement threads of a bolt installed in a tapped part in order to avoid the threads stripping remains a very current problem in the design of the thread assemblies. It does not exist a calculation method formalized for the cases where the bolt is screwed directly in a ductile material. In this article, we study the behavior of the threads stripping of a loaded assembly by using a modelling by finite elements and a rupture criterion by damage. This modelling enables us to study the different parameters likely to influence the behavior of this bolted connection. We study in particular, the influence of couple of materials constituting the connection, of the bolt-s diameter and the geometrical characteristics of the tapped part, like the external diameter and the length of engagement threads. We established an experiments design to know the most significant parameters. That enables us to propose a simple expression making possible to calculate the resistance of the threads whatever the metallic materials of the bolt and the tapped part. We carried out stripping tests in order to validate our model. The estimated results are very close to those obtained by the tests.