Abstract: We address the integer frequency offset (IFO)
estimation under the influence of the timing offset (TO) in orthogonal
frequency division multiplexing (OFDM) systems. Incorporating the
IFO and TO into the symbol set used to represent the received
OFDM symbol, we investigate the influence of the TO on the IFO,
and then, propose a combining method between two consecutive
OFDM correlations, reducing the influence. The proposed scheme
has almost the same complexity as that of the conventional
schemes, whereas it does not need the TO knowledge contrary to
the conventional schemes. From numerical results it is confirmed
that the proposed scheme is insensitive to the TO, consequently,
yielding an improvement of the IFO estimation performance over
the conventional schemes when the TO exists.
Abstract: The Markov decision process (MDP) based
methodology is implemented in order to establish the optimal
schedule which minimizes the cost. Formulation of MDP problem
is presented using the information about the current state of pipe,
improvement cost, failure cost and pipe deterioration model. The
objective function and detailed algorithm of dynamic programming
(DP) are modified due to the difficulty of implementing the
conventional DP approaches. The optimal schedule derived from
suggested model is compared to several policies via Monte
Carlo simulation. Validity of the solution and improvement in
computational time are proved.
Abstract: This study aimed to identify the alignment of
understanding and assessment practices among secondary school
teachers. The study was carried out using quantitative descriptive
study. The sample consisted of 164 teachers who taught Form 1 and 2
from 11 secondary schools in the district of North Kinta, Perak,
Malaysia. Data were obtained from 164 respondents who answered
Expectation Alignment Understanding and Practices of School
Assessment (PEKDAPS) questionnaire. The data were analysed
using SPSS 17.0+. The Cronbach’s alpha value obtained through
PEKDAPS questionnaire pilot study was 0.86. The results showed
that teachers' performance in PEKDAPS based on the mean value
was less than 3, which means that perfect alignment does not occur
between the understanding and practices of school assessment. Two
major PEKDAPS sub-constructs of articulation across grade and age
and usability of the system were higher than the moderate alignment
of the understanding and practices of school assessment (Min=2.0).
The content focused of PEKDAPs sub-constructs which showed
lower than the moderate alignment of the understanding and practices
of school assessment (Min=2.0). Another two PEKDAPS subconstructs
of transparency and fairness and the pedagogical
implications showed moderate alignment (2.0). The implications of
the study is that teachers need to fully understand the importance of
alignment among components of assessment, learning and teaching
and learning objectives as strategies to achieve quality assessment
process.
Abstract: Urban Search and Rescue (USAR) is a functional
capability that has been developed to allow the United Kingdom Fire
and Rescue Service to deal with ‘major incidents’ primarily involving
structural collapse. The nature of the work undertaken by USAR
means that staying out of a damaged or collapsed building structure is
not usually an option for search and rescue personnel. As a result
there is always a risk that they themselves could become victims. For
this paper, a systematic and investigative review using desk research
was undertaken to explore the role which structural engineering can
play in assisting search and rescue personnel to conduct structural
assessments when in the field. The focus is on how search and rescue
personnel can assess damaged and collapsed building structures, not
just in terms of structural damage that may been countered, but also
in relation to structural stability. Natural disasters, accidental
emergencies, acts of terrorism and other extreme events can vary
significantly in nature and ferocity, and can cause a wide variety of
damage to building structures. It is not possible or, even realistic, to
provide search and rescue personnel with definitive guidelines and
procedures to assess damaged and collapsed building structures as
there are too many variables to consider. However, understanding
what implications damage may have upon the structural stability of a
building structure will enable search and rescue personnel to better judge
and quantify risk from a life-safety standpoint. It is intended that this
will allow search and rescue personnel to make informed decisions
and ensure every effort is made to mitigate risk, so that they
themselves do not become victims.
Abstract: The building sector is responsible, in many
industrialized countries, for about 40% of the total energy
requirements, so it seems necessary to devote some efforts in this
area in order to achieve a significant reduction of energy
consumption and of greenhouse gases emissions.
The paper presents a study aiming at providing a design
methodology able to identify the best configuration of the system
building/plant, from a technical, economic and environmentally point
of view.
Normally, the classical approach involves a building's energy
loads analysis under steady state conditions, and subsequent selection
of measures aimed at improving the energy performance, based on
previous experience made by architects and engineers in the design
team. Instead, the proposed approach uses a sequence of two wellknown
scientifically validated calculation methods (TRNSYS and
RETScreen), that allow quite a detailed feasibility analysis.
To assess the validity of the calculation model, an existing,
historical building in Central Italy, that will be the object of
restoration and preservative redevelopment, was selected as a casestudy.
The building is made of a basement and three floors, with a
total floor area of about 3,000 square meters.
The first step has been the determination of the heating and
cooling energy loads of the building in a dynamic regime by means,
which allows simulating the real energy needs of the building in
function of its use. Traditional methodologies, based as they are on
steady-state conditions, cannot faithfully reproduce the effects of
varying climatic conditions and of inertial properties of the structure.
With this model is possible to obtain quite accurate and reliable
results that allow identifying effective combinations building-HVAC
system.
The second step has consisted of using output data obtained as
input to the calculation model, which enables to compare different
system configurations from the energy, environmental and financial
point of view, with an analysis of investment, and operation and
maintenance costs, so allowing determining the economic benefit of
possible interventions.
The classical methodology often leads to the choice of
conventional plant systems, while our calculation model provides a
financial-economic assessment for innovative energy systems and
low environmental impact.
Computational analysis can help in the design phase, particularly
in the case of complex structures with centralized plant systems, by
comparing the data returned by the calculation model for different
design options.
Abstract: Knowledge is considered as an important asset which
can help organizations to create competitive advantage. The necessity
of taking care of these assets is more important in these days – in
days of turbulent changes in business environment. Knowledge could
facilitate adaption to constant changes. The aim of this paper is to
describe how the knowledge sharing can be supported in the
manufacturing companies. The methods of case studies and grounded
theory were used to present information gained by carrying out semistructured
interviews. Results show that knowledge sharing is
supported in very similar ways in respondent companies.
Abstract: Bir El Djir is an important coastal township in Oran
department, located at 450 Km far away from Algiers on northwest of
Algeria. In this coastal area, the urban sprawl is one of the main
problems that reduce the limited highly fertile land. So, using the
remote sensing and GIS technologies have shown their great
capabilities to solve many earth resources issues.
The aim of this study is to produce land use and cover map for the
studied area at varied periods to monitor possible changes that may
occurred, particularly in the urban areas and subsequently predict
likely changes. For this, two spatial images SPOT and Landsat
satellites from 1987 and 2014 respectively were used to assess the
changes of urban expansion and encroachment during this period
with photo-interpretation and GIS approach.
The results revealed that the town of Bir El Djir has shown a
highest growth rate in the period 1987-2014 which is 1201.5 hectares
in terms of area. These expansions largely concern the new real estate
constructions falling within the social and promotional housing
programs launched by the government.
The most urban expansion is characterized by the new
construction in the form of spontaneous or peripheral precarious
habitat, but also unstructured slums settled especially in the
southeastern part of town.
Abstract: Nowadays, huge amount of multimedia repositories
make the browsing, retrieval and delivery of video contents very slow
and even difficult tasks. Video summarization has been proposed to
improve faster browsing of large video collections and more efficient
content indexing and access. In this paper, we focus on approaches to
video summarization. The video summaries can be generated in many
different forms. However, two fundamentals ways to generate
summaries are static and dynamic. We present different techniques
for each mode in the literature and describe some features used for
generating video summaries. We conclude with perspective for
further research.
Abstract: Contemporary city is a subject to rapid economic and
social changes. Therefore, it requires an active policy designed to
meet the diverse needs of their residents, build competitive position
and capacity to compete with other cities. Competitiveness of cities
depends largely on their resources but also to a large extent, on the
policies and performance of local authorities. Cooperation with social
sector also plays an important role, as it affects the use of resources
and builds an advantage over other cities.
The subject of this article is city's contemporary problems of
development with particular emphasis on central areas. This issue is a
starting point for reflection on the process of urban regeneration in
medium size cities in Poland, as well as cooperation between various
actors and their roles in the revitalization processes of Polish cities'
centers.
Abstract: Offering a Product-Service System (PSS) is a
well-accepted strategy that companies may adopt to provide a set of
systemic solutions to customers. PSSs were initially provided in a
simple form but now take diversified and complex forms involving
multiple services, products and technologies. With the growing
interest in the PSS, frameworks for the PSS development have been
introduced by many researchers. However, most of the existing
frameworks fail to examine various relations existing in a complex
PSS. Since designing a complex PSS involves full integration of
multiple products and services, it is essential to identify not only
product-service relations but also product-product/ service-service
relations. It is also equally important to specify how they are related
for better understanding of the system. Moreover, as customers tend to
view their purchase from a more holistic perspective, a PSS should be
developed based on the whole system’s requirements, rather than
focusing only on the product requirements or service requirements.
Thus, we propose a framework to develop a complex PSS that is
coordinated fully with the requirements of both worlds. Specifically,
our approach adopts a multi-domain matrix (MDM). A MDM
identifies not only inter-domain relations but also intra-domain
relations so that it helps to design a PSS that includes highly desired
and closely related core functions/ features. Also, various dependency
types and rating schemes proposed in our approach would help the
integration process.
Abstract: Despite the highly touted benefits, emerging
technologies have unleashed pervasive concerns regarding unintended
and unforeseen social impacts. Thus, those wishing to create safe and
socially acceptable products need to identify such side effects and
mitigate them prior to the market proliferation. Various methodologies
in the field of technology assessment (TA), namely Delphi, impact
assessment, and scenario planning, have been widely incorporated in
such a circumstance. However, literatures face a major limitation in
terms of sole reliance on participatory workshop activities. They
unfortunately missed out the availability of a massive untapped data
source of futuristic information flooding through the Internet. This
research thus seeks to gain insights into utilization of futuristic data,
future-oriented documents from the Internet, as a supplementary
method to generate social impact scenarios whilst capturing
perspectives of experts from a wide variety of disciplines. To this end,
network analysis is conducted based on the social keywords extracted
from the futuristic documents by text mining, which is then used as a
guide to produce a comprehensive set of detailed scenarios. Our
proposed approach facilitates harmonized depictions of possible
hazardous consequences of emerging technologies and thereby makes
decision makers more aware of, and responsive to, broad qualitative
uncertainties.
Abstract: One of the best examples, in evolution of the public
procurement, from post-soviet countries are reforms carried out in
Georgia, which brought them close to international standards of
procurement. In Georgia, public procurement legislation started
functioning short after gaining independence. The reform has passed
several stages and came in the form as it is today. It should also be
noted, that countries with economy in transition, including Georgia,
implemented all the reforms in public procurement based on
recommendations and support of World Bank, the United Nations
and other international organizations.
The aim of first adopted law was regulation of the procurement
process of budget-organizations, transparency and creation of
competitive environment for private companies to access state funds
legally. The priorities were identified quite clearly in the wording of
the law, but operation/function of this law could not be reached on its
level, because of some objective and subjective reasons. The high
level of corruption in all levels of governance can be considered as a
main obstacle reason and of course, it is natural, that it had direct
impact on the procurement process, as well as on transparency and
rational use of state funds. These circumstances were the reasons that
reforms in this sphere continued, to improve procurement process, in
particular, the first wave of reforms began after several years. Public
procurement agency carried out reform with World Bank with main
purpose of smartening the procurement legislation and its
harmonization with international treaties and agreements. Also with
the support of World Bank various activities were carried out to raise
awareness of participants involved in procurement system.
Further major changes in the legislation were filed bit later, which
was also directed towards the improvement and smarten of the
procurement process. The third wave of the reform more or less
guaranteed the transparency of the procurement process, which later
became the basis for the rational spending of state funds. The reform
of the procurement system completely changed the procedures.
Carried out reform in Georgia resulted in introducing new
electronic tendering system, which benefit the transparency of the
process, after this became the basis for the further development of a
competitive environment, which become a prerequisite for the state
rational spending. Increased number of supplier organizations
participating in the procurement process resulted in reduction of the
estimated cost and the actual cost.
Assessment of the reforms in Georgia in the field of public
procurement can be concluded, that proper regulation of the sector
and relevant policy may proceed to rational and transparent spending
of the budget from country’s state institutions. Also, the business
sector has the opportunity to work in competitive market conditions
and to make a preliminary analysis, which is a prerequisite for future
strategy and development.
Abstract: Pulmonary Function Tests are important non-invasive
diagnostic tests to assess respiratory impairments and provides
quantifiable measures of lung function. Spirometry is the most
frequently used measure of lung function and plays an essential role
in the diagnosis and management of pulmonary diseases. However,
the test requires considerable patient effort and cooperation,
markedly related to the age of patients resulting in incomplete data
sets. This paper presents, a nonlinear model built using Multivariate
adaptive regression splines and Random forest regression model to
predict the missing spirometric features. Random forest based feature
selection is used to enhance both the generalization capability and the
model interpretability. In the present study, flow-volume data are
recorded for N= 198 subjects. The ranked order of feature importance
index calculated by the random forests model shows that the
spirometric features FVC, FEF25, PEF, FEF25-75, FEF50 and the
demographic parameter height are the important descriptors. A
comparison of performance assessment of both models prove that, the
prediction ability of MARS with the `top two ranked features namely
the FVC and FEF25 is higher, yielding a model fit of R2= 0.96 and
R2= 0.99 for normal and abnormal subjects. The Root Mean Square
Error analysis of the RF model and the MARS model also shows that
the latter is capable of predicting the missing values of FEV1 with a
notably lower error value of 0.0191 (normal subjects) and 0.0106
(abnormal subjects) with the aforementioned input features. It is
concluded that combining feature selection with a prediction model
provides a minimum subset of predominant features to train the
model, as well as yielding better prediction performance. This
analysis can assist clinicians with a intelligence support system in the
medical diagnosis and improvement of clinical care.
Abstract: Enterococci are important inhabitants of the animal
intestine and are widely used in probiotic products. A probiotic strain
is expected to possess several desirable properties in order to exert
beneficial effects. Therefore, the objective of this study was to
isolate, characterize and identify Enterococcus sp. from chicken cecal
and fecal samples to determine potential probiotic properties.
Enterococci were isolated from chicken ceca and feces of thirty three
clinically healthy chickens from a local farm. In vitro studies were
performed to assess antibacterial activity of the isolated LAB (using
agar well diffusion and cell free supernatant broth technique against
Salmonella enterica serotype Enteritidis), survival in acidic
conditions, resistance to bile salts, and their survival during simulated
gastric juice conditions at pH 2.5. Isolates were identified by
biochemical carbohydrate fermentation patterns using an API 50
CHL kit and API ZYM kits and by sequenced 16S rDNA. An isolate
belonging to E. faecium species exhibited inhibitory effect against S.
enteritidis. This isolate producing a clear zone as large as 10.30 mm
or greater and was able to grow in the coculture medium and at the
same time, inhibited the growth S. enteritidis. In addition, E. faecium
exhibited significant resistance under highly acidic conditions at pH
2.5 for 8 h and survived well in bile salt at 0.2% for 24 h and showing
ability to survive in the presence of simulated gastric juice at pH 2.5.
Based on these results, E. faecium isolate fulfills some of the criteria
to be considered as a probiotic strain and therefore, could be used as a
feed additive with good potential for controlling S. Enteritidis in
chickens. However, in vivo studies are needed to determine the safety
of the strain.
Abstract: This work deals with parameter identification of
permanent magnet motors, a class of ac motor which is particularly
important in industrial automation due to characteristics like
applications high performance, are very attractive for applications
with limited space and reducing the need to eliminate because they
have reduced size and volume and can operate in a wide speed range,
without independent ventilation. By using experimental data and
genetic algorithm we have been able to extract values for both the
motor inductance and the electromechanical coupling constant, which
are then compared to measured and/or expected values.
Abstract: In this paper, the problem of fault detection and
isolation in the attitude control subsystem of spacecraft formation
flying is considered. In order to design the fault detection method, an
extended Kalman filter is utilized which is a nonlinear stochastic state
estimation method. Three fault detection architectures, namely,
centralized, decentralized, and semi-decentralized are designed based
on the extended Kalman filters. Moreover, the residual generation
and threshold selection techniques are proposed for these
architectures.
Abstract: Over the past four decades, the fatigue behavior of
nickel-based alloys has been widely studied. However, in recent
years, significant advances in the fabrication process leading to grain
size reduction have been made in order to improve fatigue properties
of aircraft turbine discs. Indeed, a change in particle size affects the
initiation mode of fatigue cracks as well as the fatigue life of the
material. The present study aims to investigate the fatigue behavior of
a newly developed nickel-based superalloy under biaxial-planar
loading. Low Cycle Fatigue (LCF) tests are performed at different
stress ratios so as to study the influence of the multiaxial stress state
on the fatigue life of the material. Full-field displacement and strain
measurements as well as crack initiation detection are obtained using
Digital Image Correlation (DIC) techniques. The aim of this
presentation is first to provide an in-depth description of both the
experimental set-up and protocol: the multiaxial testing machine, the
specific design of the cruciform specimen and performances of the
DIC code are introduced. Second, results for sixteen specimens
related to different load ratios are presented. Crack detection, strain
amplitude and number of cycles to crack initiation vs. triaxial stress
ratio for each loading case are given. Third, from fractographic
investigations by scanning electron microscopy it is found that the
mechanism of fatigue crack initiation does not depend on the triaxial
stress ratio and that most fatigue cracks initiate from subsurface
carbides.
Abstract: The thermal behavior of a large-scale, phase change material (PCM) enhanced building envelope system was studied in regard to the need for pre-fabricated construction in subtropical regions. The proposed large-scale envelope consists of a reinforced aluminum skin, insulation core, phase change material and reinforced gypsum board. The PCM impact on an energy efficiency of an enveloped room was resolved by validation of the EnergyPlus numerical scheme and optimization of a smart material location in the core. The PCM location was optimized by a minimization method of a cooling energy demand. It has been shown that there is good agreement between the test and simulation results. The optimal location of the PCM layer in Hong Kong summer conditions has been then recomputed for core thicknesses of 40, 60 and 80 mm. A non-dimensional value of the optimal PCM location was obtained to be same for all the studied cases and the considered external and internal conditions.
Abstract: The detection of moving objects from a video image
sequences is very important for object tracking, activity recognition,
and behavior understanding in video surveillance.
The most used approach for moving objects detection / tracking is
background subtraction algorithms. Many approaches have been
suggested for background subtraction. But, these are illumination
change sensitive and the solutions proposed to bypass this problem
are time consuming.
In this paper, we propose a robust yet computationally efficient
background subtraction approach and, mainly, focus on the ability to
detect moving objects on dynamic scenes, for possible applications in
complex and restricted access areas monitoring, where moving and
motionless persons must be reliably detected. It consists of three
main phases, establishing illumination changes invariance,
background/foreground modeling and morphological analysis for
noise removing.
We handle illumination changes using Contrast Limited Histogram
Equalization (CLAHE), which limits the intensity of each pixel to
user determined maximum. Thus, it mitigates the degradation due to
scene illumination changes and improves the visibility of the video
signal. Initially, the background and foreground images are extracted
from the video sequence. Then, the background and foreground
images are separately enhanced by applying CLAHE.
In order to form multi-modal backgrounds we model each channel
of a pixel as a mixture of K Gaussians (K=5) using Gaussian Mixture
Model (GMM). Finally, we post process the resulting binary
foreground mask using morphological erosion and dilation
transformations to remove possible noise.
For experimental test, we used a standard dataset to challenge the
efficiency and accuracy of the proposed method on a diverse set of
dynamic scenes.
Abstract: Meeting the growth in demand for digital services
such as social media, telecommunications, and business and cloud
services requires large scale data centres, which has led to an increase
in their end use energy demand. Generally, over 30% of data centre
power is consumed by the necessary cooling overhead. Thus energy
can be reduced by improving the cooling efficiency. Air and liquid
can both be used as cooling media for the data centre. Traditional
data centre cooling systems use air, however liquid is recognised as a
promising method that can handle the more densely packed data
centres. Liquid cooling can be classified into three methods; rack heat
exchanger, on-chip heat exchanger and full immersion of the
microelectronics. This study quantifies the improvements of heat
transfer specifically for the case of immersed microelectronics by
varying the CPU and heat sink location. Immersion of the server is
achieved by filling the gap between the microelectronics and a water
jacket with a dielectric liquid which convects the heat from the CPU
to the water jacket on the opposite side. Heat transfer is governed by
two physical mechanisms, which is natural convection for the fixed
enclosure filled with dielectric liquid and forced convection for the
water that is pumped through the water jacket. The model in this
study is validated with published numerical and experimental work
and shows good agreement with previous work. The results show that
the heat transfer performance and Nusselt number (Nu) is improved
by 89% by placing the CPU and heat sink on the bottom of the
microelectronics enclosure.