Abstract: Remotely sensed data are a significant source for monitoring and updating databases for land use/cover. Nowadays, changes detection of urban area has been a subject of intensive researches. Timely and accurate data on spatio-temporal changes of urban areas are therefore required. The data extracted from multi-temporal satellite images are usually non-stationary. In fact, the changes evolve in time and space. This paper is an attempt to propose a methodology for changes detection in urban area by combining a non-stationary decomposition method and stochastic modeling. We consider as input of our methodology a sequence of satellite images I1, I2, … In at different periods (t = 1, 2, ..., n). Firstly, a preprocessing of multi-temporal satellite images is applied. (e.g. radiometric, atmospheric and geometric). The systematic study of global urban expansion in our methodology can be approached in two ways: The first considers the urban area as one same object as opposed to non-urban areas (e.g. vegetation, bare soil and water). The objective is to extract the urban mask. The second one aims to obtain a more knowledge of urban area, distinguishing different types of tissue within the urban area. In order to validate our approach, we used a database of Tres Cantos-Madrid in Spain, which is derived from Landsat for a period (from January 2004 to July 2013) by collecting two frames per year at a spatial resolution of 25 meters. The obtained results show the effectiveness of our method.
Abstract: This paper deals with modeling and simulation of the plasma actuator with OpenFOAM. Plasma actuator is one of the newest devices in flow control techniques which can delay separation by inducing external momentum to the boundary layer of the flow. The effects of the plasma actuators on the external flow are incorporated into Navier-Stokes computations as a body force vector which is obtained as a product of the net charge density and the electric field. In order to compute this body force vector, the model solves two equations: One for the electric field due to the applied AC voltage at the electrodes and the other for the charge density representing the ionized air. The simulation result is compared to the experimental and typical values which confirms the validity of the modeling.
Abstract: In order to solve the housing problem for the low-income families, the construction of affordable housing is booming in China. However, due to various reasons, the service facilities and systems in the indemnificatory residential community meet many problems. This article established a Satisfaction Evaluation System of the Fundamental Public Services for Large-scale Indemnificatory Residential Community based on the national standards and local criteria and developed evaluation methods and processes. At last, in the case of Huagang project in Nanjing, the satisfaction of basic public service is calculated according to a survey of local residents.
Abstract: There are many types of mechanical failure on the
dental implant. In this project, the failure that needs to take into
consideration is the bone resorption on the dental implant. Human
bone has its ability to remodel after the implantation. As the dental
implant is installed into the bone, the bone will detect and change the
bone structure to achieve new biomechanical environment. This
phenomenon is known as bone remodeling. The objective of the
project is to improve the performance of dental implant by using
different types of design. These designs are used to analyze and
predict the failure of the dental implant by using finite element
analysis (FEA) namely ANSYS. The bone is assumed to be fully
attached to the implant or cement. Hence, results are then compared
with other researchers. The results were presented in the form of Von
Mises stress, normal stress, shear stress analysis, and displacement.
The selected design will be analyzed further based on a theoretical
calculation of bone remodeling on the dental implant. The results
have shown that the design constructed passed the failure analysis.
Therefore, the selected design is proven to have a stable performance
at the recovery stage.
Abstract: The expectation-confirmation model (ECM) is one of the most widely used models for evaluating information system continuance, and this model has been extended to other study backgrounds, or expanded with other theoretical perspectives. However, combining ECM with other theories or investigating the background problem may produce some disparities, thus generating inaccurate conclusions. Habit is considered to be an important factor that influences the user’s continuance behavior. This paper thus critically examines seven pairs of relationships from the original ECM and the habit variable. A meta-analysis was used to tackle the development of ECM research over the last 10 years from a range of journals and conference papers published in 2005–2014. Forty-six journal articles and 19 conference papers were selected for analysis. The results confirm our prediction that a high effect size for the seven pairs of relationships was obtained (ranging from r=0.386 to r=0.588). Furthermore, a meta-analytic structural equation modeling was performed to simultaneously test all relationships. The results show that habit had a significant positive effect on continuance intention at p
Abstract: Conical sections and shells of metal plates manufactured by 3-roller conical bending process are widely used in the industries. The process is completed by first bending the metal plates statically and then dynamic roller bending sequentially. It is required to have an analytical model to get maximum bending force, for optimum design of the machine, for static bending stage. Analytical models assuming various stress conditions are considered and these analytical models are compared considering various parameters and reported in this paper. It is concluded from the study that for higher bottom roller inclination, the shear stress affects greatly to the static bending force whereas for lower bottom roller inclination it can be neglected.
Abstract: This paper presents the results of experimental and theoretical investigations of the mechanisms of crack formation in reinforced concrete beams subjected to quasi-static bending. The boundary-value problem has been formulated in the framework of brittle fracture mechanics and has been solved by using the finite-element method. Numerical simulation of the vibrations of an uncracked beam and a beam with cracks of different size serves to determine the pattern of changes in the spectrum of eigenfrequencies observed during crack evolution. Experiments were performed on the sequential quasistatic four-point bending of the beam leading to the formation of cracks in concrete. At each loading stage, the beam was subjected to an impulse load to induce vibrations. Two stages of cracking were detected. At the first stage the conservative process of deformation is realized. The second stage is an active cracking, which is marked by a sharp change in eingenfrequencies. The boundary of a transition from one stage to another is well registered. The vibration behavior was examined for the beams strengthened by carbon-fiber sheet before loading and at the intermediate stage of loading after the grouting of initial cracks. The obtained results show that the vibrodiagnostic approach is an effective tool for monitoring of cracking and for assessing the quality of measures aimed at strengthening concrete structures.
Abstract: The aim of this work is to present a low cost adsorbent
for removing toxic heavy metals from aqueous solutions. Therefore,
we are interested to investigate the efficiency of natural clay minerals
collected from south Tunisia and their modified form using sulfuric
acid in the removal of toxic metal ions: Zn(II) and Pb(II) from
synthetic waste water solutions. The obtained results indicate that
metal uptake is pH-dependent and maximum removal was detected to
occur at pH 6. Adsorption equilibrium is very rapid and it was
achieved after 90 min for both metal ions studied. The kinetics results
show that the pseudo-second-order model describes the adsorption
and the intraparticle diffusion models are the limiting step. The
treatment of natural clay with sulfuric acid creates more active sites
and increases the surface area, so it showed an increase of the
adsorbed quantities of lead and zinc in single and binary systems. The
competitive adsorption study showed that the uptake of lead was
inhibited in the presence of 10 mg/L of zinc. An antagonistic binary
adsorption mechanism was observed. These results revealed that clay
is an effective natural material for removing lead and zinc in single
and binary systems from aqueous solution.
Abstract: In the current paper, a domain independent conduction model compatible for multi-physical system dynamic investigations is suggested. By means of a port-based approach, a classical nonlinear conduction model containing physical states is first represented. A compatible discrete configuration of the thermal domain in line with the elastic domain is then generated through the enhancement of the configuration of the conventional thermal element. The presented simulation results of a sample structure indicate that the suggested conductive model can cover a wide range of dynamic behavior of the thermal domain.
Abstract: Automatic program generation saves time, human resources, and allows receiving syntactically clear and logically correct modules. The 4-th generation programming languages are related to drawing the data and the processes of the subject area, as well as, to obtain a frame of the respective information system. The application can be separated in interface and business logic. That means, for an interactive generation of the needed system to be used an already existing toolkit or to be created a new one.
Abstract: This study involves the modeling and monitoring of an ammonia synthesis fixed-bed reactor using partial least squares (PLS) and its variants. The process exhibits complex dynamic behavior due to the presence of heat recycling and feed quench. One limitation of static PLS model in this situation is that it does not take account of the process dynamics and hence dynamic PLS was used. Although it showed, superior performance to static PLS in terms of prediction, the monitoring scheme was inappropriate hence adaptive PLS was considered. A limitation of adaptive PLS is that non-conforming observations also contribute to the model, therefore, a new adaptive approach was developed, robust adaptive dynamic PLS. This approach updates a dynamic PLS model and is robust to non-representative data. The developed methodology showed a clear improvement over existing approaches in terms of the modeling of the reactor and the detection of faults.
Abstract: As DNA microarray data contain relatively small
sample size compared to the number of genes, high dimensional
models are often employed. In high dimensional models, the selection
of tuning parameter (or, penalty parameter) is often one of the crucial
parts of the modeling. Cross-validation is one of the most common
methods for the tuning parameter selection, which selects a parameter
value with the smallest cross-validated score. However, selecting a
single value as an ‘optimal’ value for the parameter can be very
unstable due to the sampling variation since the sample sizes of
microarray data are often small. Our approach is to choose multiple candidates of tuning parameter
first, then average the candidates with different weights depending
on their performance. The additional step of estimating the weights
and averaging the candidates rarely increase the computational cost,
while it can considerably improve the traditional cross-validation. We
show that the selected value from the suggested methods often lead to
stable parameter selection as well as improved detection of significant
genetic variables compared to the tradition cross-validation via real
data and simulated data sets.
Abstract: During manned exploration of space, missions will require astronaut crewmembers to perform Extra Vehicular Activities (EVAs) for a variety of tasks. These EVAs take place after long periods of operations in space, and in and around unique vehicles, space structures and systems. Considering the remoteness and time spans in which these vehicles will operate, EVA system operations should utilize common worksites, tools and procedures as much as possible to increase the efficiency of training and proficiency in operations. All of the preparations need to be carried out based on studies of astronaut motions. Until now, development and training activities associated with the planned EVAs in Russian and U.S. space programs have relied almost exclusively on physical simulators. These experimental tests are expensive and time consuming. During the past few years a strong increase has been observed in the use of computer simulations due to the fast developments in computer hardware and simulation software. Based on this idea, an effort to develop a computational simulation system to model human dynamic motion for EVA is initiated. This study focuses on the simulation of an astronaut moving the orbital replaceable units into the worksites or removing them from the worksites. Our physics-based methodology helps fill the gap in quantitative analysis of astronaut EVA by providing a multisegment human arm model. Simulation work described in the study improves on the realism of previous efforts, incorporating joint stops to account for the physiological limits of range of motion. To demonstrate the utility of this approach human arm model is simulated virtually using ADAMS/LifeMOD® software. Kinematic mechanism for the astronaut’s task is studied from joint angles and torques. Simulation results obtained is validated with numerical simulation based on the principles of Newton-Euler method. Torques determined using mathematical model are compared among the subjects to know the grace and consistency of the task performed. We conclude that due to uncertain nature of exploration-class EVA, a virtual model developed using multibody dynamics approach offers significant advantages over traditional human modeling approaches.
Abstract: In this work we make a bifurcation analysis for a
single compartment representation of Traub model, one of the most
important conductance-based models. The analysis focus in two
principal parameters: current and leakage conductance. Study of
stable and unstable solutions are explored; also Hop-bifurcation and
frequency interpretation when current varies is examined. This study
allows having control of neuron dynamics and neuron response when
these parameters change. Analysis like this is particularly important
for several applications such as: tuning parameters in learning
process, neuron excitability tests, measure bursting properties of the
neuron, etc. Finally, a hardware implementation results were
developed to corroborate these results.
Abstract: Social networks have recently gained a growing
interest on the web. Traditional formalisms for representing social
networks are static and suffer from the lack of semantics. In this
paper, we will show how semantic web technologies can be used to
model social data. The SemTemp ontology aligns and extends
existing ontologies such as FOAF, SIOC, SKOS and OWL-Time to
provide a temporal and semantically rich description of social data.
We also present a modeling scenario to illustrate how our ontology
can be used to model social networks.
Abstract: This paper discusses the intake of combining multi-criteria
decision analysis (MCDA) with OLAP systems, to generate
an integrated analysis process dealing with complex multi-criteria
decision-making situations. In this context, a multi-agent modeling is
presented for decision support systems by combining multi-criteria
decision analysis (MCDA) with OLAP systems. The proposed
modeling which consists in performing the multi-agent system
(MAS) architecture, procedure and protocol of the negotiation model
is elaborated as a decision support tool for complex decision-making
environments. Our objective is to take advantage from the multi-agent
system which distributes resources and computational
capabilities across interconnected agents, and provide a problem
modeling in terms of autonomous interacting component-agents.
Thus, the identification and evaluation of criteria as well as the
evaluation and ranking of alternatives in a decision support situation
will be performed by organizing tasks and user preferences between
different agents in order to reach the right decision. At the end, an
illustrative example is conducted to demonstrate the function and
effectiveness of our MAS modeling.
Abstract: The paper focuses on the benefits of business process
modeling. Although this discipline is developing for many years,
there is still necessity of creating new opportunities to meet the ever
increasing users’ needs. Because one of these needs is related to the
conversion of business process models from one standard to another,
the authors have developed a converter between BPMN and EPC
standards using workflow patterns as intermediate tool. Nowadays
there are too many systems for business process modeling. The
variety of output formats is almost the same as the systems
themselves. This diversity additionally hampers the conversion of the
models. The presented study is aimed at discussing problems due to
differences in the output formats of various modeling environments.
Abstract: The Petri nets are the first standard for business
process modeling. Most probably, it is one of the core reasons why
all new standards created afterwards have to be so reformed as to
reach the stage of mapping the new standard onto Petri nets. The paper presents a business process repository based on a
universal database. The repository provides the possibility the data
about a given process to be stored in three different ways. Business
process repository is developed with regard to the reformation of a
given model to a Petri net in order to be easily simulated. Two different techniques for business process simulation based on
Petri nets - Yasper and Woflan are discussed. Their advantages and
drawbacks are outlined. The way of simulating business process
models, stored in the Business process repository is shown.
Abstract: Recently, many users have begun to frequently share
their opinions on diverse issues using various social media. Therefore,
numerous governments have attempted to establish or improve
national policies according to the public opinions captured from
various social media. In this paper, we indicate several limitations of
the traditional approaches to analyze public opinion on science and
technology and provide an alternative methodology to overcome these
limitations. First, we distinguish between the science and technology
analysis phase and the social issue analysis phase to reflect the fact that
public opinion can be formed only when a certain science and
technology is applied to a specific social issue. Next, we successively
apply a start list and a stop list to acquire clarified and interesting
results. Finally, to identify the most appropriate documents that fit
with a given subject, we develop a new logical filter concept that
consists of not only mere keywords but also a logical relationship
among the keywords. This study then analyzes the possibilities for the
practical use of the proposed methodology thorough its application to
discover core issues and public opinions from 1,700,886 documents
comprising SNS, blogs, news, and discussions.
Abstract: This study examined the mental health and behavioral
problems in early adolescence with the instrument of Achenbach
System of Empirically Based Assessment (ASEBA). The purpose of
the study was stratified sampling method was used to collect data
from 1975 participants. Multiple regression models and hierarchical
regression models were applied to examine the relations between the
background variables and internalizing problems, and the ones
between students’ performance and internalizing problems. The
results indicated that several background variables as predictors could
significantly predict the anxious/depressed problem; reading and
social study scores could significantly predict the anxious/depressed
problem. However the class as a hierarchical macro factor did not
indicate the significant effect. In brief, the majority of these models
represented that the background variables, behaviors and academic
performance were significantly related to the anxious/depressed
problem.