Abstract: Efficient utilization of spectrum resources is a
fundamental issue of wireless communications due to its scarcity.
To improve the efficiency of spectrum utilization, the spectrum
sharing for unlicensed bands is being regarded as one of key
technologies in the next generation wireless networks. A number
of schemes such as Listen-Before-Talk(LBT) and carrier sensor
adaptive transmission (CSAT) have been suggested from this aspect,
but more efficient sharing schemes are required for improving
spectrum utilization efficiency. This work considers an opportunistic
transmission approach and a dynamic Contention Window (CW)
adjustment scheme for LTE-U users sharing the unlicensed spectrum
with Wi-Fi, in order to enhance the overall system throughput. The
decision criteria for the dynamic adjustment of CW are based on
the collision evaluation, derived from the collision probability of the
system. The overall performance can be improved due to the adaptive
adjustment of the CW. Simulation results show that our proposed
scheme outperforms the Distributed Coordination Function (DCF)
mechanism of IEEE 802.11 MAC.
Abstract: The commercial companies’ management has suffered an important material and legal transformation in the last years, mainly related to the changes in the Portuguese legal framework and because of the fact they were recently object of great expansion. In fact, next to the smaller family businesses, whose management is regularly assumed by partners, companies with social investment highly scattered, whose owners are completely out from administration, are now arising. In those particular cases, the business transactions are much more complex and require from the companies’ managers a highly technical knowledge and some specific professionals’ skills and abilities. This kind of administration carries a high-level risk that can both result in great success or in great losses. Knowing that the administration performance can result in important losses to the companies, the Portuguese legislator has created a legal structure to impute them some responsibilities and sanctions. The main goal of this study is to analyze the Portuguese law and some jurisprudence about companies’ management rules and about the conflicts between the directors and the company. In order to achieve these purposes we have to consider, on the one hand, the legal duties directly connected to the directors’ functions and on the other hand the disrespect for those same rules. The Portuguese law in this matter, influenced by the common law, determines that the directors’ attitude should be guided by loyalty and honesty. Consequently, we must reflect in which cases the administrators should respond to losses that they might cause to companies as a result of their duties’ disrespect. In this way is necessary to study the business judgment rule wich is a rule that refers to a liability exclusion rule. We intend, in the same way, to evaluate if the civil liability that results from the directors’ duties disrespect can extend itself to those who have elected them ignoring or even knowing that they don´t have the necessary skills or appropriate knowledge to the position they hold. To charge directors’, without ruining entrepreneurship, charging, in the same way, those who select them reinforces the need for more responsible and cautious attitudes which will lead consequently to more confidence in the markets.
Abstract: In addition to the fact that mental health bears great significance to a particular individual, it can also be regarded as an organizational, community and societal resource. Within the Szeged Health Promotion Research Group, we conducted mental health surveys on two levels: The inhabitants of a medium-sized Hungarian town and students of a Hungarian university with a relatively big headcount were requested to participate in surveys whose goals were to define local government priorities and organization-level health promotion programmes, respectively. To facilitate professional decision-making, we defined three, pragmatically relevant, groups of the target population: the mentally healthy, the vulnerable and the endangered. In order to determine which group a person actually belongs to, we designed a simple and quick measurement tool, which could even be utilised as a smoothing method, the Mental State Questionnaire validity of the above three categories was verified by analysis of variance against psychological quality of life variables. We demonstrate the pragmatic significance of our method via the analyses of the scores of our two mental health surveys. On town level, during our representative survey in Hódmezővásárhely (N=1839), we found that 38.7% of the participants was mentally healthy, 35.3% was vulnerable, while 16.3% was considered as endangered. We were able to identify groups that were in a dramatic state in terms of mental health. For example, such a group consisted of men aged 45 to 64 with only primary education qualification and the ratios of the mentally healthy, vulnerable and endangered were 4.5, 45.5 and 50%, respectively. It was also astonishing to see to what a little extent qualification prevailed as a protective factor in the case of women. Based on our data, the female group aged 18 to 44 with primary education—of whom 20.3% was mentally healthy, 42.4% vulnerable and 37.3% was endangered—as well as the female group aged 45 to 64 with university or college degree—of whom 25% was mentally healthy, 51.3 vulnerable and 23.8% endangered—are to be handled as priority intervention target groups in a similarly difficult position. On organizational level, our survey involving the students of the University of Szeged, N=1565, provided data to prepare a strategy of mental health promotion for a university with a headcount exceeding 20,000. When developing an organizational strategy, it was important to gather information to estimate the proportions of target groups in which mental health promotion methods; for example, life management skills development, detection, psychological consultancy, psychotherapy, would be applied. Our scores show that 46.8% of the student participants were mentally healthy, 42.1% were vulnerable and 11.1% were endangered. These data convey relevant information as to the allocation of organizational resources within a university with a considerable headcount. In conclusion, The Mental State Questionnaire, as a valid smoothing method, is adequate to describe a community in a plain and informative way in the terms of mental health. The application of the method can promote the preparation, design and implementation of mental health promotion interventions.
Abstract: The objective of this study is to analyze the evolution of some social and economic indicators of Mercosur´s economies from 1980 to 2012, based on the statistics of the Latin American Integration Association (LAIA). The objective is to observe if after the accession of these economies to Mercosur (the first accessions occurred in 1994) these indicators showed better performance, in order to demonstrate if economic integration contributed to improved trade, macroeconomic performance, and level of social and economic development of member countries. To this end, the methodologies used will be a literature review and descriptive statistics. The theoretical framework that guides the work are the theories of Integration: Classical Liberal, Marxist and structural-proactive. The results reveal that most social and economic indicators showed better performance in those economies that joined Mercosur after 1994. This work is the result of an investigation already completed.
Abstract: Slope stability analyses are largely carried out by deterministic methods and evaluated through a single security factor. Although it is known that the geotechnical parameters can present great dispersal, such analyses are considered fixed and known. The probabilistic methods, in turn, incorporate the variability of input key parameters (random variables), resulting in a range of values of safety factors, thus enabling the determination of the probability of failure, which is an essential parameter in the calculation of the risk (probability multiplied by the consequence of the event). Among the probabilistic methods, there are three frequently used methods in geotechnical society: FOSM (First-Order, Second-Moment), Rosenblueth (Point Estimates) and Monte Carlo. This paper presents a comparison between the results from deterministic and probabilistic analyses (FOSM method, Monte Carlo and Rosenblueth) applied to a hypothetical slope. The end was held to evaluate the behavior of the slope and consequent risk analysis, which is used to calculate the risk and analyze their mitigation and control solutions. It can be observed that the results obtained by the three probabilistic methods were quite close. It should be noticed that the calculation of the risk makes it possible to list the priority to the implementation of mitigation measures. Therefore, it is recommended to do a good assessment of the geological-geotechnical model incorporating the uncertainty in viability, design, construction, operation and closure by means of risk management.
Abstract: Recently, fluidized bed gasification becomes an attractive technology for power generation due to its higher efficiency. The main objective pursued in this work is to investigate the producer gas production potential from sized biomass (sawdust and pigeon pea) by applying the air gasification technique. The size of the biomass selected for the study was in the range of 0.40-0.84 mm. An experimental study was conducted using a fluidized bed gasifier with 210 mm diameter and 1600 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures 700 to 900 °C, equivalence ratio 0.16 to 0.46 were studied. It was concluded that substantial amounts of producer gas (up to 1110 kcal/m3) could be produced utilizing biomass such as sawdust and pigeon pea by applying this fluidization technique. For both samples, the rise of temperature till 900 °C and equivalence ratio of 0.4 favored further gasification reactions and resulted into producer gas with calorific value 1110 kcal/m3.
Abstract: This study discusses a simple solution for the problem of shortage in learning resources for kindergarten teachers. Occasionally, kindergarten teachers cannot access proper resources by usual search methods as libraries or search engines. Furthermore, these methods require a long time and efforts for preparing. The study is expected to facilitate accessing learning resources. Moreover, it suggests a potential direction for using QR code inside the classroom. The present work proposes that QR code can be used for digitizing kindergarten curriculums and accessing various learning resources. It investigates using QR code for saving information related to the concepts which kindergarten teachers use in the current educational situation. The researchers have established a guide for kindergarten teachers based on the Egyptian official curriculum. The guide provides different learning resources for each scientific and mathematical concept in the curriculum, and each learning resource is represented as a QR code image that contains its URL. Therefore, kindergarten teachers can use smartphone applications for reading QR codes and displaying the related learning resources for students immediately. The guide has been provided to a group of 108 teachers for using inside their classrooms. The results showed that the teachers approved the guide, and gave a good response.
Abstract: A designing of a structure requires its realization on rough or sloping ground. Besides the problem of the stability of the landslide, the behavior of the foundations that are bearing the structure is influenced by the destabilizing effect of the ground’s slope. This article focuses on the analysis of the slope stability exposed to loading by introducing the different factors influencing the slope’s behavior on the one hand, and on the influence of this slope on the foundation’s behavior on the other hand. This study is about the elastoplastic modelization using FLAC 2D. This software is based on the finite difference method, which is one of the older methods of numeric resolution of differential equations system with initial and boundary conditions. It was developed for the geotechnical simulation calculation. The aim of this simulation is to demonstrate the notable effect of shear modulus « G », cohesion « C », inclination angle (edge) « β », and distance between the foundation and the head of the slope on the stability of the slope as well as the stability of the foundation. In our simulation, the slope is constituted by homogenous ground. The foundation is considered as rigid/hard; therefore, the loading is made by the application of the vertical strengths on the nodes which represent the contact between the foundation and the ground.
Abstract: Energy disaggregation has been focused by many energy companies since energy efficiency can be achieved when the breakdown of energy consumption is known. Companies have been investing in technologies to come up with software and/or hardware solutions that can provide this type of information to the consumer. On the other hand, not all people can afford to have these technologies. Therefore, in this paper, we present a methodology for breaking down the aggregate consumption and identifying the highdemanding end-uses profiles. These energy profiles will be used to build the forecast model for optimal control purpose. A facility with high cooling load is used as an illustrative case study to demonstrate the results of proposed methodology. We apply a high level energy disaggregation through a pattern recognition approach in order to extract the consumption profile of its rooftop packaged units (RTUs) and present a forecast model for the energy consumption.
Abstract: This research provides a systematic way to study and
better understand double nano-tubular structure of alunina (Al2O3) and
titania (TiO2). The TiO2 NT was prepared by immersing Al2O3
template in 0.02 M titanium fluoride (TiF4) solution (pH=3) at 25 °C
for 120 min, followed by annealing at 450 °C for 1 h to obtain anatase
TiO2 NT in the Al2O3 template. Large-scale development of film for
nanotube-based CO2 capture and conversion can potentially result in
more efficient energy harvesting. In addition, the production process
will be relatively environmentally friendly. The knowledge generated
by this research will significantly advance research in the area of
Al2O3, TiO2, CaO, and Ca2O3 nano-structure film fabrication and
applications for CO2 capture and conversion. This green energy source
will potentially reduce reliance on carbon-based energy resources and
increase interest in science and engineering careers.
Abstract: Social entrepreneurship is a new and exciting topic
that holds a great promise in helping alleviate the social problems of
the world. As a new subject, the meaning of the term is too broad and
this is counterproductive in trying to build understanding around the
concept. The purpose of this study is to identify and compare the
elements of social entrepreneurship as defined by seven international
organizations leading social entrepreneurship projects: Ashoka
Foundation, Skoll Foundation, Schwab Foundation and Yunus
Center; as well as from three other institutions fostering social
entrepreneurship: Global Social Benefit Institute, BRAC University,
and Socialab. The study used document analysis from Skoll
Foundation, Schwab Foundation, Yunus Center and Ashoka
Foundation; and open ended interview to experts from the Global
Social Benefit Institute at Santa Clara University in United States,
BRAC University from Bangladesh, and Socialab from Argentina.
The study identified three clearly differentiated schools of thought,
based on their views on revenue, scalability, replicability and
geographic location. While this study is by no means exhaustive, it
provides an indication of the patterns of ideas fostered by important
players in the field. By clearly identifying the similarities and
differences in the concept of social entrepreneurship, research and
practitioners are better equipped to build on the subject, and to
promote more adequate and accurate social policies to foster the
development of social entrepreneurship.
Abstract: In nearly all earthquakes of the past century that
resulted in moderate to significant damage, the occurrence of postearthquake
fire ignition (PEFI) has imposed a serious hazard and
caused severe damage, especially in urban areas. In order to reduce
the loss of life and property caused by post-earthquake fires, there is
a crucial need for predictive models to estimate the PEFI risk. The
parameters affecting PEFI risk can be categorized as: 1) factors
influencing fire ignition in normal (non-earthquake) condition,
including floor area, building category, ignitability, type of appliance,
and prevention devices, and 2) earthquake related factors contributing
to the PEFI risk, including building vulnerability and earthquake
characteristics such as intensity, peak ground acceleration, and peak
ground velocity. State-of-the-art statistical PEFI risk models are
solely based on limited available earthquake data, and therefore they
cannot predict the PEFI risk for areas with insufficient earthquake
records since such records are needed in estimating the PEFI model
parameters. In this paper, the correlation between normal condition
ignition risk, peak ground acceleration, and PEFI risk is examined in
an effort to offer a means for predicting post-earthquake ignition
events. An illustrative example is presented to demonstrate how such
correlation can be employed in a seismic area to predict PEFI hazard.
Abstract: Software vulnerabilities are increasing and not only impact services and processes availability as well as information confidentiality, integrity and privacy, but also cause changes that interfere in the development process. Security test could be a solution to reduce vulnerabilities. However, the variety of test techniques with the lack of real case studies of applying tests focusing on software development life cycle compromise its effective use. This paper offers an overview of how a Systematic Mapping Study (MS) about security verification, validation and test (VVT) was performed, besides presenting general results about this study.
Abstract: Within Vietnam's system of higher education, its
schools of business play a vital role in supporting the country’s
economic objectives. However, the crucial contribution of soft skills
for maximal success within the business sector has to date not been
adequately recognized by its business schools. This being so, the
development of the business school curriculum in Vietnam has not
been able to 'catch up', so to say, with the burgeoning need of
students for a comprehensive soft skills program designed to meet the
national and global business objectives of their potential employers.
The burden of the present paper is first to reveal the results of our
survey in Vietnam which make explicit the extent to which major
Vietnamese industrial employers’ value the potential role that soft
skill competencies can play in maximizing business success. Our
final task will be to determine which soft skills employers discern as
best serving to maximize the economic interests of Vietnam within
the global marketplace. Semi-structured telephone interviews have
been conducted with the 15 representative Head Employers of
Vietnam's reputedly largest and most successful of the diverse
business enterprises across Vietnam. The findings of the study
indicate that all respondents highly value the increasing importance
of soft skills in business success. Our critical analysis of respondent
data reveals that 19 essential soft skills are deemed by employers as
integral to business workplace efficacy and should thus be integrated
into the formal business curriculum. We are confident that our study
represents the first comprehensive and specific survey yet undertaken
within the business sector in Vietnam which accesses and analyses
the opinions of representative employers from major companies
across the country in regard to the growing importance of 19 specific
soft skills essential for maximizing overall business success. Our
research findings also reveal that the integration into business school
curriculums nationwide of the soft skills we have identified is of
paramount importance to advance the national and global economic
interests of Vietnam.
Abstract: Connected vehicles are equipped with wireless sensors
that aid in Vehicle to Vehicle (V2V) and Vehicle to Infrastructure
(V2I) communication. These vehicles will in the near future
provide road safety, improve transport efficiency, and reduce traffic
congestion. One of the challenges for connected vehicles is how
to ensure that information sent across the network is secure. If
security of the network is not guaranteed, several attacks can occur,
thereby compromising the robustness, reliability, and efficiency of
the network. This paper discusses existing security mechanisms and
unique properties of connected vehicles. The methodology employed
in this work is exploratory. The paper reviews existing security
solutions for connected vehicles. More concretely, it discusses
various cryptographic mechanisms available, and suggests areas
of improvement. The study proposes a combination of symmetric
key encryption and public key cryptography to improve security.
The study further proposes message aggregation as a technique to
overcome message redundancy. This paper offers a comprehensive
overview of connected vehicles technology, its applications, its
security mechanisms, open challenges, and potential areas of future
research.
Abstract: The technological paradigm of the disaster
management field, especially in the case of governmental
intervention strategies, is generally based on rapid and flexible
accommodation solutions. From various technical solution patterns
used to address the immediate housing needs of disaster victims, the
adaptive re-use of existing buildings can be considered to be both
low-cost and practical. However, there is a scarcity of analytical
methods to screen, select and adapt buildings to help decision makers
in cases of emergency. Following an extensive literature review, this
paper aims to highlight key points and problem areas associated with
the adaptive re-use of buildings within the disaster management
context. In other disciplines such as real estate management, the
adaptive re-use potential (ARP) of existing buildings is typically
based on the prioritization of a set of technical and non-technical
criteria which are then weighted to arrive at an economically viable
investment decision. After a disaster, however, the assessment of the
ARP of buildings requires consideration of different/additional layers
of analysis which stem from general disaster management principles
and the peculiarities of different types of disasters, as well as of their
victims. In this paper, a discussion of the development of an adaptive
re-use potential (ARP) assessment model is presented. It is thought
that governmental and non-governmental decision makers who are
required to take quick decisions to accommodate displaced masses
following disasters are likely to benefit from the implementation of
such a model.
Abstract: The main purposes of this study are to develop a scale
that reflects emerging theoretical understandings of new media
credibility, based on the evolution of credibility studies in western
researches, identification of the determinants of credibility in the
media and its components by comparing traditional and new media
credibility scales and building accumulative scale to test new media
credibility. This approach was built on western researches using
conceptualizations of media credibility, which focuses on four
principal components: Source (journalist), message (article), medium
(newspaper, radio, TV, web, etc.), and organization (owner of the
medium), and adding user and cultural context as key components to
assess new media credibility in particular. This study’s value lies in
its contribution to the conceptualization and development of new
media credibility through the creation of a theoretical measurement
tool. Future studies should explore this scale to test new media
credibility, which represents a promising new approach in the efforts
to define and measure credibility of all media types.
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: The idea of cropping-system is a method used by
farmers. It is an environmentally-friendly method, protecting the
natural resources (soil, water, air, nutritive substances) and increase
the production at the same time, taking into account some crop
particularities. The combination of this powerful method with the
concepts of genetic algorithms results into a possibility of generating
sequences of crops in order to form a rotation. The usage of this type
of algorithms has been efficient in solving problems related to
optimization and their polynomial complexity allows them to be used
at solving more difficult and various problems. In our case, the
optimization consists in finding the most profitable rotation of
cultures. One of the expected results is to optimize the usage of the
resources, in order to minimize the costs and maximize the profit. In
order to achieve these goals, a genetic algorithm was designed. This
algorithm ensures the finding of several optimized solutions of
cropping-systems possibilities which have the highest profit and,
thus, which minimize the costs. The algorithm uses genetic-based
methods (mutation, crossover) and structures (genes, chromosomes).
A cropping-system possibility will be considered a chromosome and
a crop within the rotation is a gene within a chromosome. Results
about the efficiency of this method will be presented in a special
section. The implementation of this method would bring benefits into
the activity of the farmers by giving them hints and helping them to
use the resources efficiently.
Abstract: The aim of the paper is to investigate the effect of
corporate social responsibility (CSR) CSR on the National
Commercial Bank (NCB) in Saudi Arabia. In order to achieve this, a
case study was made of the CSR activities of this bank from the
perspective of its branch managers. The NCB was chosen as it was
one of the first Saudi banks to engage in CSR and currently has a
wide range of CSR initiatives. A qualitative research method was
used. Open-ended questionnaires were administered to eighty branch
managers of the NCB, with fifty-five usable questionnaires returned
and twenty managers were interviewed as part of the primary
research. Data from both questionnaires and interviews were
analysed using qualitative content analysis. Six themes emerged from
the questionnaire findings were used to develop the interview
questions. These themes are the following: Awareness of employees
about CSR in the NCB; CSR activities as a type of investment;
Government and media support; Increased employee loyalty in the
NCB; Prestige and profit to the NCB; and View of CSR in Islam.
This paper makes a theoretical contribution in that it investigates and
increases understanding of the effect of CSR on the NCB in Saudi
Arabia. In addition, it makes a practical contribution by making
recommendations which can support the development of CSR in the
NCB. A limitation of the paper is that it is a case study of only one
bank. It is therefore recommended that future research could be
conducted with other banks in Saudi Arabia, or indeed, with a range
of other types of firm within the financial services area in Saudi
Arabia. In this way, the same issues could be explored but with a
greater potential generalisability of findings of CSR within the Saudi
Arabian financial services industry. In addition, this paper takes a
qualitative approach and it is suggested that future research be carried
out using mixed methods, which could provide a greater depth of
analysis.