67 research outputs found
Measuring engagement on Twitter using a composite index: An application to social media influencers.
Engagement on social media networks is a complex concept involving numerous interconnected and challenging-to-evaluate elements.
We propose a composite index as a tool to quantify the engagement on the social network Twitter, recently converted on X, and we use this composite index for evaluating a group of Social Media Influencers (SMI). Due to the multicriteria nature of the engagement, we calculate the synthetic indicator using the multicriteria method TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). We consider two approach for measuring the engagement: the production approach, the follower. Consequently, we obtain three rankings, one for each approach and a third, which is global. A comparison of these three rankings shows the suitability and pertinence of the three approach. This represents a recent finding when contrasted with previous research, which solely focused on either one of the approaches (Harrigan, et al.2021, Veale et al. 2015Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
A Risk Assessment Method of Bridge Facilities Damage in the Aspect of Potential Terrorist Attacks
The question of terrorism is becoming a principal problem which influences social safety. Terrorist acts are aimed at frightening people and destabilisation of normal functioning of the state. Terrorists are trying to achieve this goal by bombing civilians and public utility facilities including transport system facilities. One of the elements of a transport system is its infrastructure consisting of roads, railways and bridge facilities. This last element encompasses for example bridges, viaducts, flyovers and culverts. Taking into account the fact that bridge facilities are extremely sensitive to terrorist attacks, the authors of this article decided to focus on them in this study. The work presents an original method of damage risk assessment in engineering facilities in the aspect of potential terrorist attacks. The method is based on two selected multi-criteria optimisation methods. The subject of analyses were four selected bridge facilities. The results of the conducted research and analyses were risk assessments of selected bridges. An advantage of the presented solution is the possibility to justify the adopted hierarchy of decision variants. Using the proposed method one can obtain specific numerical values. They can be used in further analyses conducted on a wider scale and to build a hierarchized database of facilities prone to terrorist attacks
Stochastic Dominance in Wheat Variety Development and Release Strategies
Variety development and release decisions involve tradeoffs between yields and characteristics valued by end-users, as well as uncertainties about agronomic, quality, and economic variables. In this study, methods are developed to determine the value of varieties to growers and end-users including the effects of variability in economic, agronomic, and quality variables. The application is to hard red spring (HRS) wheat, a class of wheat for which these tradeoffs and risks are particularly apparent. Results indicate two experimental varieties provide improvements in grower and end-user value, relative to incumbents. Stochastic dominance techniques and statistical tests are applied to determine efficient sets and robustness of the results. A risk-adjusted portfolio model, which simultaneously incorporates correlations between grower and end-use characteristics, is also developed to compare the portfolio value of varieties.end-user value, grower value, portfolio value, stochastic dominance, tradeoffs, variety development, wheat, Crop Production/Industries,
Análise da sustentabilidade do uso agro-florestal no concelho de Alcoutim
Dissertação de Mestrado, Gestão e Conservação da Natureza, 20 de Outubro de 2015, Universidade dos Açores.Alcoutim é um concelho do interior de Portugal, que como muitos outros se caracteriza pelo envelhecimento da sua população e o abandono da terra pelos mais jovens. A par desta situação foi considerada como região-piloto para estudos sobre a desertificação, refletindo a degradação dos solos e baixa produção dos mesmos. Para poderem contornar estas situações os agricultores recorreram a financiamentos e reconverteram as terras agrícolas em florestais, arborizando-as. Deixando de produzir algumas espécies adaptadas ao ecossistema e cuja qualidade é reconhecida por muitos como única. Esta conjuntura agrícola e florestal é fruto de orientações de políticas agroflorestais, através de Instrumentos Legais de Ordenamento e de Financiamento.
Assim, propõe-se avaliar a sustentabilidade do uso agro-florestal existente no território do concelho de Alcoutim, através de uma metodologia que integre diferentes fatores associados à estrutura de uso, com particular relevo para as potencialidades genéricas de utilização do solo, os processos de degradação do solo resultantes e o valor ecológico associado aos usos e respetivo padrão de distribuição. Desta forma, poderão ser propostos indicadores a seguir no âmbito de futuras políticas agroflorestais para a região, contribuindo-se para o estabelecimento de uma matriz de sustentabilidade de uso.
Para o efeito recorreu-se a uma metodologia de análise espacial multicritério – o Processo de Análise Hierárquica (AHP - Analytic Hierarchy Process). Este método permitiu identificar as aptidões do solo para um conjunto de espécies com interesse agrícola e florestal.
Verificou-se com este estudo, que o concelho de Alcoutim tem como função principal a protecção, tal como definido no PROF Algarve. No entanto, de forma a garantir uma gestão multifuncional e sustentabilidade há que preconizar orientações e operações no sentido da função produção.ABSTRACT: Alcoutim is a village of the interior of Portugal that is characterized for the aging of its population and by the abandonment of the land. Along with this situation it was considered as study-region-pilot for studies on desertification assessment, reflecting the degradation of the soil and low production. To be able to skirt these situations the agricultures farmers had appealed for fundings and hadin order to reconvert agricultural lands into forest, leaving the production of some agricultural and forestal species more suitable to the ecosystem and whose the quality is recognized. This agricultural and forest conjuncture is a resultfruit of guidelines of agro-forest politics, transposed in theto legal instruments of order and the programs of financing programs.
Thus, it was proposed inthis workis considered to evaluate the sustentability of the existing agroforestal use in the Alcoutim region, through the application of amethodology that integrates different land use structure factors, levels of degradation of the soil, ecological value and distribution patterns, create the way to delineate and to define agro-forest politics that guarantee, effectively, the susceptibility of the studied areaterritory-target.
For that pourpose it was used a spatial multicritera Analysis methodology Para o efeito recorreu-se a uma metodologia de análise espacial multicritério - the Analytic Hierarchy Process (AHP). This method método allowed to identify the soil suitability to a set of species with agrarian and florestal value
DECISION SUPPORT CONCEPT TO MANAGEMENT OF CONSTRUCTION PROJECTS - PROBLEM OF CONSTRUCTION SITE SELECTION
The aim of this paper is to present Decision Support Concept (DSC) for management of construction projects. Focus of our research is in application of multicritera methods (MCM) to decision making in planning phase of construction projects (related to the problem of construction sites selection). The problem is identified as a significant one from many different aspects such as economic aspect, civil engineering aspect, etc. what indicates the necessity for evaluation of multiple sites by several different criteria. Therefore, DSC for construction site selection based on PROMETHEE method is designed. In order to define the appropriate criteria, their weights and preference functions for the concept, three groups of stakeholders are involved (investors, construction experts and experts for real estate market) in its design. AHP method has been used for determination of criteria weights. The model has been tested on the problem of site selection for construction of residential-commercial building in four largest cities in Croatia
Evolutionary Search for Minimal Elements in Partially Ordered Finite Sets
The task of finding minimal elements of a partially ordered set is a generalization of the task of finding the global minimum of a real valued function or of finding pareto optimal points of a multicriteria optimization problem. It is shown that evolutionary algorithms are able to converge to the set of minimal elements in finite time with probability one, provided that the search space is finite, the time invariant variation operator is associated with a positive transition probability function and that the selection operator obeys the so called elite preservation strategy
Modeling on Establishment of Sustainable Paddy Field Zone in Bekasi Regency, Indonesia
The background of this study is paddy fields conversion that continues to occur along the northern coast of Java that threatens national food security. Regional Spatial Plan (RTRW) and Sustainable Food Agricultural Land Protection Program (LP2B) are unable to control paddy field conversion. This research was conducted to establishment a sustainable paddy field zone model using logistic regression and multicriteria evaluation. The research location is in Bekasi Regency, one of West Java's rice production centers which is Jakarta buffer area with a high level of paddy field conversion. The model builds upon the characteristics of local paddy field conversion by considering the concept of sustainable development. Important variables that support the paddy field conversions are the distance to settlements, housings, roads, regency/city capitals and industrial estates. Results of logistic regression then become the input for weighted criteria to develop three policy scenarios of paddy fields protection; standard, protective and permissive in order to support regional development. This model will obtain protected paddy field priorities as well as a buffer for other paddy fields in surrounding area. Keywords: logistic regression, multicriteria evaluation, sustainable paddy fields zon
Decision support system to urban infrastructure maintenance management
Life-cycle management of urban infrastructure projects is very complex process from both management and economic aspects. Focus of this research is on urban infrastructure maintenance phase of a life-cycle, especially on decision making in maintenance problems. Urban infrastructure maintenance management deals with complex decision making process. The reasons for a complexity are: lots of participants, multi-disciplinarity, huge quantity of information, limited budget, conflict goals and criteria. These facts indicate that decision making processes in urban infrastructure management undoubtedly belong to ill-defined problems. In order to cope with such complexity and to help project managers during decision making processes this research proposes an application of multicriteria methods. Multicriteria methodology proposed herein is applied on priority setting problem. It starts with goal analysis followed by definition of urban infrastructure elements and development of adequate criteria set. Evaluation of criteria importance (weights) is based on a set of experts’ opinions processed by AHP method. An assessment of maintenance conditions of urban infrastructure elements is provided trough monitoring process. The way of using proper forms and procedures for data collection is presented as well. All collected data are processed by PROMETHEE multicriteria methods. The main result of a multicriteria process is priority maintenance list for urban infrastructure elements. The methodology is tested on road infrastructure of town of Split
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