How crowdsourcing impacts prices and customer satisfaction: the Airbnb case

The travel accommodation industry has changed drastically due to the sharing economy. This sharing economy depends significantly on crowdsourcing in the form of quantitative and qualitative reviews. In this thesis, we study the impact of expressed sentiments in the text reviews on listing prices; we explore differences in the factors that lead to satisfaction according to customer origin and the effects of external shocks on Airbnb´s prices. We employ NLP to extract the sentiment and emotion scores to be modeled as a function of different characteristics and geophysical information. Our study provides an important contribute to the research on pricing and customer satisfaction in the sharing economy by finding a significant effect of the expression of positive sentiments on prices, describing the differences in the factors that lead to satisfaction according to customer origin, and revealing that guests moved away from main municipalities and valued listings with more bedrooms during the Covid-19 pandemic

Automatização de testes SIP

As redes IP são actualmente as principais infra- estruturas de comunicação utilizadas por um conjunto crescente de aplicações e serviços heterogéneos, nos quais se incluem os serviços de voz. Neste sentido, as funções de transmissão e gestão de sessões são muitas vezes asseguradas por protocolos dedicados, como seja o exemplo do Real-Time Transport Protocol (RTP) e o Session Initiation Protocol (SIP). O protocolo SIP apresenta um papel preponderante na gestão de sessões, desempenhando funções vitais num conjunto extenso de soluções. Contudo, a disseminação do protocolo acarreta alguns desafios, tais como a validação e teste de soluções SIP. Estes processos de validação necessitam de considerar diversos fatores, como seja o caso da análise de cabeçalhos, validação de valores dinâmicos, verificação de fluxos de mensagens, entre outros. Nesta perspetiva, a validação manual de soluções SIP apresenta-se como um processo moroso e dispendioso, sendo crucial o desenvolvimento de processos automatizados nesta área. Neste contexto, este resumo alargado aborda e analisa de forma integrada a temática geral da validação de soluções SIP, apresentando também ferramentas e aplicações capazes de auxiliarem os processos de automatização de testes de soluções SIP

Structural Optimization Techniques Combined With Meshless Methods: A Review

Structural optimization has been growing in recent years, as it is an excellent tool to obtain reliable and high-performance products. In addition to reducing the waste of resources and emissions as well as the production cost, this can be applied in several areas from engineering to medicine. The numerical method most used in recent decades to obtain structurally optimized parts is the finite element method (FEM) and it is included in the group called mesh-based methods. However, the application of these methods in parts with complex geometries and in large deformation problems result in low accuracy and instable solutions. In order to solve this problem, in the last decades, methods that are independent of a mesh have been developed to obtain unknown variables, called meshless methods. Although meshless methods are still recent and there are few documentations, these have been showing good results compared to the mesh-based methods, proving to be a good alternative. Considering what has been said previously, this work has as main objective the study and analysis of parts subjected to structural optimization using mesh-based and meshless methods, in order to compare the results and verify the benefits of using a type of method instead of the other.A optimização estrutural tem vindo a crescer nos últimos anos, uma vez que é uma excelente ferramenta para a obtenção de produtos fiáveis e de alto desempenho. Para além de que reduz o gasto de recursos e emissões assim como o preço de produção das mesmas, esta pode ser aplicada em diversas áreas desde a engenharia à medicina. O método numérico mais utilizado nas últimas décadas para a obtenção de partes estruturalmente optimizadas é o método dos elementos finitos (MEF), o qual pode ser incluído no grupo denominado de métodos com malha. No entanto, a aplicação destes métodos em partes com geometrias complexas e em problemas com grandes deformações resultam em soluções com pouca precisão e de baixa estabilidade. De modo a solucionar este problema, nas últimas décadas, têm vindo a ser desenvolvidos métodos que são independentes de uma malha para a obtenção das varáveis desconhecidas, denominados de métodos sem malha. Apesar dos métodos sem malha ainda serem recentes e existir pouca documentação, estes têm vindo a mostrar bons resultados comparativamente aos métodos com malha provando ser uma boa alternativa. Tendo em conta o referido anteriormente, este trabalho tem como objectivo principal o estudo e análise de partes submetidas a optimização estrutural utilizando métodos com malha e sem malha, de modo a comparar os resultados e verificar os benefícios da utilização de um tipo de método relativamente ao outro

An axiomatic design framework to design interoperable buyer–supplier dyads

Cooperation arrangements in the form of buyer–supplier dyads are a way that companies have found to deal with the current competitive environment. Despite the contributions in the interoperability literature, a cohesive framework is lacking that would allow the systematization of solutions for interoperable problems in such cooperation. Therefore, we propose a framework for systematically detail interoperability issues and to provide solutions that fit business conditions.Through a case study conducted on an automotive dyad, it is possible to achieve a better interoperable scenario, by systematically addressing the issues and providing solutions that comply with the AD independence axiom.authorsversionpublishe

Recent Advances in Smart Farming

The Digital Transformation, which has the Internet of Things (IoT) as one of its pillars, is penetrating all aspects of our society with dramatic effects. In fact, buzzwords such as “Smart homes”, “Smart offices”, “Smart health” and “Smart factories”, to name just a few, have become a commonplace and reflect the profound structural changes that the Digital Transformation is having in the way citizens live their lives and how businesses and industries are organized.info:eu-repo/semantics/publishedVersio

Foreword to the Special Issue on Advanced IoT Technologies in Agriculture

In recent decades, the perception of the impact of humanity’s ecological footprint has changed dramatically; it is now widely recognized that natural resources are limited and sensitive, and that their indiscriminate use is unsustainable and deeply impacts the well-being of people, animals and plants [1,2,3]. The awareness that in order to reverse this problem, we must Reduce, Reuse, and Recycle, leads to the emergence of new and disruptive paradigms in most aspects of human activity, including agriculture [4,5]. In fact, agriculture has a tremendous impact on food supplies for the world, but also on the environment, and can compromise the ecological balance, thus, endangering sustainability [6]. The search for new methodologies applied to agricultural production addresses recent technologies, most of which arise from the Internet of Things (IoT), enabling a massive and unprecedented deployment of digital devices and services in a range of application domains that always increases [6,7,8]. This trend, commonly referred to as Smart Farm, Precision Livestock Farm or Farm 4.0, consists of the use of a wide range of sensors that monitor the evolution of the impacted conditions in agriculture, transmitting these data through communication systems, typically wirelessly. These data are then analyzed, often using Artificial Intelligence techniques, supporting management decisions with the goal to optimize agricultural production, including economical aspects such as productivity, quality and profitability, and sustainability [9,10]. The management of agricultural processes is based on accurate information, both on current conditions and on the forecast of future developments, and it allows for gains in the efficiency of agricultural processes, both in terms of economics and environmental impact [7]. Indeed, we intend with this Special Issue on Advanced IoT Technologies in Agriculture to present developments in research, focusing on the application of new methods to pinpoint or solve problems and constraints in agriculture and livestock production, based on IoT, making use of emerging technologies such as large data, sensor networks, image analysis, unmanned aerial vehicles (UAV), mobile applications, cloud computing, robots or artificial intelligence. Examples of the application of such technologies to irrigation, fertilization, seeding, soil management, pest and disease detection, animal feeding, breeding and welfare, impacting on farming productivity, profit and environment sustainability, are also welcome.info:eu-repo/semantics/publishedVersio

A Method to Capture Activity Diagrams from Ontological Model

AbstractActivity Theory is a useful framework to capture the exclusive features of people's work. A minimum context must be known to understand a community's (i.e., group of people) work. This social and cooperative context is called an Activity and it proceeds within mediation, work division, tools, and social rules. The collective activity is linked to a common purpose i.e. the objective of the activity of which people, that participate on it, are not often aware.There are several methods of using Activity Theory Diagrams to model individual's work however it is considered difficult to obtain useful Activity Diagram for Enterprises. This paper explains how to develop Activity Diagrams from an ontological model of an enterprise. The ontological model is described in DEMO The paper includes linking DEMO Diagrams with Activity Diagrams proposed by Engeström. The integration covers various components of a particular activity: the participants, work rules, social tools, goals, and motives. The paper uses a real case study to validate concept

Precision Agriculture for Crop and Livestock Farming—Brief Review

In the last few decades, agriculture has played an important role in the worldwide economy. The need to produce more food for a rapidly growing population is creating pressure on crop and animal production and a negative impact to the environment. On the other hand, smart farming technologies are becoming increasingly common in modern agriculture to assist in optimizing agricultural and livestock production and minimizing the wastes and costs. Precision agriculture (PA) is a technology-enabled, data-driven approach to farming management that observes, measures, and analyzes the needs of individual fields and crops. Precision livestock farming (PLF), relying on the automatic monitoring of individual animals, is used for animal growth, milk production, and the detection of diseases as well as to monitor animal behavior and their physical environment, among others. This study aims to briefly review recent scientific and technological trends in PA and their application in crop and livestock farming, serving as a simple research guide for the researcher and farmer in the application of technology to agriculture. The development and operation of PA applications involve several steps and techniques that need to be investigated further to make the developed systems accurate and implementable in commercial environments.info:eu-repo/semantics/publishedVersio

Contributos de Gaspar Frutuoso para o conhecimento das águas interiores dos Açores

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Se hoje temos conhecimento das características e da biodiversidade das lagoas e ribeiras dos Açores e reconhecemos a sua importância apesar do impacte que as atividades humanas exerceram sobre estes ecossistemas, pouco sabemos sobre como é que eles eram quando os primeiros povoadores chegaram a estas ilhas. Há fundamentalmente duas maneiras de descobrirmos as características destes ecossistemas no passado: as fontes bibliográficas, isto é, os escritos antigos, e o estudo dos vestígios que ficam acumulados nos seus sedimentos, por outras palavras, através da paleolimnologia. É neste ponto que chegamos à obra de Gaspar Frutuoso e ao seu contributo para o estudo dos ecossistemas aquáticos interiores dos Açores. Gaspar Frutuoso (1522-1591) escreveu seis livros que compõe “Saudades da Terra” onde descreve a geografia física e humana das ilhas dos Açores, Madeira e Canárias nos séculos XV e XVI. Esta obra constitui o relato mais completo dos arquipélagos macaronésios neste período e a principal fonte de informação sobre a sua geografia, história, economia, cultura, fauna e flora. […].info:eu-repo/semantics/publishedVersio

Redesigning a Manufacturing System Based on Functional Independence: The Case of a Tree Nursery

AbstractThe engineering of manufacturing systems encompasses two main areas of development: the manufacturing process (manufacturing technologies, and flow and handling of materials), and the production management (flow of information - signals). These two areas must be designed to perform according to the expressed needs. This paper shows that the Axiomatic Design (AD) theory can be used to analyse a manufacturing system to find the origin of the lack of productivity, and, subsequently, to redesign a solution avoiding the weakness points. A case study of a tree nursery of a large wood production enterprise was used to show the application of the axiomatic design principles, particularly through analysing the design equation and including new design parameters with the independence in mind. The redesign solution based on the independence of functions promoted the simplification of the information (signals) flow, avoiding the identification of each production element, and avoiding errors, which increases the productivity and the production volume, by elimination of waste of time in production operations. The proposed solution brought results that encourage the application of AD to increment the productivity of manufacturing systems, in alternative to expensive investments