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- Managing in a foreign country: the influence of culture in management decisionsPublication . Reis, Nuno; Ferreira, Manuel Portugal; Santos, João CarvalhoThe world’s increasingly global economics is well documented fact. Globalization means people worldwide are becoming more similar, but there are still very important differences. Culture is an important factor that makes two countries unlike. In this paper we present three conceptual propositions on the effects of culture in management, at three different levels (corporate, business and functional). We argue that culture plays influences the management decisions at all three levels, affecting the firm’s success.
- A integração da empresa em redes industriais: minimizar os efeitos da distância psíquica na internacionalização de empresasPublication . Santos, João Carvalho; Ferreira, Manuel Portugal; Reis, NunoA abordagem de redes para a internacionalização tem sido estudada por diversos investigadores na área dos negócios internacionais. As empresas envolvem-se crescentemente em negócios internacionais, pelo que necessitam de aprender a adaptar-se às diferenças que encontram nos mercados externos. Neste artigo propomos um modelo conceptual que sugere que a integração em redes industriais reforça a capacidade competitiva das empresas nos mercados externos. Pertencer a redes de empresas permite ter acesso a conhecimento que facilita a entrada nos mercados internacionais, melhor adaptação a ambientes económica, politica, legal e culturalmente diferentes do seu país de origem. A integração em redes permite, portanto, reduzir a distância psíquica percebida. A partir da revisão de literatura das teorias da internacionalização, com especial enfoque na escola de Uppsala, das redes industriais e do conceito de performance, discutimos a importância das redes de industriais na internacionalização das empresas.
- A spatially stochastic epidemic model with partial immunization shows in mean field approximation the reinfection thresholdPublication . Stollenwerk, Nico; van Noort, Sander; Martins, José; Aguiar, Maíra; Hilker, Frank; Pinto, Alberto; Gomes, GabrielaRecently, the notion of a reinfection threshold in epidemiological models of only partial immunity has been debated in the literature. We present a rigorous analysis of a model of reinfection which shows a clear threshold behaviour at the parameter point where the reinfection threshold was originally described. Furthermore, we demonstrate that this threshold is the mean field version of a transition in corresponding spatial models of immunization. The reinfection threshold corresponds to the transition between annular growth of an epidemics spreading into a susceptible area leaving recovered behind and compact growth of a susceptible-infected-susceptible region growing into a susceptible area. This transition between annular growth and compact growth was described in the physics literature long before the reinfection threshold debate broke out in the theoretical biology literature.
- Ad-hoc changes in IoT-aware business processesPublication . Domingos, Dulce; Martins, Francisco; Martinho, Ricardo; Silva, MárioThe Internet of Things makes it possible to adapt the behaviour of business processes in response to real-time context updates. In addition, physical items can run and validate parts of the business processes and optimise their execution, while reducing message transmissions. State-of-the-art event-driven, service-oriented architecture approaches contribute to enabling inter-organisational collaboration and interoperability of heterogeneous hardware, but their applicability is limited to preplanned, well-structured processes. We take a step forward by supporting ad-hoc changes within business processes, considering changes in the state of the Things; likewise, whenever needed, the software controlling the behaviour of sensors may be dynamically reconfigured as a result of changes in the functional specifications of business processes.
- Hybrid Honey Bees Mating Optimisation algorithm to assign terminals to concentratorsPublication . Bernardino, Eugénia M.; Bernardino, Anabela M.; Sánchez-Pérez, Juan Manuel; Gómez-Pulido, Juan Antonio; Vega-Rodríguez, Miguel AngelIn this paper we propose a new approach to assign terminals to concentrators using a Hybrid Honey Bees Mating Optimisation algorithm. Honey Bees Mating Optimisation (HBMO) algorithm is a swarm-based optimisation algorithm, which simulates the mating process of real honey bees. We apply a hybridisation of HBMO to solve a combinatorial optimisation problem known as Terminal Assignment Problem (TAP). The purpose is to connect a given set of terminals to a given set of concentrators and minimise the link cost to form a communication network. The feasibility of Hybrid HBMO is demonstrated and compared with the solutions obtained by other algorithms from literature over different TAP instances.
- Leveraging temporal expressions for segmented-based information retrievalPublication . Craveiro, Olga; Macedo, Joaquim; Madeira, HenriqueThe extraction of temporal information from text documents is becoming increasingly important in many applications such as natural language processing, information retrieval, question answering, etc. Indeed, the temporal dimension plays a key role on most of these systems, promoting better performance. Our goal is the definition of a temporal document representation, incorporating the time dimension into information retrieval model to improve the quality of the results. Our approach is based on temporal segmentation of documents. Temporal-aware retrieval models may explore a richer temporal document representation, enabled by segmentation. To achieve this, first we must identify temporal expressions and capture, when possible, their normalized time values. Starting from our prior work on temporal expressions recognition, we present in this paper, a resolution tool that achieves promising results in a Portuguese collection. Furthermore, a temporal characterization of the used collection shows enough and suitable information for a meaningful temporal document segmentation.
- A Hybrid Population-Based Incremental Learning algorithm for load balancing in RPRPublication . Bernardino, Anabela M.; Bernardino, Eugénia M.; Sánchez-Pérez, Juan Manuel; Gómez-Pulido, Juan Antonio; Vega-Rodríguez, Miguel AngelWhen managed properly, the ring networks are uniquely suited to deliver a large amount of bandwidth in a reliable and inexpensive way. An optimal load balancing is very important, because it increases the system capacity and improves the overall ring performance. An important optimisation problem in this context is the Weighted Ring Arc Loading Problem (WRALP). It consists of the design, in a communication network of a transmission route (direct path) for each request, such that high load on the ring arcs will be avoided. WRALP asks for a routing scheme such that the maximum load on the ring arcs will be minimum. In this paper we study WRALP without demand splitting and we propose a Hybrid Populationbased Incremental Learning (HPBIL) to solve it. We show that HPBIL is able to achieve good solutions, improving the results obtained by previous approaches.
- Feeding habits of Solea senegalensis in earthen ponds in Sado estuaryPublication . Castelo Branco, Maria Ana; Arruda, Marco A.; Gamito, SofiaThe senegale sole, Solea senegalensis Kaup, 1858, is a commercially valuable fish and it is beginning to be cultured in a semi-intensive way in fish farms in southern European countries. The present study was initiated to investigate the diet of S. senegalensis under semi-extensive conditions. The feeding habits of sole were studied in two earthen ponds of a fish farm in the Sado estuary. In one earthen pond, artificial fish ration was given. S. senegalensis feeds on few prey items, its diet is mainly composed of insect larvae (Chironomus salinarus) and polychaeta (Hediste diversicolor). The diet composition of this species suggests feeding specialization, by consuming mainly annelids and insect larvae and by avoiding other items, extremely abundant in the environment, such as gastropods. In the water reservoir where ration was given, some fish consumed simultaneously benthic organism together with ration. However, benthic organisms seem to be the most important component of S. senegalensis diet.
- Tone Mapping Operators on Small Screen Devices: An Evaluation StudyPublication . Urbano, C.; Magalhães, L.; Moura, J.; Bessa, M.; Marcos, A.; Chalmers, A.In the last decade, an increasing number of techniques have been developed to reproduce high dynamic range imagery on traditional displays. These techniques, known as Tone Mapping Operators (TMOs), have been compared and ranked in different ways according to several image characteristics. However, none of these algorithms has been developed specifically for small screen devices (SSD). In this paper, we present an evaluation of currently used TMOs to show that SSDs with limited size, resolution and colour depth require specific research to find or create an appropriate solution. The research described in this paper is based on psychophysical experiments; using three different types of displays (CRT, LCD and SSD). The obtained results show that rankings obtained are similar for the LCD and CRT but are significantly different for the SSD. Furthermore, these rankings show additionally that some characteristics of TMOs need to be emphasized to obtain better high-fidelity mapped images for SSDs.
- Effects of Channel Estimation on Multiuser Virtual MIMO-OFDMA Relay-Based NetworksPublication . Jiménez, Víctor P. Gil; Ribeiro, Carlos; Gameiro, Atilio; Armada, Ana GarcíaA practical multiuser cooperative transmission scheme denoted as Virtual Maximum Ratio Transmission (VMRT) for multiple-input multiple-output-orthogonal frequency division multiple access (MIMO-OFDMA) relay-based networks is proposed and evaluated in the presence of a realistic channel estimation algorithm and using low-density parity-check (LDPC) codes. It is shown that this scheme is robust against channel estimation errors. It offers diversity and array gain, keeping the complexity low with a multiuser and multiantenna channel estimation algorithm that is simple and efficient. In addition, the combination with LDPC codes provides improved gains; diversity gains larger than 6dB can be easily obtained with a reduced number of relays. Thus, this scheme can be used to extend coverage or increase system throughput by using simple cooperative OFDMA-based relays.