Non-Smooth Dynamics and Multiple Equilibria in a Cournt-Ramsey Model with Endogenous Markups

We consider a Ramsey model with a continuum of Cournotian industries where free entry generates an endogenous markup. The model produces two different regimes, monopoly and oligopoly, resulting in non-smooth dynamics. We analyze the global dynamics of the model, demonstrating the model may exhibit heteroclinic orbits connecting multiple equilibria. Small transitory changes in parameters can lead to large permanent effects and there can be a Rostovian poverty trap separating a low-capital and high-markup equilibrium from a high-capital low-markup equilibrium. The paper applies recent results from applied mathematics for non-smooth dynamic systems.Endogenous markups; Non-smooth dynamics; Discontinuity induced bifurcations; Heteroclinic orbits.

Intercultural interpretation discourses, techniques and strategies used by tour guides in the Coach Museum, Lisbon : Eight issues

The Coach Museum in Lisbon houses one of the finest collections of coaches in the world. It is the second most visited museum in Portugal and it is often included in the Lisbon city tour. Tourist guides often perform visits to the museum. They are mediators between heritage and tourists, involving them not only in the collection but also in the life of the people who used the coaches. A guided tour to the museum can be either a nightmare or nice dream. It will be a nightmare if the guide conveys uninteresting information about the objects and vehicles exhibited, if s/he is centred on him/herself. But it can also be very lively and interesting if interpretation strategies are centred around the tourist and his/her culture. The aim of intercultural interpretation is to awaken different kinds of emotions in the tourist, from piety to amusement, using fantasy and reality. This paper discusses the different characteristics tourist guides’ interpretation assumes in Lisbon’s Coach Museum. The researcher heard the speech of fifty professional guides visiting the museum, during the months of September and October 2009. Data obtained were included in his PhD thesis. The anthropological technique applied is direct observation, defined as “direct involvement of the field researcher with the social group studied, within the parameters of the group standards” (Iturra, 1987: 149). The paper is divided into the following parts: introduction (including tourist information versus intercultural heritage interpretation, methodology, interpretation- eight issues, and final considerations. The observation of tourist guides in their working context allowed the identification of the intercultural skills developed by these professionals, the interpretative strategies adopted in communication, and some behavioural patterns of both guides and tourists.info:eu-repo/semantics/publishedVersio

NO-TILL PROVIDES THE OPPORTUNITY TO MANAGE UNDERGROUND INTERACTIONS BETWEEN ARBUSCULAR MYCORRHIZAL FUNGI, WEEDS AND CROP PLANTS UNDER MEDITERRANEAN CONDITIONS

Early colonization of crop roots by arbuscular mycorrhiza (AM) is considered beneficial but its importance likely depends on the possible stresses faced by the host plant. Manganese toxicity is one such stress that AM can alleviate. Colonization initiated by extraradical mycelium (ERM) is faster than other sources of inoculum. No-till creates the possibility of encouraging inoculation via this source. At seeding time the ERM available for colonizing plants under no-till would have developed in association with previous crops or those weeds that germinated after the first autumn rain. However, the long, hot and dry summer under Mediterranean conditions might reduce the effectiveness of the ERM to colonize the new crop. The hypothesis that an intact ERM developed by weeds can affect the earlier AM colonization of wheat and alleviate Mn toxicity was tested in a pot experiment. Two mycotrophic (Ornithopus compressus L., Lolium rigidum Gaudin), and one non-mycotrophic (Silene galica L) weed species were grown for 7 weeks before being controlled with Glyphosate (the ERM remaining intact) or by mechanical disturbance (which also disrupted the ERM). Wheat was then planted and allowed to grow for 21 days. AM colonization, plant dry weight and shoot nutrient content were evaluated for both weeds and wheat. When an intact mycelium was present at the seeding of wheat (treatments with Ornithopus compressus and Lolium rigidum controlled by Glyphosate) there was a threefold increase in the AM colonization rate and growth of the crop compared with results for all the other treatments. The enhanced growth of wheat was associated with an alleviation of Mn toxicity, consistent with the hypothesis. However, there was a significant difference of the wheat growth after Ornithopus and Lolium (1.9 times), suggesting functional diversity within mycotrophic weeds and crops

Miss SAIGON - Missing Signal Appraising in Globally Optimized Networks

Desde a implementação de sistemas elétricos de transporte e distribuição de energia, os operadores de redes sempre focaram-se no conhecimento da rede, quer seja por implementação de sensores de medição e telemetria para medição local e comunicação com centros de controlo, quer por estimação de eventuais estados da rede através de modelização matemática do comportamento da mesma. Com o surgimento dos primeiros Estimadores de Estados, também surge o problema de estimação de topologia no qual é necessário conhecer a topologia correta da rede para executar tais Estimadores de Estados.Por vezes nos centros de controlo, o conhecimento da rede é reduzido, seja pela falha de intercomunicação ou por ausência de medidores locais. Tendo em consideração o vasto historial de uma rede e os estados que as variáveis de medição podem tomar, é possível construir um processador de topologia de modo a determinar o estado de um interruptor, ou seja, se a linha encontra-se aberta ou fechada. Nesta dissertação é demonstrado todos os procedimentos efetuados na formulação de um processador de topologia baseado numa ferramenta de Deep Learning - CNN (Convolutional Neural Networks) - de modo a determinar o estado desse mesmo interruptor em várias situações exemplo com uma boa taxa de acerto mesmo em situações limite de ausência de informação.A topologia interna de uma subestação também é alvo de estudo, no qual, na ausência de medições internas é possível caracterizar o arranjo interno dos interruptores que a constituem. Esta dissertação pretende fornecer uma abordagem do problema de estimação de topologia em cenários reais de fraco conhecimento da rede fornecendo uma boa alternativa aos modelos tradicionais já existentes

The logic behind negotiation : from pre-argument reasoning to argument-based negotiation

The use of agents in Electronic Commerce environments leads to the necessity to introduce some formal analysis and definitions. A 4-step method is introduced for developing EC-directed agents, which are able to take into account non-linearites such as gratitude and agreement. Negotiations that take into account a multi-step exchange of arguments provide extra information, at each step, for the intervening agents, enabling them to react accordingly. This argument-based negotiation among agents has much to gain from the use of Extended Logic Programming mechanisms. Incomplete information is common in EC scenarios; therefore arguments must also take into account the presence of statements with an unknown valuation

An open-source UFBGA µ-board for wearable devices

This paper presents the development of an open-source, low-sized, BGA microcontroller breakout board, that can be used for the development of wearable and cyber-physical prototypes. The board is based on the low power, 8-bit, ATtiny20-CCU Microchip AVR microcontroller. The ATtiny20-CCU can be programmed without bootloader, using the Atmel Tiny Programming Interface (TPI), instead of In-System Programming (ISP). The C code used to program the microcontroller can be written and compiled using the Microchip Studio freeware platform. The ATtiny20-CCU Ultra Fine-pitch Ball Grid Array (UFBGA) packaging technology allows the shrinkage of the conceived Electroless Nickel-Immersion Gold (ENIG) Printed Circuit Board (PCB) to a size of only 15.5 × 13 mm. Its low cost also makes it a viable option for developing many educational electronic projects, especially for Instrumentation and Assistive Technology. The contribution of this paper is mainly the hardware prototype design, the PCB manufacturing, building and test of a very low-sized open source µ-breakout PCB board, for wearable Instrumentation applications, towards the emergent Society/Industry 5.0.publishersversionpublishe

Calcium identification and scoring based on echocardiography imaging

Currently, an echocardiography expert is needed to identify calcium in the aortic valve, and a cardiac CT-Scan image is needed for calcium quantification. When performing a CT-scan, the patient is subject to radiation, and therefore the number of CT-scans that can be performed should be limited, restricting the patient's monitoring. Computer Vision (CV) has opened new opportunities for improved efficiency when extracting knowledge from an image. Applying CV techniques on echocardiography imaging may reduce the medical workload for identifying the calcium and quantifying it, helping doctors to maintain a better tracking of their patients. In our approach, we developed a simple technique to identify and extract the calcium pixel count from echocardiography imaging, by using CV. Based on anonymized real patient echocardiographic images, this approach enables semi-automatic calcium identification. As the brightness of echocardiography images (with the highest intensity corresponding to calcium) vary depending on the acquisition settings, we performed echocardiographic adaptive image binarization. Given that blood maintains the same intensity on echocardiographic images – being always the darker region – we used blood structures in the image to create an adaptive threshold for binarization. After binarization, the region of interest (ROI) with calcium, was interactively selected by an echocardiography expert and extracted, allowing us to compute a calcium pixel count, corresponding to the spatial amount of calcium. The results obtained from our experiments are encouraging. With our technique, from echocardiographic images collected for the same patient with different acquisition settings and different brightness, we were able to obtain a calcium pixel count, where pixels values show an absolute pixel value margin of error of 3 (on a scale from 0 to 255), that correlated well with human expert assessment of calcium area for the same images.Atualmente, é necessário um perito em ecocardiografia para identificar o cálcio na válvula aórtica, e é necessária uma imagem Tomográfica Computorizada (TAC) cardíaca para a quantificação do cálcio. Ao realizar uma TAC, o paciente é sujeito a radiação, pelo que o número de TACs que podem ser realizadas deve ser limitado, restringindo a monitorização do paciente. A Visão por Computador (VC) abriu novas oportunidades para uma maior eficiência na extração de conhecimentos de uma imagem. A aplicação de técnicas de VC na ecocardiografia pode reduzir a carga de trabalho médico para identificar o cálcio e quantificálo, ajudando os médicos a manter um melhor acompanhamento dos seus pacientes. Na nossa abordagem, desenvolvemos uma técnica simples para identificar e extrair o número de pixéis de cálcio da ecocardiografia, através da utilização de VC. Com base em ecocardiografias anónimas de doentes reais, esta abordagem permite a identificação semiautomática do cálcio. Como o brilho das imagens de ecocardiografia (com a intensidade mais elevada corresponde ao cálcio) varia consoante os parâmetros de aquisição, realizámos a binarização das ecocardiografias de forma adaptativa. Dado que o sangue mantém a mesma intensidade nas ecocardiografias - sendo sempre a região mais escura - utilizámos estruturas sanguíneas na imagem para criar um limiar adaptativo para a binarização. Após a binarização, a região de interesse (ROI) com cálcio, foi selecionada interactivamente por um especialista em ecocardiografia e extraída, permitindo-nos calcular o número de pixéis de cálcio, correspondente à quantidade espacial de cálcio. Os resultados obtidos com as nossas experiências são encorajadores. Com a nossa técnica, a partir de ecocardiografias recolhidas para o mesmo paciente com diferentes configurações de aquisição e diferentes brilhos, conseguimos obter uma contagem de pixéis de cálcio, onde os valores de pixéis mostram uma margem de erro absoluta de 3 (numa escala de 0 a 255), que se correlacionou bem com a avaliação humana perita da área de cálcio para as mesmas imagens

Electric power generating bicycle

It is manifest the growing interest in both personal health and environmental issues. The device described on this paper contemplates both aspects: generating environment-friendly electric power while keeping fit. A car alternator excited through a 12V battery is coupled to a mountain bicycle, and this arrangement enables the lighting of six halogen lamps, if a cyclist pedals fast enough. Such a machine gives rise to the thought of a self-powered gymnasium. Considerable physical effort is required in order to make the lamps glow, which is pedagogical since it shows clearly that spending energy is much easier than generating it

Effects of Backpack Load and Trekking Poles on Energy Expenditure During Field Track Walking

This study evaluates the effects of the use of backpack load and trekking poles on feld track walking energy expenditure. Twenty male volunteer pole walkers (age: 22.70 ± 2.89 years; body mass: 77.90 ± 11.19 kg; height: 1.77 ± 0.06 m; percentage of body fat: 14.6 ± 6.0 %) walked at a self-selected pace on a pedestrian feld track over a period of more than six months. Each subject was examined at random based on four walking conditions: non-poles and non-load, with poles and non-load, nonpoles and with load, with poles and with load. Heart rate, oxygen uptake and energy expenditure were continuously recorded by a portable telemetric system. Non-load walking speed was lower during walking with poles when compared with no poles (p ≤ 0.05). Oxygen uptake, energy expenditure and heart rate varied signifcantly across different conditions. Our results suggest that the use of trekking poles does not influence energy expenditure when walking without an additional load, but it can have an effect during backpack load walking. Moreover, our results indicate that the use of trekking poles may not be helpful to lower the exertion perceived by the subjects when walking with an additional load.info:eu-repo/semantics/publishedVersio