Automatic landing on aircraft carrier by visual servoing

International audienceThe landing on carrier is a very difficult task even for trained pilots. This paper presents a method to land automatically using aircraft sensors and three visual features inspired by visual cues used by pilots. These features whose link with the aircraft state is established, are introduced in a control scheme using a linearized aircraft model. The control law demonstrates a large convergence domain using simulated visual features and a 3D tracker applied on synthetic images

Модель похибки вимірювального трансформатора напруги

QC 20160524</p

КИХ-фильтры с независимым управлением фазочастотной характеристикой

Рассматривается структурная реализация цифровых КИХ фильтров методом частотной выборки с возможностью управления фазочастотной характеристикой в реальном времени. Приводятся характеристики элементарных цифровых фильтров, алгоритм сложения их выходных сигналов и способ смещения фазочастотной характеристики.Розглядається проектування та структурна реалізація цифрових КІХ-фільтрів методом частотної вибірки з можливістю управління фазочастотною характеристикою в реальному часі. Наводяться характеристики елементарних цифрових фільтрів, алгоритм складання їх вихідних сигналів і спосіб зміщення фазочастотної характеристики.The structural realization of digital FIR-filters using frequency sampling with real time control of phase-frequency characteristic is considered. The characteristics of elementary digital filters, the algorithm of their output signals summation and the way of phase-frequency characteristic shift are given

Creating spatial synergies around food in cities

This paper focusses on the phenomenon of multifunctional urban food initiatives (MUFIs) and how, using food as a vehicle, they provide integrative solutions for a number of social, environmental and economic problems in European cities. Through an in-depth investigation of three MUFIs in the UK, Latvia and Belgium, the paper aims to increase understanding on how different activities are combined within MUFIs, leading to the creation and strengthening of synergies: both internal, between the different activities performed within MUFIs, and external synergies between the MUFI and the (peri-) urban environment in which it operates. The three cases illustrate that the dense and complex urban environment in which they are situated provides possibilities to create a wide, diverse network around food, leading to a high potential for synergies to occur. In this way, MUFIs can respond to specific urban needs, which are not addressed by the state, and therefore have an important signalling function. For the MUFIs themselves, although being multifunctional increases opportunities, it is also a challenge to find the right balance between the different functions and not to lose sight of the economic side of the business. Local governments can support MUFIs by providing space for them, room to experiment, adapting regulations to get MUFIs out of the “grey zones” of legislation, and by starting to strategically think about food in their city region

Viability and Burden of Leishmania in Extralesional Sites during Human Dermal Leishmaniasis

Understanding of the dynamics and distribution of Leishmania in the human host is fundamental to the targeting of control measures and their evaluation. Amplification of parasite gene sequences in clinical samples from cutaneous leishmaniasis patients has provided evidence of Leishmania in blood, other tissues and sites distinct from the lesion and of persistence of infection after clinical resolution of disease. However, there is uncertainty about the interpretation of the presence of Leishmania DNA as indicative of viable parasites. Because RNA is short-lived and labile, its presence provides an indicator of viability. We amplified Leishmania 7SLRNA, a molecule involved in intracellular protein translocation, to establish viability and estimate parasite load in blood monocytes, tonsil swab samples, and tissue fluid from healthy skin of patients with dermal leishmaniasis. Results showed that during active dermal leishmaniasis, viable Leishmania are present in blood monocytes, tonsils and normal skin in quantities similar to that in lesions, demonstrating widespread dissemination of infection and subclinical involvement of tissues beyond the lesion site. Leishmania 7SLRNA will be useful in deciphering the role of human infection in transmission

Africa’s response to the COVID-19 pandemic : A review of the nature of the virus, impacts and implications for preparedness

Background: COVID-19 continues to wreak havoc in different countries across the world, claiming thousands of lives, increasing morbidity and disrupting lifestyles. The global scientific community is in urgent need of relevant evidence, to understand the challenges and knowledge gaps, as well as the opportunities to contain the spread of the virus. Considering the unique socio-economic, demographic, political, ecological and climatic contexts in Africa, the responses which may prove to be successful in other regions may not be appropriate on the continent. This paper aims to provide insight for scientists, policy makers and international agencies to contain the virus and to mitigate its impact at all levels. Methods: The Affiliates of the African Academy of Sciences (AAS), came together to synthesize the current evidence, identify the challenges and opportunities to enhance the understanding of the disease. We assess the potential impact of this pandemic and the unique challenges of the disease on African nations. We examine the state of Africa’s preparedness and make recommendations for steps needed to win the war against this pandemic and combat potential resurgence. Results: We identified gaps and opportunities among cross-cutting issueswhich must be addressed or harnessed in this pandemic. Factors such as the nature of the virus and the opportunities for drug targeting, point of care diagnostics, health surveillance systems, food security, mental health, xenophobia and gender-based violence, shelter for the homeless, water and sanitation, telecommunications challenges, domestic regional coordination and financing. Conclusion: Based on our synthesis of the current evidence, while there are plans for preparedness in several African countries, there are significant limitations. A multi-sectoral efforts from the science, education, medical, technology, communication, business, and industry sectors, as well as local communities, must work collaboratively to assist countries in order to win this fight

Infrastructure transformation as a socio-technical process - Implications for the governance of energy distribution networks in the UK

This paper seeks to uncover and examine the complex set of governance challenges associated with transforming energy distribution networks, which play a key enabling role in a low carbon energy transition. We argue that, although the importance of such infrastructure networks to sustainability and low carbon transitions in the energy, water and mobility sectors is clear, there is relatively little understanding of the social and institutional dimension of these systems and appropriate governance strategies for their transformation. This may be because the prevalent model of infrastructure governance in the energy and other sectors has prioritised short term time horizons and static efficiencies. In this paper we draw on the social shaping of technology literature to develop a broader understanding of infrastructure change as a dynamic socio-technical process. The empirical focus of the paper is on the development of more flexible and sustainable energy distribution systems as key enablers for the UK's low carbon transition. Focusing on electricity and heat networks we identify a range of governance challenges along different phases of the 'infrastructure lifecycle', and we draw lessons for the development of governance frameworks for the transformation of energy infrastructure more generally