Amboseli entre compétition politique et protection de la faune

NoLe Parc National d’Amboseli, situé dans le District de Olkejuado (sud Kenya), est depuis 2005 l’objet d’une controversesur son statut qui met en lumière un certain nombre d’enjeux politiques liés à son existence. A la fois réserve naturelleet ressource politique, le cas d’Amboseli démontre la dépendance des mesures de protection de la faune au jeu politiquelocal et national

A surface acoustic wave touchscreen-type device using two transducers

Current wireless human-computer interaction devices such as wireless mice and touchscreens, by and large, incorporate a sophisticated electronic architecture. The sophistication achieves wireless capabilities but carries over a cost overhead. In this paper we lay the foundation for developing a novel human-computer interaction device with reduced hardware sophistication. We developed a surface acoustic wave touchscreen-type device using only two transducers, as opposed to, typically, three or more transducers in conventional surface acoustic wave touchscreens. The transducers are mounted on a glass surface and connected into the line-in of a stereo sound card. User-initiated taps are detected, analysed and located on the surface, and the mouse cursor is moved to the computed screen location.Telkom, CISCO, THRI

Real-time gesture recognition using eigenvectors

This paper discusses an implementation for gesture recognition using eigenvectors under controlled conditions. This application of eigenvector recognition is trained on a set of defined hand images. Training images are processed using eigen techniques from the OpenCV image processing library. Test images are then compared in real-time. These techniques are outlined below.Telkom. CISCO, THRI

KernTune: Self-tuning Linux kernel performance using support vector machines

Self-tuning has been an elusive goal for operating systems and is becoming a pressing issue for modern operating systems. Well-trained system administrators are able to tune an operating system to achieve better system performance for a specific system class. Unfortunately, the system class can change when the running applications change. Our model for self-tuning operating system is based on a monitor-classify-adjust loop. The idea of this loop is to continuously monitor certain performance metrics, and whenever these change, the system determines the new system class and dynamically adjusts tuning parameters for this new class. This paper describes KernTune, a prototype tool that identifies the system class and improves system performance automatically. A key aspect of KernTune is the notion of Artificial Intelligence (AI) oriented performance tuning. It uses a support vector machine (SVM) to identify the system class, and tunes the operating system for that specific system class. This paper presents design and implementation details for KernTune. It shows how KernTune identifies a system class and tunes the operating system for improved performance

Parameterisation of underwater light fields in the Arctic Ocean and associated impact on biological processes

Accurate characterisation of underwater light is an integral component in modelling the dynamics of marine ecosystems, particularly primary production and animal migration patterns. Existing methods of estimating light fields either rely on satellite data, in situ measurements or radiative transfer models that only operate when the sun is above the horizon. These methods are of limited use in Arctic waters, particular during Polar Night due to extended periods of extremely low light levels and prolonged periods when the sun remains below horizon. Estimating underwater light in the region is further hindered by the optical complexities introduced by widespread and seasonally varying snow and ice cover, and many current ecosystem models either simplify these under-ice light fields or excluding them entirely, potentially disregarding biologically significant light levels. This work presents a model of spectrally resolved underwater light that demonstrates the ability to simulate light levels over the full year into the period of Polar Night and is validated by in situ data. Downwelling spectral irradiance in the photosynthetically active radiation (PAR, 400 – 700nm) range is calculated in both open and ice-covered water columns and includes multiple reflection amplification effects of above surface irradiance between snow and cloud. Validation of downwelling broadband irradiance in open waters shows a mean absolute error of 20% of above surface irradiance to penetrate through thin ice ( 20% of total productivity. In open waters, calculations of primary production were found to be highly sensitive to the parameterisation of the diffuse attenuation coefficient of light. Comparing the results of various light field models designed for use in the Arctic showed a factor 12 difference in calculated water column productivity when using output irradiances to drive a model of primary production. Comparing modelled underwater spectral irradiance to the diel vertical migration (DVM) patterns of Arctic krill in early spring 2018 showed that the spectral distribution of light may act as a trigger mechanism for DVM. Results appear to indicate that although diurnal changes in the magnitude of downwelling irradiance largely drives bulk migration patterns, the population of krill also responded to changes in the ratio of green to blue light, driven by changes in lunar and solar elevations, preferring to occupy regions of the water column with a dominant blue colour of underwater light.Accurate characterisation of underwater light is an integral component in modelling the dynamics of marine ecosystems, particularly primary production and animal migration patterns. Existing methods of estimating light fields either rely on satellite data, in situ measurements or radiative transfer models that only operate when the sun is above the horizon. These methods are of limited use in Arctic waters, particular during Polar Night due to extended periods of extremely low light levels and prolonged periods when the sun remains below horizon. Estimating underwater light in the region is further hindered by the optical complexities introduced by widespread and seasonally varying snow and ice cover, and many current ecosystem models either simplify these under-ice light fields or excluding them entirely, potentially disregarding biologically significant light levels. This work presents a model of spectrally resolved underwater light that demonstrates the ability to simulate light levels over the full year into the period of Polar Night and is validated by in situ data. Downwelling spectral irradiance in the photosynthetically active radiation (PAR, 400 – 700nm) range is calculated in both open and ice-covered water columns and includes multiple reflection amplification effects of above surface irradiance between snow and cloud. Validation of downwelling broadband irradiance in open waters shows a mean absolute error of 20% of above surface irradiance to penetrate through thin ice ( 20% of total productivity. In open waters, calculations of primary production were found to be highly sensitive to the parameterisation of the diffuse attenuation coefficient of light. Comparing the results of various light field models designed for use in the Arctic showed a factor 12 difference in calculated water column productivity when using output irradiances to drive a model of primary production. Comparing modelled underwater spectral irradiance to the diel vertical migration (DVM) patterns of Arctic krill in early spring 2018 showed that the spectral distribution of light may act as a trigger mechanism for DVM. Results appear to indicate that although diurnal changes in the magnitude of downwelling irradiance largely drives bulk migration patterns, the population of krill also responded to changes in the ratio of green to blue light, driven by changes in lunar and solar elevations, preferring to occupy regions of the water column with a dominant blue colour of underwater light

Online natural myocontrol of combined hand and wrist actions using tactile myography and the biomechanics of grasping

Connan M, Kõiva R, Castellini C. Online natural myocontrol of combined hand and wrist actions using tactile myography and the biomechanics of grasping. Frontiers in Neurorobotics. 2020;14: 11.Objective: Despite numerous recent advances in the field of rehabilitation robotics, simultaneous and proportional control of hand and/or wrist prostheses is still unsolved. In this work we concentrate on myocontrol of combined actions, for instance power grasping while rotating the wrist, by only using training data gathered from single actions. This is highly desirable since gathering data for all possible combined actions would be unfeasibly long and demanding for the amputee. Approach: We first investigated physiologically feasible limits for muscle activation during combined actions. Using these limits we involved 12 intact participants and one amputee in a Target Achievement Control test, showing that tactile myography, i.e. high-density force myography, solves the problem of combined actions to a remarkable extent using simple linear regression. Since real-time usage of many sensors can be computationally demanding, we compare this approach with another one using a reduced feature set. These reduced features are obtained using a fast, spatial first-order approximation of the sensor values. Main results: By using the training data of single actions only, i.e. power grasp or wrist movements, subjects achieved an average success rate of 70.0% in the target achievement test using ridge regression. When combining wrist actions, e.g. pronating and flexing the wrist simultaneously, similar results were obtained with an average of 68.1%. If a power grasp is added to the pool of actions, combined actions are much more difficult to achieve (36.1%). Significance: To the best of our knowledge, for the first time, the effectiveness of tactile myography on single and combined actions is evaluated in a target achievement test. The present study includes 3 DoFs control instead of the two generally used in the literature. Additionally, we define a set of physiologically plausible muscle activation limits valid for most experiments of this kind

Cross-cultural filmmaking

Faire des films et écrire des textes Depuis le début des années soixante, les documentaristes ont eu la possibilité de filmer en son synchrone presque partout dans le monde. Depuis le milieu des années soixante-dix, les caméras portables vidéo sont aussi largement disponibles et elles deviennent plus accessibles, moins chères, plus performantes de jour en jour. Le film rend les peuples et leurs cultures vivants sur l’écran, capturant la sensation de présence vivante d’une manière que ni les m..

Improving the international and regional, legal and policy framework in the prevention of sexual exploitation and abuse of women and children by international and regional peacekeepers

This dissertation will examine how an international and regional, legal and policy framework can be used to prevent continuing sexual exploitation and abuse by international and regional peacekeepers. It will examine what the different laws and policies contained within the framework currently articulate about sexual exploitation and abuse of women and children in peacekeeping settings, and evaluate their effectiveness at preventing this kind of misconduct. This dissertation will conclude by exploring how the effectiveness of the overall framework could be further improved