2,924 research outputs found

    Review of R and D on Water Hyacinth Utilization in the Philippine Republic

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    The operations of a Filipino inventor were observed with a view toward determining the technical-economic potential of his hyacinth utilization concepts if the highly fibrous portion of the plant were separated from the other components. Subjects of particular interest include: (1) water hyacinth harvesting techniques, volumes and costs; (2) hyacinth defibering processes; and (3) uses of hyacinth materials for production of animal feeds, paper fibers, particle boards, acoustic and insulation boards, various vitamins and minerals (especially Vitamin A), food products, pesticides, and medicinal and pharmaceutical products

    Finite-time stabilization of homogeneous non-Lipschitz systems

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    This paper focuses on the problem of finite-time stabilization of homogeneous, non-Lipschitz systems with dilations. A key contribution of this paper is the design of a virtual recursive Holder, non-Lipschitz state feedback, which renders the non-Lipschitz systems in the special case dominated by a lower-triangular nonlinear system finite-time stable. The proof is based on a recursive design algorithm developed recently to construct the virtual Holder continuous, finite-time stabilizer as well as a C1 positive definite and proper Lyapunov function that guarantees finite-time stability of the non-Lipschitz nonlinear systems

    Evaluación de los modelos ultraestructurales y de efectos aleatorios empleados en la recuperación de anillas para estimar las relaciones entre las tasas de supervivencia y las tasas de cosecha en poblaciones bajo explotación

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    Increased population survival rate after an episode of seasonal exploitation is considered a type of compensatory population response. Lack of an increase is interpreted as evidence that exploitation results in added annual mortality in the population. Despite its importance to management of exploited species, there are limited statistical techniques for comparing relative support for these two alternative models. For exploited bird species, the most common technique is to use a fixed effect, deterministic ultrastructure model incorporated into band recovery models to estimate the relationship between harvest and survival rate. We present a new likelihood–based technique within a framework that assumes that survival and harvest are random effects that covary through time. We conducted a Monte Carlo simulation study under this framework to evaluate the performance of these two techniques. The ultrastructure models performed poorly in all simulated scenarios, due mainly to pathological distributional properties. The random effects estimators and their associated estimators of precision had relatively small negative bias under most scenarios, and profile likelihood intervals achieved nominal coverage. We suggest that the random effects estimation method approach has many advantages compared to the ultrastructure models, and that evaluation of robustness and generalization to more complex population structures are topics for additional research.El aumento en la tasa de supervivencia poblacional ocurrido tras un episodio de explotación estacional se considera como un tipo de respuesta compensatoria por parte de la población. La ausencia de un aumento se interpreta como una evidencia de que la explotación se traduce en una mayor mortalidad anual de la población. Pese a su importancia para la gestión de especies bajo explotación, sólo se dispone de un número limitado de técnicas estadísticas que permiten comparar el apoyo relativo que reciben estos dos modelos alternativos. Para las especies de aves bajo explotación, la técnica más habitual consiste en utilizar un modelo de efectos fijos, de ultraestructura determinista, incorporado a los modelos de recuperación de anillas para estimar la relación entre la tasa de cosecha y la tasa de supervivencia. En el presente estudio explicamos cómo emplear una nueva técnica basada en la razón de verosimilitud, en un marco que asume que la supervivencia y la cosecha son efectos aleatorios que covarían a lo largo del tiempo. Para ello, llevamos a cabo un estudio bajo dicho marco utilizando la simulación Monte Carlo, con objeto de evaluar el rendimiento de las dos técnicas mencionadas. El rendimiento de los modelos ultraestructurales fue bastante deficiente en todos los escenarios simulados, obedeciendo, principalmente, a propiedades distribucionales patológicas. Los estimadores de efectos aleatorios y sus estimadores de precisión asociados presentaron un sesgo relativamente pequeño en la mayor parte de los escenarios, mientras que los intervalos de verosimilitud del perfil alcanzaron una cobertura nominal. Sugerimos que el planteamiento basado en el método de estimación mediante modelos de efectos aleatorios brinda numerosas ventajas en comparación con los modelos ultraestructurales, y que la evaluación de la robustez y la generalización a estructuras poblacionales más complejas constituyen temas para una investigación adicional

    Cognitive behavioral therapy for the management of multiple sclerosis–related pain: a randomized clinical trial

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    BACKGROUND: Pain is a common and often debilitating symptom among persons with multiple sclerosis (PwMS). Besides interfering with daily functioning, pain in MS is associated with higher levels of depression and anxiety. While cognitive-behavioral therapy (CBT) for pain has been found to be an effective treatment in other populations, there has been a dearth of research in PwMS. METHODS: PwMS with at least moderate pain severity (N = 20) were randomly assigned to one of two groups: CBT plus standard care (CBT/SC) or MS-related education plus standard care (ED/SC), each of which met for 12 sessions. Changes in pain severity, pain interference, and depressive symptom severity from baseline to the 15 week follow-up were assessed using a 2×2 factorial design. Participants also rated their satisfaction with their treatment and accomplishment of personally meaningful behavioral goals. RESULTS: Both treatment groups rated their treatment satisfaction as very high and their behavioral goals as largely met, although only the CBT/SC group's mean goal accomplishment ratings represented significant improvement. While there were no significant differences between groups post-treatment on the three primary outcomes, there was an overall improvement over time for pain severity, pain interference, and depressive symptom severity. CONCLUSIONS: CBT or education-based programs may be helpful adjunctive treatments for PwMS experiencing pain.Accepted manuscrip

    Use of foot for direct interactions with entities of a virtual environment displayed on a mobile device

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    With this paper, we report a novel wearable in-terface dedicated to provide new types of 3D interactions with mobile devices. Proposed interface is based on the fact that the foot can be exploited in the interaction with a virtual 3D world. By using several force sensors incorporated in the sole and an accelerometer attached to the shoe; gestures performed with the foot are interpreted in order to let the user interact with a 3D virtual environment. Being located inside a shoe this interface is fully compatible to constraints related to mobile devices. Indeed as a wearable and transparent device it can be carried everywhere and therefore can be exploited everywhere

    Toilet assistive system designed for the reduction of accidental falls in the bathroom using admittance controller

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    This paper suggests an assistive system for the toilet with the objective of measuring human activities and to provide intelligent mechanical assistance to help seating and standing. The project intends to develop a seating assistance as a technical aid in order to reduce accidents and falls in the bathroom. The preferred technique is human-robot physical interaction algorithms known in collaborative robotics (cobot) and adapting it to a personalized assistance technology installed on a smart toilet. First, the design of the mechanical assistance is presented. Then, an admittance controller is designed and implemented in order to help the user in a similar way as a cobot could be used. This technique could be used to assist the user and improve balance with adequate training and an adequate configuration of the admittance controller

    Design of a serious game for learning vibrotactile messages

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    To prevent accidental falls, we have designed an augmented shoe aiming at assisting a user when walking. For this, the risk level (low, medium, high and very high) represented by the current situation is conveyed to the user through vibrotactile messages. In this paper, we describe the design of a serious game dedicated to learning of these signals. The game is centered on a virtual maze, whose parts are associated with the four risk levels. To explore this maze, fitted with a pair of the augmented shoes, the user is invited to walk in a room, completely empty, whose dimensions are mapped to those of the virtual maze. When moving, for each area explored the corresponding signal is delivered to the user through the augmented shoes. An initial experiment confirmed the idea that vibrotactile messages can serve for communicating the level of risk

    Active stability observer using artificial neural network for intuitive physical human–robot interaction

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    Physical human-robot interaction may present an obstacle to transparency and operations’ intuitiveness. This barrier could occur due to the vibrations caused by a stiff environment interacting with the robotic mechanisms. In this regard, this paper aims to deal with the aforementioned issues while using an observer and an adaptive gain controller. The adaptation of the gain loop should be performed in all circumstances in order to maintain operators’ safety and operations’ intuitiveness. Hence, two approaches for detecting and then reducing vibrations will be introduced in this study as follows: 1) a statistical analysis of a sensor signal (force and velocity) and 2) a multilayer perceptron artificial neural network capable of compensating the first approach for ensuring vibrations identification in real time. Simulations and experimental results are then conducted and compared in order to evaluate the validity of the suggested approaches in minimizing vibrations

    A serious game for training balance control over different types of soil

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    It is known that the type of the soil can affect balance. Here we report a serious game designed for training users at maintaining balance over five types of soil (broken stone, stone dust, sand, concrete and wood). By using an augmented shoe and proposed navigation metaphor, in this game, the user is invited to browse a maze while standing balance over the physical grounds. During the exploration, exercises targeting assessment of balance control are suggested. To insure the effectiveness of this training program, four exercises based on the Berg Balance Scale and the Tinetti Balance Assessment Tool are incorporated in the game
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