1,569,950 research outputs found

    Control of St. Louis encephalitis

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    "June 1976, reprinted 1981.

    Vector Control in Indonesia: Decentralization; Responsibility at Peripheric Level

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    Pemberantasan vektor di Indonesia, suatu kebijaksanaan nasional yang melaksanakan penyemprotan rumah dengan DDT dewasa ini, banyak kendalanya. Menghadapi kendala tersebut, suatu kebljaksanaan baru telah diajukan, yaitu pemacuan suatu sistem survailans sederhana, yang dimonitor pada tingkat desa (desa endemis malaria). Penyuluhan kesehatan ditingkatkan, dan masyarakat diberi penyuluhan tentang terjadinya penularan penyakit malaria dan cara-cara pencegahan vektornya.Pengelolaan lingkungan yang sederhana dan cara pemberantasan tepat guna lain yang dapat dilaksanakan oleh masyarakat disarankan. Indikator sederhana tentang peningkatan kepadatan vektor dicari, agar masyarakat dapat mengawasi indikator tersebut. Indikator ini dapat dijadikan alat bagi ko-assisten entomolog untuk memonitor dan melaporkan peningkatan dalam kepadatan vektor untuk penanganan pemberantasan segera agar peningkatan vektor lebih lanjut dan penularan penyakit dapat dtegah.Strategi pencegahan/pengendalian vektor malaria maupun DHF dibicarakan dalam makalah ini

    Thrust vector control apparatus Patent

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    Thrust vector control by secondary injection of fluid into rocket nozzle flow field to separate exhaust flo

    Speed sensorless field oriented control of ac induction motor using model reference adaptive system

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    In order implement the vector control technique, the motor speed information is required. Incremental encoder, resolvers and tachogenerator, are used to reveal the speed. These sensors require careful mounting and alignment and special attention is required with electrical noises. Sensorless speed vector control is greatly used and applied in induction machine drives instead of scalar control and vector control for their robustness and reliability, and very low maintenance cost. In this project MRAS based techniques are used to estimate the rotor speed based on rotor flux estimation, the estimated speed in the MRAS algorithm is used as a feedback for the vector control system. The model reference adaptive control system is predicated on the comparison between the outputs of adjustable model and reference model. The error between them is employed to drive a suitable adaptation mechanism which generates the estimated rotor speed for the adjustable model. And indirect vector control scheme controls the flux and torque by restricting the torque and flux errors with respective hysteresis bands, and motor flux and torque are controlled by the stator voltage space vectors using optimum inverter switching table. Modeling and simulation of the induction machine and the vector control drives implemented in MATLAB/SIMULINK. Simulation results of proposed MRAS and indirect vector control technique are presented

    Velocity vector control system augmented with direct lift control

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    A pilot-controlled stability control system that employs direct lift control (spoiler control) with elevator control to control the flight path angle of an aircraft is described. A computer on the aircraft generates an elevator control signal and a spoiler control signal, using a pilot-controlled pitch control signal and pitch rate, vertical velocity, roll angle, groundspeed, engine pressure ratio and vertical acceleration signals which are generated on the aircraft. The direct lift control by the aircraft spoilers improves the response of the aircraft flight path angle and provides short term flight path stabilization against environmental disturbances

    Optimal Control of One-Qubit Gates

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    We consider the problem of carrying an initial Bloch vector to a final Bloch vector in a specified amount of time under the action of three control fields (a vector control field). We show that this control problem is solvable and therefore it is possible to optimize the control. We choose the physically motivated criteria of minimum energy spent in the control, minimum magnitude of the rate of change of the control and a combination of both. We find exact analytical solutions.Comment: 5 page

    Study of vortex valve for medium temperature solid propellants

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    Fluid state vortex valve secondary injection control system shows considerable promise for future application to solid propellant rocket engine thrust vector control. The single axis injection system tested would be capable of providing secondary injection thrust vector control using 2000 deg F gas

    High Effective Coverage of Vector Control Interventions in Children After Achieving Low Malaria Transmission in Zanzibar, Tanzania.

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    \ud \ud Formerly a high malaria transmission area, Zanzibar is now targeting malaria elimination. A major challenge is to avoid resurgence of malaria, the success of which includes maintaining high effective coverage of vector control interventions such as bed nets and indoor residual spraying (IRS). In this study, caretakers' continued use of preventive measures for their children is evaluated, following a sharp reduction in malaria transmission. A cross-sectional community-based survey was conducted in June 2009 in North A and Micheweni districts in Zanzibar. Households were randomly selected using two-stage cluster sampling. Interviews were conducted with 560 caretakers of under-five-year old children, who were asked about perceptions on the malaria situation, vector control, household assets, and intention for continued use of vector control as malaria burden further decreases. Effective coverage of vector control interventions for under-five children remains high, although most caretakers (65%; 363/560) did not perceive malaria as presently being a major health issue. Seventy percent (447/643) of the under-five children slept under a long-lasting insecticidal net (LLIN) and 94% (607/643) were living in houses targeted with IRS. In total, 98% (628/643) of the children were covered by at least one of the vector control interventions. Seasonal bed-net use for children was reported by 25% (125/508) of caretakers of children who used bed nets. A high proportion of caretakers (95%; 500/524) stated that they intended to continue using preventive measures for their under-five children as malaria burden further reduces. Malaria risk perceptions and different perceptions of vector control were not found to be significantly associated with LLIN effective coverage While the majority of caretakers felt that malaria had been reduced in Zanzibar, effective coverage of vector control interventions remained high. Caretakers appreciated the interventions and recognized the value of sustaining their use. Thus, sustaining high effective coverage of vector control interventions, which is crucial for reaching malaria elimination in Zanzibar, can be achieved by maintaining effective delivery of these interventions
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