15,513 research outputs found
The wall effect in cavity flow
A non-linear theory for the calculation of the flow field of an oblique flat plate under blockage condition is given using the techniques of integral equations. Numerical results are obtained with the aid of a high speed digital computer for the plate situated mid-channel at values of the angle of attack from 50 to 90° and the channel width-chord ratio from 3 to 20. Also obtained are results for the plate situated at two different off-center positions for a channel width-chord ratio 5 and angles of attack less than 30°
Construction of nested space-filling designs
New types of designs called nested space-filling designs have been proposed
for conducting multiple computer experiments with different levels of accuracy.
In this article, we develop several approaches to constructing such designs.
The development of these methods also leads to the introduction of several new
discrete mathematics concepts, including nested orthogonal arrays and nested
difference matrices.Comment: Published in at http://dx.doi.org/10.1214/09-AOS690 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
A Computer Method for Calculation of the Complete and Incomplete Elliptic Integrals of the Third Kind
Numerical approximations and a Fortran IV program are given
for the calculation by an IBM 7090 computer of the complete and incomplete elliptic integrals of the third kind. In its present form results are limited to six decimal places, but the method is valid for all values of amplitude φ, modulus k and real values of the parameter a^2. For
the purpose of completeness, adaptations of other programs for complete and incomplete elliptic integrals of the first and second kind are also presented
Malaria among antenatal clients attending primary health care facilities in Kano state, Nigeria
Background: Malaria in pregnancy remains a major public health problem especially in sub-Saharan Africa. However, the prevalence of clinical and asymptomatic infection among antenatal client (ANC) attendees is largely unknown, especially at primary health care (PHC) level in northern Nigeria. This study assessed the prevalence of fever, malarial parasitemia and anemia among pregnant women attending PHC facilities in Kano, northern Nigeria.Methods: A cross-sectional descriptive study was conducted among 360 ANCs attending PHC facilities in two Local Government Areas (LGAs) in Kano state. Data were collected using a pre-tested semi-structured interviewer administered questionnaire. Blood samples were also obtained for thin blood smear for malaria parasite using Giemsa staining technique. Hemoglobin was estimated from the Packed Cell Volume (PCV) determined using hematocrit.Results: Age of the subjects ranged from 15 to 42 years with a mean } SD of 24.0 } 6.0. Up to 39.2% (n = 141) (95% Confi dence Interval = 34.1.44.4%) of the subjects were found to have malarial parasitemia. Exactly 36.2% (n = 51) of those with parasitemia had fever (temperature . 37.5oC) while 63.8% (n = 90) of them were asymptomatic. Anemia,(hemoglobin of .11 g/dl) was found in 48.1% (n = 173) of the respondents. A higher proportion of primigravid and secondigravid clients (61% vs. 39%) and younger pregnant women (54.6% vs. 45.4%) had malarial parasitemia compared to multigravid and older women, respectively. Similarly, a signifi cantly higher proportion (67.6%) ofanemic ANC clients had malarial parasitemia. (ƒÔ2 = 113.25, df = 1, P < 0.05).Conclusion: Malarial infection is common among the ANC clients attending PHC facilities in Kano state and the infection is commonly associated with anemia. Intermittent Preventive Treatment (IPT) should be provided especially among primigravid, secondigravid and younger mothers at PHC centres
Active interaction control applied to a lower limb rehabilitation robot by using EMG recognition and impedance model
Purpose
– The purpose of this paper is to propose a seamless active interaction control method integrating electromyography (EMG)-triggered assistance and the adaptive impedance control scheme for parallel robot-assisted lower limb rehabilitation and training.
Design/methodology/approach
– An active interaction control strategy based on EMG motion recognition and adaptive impedance model is implemented on a six-degrees of freedom parallel robot for lower limb rehabilitation. The autoregressive coefficients of EMG signals integrating with a support vector machine classifier are utilized to predict the movement intention and trigger the robot assistance. An adaptive impedance controller is adopted to influence the robot velocity during the exercise, and in the meantime, the user’s muscle activity level is evaluated online and the robot impedance is adapted in accordance with the recovery conditions.
Findings
– Experiments on healthy subjects demonstrated that the proposed method was able to drive the robot according to the user’s intention, and the robot impedance can be updated with the muscle conditions. Within the movement sessions, there was a distinct increase in the muscle activity levels for all subjects with the active mode in comparison to the EMG-triggered mode.
Originality/value
– Both users’ movement intention and voluntary participation are considered, not only triggering the robot when people attempt to move but also changing the robot movement in accordance with user’s efforts. The impedance model here responds directly to velocity changes, and thus allows the exercise along a physiological trajectory. Moreover, the muscle activity level depends on both the normalized EMG signals and the weight coefficients of involved muscles
Decoherence-Based Quantum Zeno Effect in a Cavity-QED System
We present a decoherence-based interpretation for the quantum Zeno effect
(QZE) where measurements are dynamically treated as dispersive couplings of the
measured system to the apparatus, rather than the von Neumann's projections. It
is found that the explicit dependence of the survival probability on the
decoherence time quantitatively distinguishes this dynamic QZE from the usual
one based on projection measurements. By revisiting the cavity-QED experiment
of the QZE [J. Bernu, et al., Phys. Rev. Lett, 101, 180402 (2008)], we suggest
an alternative scheme to verify our theoretical consideration that frequent
measurements slow down the increase of photon number inside a microcavity due
to the nondemolition couplings with the atoms in large detuning.Comment: 4 pages, 3 figure
Role of International Fund for Agricultural Development/ Community Based Agricultural and Rural Development Programme (IFAD/CBARDP) in Improving the Livelihood of Rural Women: A Case Study of Aliero Local Government Area, Kebbi State, Nigeria
This study examined the role of IFAD/CBARDP on improving rural women’s livelihood in Kebbi State, Nigeria. Multistage sampling technique was adopted to select 80 IFAD participating women. Structured questionnaire was used in data collection. Descriptive statistics was used to present the data obtained. Majority of the women were married, and at active productive ages. Qur’anic education was the common educational status of the participants. The findings also reveal that all the IFAD participating women were provided with assistance based on needs and interest and the common assistance provided was the training on tailoring, knitting, soap and cream making and later the participants were provided with such machines. In addition, the participants were also provided cash loan. The programme has lead to improvement of the living standards of the participants after programme participation. Attitudinal dispositional test using 3 points Likert’s scale reveal that the participating women strongly agreed that the programme has improved their living standard, the loan was adequate, and all the assistance provided was based on their needs and interest. It is concluded that the participating women were involved in decision making, most especially on the assistance provided, and the management of the assistance. It’s recommended that effort should be geared towards increasing women participation in any intervention programme that could uplift the livelihood of the rural communities.Keywords: Role, IFAD/CBARDP, Poverty Reduction, participating women, Kebbi Stat
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