377 research outputs found
Radicchio cultivation under different sprinkler irrigation systems
Gun sprinklers were commonly used in Italy to irrigate Radicchio. Although this high-pressure irrigation system allows large areas to be irrigated in a short time, it has some major disadvantages. Disadvantages include the impact of the drops on the soil and crop can be very strong, the high volume of water used tends to increase water use and runoff and water distribution uniformity is low. A 3-year experiment was conducted in North-East Italy in order to evaluate the possibility of using a mini-sprinkler irrigation system with low-volume application rates. The use of mini-sprinkler resulted in a higher distribution uniformity, higher Christiansen uniformity coefficient and a higher water use efficiency. Energy cost was also lower when the mini-sprinkler system was used for irrigation as compared to the irrigation gun system. Radicchio head weight and marketable yield were higher when plants were irrigated with the mini-sprinkler as compared to those irrigated with the irrigation gun. Therefore, the use of mini-sprinklers resulted in not only a reduction in water use and energy cost but also an increase in radicchio production
An Application of Time Series Analysis in Modeling Monthly Rainfall Data for Maiduguri, North Eastern Nigeria
Time series analysis and forecasting has become a major tool in different applications in meteorological phenomena such as rainfall, humidity, temperature, draught and so on; and environmental fields. Among the most effective approaches for analyzing time series data is the ARIMA (Autoregressive Integrated Moving Average) model introduced by Box and Jenkins. In this study, Box-Jenkins methodology was used to model monthly rainfall data taken from Maiduguri Airport Station for the period from 1981 to 2011 with a total of 372 readings. ARIMA (1, 1,0) model was developed. This model was used to forecast monthly rainfall for the upcoming 44 months (3 years 8 months) to help decision makers establish priorities in terms of water demand management and agriculture. Thus, ARIMA (1, 1,0) provides a good fit for the rainfall data of Maiduguri and is appropriate for short term forecast.Key Words: Time Series Analysis, Rainfall Model, Forecasting, ARIMA
Socio-Economic and Demographic Classification of HIV/AIDS Patients: Using Cluster Analysis
HIV/AIDS has been spreading in an alarming rate since the beginning of the pandemic. It is estimated that at least half of the affected ones are between 15-24 years. These have called for a concerted effort to save this segment of the population for many reasons. Against this background the study was aimed at classifying socio economic and demographic several of 1500 patients, registered with the university of Maiduguri teaching hospital from 2009 to 2013.Cluster analysis was employed on the set data. The distance which shows similarly between the variable using the coefficient distance was calculated. Dendogram were formed for agglomerative schedule. It was observed that the dendogram formed by the various methods differs according to their coefficient. Even though the single, complete and ward follow similar pattern of cluster except the centriod method, which differ and gave different pattern. Keywords: Agglomerative, Cluster Analysis, Dendogram, and Hierarchica
Effect of Values Clarification Counselling Technique on Aggressive Behaviour among Senior Secondary School Students in Kontagora Metropolis, Niger State
This study examined the effect of values clarification counselling techniques on aggressive behaviour among senior secondary school students in Kontagora metropolis, Niger State. Pretest posttest quasi experimental research design was adopted. The target population for the study consists of senior secondary school students. A sample size of 15 participants was purposively selected from senior secondary school two students for the study consisting of 11 males and 4 females. An instrument titled Students Aggressive Behaviour Questionnaire (SABQ) was used to obtain data for both pre and posttest. The intervention sessions lasted for ten weeks (two sessions of 60 minutes each per week) during the third term 2021/2022 academic session. Data collected were analyzed using descriptive statistical tools of mean, standard deviation and inferential statistical tools of paired sample t-test. The findings revealed that values clarification counselling technique had a significant effect on hostile, emotional and relational aggressive behaviour among students with t=11.00, p=.000; t=6.15, p=.000 and t=7.54, p=.000 respectively. It was concluded that values clarification counselling technique was effective in reducing aggressive behaviour among senior secondary school students. It was therefore recommended among others that, school counsellors and psychologists should employ values clarification counselling techniques in reducing aggressive behaviour among senior secondary school students
Improving the generalisation of genetic programming models with evaluation time and asynchronous parallel computing
In genetic programming (GP), controlling complexity often means reducing the size of evolved expressions. However, previous studies show that size reduction may not avoid model overfitting. Therefore, in this study, we use the evaluation time --- the computational time required to evaluate a GP model on data --- as the estimate of model complexity. The evaluation time depends not only on the size of evolved expressions but also their composition, thus acting as a more nuanced measure of model complexity than size alone. To constrain complexity using this measure of complexity, we employed an explicit control technique and a method that creates a race condition. We used a hybridisation of GP and multiple linear regression (MLRGP) that discovers useful features to boost training performance in our experiments. The improved training increases the chances of overfitting and facilitates a study of how managing complexity with evaluation time can address overfitting. Also, MLRGP allows us to observe the relationship between evaluation time and the number of features in a model. The results show that constraining evaluation time of MLRGP leads to better generalisation than both plain MLRGP and with an effective bloat-control
Time Control or Size Control? Reducing Complexity and Improving Accuracy of Genetic Programming Models
Complexity of evolving models in genetic programming (GP) can impact both the quality of the models and the evolutionary search. While previous studies have proposed several notions of GP model complexity, the size of a GP model is by far the most researched measure of model complexity. However, previous studies have also shown that controlling the size does not automatically improve the accuracy of GP models, especially the accuracy on out of sample (test) data. Furthermore, size does not represent the functional composition of a model, which is often related to its accuracy on test data.
In this study, we explore the {\em evaluation time} of GP models as a measure of their complexity; we define the evaluation time as the time taken to evaluate a model over some data. We demonstrate that the evaluation time reflects both a model’s size and its composition; also, we show how to measure the evaluation time reliably.
To validate our proposal, we leverage four well-known methods to size-control but to control evaluation times instead of the tree sizes; we thus compare size-control with time-control.
The results show that time-control with a nuanced notion of complexity produces more accurate models on 17 out of 20 problem scenarios. Even when the models have slightly greater times and sizes, time-control counterbalances via superior accuracy on both training and test data. The paper also argues that time-control can differentiate functional complexity even better in an identically-sized population. To facilitate this, the paper proposes Fixed Length Initialisation (FLI) that creates an identically-sized but functionally-diverse population. The results show that while FLI particularly suits time-control, it also generally improves the performance of size-control. Overall, the paper poses evaluation-time as a viable alternative to tree sizes to measure complexity in GP
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An ERP Investigation on Visuotactile Interactions in Peripersonal and Extrapersonal Space: Evidence for the Spatial Rule
The spatial rule of multisensory integration holds that cross-modal stimuli presented from the same spatial location result in enhanced multisensory integration. The present study investigated whether processing within the somatosensory cortex reflects the strength of cross-modal visuotactile interactions depending on the spatial relationship between visual and tactile stimuli. Visual stimuli were task-irrelevant and were presented simultaneously with touch in peripersonal and extrapersonal space, in the same or opposite hemispace with respect to the tactile stimuli. Participants directed their attention to one of their hands to detect infrequent tactile target stimuli at that hand while ignoring tactile targets at the unattended hand, all tactile nontarget stimuli, and any visual stimuli. Enhancement of ERPs recorded over and close to the somatosensory cortex was present as early as 100 msec after onset of stimuli (i.e., overlapping with the P100 component) when visual stimuli were presented next to the site of tactile stimulation (i.e., perihand space) compared to when these were presented at different locations in peripersonal or extrapersonal space. Therefore, this study provides electrophysiological support for the spatial rule of visual–tactile interaction in human participants. Importantly, these early cross-modal spatial effects occurred regardless of the locus of attention. In addition, and in line with previous research, we found attentional modulations of somatosensory processing only to be present in the time range of the N140 component and for longer latencies with an enhanced negativity for tactile stimuli at attended compared to unattended locations. Taken together, the pattern of the results from this study suggests that visuotactile spatial effects on somatosensory processing occur prior and independent of tactile–spatial attention
IFNAR1 Controls Progression to Cerebral Malaria in Children and CD8+ T Cell Brain Pathology in Plasmodium berghei-Infected Mice
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There is no public supplementary material available.Development of cerebral malaria (CM), a severe and fatal form of clinical Plasmodium falciparum infection, results from a damaging cascade of vascular, inflammatory, and immunological host responses that leads to brain injury. Progression to CM can be modified by host genetic factors. Our case-control study in Angolan children aimed at highlighting the role of IFN (α, β) receptor 1 (IFNAR1) in progression to CM. We report a robust association between IFNAR1 and CM protection, as well as detailed studies showing analogous protection from experimental CM in Ifnar1(-/-) mice infected with P. berghei ANKA. We developed a novel cell-transfer protocol that enables spleen cell priming in the absence of disease. This led to the discovery that IFNAR1 expression in CD8(+) T cells is crucial and can abrogate resistance to experimental CM in Ifnar1(-/-) mice. Splenic CD8(+) T cells from Ifnar1(-/-) mice are functionally activated upon infection, yet are unable to mediate experimental CM development within the brain tissue. Our findings prove that IFNAR1 signaling unleashes CD8(+) T cell effector capacity, which is vital for CM, and raises the hypothesis that the cohesive role of IFNAR1 in both human and mouse CM operates through CD8(+) T cell triggering.FCT fellowships: (SFRH/BD/33564/2008, SFRH/BPD/29354/2006)
Field trial of SDN-controlled probabilistic constellation shaping supporting multiple rates over a coupled-core multi-core fiber
A SDN controller configures probabilistic constellation shaping through NETCONF optimizing spectral efficiency according to the path length or degradations due to soft failure. The integrated data and control planes are demonstrated with multiple rates (800-850-900-950-1000Gb/s) in a field trial employing multi-core fiber with 4-coupled cores
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