EMI Data Research Articles

Effectiveness of Implementation of Electronic Malaria Information System as the National Malaria Surveillance System in Thailand.

BackgroundIn moving toward malaria elimination, one strategy is to implement an active surveillance system for effective case management. Thailand has developed and implemented the electronic Malaria Information System (eMIS) capturing individualized electronic records of suspected or confirmed malaria cases.ObjectiveThe main purpose of this study was to determine how well the eMIS improves the quality of Thailand’s malaria surveillance system. In particular, the focus of the study was to evaluate the effectiveness of the eMIS in terms of the system users’ perception and the system outcomes (ie, quality of data) regarding the management of malaria patients.MethodsA mixed-methods technique was used with the framework based on system effectiveness attributes: data quality, timeliness, simplicity, acceptability, flexibility, stability, and usefulness. Three methods were utilized: data records review, survey of system users, and in-depth interviews with key stakeholders. From the two highest endemic provinces, paper forms matching electronic records of 4455 noninfected and 784 malaria-infected cases were reviewed. Web-based anonymous questionnaires were distributed to all 129 eMIS data entry staff throughout Thailand, and semistructured interviews were conducted with 12 management-level officers.ResultsThe eMIS is well accepted by system users at both management and operational levels. The data quality has enabled malaria personnel to perform more effective prevention and control activities. There is evidence of practices resulting in inconsistencies and logical errors in data reporting. Critical data elements were mostly completed, except for a few related to certain dates and area classifications. Timeliness in reporting a case to the system was acceptable with a delay of 3-4 days. The evaluation of quantitative and qualitative data confirmed that the eMIS has high levels of simplicity, acceptability, stability, and flexibility.ConclusionsOverall, the system implemented has achieved its objective. The results of the study suggested that the eMIS helps improve the quality of Thailand’s malaria surveillance system. As the national malaria surveillance system, the eMIS’s functionalities have provided the malaria staff working at the point of care with close-to-real-time case management data quality, covering case detection, case investigation, drug compliance, and follow-up visits. Such features has led to an improvement in the quality of the malaria control program; the government officials now have quicker access to both individual and aggregated data to promptly react to possible outbreak. The eMIS thus plays one of the key roles in moving toward the national goal of malaria elimination by the next decade.

Integrating auxiliary data and geophysical techniques for the estimation of soil clay content using CHAID algorithm

This study was conducted to estimate soil clay content in two depths using geophysical techniques (Ground Penetration Radar—GPR and Electromagnetic Induction—EMI) and ancillary variables (remote sensing and topographic data) in an arid region of the southeastern Iran. GPR measurements were performed throughout ten transects of 100m length with the line spacing of 10m, and the EMI measurements were done every 10m on the same transect in six sites. Ten soil cores were sampled randomly in each site and soil samples were taken from the depth of 0–20 and 20–40cm, and then the clay fraction of each of sixty soil samples was measured in the laboratory. Clay content was predicted using three different sets of properties including geophysical data, ancillary data, and a combination of both as inputs to multiple linear regressions (MLR) and decision tree-based algorithm of Chi-Squared Automatic Interaction Detection (CHAID) models. The results of the CHAID and MLR models with all combined data showed that geophysical data were the most important variables for the prediction of clay content in two depths in the study area. The proposed MLR model, using the combined data, could explain only 0.44 and 0.31% of the total variability of clay content in 0–20 and 20–40cm depths, respectively. Also, the coefficient of determination (R2) values for the clay content prediction, using the constructed CHAID model with the combined data, was 0.82 and 0.76 in 0–20 and 20–40cm depths, respectively. CHAID models, therefore, showed a greater potential in predicting soil clay content from geophysical and ancillary data, while traditional regression methods (i.e. the MLR models) did not perform as well. Overall, the results may encourage researchers in using georeferenced GPR and EMI data as ancillary variables and CHAID algorithm to improve the estimation of soil clay content.

Evaluating a DVD promoting breast cancer awareness among black women aged 25–50 years in East London

BackgroundThe mean age of presentation for breast cancer among black women is substantially earlier than their white counterparts. Black women also present with adverse prognostic factors that have major clinical...

A Geostatistical Approach to Estimate Soil Moisture as a Function of Geophysical Data and Soil Attributes

Successful implementation of site-specific irrigation requires an understanding of within-field-variability of soil parameters. These parameters can be estimated by direct sampling or by indirect surveying using geophysical data. The geophysical outputs are quite sensitive to soil water content; therefore, they can be used as covariates in soil water content (SWC) estimation.The objectives of this study were to use geophysical and soil data as auxiliary variables in the estimation of soil water content through geostatistical techniques.The surveys were carried out in a test site at the agricultural experimental farm located in south-eastern Italy in dry and wet soil conditions. The plot was surveyed with an EMI sensor and two different mono-static GPR systems, one with central frequencies of 600/1600MHz and the other with a central frequency of 250MHz. Forty-eight soil cores were collected for laboratory analysis of textural properties. One hundred and sixteen soil samples up to 0.30m-depth were collected to measure the SWC with gravimetric method. Kriging with external drift (KED), a non-stationary geostatistical technique, was used to estimate SWC with EMI, GPR and soil data as covariates. Cross-validation test was used to assess the goodness of the estimates and compare KED with ordinary kriging.The results showed that the approach using the auxiliary variables can be preferred to univariate kriging in terms of correlation between true and estimated values and capability of interpretation of spatial variability. Kriging with external drift proved to be a valid tool in sensor data fusion and could be effectively applied in Precision Irrigation.

A New Physics-Based Approach for Estimating a Buried Object's Location, Orientation and Magnetic Polarization from EMI Data

A new physics-based expression is presented for determining a buried object’s location, orientation and magnetic polarizibility. The approach assumes the target exhibits a dipolar response and requires only three global values: a magnetic field vector H, a vector potential A and a scalar magnetic potential ψ, all at a single location in space. Among these values, only the scattered magnetic field, H, is measurable with current electromagnetic induction sensors. Therefore, in order to estimate the scattered magnetic scalar and vector potentials from data, a numerical technique called the normalized surface magnetic source (NSMS) method is employed. Originally, in the NSMS model, the scattered magnetic field outside the object is reproduced mathematically by equivalent magnetic charges distributed on a three-dimensional (3-D) closed surface. Here, a two-dimensional (2-D) implementation of the NSMS that uses elementary magnetic dipoles, instead of magnetic charges distributed on a planar surface placed under...

Rapid evaluation of multifrequency EMI data to characterize buried structures at a historical Jesuit Mission in Argentina

We present results from a geophysical prospection at a historical Jesuit Mission, located in San Ignacio (Misiones-Argentina), declared World Monument some years ago. We studied different sectors looking for buried structures; the total area under study covered 36 ha. In this work we will show the results obtained in a sector that at the time of the prospection was at imminent risk of being damaged by a wrong management of the historical resource. To optimize the data acquisition and the preliminary in-situ analysis of the results, we performed an electromagnetic survey using a multifrequency electromagnetic induction device (GEM-2) to have a first insight of the near surface electrical distribution. From 2D and 3D visualization of data, different targets were identified as possible historical structures. Around these anomalous zones, we performed different dipole–dipole profiles, forming high resolution grids for later 3D inversions. Further inversions of the electric and electromagnetic data completed the characterization of the anomalies. One of the main results of this work is that the 3D electric image obtained from 1D inversion of electromagnetic data coincides with the 3D images obtained from resistivity inversion, but at a much less time consuming cost.

Aplicação do método eletromagnético indutivo (EM) no monitoramento de contaminantes em subsuperfície

O uso combinado de pocos de amostragem e tecnicas geofisicas constitui a maneira mais adequada para identificacao e o monitoramento de areas contaminadas. Este procedimento permite a locacao de pocos de amostragem e de monitoramento em pontos estrategicos, otimizando resultados e minimizando gastos. O metodo geofisico Eletromagnetico Indutivo (EM) apresenta amplas possibilidades de aplicacao em estudos ambientais devido a facilidade na aquisicao de dados, versatilidade do equipamento em campo e a possibilidade de varredura de grandes areas num curto espaco de tempo. Este trabalho realiza uma analise comparativa de dados EM obtidos no ano de 1992 e em 2003. O local estudado e uma area industrial que apresenta contaminacao do solo e agua subterrânea por Benzeno, Tolueno, Xileno, 1,2 dicloroetano, Sodio e Cloreto, produto da infiltracao de efluentes quimicos diretamente do solo. Os resultados indicam uma acentuada atenuacao da pluma contaminante, com provavel reducao no grau de contaminacao. Os compostos de fase leve (LNAPLs) apresentaram maior tendencia de migracao horizontal, concomitante ao movimento da agua subterrânea. Os compostos de fase densa (DNAPLs) apresentaram uma tendencia mais acentuada de migracao no sentido vertical, possivelmente devido a ausencia de superficies impermeaveis. Os compostos inorgânicos acompanharam o fluxo dos compostos de fase liquida nao aquosa (NAPLs), o que por sua vez permitiu a caracterizacao da pluma de contaminacao como um corpo condutivo em relacao as areas adjacentes.

EMI data from an archaeological resistive target revisited

In a previous work, we presented the analysis and interpretation of geophysical data acquired at the Floridablanca archaeological site in Patagonia, Argentina. The electromagnetic induction method (EMI) was used to detect and localize the anomalous zone of interest quickly. Afterwards, a quantitative characterization of the structure responsible for this anomaly was achieved by inverting geoelectrical data.In this work, we re‐analyse the EMI data to discover whether it could also provide us with quantitative information about our target, which exhibits a resistive signature with respect to the host medium. First, an alternative visualization of the data is carried out; this allows us to detect some features of the anomaly that could not be distinguished before. It also makes clear which of the configurations used in the data acquisition exhibits the best sensitivity and resolution. The EMI data corresponding to the anomalous zone are then adjusted with a trial‐and‐error procedure, using a 2D forward modelling method based on a Raleigh–Fourier approach. The response of two adobe walls with a tile deposit in between them is calculated and the resulting model shows good agreement with the model obtained from the inversion of the geoelectrical data. Also, the synthetic response of two adobe walls without the tile deposit is calculated; we find that this response is different and the data cannot be adjusted with this model. We conclude that the EMI method is appropriate for discriminating different types of resistive structure and that it can be used to obtain quantitative information when 2D modelling is performed.

Statistical and Adaptive Signal Processing For UXO Discrimination for Next-Generation Sensor Data

Until recently, detection algorithms could not reliably distinguish between buried UXO and clutter, leading to many false alarms. Over the last several years modern geophysical techniques have been developed that merge more sophisticated sensors, underlying physical models, statistical signal processing algorithms, and adaptive training techniques. These new approaches have dramatically reduced false alarm rates, although for the most part they have been applied to data collected at sites with relatively benign topology and anomaly densities. On more challenging sites, performance of even these more modern discrimination approaches is still quite poor. As a result, efforts are underway to develop a new generation of UXO sensors that will produce data streams of multi-axis vector or gradiometric measurements, for which optimal processing has not yet been carefully considered or developed. We describe a research program to address this processing gap, employing a synergistic use of advanced phenomenologicalmodeling and signal-processing algorithms. The key foci of the program are (1) development of new physics-based signal processing approaches applicable to the problem in which vector data is available from such sensors; and (2) development of the theory of optimal experiments to guide the optimal design and deployment of the new sensor modalities. Here, we present initial results using simulated data obtained with our phenomenological models that indicate that optimal processing of features extracted from multi-axis EMI data can provide substantial improvements in discrimination performance over processing of features extracted from single-axis data.

Contribution of the relative velocity between source and receivers to electromagnetic fields in the sea

The analysis of the primary electromagnetic fields caused by steady state or transient electric current flowing along a current loop moving with a constant velocity below the sea surface has several applications. It supports the analysis of submarine physical data and it is useful for protecting ships from the threat of sea mines. The usual approach to the solution for the primary field starts from a hertz vector potential in the frequency domain due to a magnetic dipole. Subsequently it employs Fourier, Laplace, and Hankel transforms to describe the time variation of the primary electromagnetic induced field due to a loop. The result is applicable to both shallow and deep sea water environments. Because of the difference in velocity between source and receiver, a careful application of the convolution integral is necessary in order to adapt the source pulse solution to any type of transmitting current waveform. Furthermore, since the scattered field represents a fraction of the primary field, even minor differences in it caused by the differential velocity renders inadequate interpretation of EMI data.

Emis data reviews. Properties of amorphous silicon: a book of EMIS data reviews

Emis data reviews. Properties of amorphous silicon: a book of EMIS data reviews