Malaria transmission in the vicinity of impounded water: evidence from the Koka Reservoir, Ethiopia

Malaria / Waterborne diseases / Disease vectors / Habitats / Disease control / Entomology / Epidemiology / Surveys / Dams / Reservoirs / Villages / Case studies / Africa / Ethiopia / Koka Reservoir / Rift Valley / Awash River Basin

Techniques of detection, estimation and coding for fading channels

The thesis describes techniques of detection, coding and estimation, for use in high speed serial modems operating over fading channels such as HF radio and land mobile radio links. The performance of the various systems that employ the above techniques are obtained via computer simulation tests. A review of the characteristics of HF radio channels is first presented, leading to the development of an appropriate channel model which imposes Rayleigh fading on the transmitted signal. Detection processes for a 4.8 kbit/s HF radio modem are then discussed, the emphasis, here, being on variants of the maximum likelihood detector that is implemented by the Viterbi algorithm. The performance of these detectors are compared with that of a nonlinear equalizer operating under the same conditions, and the detector which offers the best compromise between performance and complexity is chosen for further tests. Forward error correction, in the form of trellis coded modulation, is next introduced. An appropriate 8-PSK coded modulation scheme is discussed, and its operation over the above mentioned HF radio modem is evaluated. Performance comparisons are made of the coded and uncoded systems. Channel estimation techniques for fast fading channels akin to cellular land mobile radio links, are next discussed. A suitable model for a fast fading channel is developed, and some novel estimators are tested over this channel. Computer simulation tests are also used to study the feasibility of the simultaneous transmission of two 4-level QAM signals occupying the same frequency band, when each of these signals are transmitted at 24 kbit/s over two independently fading channels, to a single receiver. A novel combined detector/estimator is developed for this purpose. Finally, the performance of the complete 4.8 kbit/s HF radio modem is obtained, when all the functions of detection, estimation and prefiltering are present, where the prefilter and associated processor use a recently developed technique for the adjustment of its tap gains and for the estimation of the minimum phase sampled impulse response

Power smoothing and energy storage sizing of vented oscillating water column wave energy converter arrays

Oscillating water column wave energy converter arrays can be arranged to enhance the energy production and quality of power delivered to the grid. This study investigates four different array configurations of vented oscillating water columns and their effect on power quality and capacity of the energy storage systems required to absorb power fluctuation. Configuring the array of vented oscillating water columns as a nearshore detached breakwater allows combining the benefits of their complementary features. This increases the economic optimization of wave energy converters, paving the path to the energy market. The operations of the integration schemes are evaluated using the results obtained from simulations carried out using MATLAB/Simulink software. Simulation results show that the array of vented oscillating water columns and array of vented oscillating water columns as nearshore detached breakwater configurations increase the quality of power delivered to the grid and reduce the capacity of the energy storage systems required

Nutritional Evaluation of Different Mango Varieties available in Sri Lanka

The study was carried out to evaluate the nutritional properties of five varieties (Willard, Karthakolomban, Malwana, Bettiamba and Gira Amba) of mango. Nutritional properties were significantly (p 0.05) varied among the different mango varieties. The highest edible portion (79.49%), total soluble solids (0.75%), ash, total carbohydrate, sugar (30.56 mg/100 gm) and crude fiber were found in Karthakolomban. The highest amount of fat and moisture content were found in Malwana. The maximum amount of caloric value was found in Bettiamba. Gira Amba variety indicated the highest amount of protein content among the other mango varieties. Gira Amba has the highest titratable acidity meanwhile Karthakolomban has the lowest value considerably. Mango verities in this study possess pH values without any significant deviations and Bettiamba was recorded as the variety with highest pH value meanwhile Malwana claimed to be the lowest. Therefore, this study contributed to the identification of the characteristic biochemical properties of several prominent Sri Lankan mango varieties

Remote sensing and hydrologic models for performance assessment in Sirsa Irrigation Circle, India

Irrigation management / Irrigation systems / Irrigation canals / Performance evaluation / Remote sensing / GIS / Models / Irrigated farming / Hydrology / Satellite surveys / Irrigation scheduling / Evapotranspiration / India

Malaria and land use: a spatial and temporal risk analysis in Southern Sri Lanka

Malaria / Waterborne diseases / Disease vectors / Land use / Water use / GIS / Statistical analysis / Risks / Mapping / Public health / Sri Lanka / Uda Walawe / Thanamalvila / Embilipitiya

Evaluation with uncertainty

Experimental uncertainty arises as a consequence of: (1) bias (systematic error), and (2) variance in measurements. Popular evaluation techniques only account for the variance due to sampling of experimental units, and assume the other sources of uncertainty can be ignored. For example, only the uncertainty due to sampling of topics (queries) and sampling of training:test datasets is considered in standard information retrieval (IR) and classifier system evaluation respectively. However, incomplete relevance judgements, assessor disagreement, non-deterministic systems, and the measurement bias can also cause uncertainty in these experiments. In this thesis, the impact of other sources of uncertainty on evaluating IR and classification experiments are investigated. The uncertainty due to:(1) incomplete relevance judgements in IR test collections,(2) non-determinism in IR systems / classifiers, and (3) high variance of classifiers is analysed using case studies from distributed information retrieval and information security. The thesis illustrates the importance of reducing and accurately accounting for uncertainty when evaluating complex IR and classifier systems. Novel techniques to(1) reduce uncertainty due to test collection bias in IR evaluation and high classifier variance (overfitting) in detecting drive-by download attacks,(2) account for multidimensional variance due to sampling of IR systems instances from non-deterministic IR systems in addition to sampling of topics, and (3) account for repeated measurements due to non-deterministic classification algorithms are introduced

Statistical comparisons of non-deterministic IR systems using two dimensional variance

Retrieval systems with non-deterministic output are widely used in information retrieval. Common examples include sampling, approximation algorithms, or interactive user input. The effectiveness of such systems differs not just for different topics, but also for different instances of the system. The inherent variance presents a dilemma - What is the best way to measure the effectiveness of a non-deterministic IR system? Existing approaches to IR evaluation do not consider this problem, or the potential impact on statistical significance. In this paper, we explore how such variance can affect system comparisons, and propose an evaluation framework and methodologies capable of doing this comparison. Using the context of distributed information retrieval as a case study for our investigation, we show that the approaches provide a consistent and reliable methodology to compare the effectiveness of a non-deterministic system with a deterministic or another non-deterministic system. In addition, we present a statistical best-practice that can be used to safely show how a non-deterministic IR system has equivalent effectiveness to another IR system, and how to avoid the common pitfall of misusing a lack of significance as a proof that two systems have equivalent effectiveness