Monthly and Diurnal Variability of Rain Rate and Rain Attenuation during the Monsoon Period in Malaysia

Rain is the major source of attenuation for microwave propagation above 10 GHz. In tropical and equatorial regions where the rain intensity is higher, designing a terrestrial and earth-to-satellite microwave links is very critical and challenging at these frequencies. This paper presents the preliminary results of rain effects in a 23 GHz terrestrial point-to-point communication link 1.3km long. The experimental test bed had been set up at Skudai, Johor Bahru, Malaysia. In this area, a monsoon equatorial climate prevails and the rainfall rate can reach values well above 100mm/h with significant monthly and diurnal variability. Hence, it is necessary to implement a mitigation technique for maintaining an adequate radio link performance for the action of very heavy rain. Since we now know that the ULPC (Up Link Power Control) cannot guarantee the desired performance, a solution based on frequency band diversity is proposed in this paper. Here, a secondary radio link operating in a frequency not affected by rain (C band for instance) is placed parallel with the main link. Under no rain or light rain conditions, the secondary link carries without priority radio signals. When there is an outage of the main link due to rain, the secondary link assumes the priority traffic. The outcome of the research shows a solution for higher operating frequencies during rainy events

Melanoma Skin Cancer and Nevus Mole Classification using Intensity Value Estimation with Convolutional Neural Network

Melanoma skin cancer is one of the most dangerous and life-threatening cancer. Exposure to ultraviolet rays may damage the skin cell's DNA, which causes melanoma skin cancer. However, it is difficult to detect and classify melanoma and nevus mole at the immature stages. In this work, an automatic deep learning system is developed based on the intensity value estimation with a convolutional neural network model (CNN) to detect and classify melanoma and nevus mole more accurately. Since intensity levels are the most distinctive features for object or region of interest identification, the high-intensity pixel values are selected from the extracted lesion images. Incorporating those high-intensity features into the CNN improves the overall performance of the proposed model than the state-of-the-art methods for detecting melanoma skin cancer. To evaluate the system, we used 5-fold cross-validation. Experimental results show that a superior percentage of accuracy (92.58%), sensitivity (93.76%), specificity (91.56%), and precision (90.68%) are achieved.Comment: The paper has been accepted for publication in Computer Science journal: http://journals.agh.edu.pl/csc

Pavement maintenance procedures with and without milling materials

AbstractThis study evaluates maintenance treatment followed by different Districts of New Mexico Department of Transportation (NMDOT). In addition, two case studies on the use of old pavement materials, called the “millings”, in maintenance projects are reported. Based on this study, it is observed that none of the Districts have a written procedure for maintenance work. Rather Districts rely on the experience of the maintenance crew for conducting maintenance projects. All Districts prefer to use chip seal for maintenance irrespective of distress conditions of the pavements. Patching and crack sealing are usually done before chip sealing to extend the life of the chip seals. Sand seal, scrub seal, and slurry seal projects are not done by District maintenance crews but by outside contractors. It is also observed that all Districts are interested in using millings in maintenance projects and most have already used millings in at least one maintenance project with some success and failure. Most of the Districts have used coarse fraction of millings in chip seal projects successfully. However, they failed to find a proper way to process the fine fractions of millings. Case Study I shows that fine millings can be used to construct thin overlay when mixed with emulsion in pug mill or hot drums. Case Study II concludes that fine millings can be used as fine/sand seal successfully following the same procedure and using the same equipment as chip seal

Inferences in longitudinal multinomial fixed and mixed models

Analyzing categorical data collected over time is an important research topic. Even though there exists numerous studies on analysis of categorical data in cross sectional setup, the analysis of this type of data in the longitudinal setup is, however, not adequately addressed. In this thesis, we develop two correlation models for multinomial (> 2 categories) longitudinal data, namely, a conditional linear probability based model and a non-linear logistic probability based model; and provide likelihood inferences for category effects, fixed covariate effects and correlations or dynamic dependence parameters. The inferences are done for both complete history and contingency tables based data. For the history based data, the thesis also models the influences of individual random effects in addition to the fixed covariate effects. Furthermore, as in many practical situations the number of individuals involved in the study may be small, in the thesis, we have examined the finite sample performance of the likelihood estimates both in fixed and mixed model setups

Zero Truncated Bivariate Poisson Model: Marginal-Conditional Modeling Approach with an Application to Traffic Accident Data

Abstract A new covariate dependent zero-truncated bivariate Poisson model is proposed in this paper employing generalized linear model. A marginal-conditional approach is used to show the bivariate model. The proposed model with estimation procedure and tests for goodness-of-fit and under (or over) dispersion are shown and applied to road safety data. Two correlated outcome variables considered in this study are number of cars involved in an accident and number of casualties for given number of cars

EXPERIMENTAL ANALYSIS ON THE PHOTOVOLTAICTHERMAL SOLAR COLLECTOR WITH COMPOUND PARABOLIC CONCENTRATOR USING PHASE CHANGE MATERIAL-TOWARDS SOLAR ENERGY UTILIZATION

In this study, the performance of a photovoltaic-thermal solar collector with compound parabolic collector for clear day in winter and summer season was investigated. Phase change material storage unit, compound parabolic collector unit, photovoltaic thermal unit were integrated into one piece to reduce the area to get higher performance and better concentration ratio. The performance of water flow rate, heat removal factor, amount of energy storage of the collector in winter season and comparison of temperature variation, total generated energy, performance factor in summer season by varying different parameters were evaluated. Water flow rate increases up to 0.004 kg/s corresponding to the thermal efficiency of around 42%. Heat removal factor for thermal collector was in the range of 0.94-0.96, which indicates better energy gain of the system and effective outlet water temperature was found 55 0C in winter season. The total generated thermal energy 1500W and maximum performance factor of a collector was 0.0135 kW-1m2 in summer season. Finally total efficiency of a collector varies from 58% -68% in summer season

Genome wide association mapping of grain arsenic, copper, molybdenum and zinc in rice (Oryza sativa L.) grown at four international field sites

Peer reviewedPublisher PD

Rice grain cadmium concentrations in the global supply-chain

One of cadmium’s major exposure routes to humans is through rice consumption. The concentrations of cadmium in the global polished (white), market rice supply-chain were assessed in 2270 samples, purchased from retailers across 32 countries, encompassing 6 continents. It was found on a global basis that East Africa had the lowest cadmium with a median for both Malawi and Tanzania at 4.9 μg/kg, an order of magnitude lower than the highest country, China with a median at 69.3 μg/kg. The Americas were typically low in cadmium, but the Indian sub-continent was universally elevated. In particular certain regions of Bangladesh had high cadmium, that when combined with the high daily consumption rate of rice of that country, leads to high cadmium exposures. Concentrations of cadmium were compared to the European Standard for polished rice of 200 μg/kg and 5% of the global supply-chain exceeded this threshold. For the stricter standard of 40 μg/kg for processed infant foods, for which rice can comprise up to 100% by composition (such as rice porridges, puffed rice cereal and cakes), 25% of rice would not be suitable for making pure rice baby foods. Given that rice is also elevated in inorganic arsenic, the only region of the world where both inorganic arsenic and cadmium were low in grain was East Africa