Scalable Hierarchical Gaussian Process Models for Regression and Pattern Classification

Gaussian processes, which are distributions over functions, are powerful nonparametric tools for the two major machine learning tasks: regression and classification. Both tasks are concerned with learning input-output mappings from example input-output pairs. In Gaussian process (GP) regression and classification, such mappings are modeled by Gaussian processes. In GP regression, the likelihood is Gaussian for continuous outputs, and hence closed-form solutions for prediction and model selection can be obtained. In GP classification, the likelihood is non-Gaussian for discrete/categorical outputs, and hence closed-form solutions are not available, and approximate inference methods must be resorted

Downscaling Aerosol Optical Thickness from Satellite Observations: Physics and Machine Learning Approaches

In recent years, the satellite observation of aerosol properties has been greatly improved. As a result, the derivation of Aerosol Optical Thickness (AOT), one of the most popular atmospheric parameters used in air pollution monitoring, over ocean and continents from satellite observations shows comparable quality to ground-based measurements. Satellite AOT products is often applied for monitoring at global scale because of its coarse spatial resolution. However, monitoring at local scale such as over cities requires more detailed AOT information. The increase spatial resolution to suitable level has potential for applications of air pollution monitoring at global-to-local scale, detecting emission sources, deciding pollution management strategies, localizing aerosol estimation, etc. In this thesis, we investigated, proposed, implemented and validated algorithms to derive AOT maps with spatial resolution increased up to 1×1 km2 from MODerate resolution Imaging Spectrometer (MODIS) observations provided by National Aeronautics and Space Administration (NASA), while MODIS standard aerosol products provide maps at 10×10 km2 of spatial resolution. The solutions are considered on two perspectives: dynamical downscaling by improving the algorithm for remote sensing of tropospheric aerosol from MODIS and statistical downscaling using Support Vector Regression

Desarrollo de la presión del sujetador: Sistema de medición con aire y sensor de presión

Introduction: This paper is the result of the research “Development of bra pressure measuring system using air pressure sensor” developed in the Ha Noi University of Science and Technology in 2019.  Proplem: The pressure of the bra on the human body affects the comfort of the wearer and the wearer's health. Therefore, bra pressure is one of the most important parameters taken into account when designing and manufacturing bras. Objective: To determine the pressure value of a bra, it is necessary to use a suitable pressure measuring device. Methodology: The device operates on the principle of resitive gas pressure sensor, with 8 measuring channels. The system is controlled by the computer via programming software in the Visual C language, measuring the pressure of the shirt on the position on the curved surface of the human body. Pressure values ​​and timed charts are displayed on the computer. The measuring device was tested with GE Druck DPI 610 pressure generator.  Results: Test results showed that the device has a sensitivity of 0.01 kPa, measuring range from 0.1to 10 kPa and an accuracy of 0.01 kPa. Conclusion: This measurement system is important for objectively assessing the pressure of the bra on the wearer.  Originality: This paper presents the results of research and design of the PB228 system when measuring the pressure of the bra on the wearer's body in static, dynamic and static-dynamic combined states.  Limitations: The accuracy of the device only applies in standard condition

A Study of Asparagus Preservation Capacity of Chitosan-Alginate and Chitosan-Carrageenan Biofilms

Fresh postharvest green asparagus rapidly deteriorate due to its senescence process and high transpiration rate. This thesis aims to utilize the available sources of carrageenan and alginate for combining with pure chitosan coating solution, thus create a new multi-component coating that can overcome the limitations of pure chitosan coating, and show more effective in maintaining the quality of postharvest green asparagus. The gel solution ratio 2:1 (v/v) of chitosan 1% (w/v) and alginate 0.2% (w/v), had ability to prolong shelf-life of asparagus for 3 days (from weight loss point of view) and 7 days (from visual quality point of view) compared to control sample. The weight loss was less than about 12% and also ensured lower firmness change, maintained higher chlorophyll content, exhibiting better quality of asparagus compared to control and chitosan coated sample. The chitosan-alginate (2:1 v/v) coated asparagus achieved highest sensory score in day 7 and 14 of storage and lowest total aerobic growth in 14 days of storage at 4 ºC. The coating biofilm of chitosan-alginate could be considered as the new multi-component edible coating which showed high effectiveness in quality preservation and shelf-life extension of asparagus

Pre-treatment potential of electro-coagulation process using aluminum and titanium electrodes for instant coffee processing wastewater

This study aimed at investigating the potential of electrocoagulation (EC) process using Al-Al and Al-Ti electrodes for the pre-treatment of instant coffee processing wastewater. Effects of various operating conditions, including cell voltage, time of treatment, inter-electrode distance, pH of solution, solution conductivity and agitation speed on the removals of chemical oxygen demand (COD) and color were considered. The maximum removal of COD and color was achieved at 87% and 99%, respectively, corresponding to COD and color in the effluents of 359-384 mg/L and 58-101 Pt-Co. Biodegradability of treated wastewater was significantly improved since BOD5/COD increased from initial value of 0.42 to 0.65 after treatment. Nether mixing nor adding of electrolyte was recommended. Moreover, the COD removal kinetics during EC process appeared to follow the first-order kinetic model. The operating costs were also determined as a reference for cost assessment of the treatment

ADSORPTION OF MERCURIC ION FROM AQUEOUS SOLUTIONS USING MODIFIED FLY ASH

In this study, fly ash was treated with NaOH solution (FAN) before modifying with (3-mercaptopropyl) triethoxysilane - MPTMS (FAMPS). By using FTIR, FESEM, XRD, EDX, and BET techniques, the change in structure, composition and morphology of FAN and FAMPS was evaluated. The FTIR spectra of FAN and FAMPS showed that there is no chemical reaction between the MPTMS and FAN. After modification, the FAMPS has a rough surface with composition difference from the FAN. Mercuric ion adsorption behavior as well as adsorptionisotherm models (Langmuir and Freundlich) of the FAN and FAMPS were also investigated and discussed. Thanks to FAN modification, the mercuric ion removal percent of the FAMPS was higher than that of the FAN. Owing to the adsorption data, Freundlich isotherm modelwas fitted for the mercuric ion adsorption process

Selection of suitable fragment from rbcL gene for DNA barcode analysis of family Halymeniaceae, Rhodophyta

Among the members of Halymeniaceae family, Grateloupia sensu lato occupies the largest composition in species. Classification based on morphological traits is difficult due to the highly variable terete to blade-like thalli among the members of this genus that usually leads to misidentification. Molecular systematics has been applied to classify Grateloupia sensu lato so that the taxonomists acquire a better understanding of the species diversity in general. The plastid gene encoding the large subunit of ribulose-1,5-bisphosphate-carboxylase-oxygenase (rbcL) was the focus of numerous marine algal studies concerning phylogeny and molecular evolution. However, using the full length of rbcL showed disadvantages such as cost and time consuming due to two times of sequencing and two times of PCR. In the present study, the shorter sequence, fragment 773 bp at 5’ end and fragment 579 bp at 3’ end of rbcL were applied and compared for the phylogenetic analysis of Halymeniaceae members. The results indicated there are no differences of topological phylogenetic trees, species resolution within genus and genus resolution within the family between fragment 773 bp at 5’ and the full length of rbcL. Therefore, we conclude that fragment 773 bp at 5’ should be used as DNA barcodes for the Halymeniaceae to reduce the cost and time during phylogenetic analysis. Two taxa Grateloupia newly collected in Vietnam were grouped to the known Phyllymenia, a new genus in Vietnam

Antibacterial activities of the extracts of Mimosa pudica L. an in-vitro study

Mimosa pudica L., also called sensitive plant or touch-me-not, belongs to the genus Mimosa (Family: Mimosaceae). This plant grows as a weed in nearly every parts of Vietnam and is used as a traditional medicine for the treatment of some diseases. This study aims to evaluate the antibacterial activity of the water and ethanol extracts of this plant by using disc diffusion method. The total flavonoid as quercetin equivalent (QE) per gram (dry weight) of these two extracts was also estimated. The result of tests for in-vitro antibacterial activity indicates that the ethanol extract showed significant activity against E.coli, S.aureus, B.subtilis and S.typhi with the zone of inhibition was 11mm, 19mm, 17mm and 16mm respectively. The water extract only inhibited the growth of S.aureus (14mm) and B.subtilis (15mm) and there was no resistance against E.coli and S.typhi. The analysis of total flavonoid content found that the ethanol extract contains higher amount of flavonoid than water extract and flavonoid is responsible mainly for the antibacterial activity of Mimosa pudica L

Level of Factors impact on the Buyers’ Intention in Buying Private Health Insurance with the Case of Vietnam Non-Life Insurance Companies

The study aims to determine the influence of factors affecting the intention to purchase private health insurance at non-life insurance companies in Vietnam. The samples were surveyed from 500 people from many areas but mostly in Hanoi. The study identified and clarified 5 independent factors affecting the intention to buy private health insurance at non-life health insurance companies in Vietnam. The analysis results show 5 variables: "Past experience", "Perception of service quality of insurance companies", "Perceived behavioral control", "Attitude towards risks and private health insurance ", and the variable "Subjective norms on private health insurance" affect people's intention to buy private health insurance. Several policies have been proposed to increase customers' intention to buy private health insurance at non-life insurance companies from the analysis. To raise customer's intention to purchase private health insurance, the research team recommends non-life insurance company to improve service quality, especially after-sales service, the quality and expertise of staff, and the government to complete policies and legal framework on private health insurance. Moreover, the research team also recommend to renovate the quality of organizing the private health insurance regime and form the basis of the entire population pathology record. Keywords: private health insurance, intention to purchase, non-life insurance company. DOI: 10.7176/EJBM/12-27-06 Publication date:September 30th 202