Microplastics Contamination in a High Population Density Area of the Chao Phraya River, Bangkok

Microplastics (MPs) are distributed globally, including in aquatic environments. While a large number of studies on MPs in marine environments have been performed, few studies are available in freshwater environments. Therefore, the distribution of MPs in surface water and sediment from the Chao Phraya River at Tha Prachan, a high population density area of Bangkok, was investigated. Water samples were collected by a manta trawl with a net mesh size of 300 mm. Sediment samples were collected by a Van Veen grab sampler. The total number and concentration of MPs in the water samples were found to be 104 particles/m3 and 805.20 mg/m3, respectively. The dominant MPs were fragments, 0.5 to 1.0 mm in size, for the water samples. In the sediment, MPs were detected only in a size range of 0.053 to 0.5 mm with a total number and concentration of 2,290 particles/kg and 650 mg/kg, respectively. The presence of different types of MPs was confirmed by Fourier-transform infrared spectroscopy with a dominant abundance of polypropylene, polyethylene, and polystyrene. In brief, this study suggests that high levels of MPs occur not only in the water but also in the sediment of the Chao Phraya River at Tha Prachan area

Catholic Relief Services: Information and Communication Technology in Monitoring and Evaluation

In February 2015, Catholic Relief Services (CRS) Vietnam initiated a new project to support the reintegration and rehabilitation of survivors of accidents involving landmines and explosive remnants of war (ERW). With funding from the Office of Weapons Removal and Abatement in the U.S. Department of State’s Bureau of Political-Military Affairs (PM/WRA), CRS’ Access and Reintegration (A&R) project takes a comprehensive approach to serving the needs of 3,219 survivors of landmines and unexploded ordnance (UXO) in Quang Binh and Quang Tri provinces. Through collaboration with the Government of Vietnam’s provincial Department of Labor, Invalids and Social Affairs (DOLISA), CRS provides survivors with access to medical care, rehabilitation, and social and livelihood support services. The key to success has been establishing an effective and functional coordination system at the local level for referrals, strengthening a network of community-based workers, and supporting families to provide appropriate, home-based care and support. CRS’ A&R project creates a network of support that ensures increased access to comprehensive services for survivors and advances their reintegration into society. The A&R Project has established a model for scaling to six affected districts in the targeted provinces and beyond

Energy Efficiency and Privacy Protection in Cellular Networks

Smartphones have become an essential part of our society. The benefits of having an always present, highly capable device cannot be overstated. As more aspects of our life depend on our smartphones, it is more important than ever to ensure the availability of those devices. However, their big advantages also come with big risks. The fact that we have our smartphones with us all the time means that it is easier than ever to collect our information, sometimes without our consent. In this dissertation, we study the two pressing concerns in cellular communications: energy efficiency and privacy protection. We focus on LTE networks, the current most advanced global standard for cellular communications. In the first part of the dissertation, we study the energy efficiency problem from both device and network perspectives. From the device point of view, we introduce a new angle to address the battery life concern. We recognize that the value of battery for the users is not always the same, and that it depends on the user usage. We also identify, and show in real network, diversity of usage, the phenomenon that at any instant, there is a diverse distribution of smartphone usage among cellular users. We propose ``Battery Deposit Service'' (BDS), a cooperative system which makes use of device-to-device (D2D) communications underlaying cellular networks to provide energy sharing in the form of load sharing. We design BDS to take advantage of diversity of usage to maximize the utility of smartphone battery. We show that our system increases battery life of cellular users, at almost no cost to the rest of the network. BDS is designed to be compatible to LTE architecture. From the network point of view, we design an energy efficient D2D relay system underlaying LTE networks. We minimize transmission power of smartphones by considering relay selection, resource allocation and power control. The overall problem is prohibited due to its exponential search space. We develop a divide-and-conquer strategy which splits the overall problem into small sub-problems. We relate these sub-problems to well-studied graph theoretic problems, and take advantage of existing fast algorithms. We show that our algorithms meet the runtime requirement of real-time LTE operations. In the second part of the dissertation, we address a privacy concern in LTE networks. In particular, we show that user location can be leaked in current LTE paging architecture. We propose a mechanism based on signal processing to remedy this vulnerability. Our method makes use of physical layer identification, which are low-power tags embedded on the wireless waveform, to signal paging messages to user devices. We show that our method is stealthy and robust, and that it mitigates the aforementioned privacy issue

COMPUTER AIDED TAXI DISPATCHING. SPECIFICATION OF THE SYSTEM.

Taxi is one of the most important transporters in the public. However, how to make the taxi services more efficient in order to benefit not only taxi owners but also taxi drivers is one of the most interesting questions recently, especially when other competitors in this service are becoming more and more. In the current situation, there is no suggested service that drivers can rely on, which would recommend the highly possible pickup point that will most likely to have the customers at the particular time and location. At the moment, taxi drivers only believe in their routines to go to the station that is believed to have awaiting customers. Therefore, the idea of building a solution which can have a logical suggestion for drivers could be a promising project, that will satisfy not only taxi owners but also drivers and customers. The aim of the thesis is going to find a general solution in order to make the idea becoming real. Besides, some interesting topic such as the machine learning technique and neural network are also the main parts of the thesis as they were selected as the solution for the problem

Conceptual Lanchester-type Decapitation Warfare Modelling

Decapitation operation has existed for a long time in military history; however, it was notuntil March 2003 'decapitation attack' became a well known term in the mass media. This paperis based on the connotation of decapitation based on historical study and refines the term intomilitary strategic concept of decapitation strategy. Ideas derived from detailed studies onLanchester-type combat models are used to describe the effectiveness of conventional regularforces under decapitation warfare, which includes asymmetric, nonlinear, stand-off and specialoperation forces (SOF) operations. A conceptual model is presented to describe the effects ofthe decapitation strategy on the regular battlefield. With extensive coverage of operational factorssuch as robustness of forces, time difference between combats, undermining effects, breakpoints,attrition rates, total force level and force allocation, the model is suitable to analyse complexscenario with different types of military operations consisting of decapitation strategy. Anillustrative example is provided to demonstrate the application of the model. The conceptualmodel is built based on hypotheses, assumptions, and criteria. In the absence of historical data,no data analysis and parameter estimation are involved

White Matter, Gray Matter and Cerebrospinal Fluid Segmentation from Brain Magnetic Resonance Imaging Using Adaptive U-Net and Local Convolutional Neural Network

According to the World Alzheimer Report 2015, 46 million people are living with dementia in the world. The diagnosis of diseases helps doctors treating patients better. One of the signs of diseases is related to white matter, grey matter and cerebrospinal fluid. Therefore, the automatic segmentation of three tissues in brain imaging especially from magnetic resonance imaging (MRI) plays an important role in medical analysis. In this research, we proposed an effective approach to segment automatically these tissues in three-dimensional (3D) brain MRI. First, a deep learning model is used to segment the sure and unsure regions. In the unsure region, another deep learning model is used to classify each pixel. In the experiments, an adaptive U-net model is used to segment the sure and unsure regions, and the Local Convolutional Neural Network (CNN) model with multiple inputs is used to classify each pixel only in the unsure region. Our method was evaluated with a real image database, Internet Brain Segmentation Repository database, with 18 persons (IBSR 18) (https://www.nitrc.org/projects/ibsr) and compared with state of art methods being the results very promising

Magneto-transport properties of monolayer borophene in perpendicular magnetic field: influence of electron-phonon interaction

The magneto-transport properties of a borophene monolayer in a perpendicular magnetic field B are studied via calculating the conductivity tensor and resistance under electron-optical phonon interaction by using the linear response theory. Numerical results are obtained and discussed for some specific parameters. The magnetic field-dependent longitudinal conductivity shows the magneto-phonon resonance effect that describes the transition of electrons between Landau levels by absorbing/emitting an optical phonon. The Hall conductivity increases first and then decreases with the magnetic field strength. Also, the longitudinal resistance increases significantly with increasing temperature, which shows the metal behaviour of the material. Practically, the observed magneto-phonon resonance can be applied to experimentally determine some material parameters, such as the distance between Landau levels and the optical phonon energy

Impact of Agency Costs on Firm Performance: Evidence from Vietnam

An assumption in agency costs theory is that agency costs can exert a negative impact on firm performance. In this study, we examine the impact of agency costs on firm performance of Vietnamese listed companies. Our sample includes 736 companies in Vietnam during the period om 2010 to 2015. We find that agency costs exert a negative impact on firm performance. Our results are robust to alternative econometric models, including an instrumental variables technique and a system generalized method of moment model. In addition, we show that a debt instrument can be a useful tool to reduce the negative impact of agency costs on firm performance