The Meeting of Acquaintances: A Cost-efficient Authentication Scheme for Light-weight Objects with Transient Trust Level and Plurality Approach

Wireless sensor networks consist of a large number of distributed sensor nodes so that potential risks are becoming more and more unpredictable. The new entrants pose the potential risks when they move into the secure zone. To build a door wall that provides safe and secured for the system, many recent research works applied the initial authentication process. However, the majority of the previous articles only focused on the Central Authority (CA) since this leads to an increase in the computation cost and energy consumption for the specific cases on the Internet of Things (IoT). Hence, in this article, we will lessen the importance of these third parties through proposing an enhanced authentication mechanism that includes key management and evaluation based on the past interactions to assist the objects joining a secured area without any nearby CA. We refer to a mobility dataset from CRAWDAD collected at the University Politehnica of Bucharest and rebuild into a new random dataset larger than the old one. The new one is an input for a simulated authenticating algorithm to observe the communication cost and resource usage of devices. Our proposal helps the authenticating flexible, being strict with unknown devices into the secured zone. The threshold of maximum friends can modify based on the optimization of the symmetric-key algorithm to diminish communication costs (our experimental results compare to previous schemes less than 2000 bits) and raise flexibility in resource-constrained environments.Comment: 27 page

Total flow of N and P in Vietnam urban wastes

The amount of organic matters, N and P, is quite significant in urban wastes, especially in wastewater and solid wastes. It was found from this study that their production was about 302,241 ton of TN/day and 54,682 ton of TP/day. During the urbanization and industrialization, these numbers continue to increase. These nutrient matters can be used in agriculture as well as in other practices. Nevertheless, they will become pollutants when being discharged to surrounding environment (rivers, lakes, etc.) as they cause water eutrophication and increase risks for water supply

A Conflict Model of Stagflation

This paper introduces a Lotka-Volterra-Goodwin model to study inflation and unemployment in the context of the distributional conflict between labor and capital. It was shown that the 1960-81 period was marked by a positively-sloped, long-run Phillips curve which first rose only slightly but became steeper later on. The stagflation phenomenon was attributed to the dominance of the wage-push over the profit-push. It was found that during 1970s workers' expectations and demands for higher wages and living standards greatly exceeded the paying capacity of the economy which was already severely limited by the supply shocks.

Potential reuse of coal mine wastewater: a case study in Quang Ninh, Vietnam

In Vietnam, the local regulation and environmental impact are driving coal mining industry to reuse the large volume of wastewater it produces. The co-research project between National University of Civil Engineering (NUCE) and Mitsubishi Rayon Corporation (MRC) has started early 2013 to evaluate if the MRC membranes could be a great tool for treatment of coal mine wastewater for reuse. The experiment were conducted at one of coal mine plants in Quang Ninh province, Vietnam. It was found that pre-treatment of coal mine wastewater was an important part in the treatment process. The MRC membrane was a significant barrier to maintain stable and high quality effluent to meet the requirement of Vietnam national technical standard for domestic use

Employment opportunities for Vietnamese American fisherfolk affected by the BP gulf oil spill in Louisiana

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 63-65).This thesis explores potential employment opportunities in energy efficiency construction and aquaculture for Vietnamese American fisherfolk significantly impacted by the BP oil spill in Louisiana. First, the thesis explains the history of the Vietnamese American community in Louisiana and the affects of Hurricane Katrina as well as the BP oil spill on the community. This is done in order to build the case for the need to look for alternative employment for dislocated Vietnamese American fisherfolk. Second, it assesses the skills and job suitability for Vietnamese American dislocated fisherfolk. It then explores the potential growth of the energy efficiency construction and aquaculture industries in Louisiana. Finally, the thesis concludes with recommendations for how Vietnamese American fisherfolk can enter these industries and how Mary Queen of Vietnam Community Development Corporation can further explore future employment opportunities for dislocated Vietnamese American fisherfolk.by Mai T. Dang.M.C.P

Synthesis and Characterization of β-Cyclodextrin/alginate Nanoparticle as a Novel Drug Delivery System

The aim of this work was to study a novel nanoparticle system formed from alginate and β-cyclodextrin by ionotropic gelation method and to evaluate their potential for the association and delivery of drugs. The nanoparticles were prepared by electrostatic interactions between Ca2+/alginate gel and β-cyclodextrin. Morphology and structure characterization of nanoparticles was investigated by scanning electron micrographs (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FTIR). The nanoparticle size was about 50 – 80 nm and their structure quite regular and consistent. Ketoprofen, chosen as a model drug, was incorporated into the nanocarriers with association efficiency of 50.7 % and loading efficiency of 5.7 %. Ketoprofen released from the nanoparticles was 57 % at pH 7.4 and 69 % at pH 5.0 for 4 h

From the factory to the field: considerations of product characteristics for insecticide-treated net (ITN) bioefficacy testing

BACKGROUND: Insecticide-treated nets (ITNs) undergo a series of tests to obtain listing by World Health Organization (WHO) Prequalification. These tests characterize the bioefficacy, physical and chemical properties of the ITN. ITN procurers assume that product specifications relate to product performance. Here, ITN test methods and their underlying assumptions are discussed from the perspective of the ITN manufacturing process and product characteristics. METHODS: Data were extracted from WHO Pesticide Evaluation Scheme (WHOPES) meeting reports from 2003 to 2017, supplemented with additional chemical analysis to critically evaluate ITNs bioassays with a focus on sampling, washing and wash resistance, and bioefficacy testing. Production methods for ITNs and their impact on testing outcomes are described. RESULTS AND RECOMMENDATIONS: ITNs are not homogenous products. They vary within panels and between the sides and the roof. Running tests of wash resistance using a before/after tests on the same sample or band within a net reduces test variability. As mosquitoes frequently interact with ITN roofs, additional sampling of the roof when evaluating ITNs is advisable because in nets where roof and sides are of the same material, the contribution of roof sample (20-25%) to the average is less than the tolerance for the specification (25%). Mosquito mortality data cannot be reliably used to evaluate net surface concentration to determine regeneration time (RT) and resistance to washing as nets may regenerate beyond the insecticide concentrations needed to kill 100% of susceptible mosquitoes. Chemical assays to quantify surface concentration are needed. The Wash Resistance Index (WRI) averaged over the first four washes is only informative if the product has a log linear loss rate of insecticide. Using a WRI that excludes the first wash off gives more reliable results. Storage conditions used for product specifications are lower than those encountered under product shipping and storage that may exceed 50 degrees C, and should be reconsidered. Operational monitoring of new ITNs and linking observed product performance, such as bioefficacy after 2 or 3 years of use, with product characteristics, such as WRI, will aid the development of more robust test methods and product specifications for new products coming to market