ASSISTments

This project focuses on two main purposes. The contents in Skill Builder along with problem sets from Electronix Tutor and AutoTutor are constructed in a way that student will be assigned randomly to either Skill Builder or AutoTutor only or an arbitrary combination of these two sources. The second purpose is to compare the effectiveness of the order of the problem sets. A study is then conducted using the problem sets from Skill Builder and external sources such as BBN’s Electronix Tutor and Auto Tutor. For each problem sets, students will be randomly assigned different order of the problems. Analysis from the collected data will help determine which order of the problem sets is more efficient method to improve trainees’ process of mastering a skill

Smart Home System

This project involves the design and implementation of a Smart Home system using IoT solutions. Three types of sensors, namely an occupancy sensor, a light sensor and a temperature sensor, along with a security camera are used and incorporated with a microcontroller in a master/slave architecture via Zigbee, a short-range network communication. The data collected from these sensors is transmitted to a cloud-based platform through Wi-Fi for analyzing and downloading to personal smartphones via a designated user interface. The entire system can be controlled both by users’ smartphones and by personal computers

Determinants Influencing Liquidity of Listed Steel Firms in Vietnam

This study is conducted to investigate the impact levels of determinants influencing liquidity of listed steel firms on Vietnam Stock Exchange. Data were collected from audited financial statements of 25 listed food processing firms from 2014 to 2017. This research employs the least squares method (OLS) and tests to determine the influence of factors on the liquidity of listed sample firms. The results indicate that return on assets (ROA), operating period (AGE) and asset structure (AS) have positive impacts on the liquidity. In contrast, the firm size and debt ratio has the opposite effects. Based on the findings, a number of recommendations are proposed to increase the liquidity ratio of listed firms in the future. Keywords: Liquidity, steel firms, determinants, Vietnam Stock Exchange DOI: 10.7176/EJBM/11-7-10 Publication date:March 31st 201

Hardware Architectures of Visible Light Communication Transmitter and Receiver for Beacon-based Indoor Positioning Systems

High-speed applications of Visible Light Communications have been presented recently in which response times of photodiode-based VLC receivers are critical points. Typical VLC receiver routines, such as soft-decoding of run-length limited (RLL) codes and FEC codes was purely processed on embedded firmware, and potentially cause bottleneck at the receiver. To speed up the performance of receivers, ASIC-based VLC receiver could be the solution. Unfortunately, recent works on soft-decoding of RLL and FEC have shown that they are bulky and time-consuming computations. This causes hardware implementation of VLC receivers becomes heavy and unrealistic. In this paper, we introduce a compact Polar-code-based VLC receivers. in which flicker mitigation of the system can be guaranteed even without RLL codes. In particular, we utilized the centralized bit-probability distribution of a pre-scrambler and a Polar encoder to create a non-RLL flicker mitigation solution. At the receiver, a 3-bit soft-decision filter was implemented to analyze signals received from the VLC channel to extract log-likelihood ratio (LLR) values and feed them to the Polar decoder. Therefore, the proposed receiver could exploit the soft-decoding of the Polar decoder to improve the error-correction performance of the system. Due to the non-RLL characteristic, the receiver has a preeminent code-rate and a reduced complexity compared with RLL-based receivers. We present the proposed VLC receiver along with a novel very-large-scale integration (VLSI) architecture, and a synthesis of our design using FPGA/ASIC synthesis tools

Modeling labor productivity in high-rise building construction projects using neural networks

Labor productivity in building construction has long been a focused research topic due to the high contribution of labor cost in the building total costs. This study, among a few studies that used scaled data that were collected directly from measuring equipment and onsite activities, utilized neural networks to model the productivity of two main construction tasks and influencing factors. The neural networks show their ability to predict the behaviors of labor productivity of the formwork and rebar tasks in a test case of a high-rise building. A multilayer perceptron that had two layers and used sigmoid as its activation function provided the best effectiveness in predicting the relations among data. Among eleven independent factors, weather (e.g., temperature, precipitation, sun) generally played the most important role while crew factors were distributed in the mid of the ranking and the site factor (working floor height) played a mild role. This study confirms the robustness of neural networks in productivity research problems and the importance of working environments to labor productivity in building construction. Managerial implications, including careful environmental factors and crew structure deliberation, evolved from the study when labor productivity improvement is considered

A DSC/TGA STUDY OF THE HETEROGENEOUS NUCLEATION OF CRYSTALLIZATION IN POLYPROPYLENE COPOLYMER

The study is aimed at the evaluation of the influence of nucleating agent (t-butyl)benzoic aluminum (NA) in changing clarity, crystallization temperature (Tp) and radiation resistant properties of polypropylene copolymer, PP (co) with 6% of ethylene. It has been shown that crystallization temperature of PP (co)+NA did not change when the content of the NA less than 2%, but the super cooling temperature is a little bit increased when the content of the NA was 2 or higher than 2%. Clarity of the blend comprising of PP (co)+NA decreases with the addition of 2% or more NA (t-butyl)benzoic aluminum. However, the increase of the supercooling temperature makes possible to improve radiation resistance of the material

Carrageenophyte-attached and planktonic bacterial communities in two distinct bays of Vietnam: Eutrophication indicators and insights on ice-ice disease

The composition of the bacterial community of carrageenophyte-attached and planktonic bacteria was studied in two bays of Vietnam with contrasting anthropogenic inputs to assess their role as ecological indicators. Clear differences (~73% dissimilarity) between carrageenophyte-attached bacteria and bacterioplankton were detected in terms of genus composition: mainly Agaribacter, Ruegeria, Alteromonas, the Pir4 lineage and Vibrio for the carrageenophytes and Candidatus Actinomarina, HIMB 11, NS groups and SAR clades for the bacterioplankton. The copiotrophic nature, potential for complex-polymer degradation, and ability to form and defend biofilms were common features inferred for the carrageenophyte-attached microbiome. Significant differences between the bays were detected in the concentration of most inorganic nutrients. More eutrophic conditions and presumptive wastewater pollution in Cam Ranh (CR) bay were primarily indicated by the dominance of Rubripirellula, Leptobacterium, Hypnocyclicus and Porphyrobacter and their correlations with phosphate. In terms of bacterioplankton, the influence of intensive aquaculture in CR bay was suggested by the dominance of the NS5 and NS4 marine groups, the SUP05 cluster, Flavobacteriaceae unclassified and SAR 11 clade III as well as their strong correlations with ammonium and phosphate. The link between silicate and other inorganic nutrients suggests freshwater input in CR bay. Arenicellaceae unclassified and Formosa were also potential indicators of eutrophication. Operational taxonomic units (OTUs) of Marinagarivorans, Cobetia, Vibrio, Alteromonas and Pseudoalteromonas were typical of the carrageenophytes showing ice-ice disease symptoms. Vibrio and Alteromonas were also common among healthy macroalgae, and differences at the OTU level suggested potential succession of species from the healthy to the diseased state. The probable beneficial roles of some bacteria, such as Ruegeria, Cutibacterium and unidentified members of the family Rhizobiaceae, were discussed. This study provides pioneering insights into the bacterial community composition of carrageenophytes and highlights their ecological value as strong indicators of the sources of organic matter, anthropogenic impacts and health status of marine systems.Fil: Kopprio, Germán Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Leibniz - Institute of Freshwater Ecology and Inland Fisheries; Alemania. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; VietnamFil: Cuong, Le Huu. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; Vietnam. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; VietnamFil: Luyen, Nguyen Dinh. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; Vietnam. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; VietnamFil: Duc, Tran Mai. Vietnam Academy of Science and Technology. Nhatrang Institute of Technology Research and Application; VietnamFil: Ha, Tran Hong. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; VietnamFil: Huong, Le Mai. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; Vietnam. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; VietnamFil: Gärdes, Astrid. Leibniz - Institute of Freshwater Ecology and Inland Fisheries; Alemania. University of Applied Sciences; Alemania. Alfred-Wegener-Institut. Helmholtz-Zentrum für Polar und Meeresforschung; Alemani