Extended network and algorithm finding maximal flows

Graph is a powerful mathematical tool applied in many fields as transportation, communication, informatics, economy, In ordinary graph the weights of edges and vertexes are considered independently where the length of a path is the sum of weights of the edges and the vertexes on this path. However, in many practical problems, weights at a vertex are not the same for all paths passing this vertex, but depend on coming and leaving edges. The paper develops a model of extended network that can be applied to modelling many practical problems more exactly and effectively. The main contribution of this paper is algorithm finding maximal flows on extended networks

Behavior of monolithic prestressed concrete slab track at highway-railway grade crossings

Highway-railway grade crossings are an important part of the transportation system. It allows two types of vehicles to operate in the same areas. Researchers have previously studied the grade crossings, but research on the monolithic prestressed concrete slab (PSCS) track at grade crossings for 1,000mm gauge is limited. At present, there are many types of grade crossing structures that are using in Vietnam. However, these structures still have many disadvantages in the operation process. A new structure type of grade crossing for PSCS is proposed to apply for the 1,000 mm gauge to overcome the main disadvantages of existing structural types. This paper presents test production and experimental measurements to analyze the behavior of PSCS. Test samples of monolithic PSCS were produced in factory. Measurement experiments were conducted in the laboratory. The results of the manufacturing and testing process presented in this paper show that this structure completely meets the criteria of stability and durability under the effect of test loads

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

Discovering Water Quality Changes and Patterns of the Endangered Thi Vai Estuary in Southern Vietnam through Trend and Multivariate Analysis

Temporal and spatial water quality data are essential to evaluate human health risks. Understanding the interlinking variations between water quality and socio-economic development is the key for integrated pollution management. In this study, we applied several multivariate approaches, including trend analysis, cluster analysis, and principal component analysis, to a 15-year dataset of water quality monitoring (1999 to 2013) in the Thi Vai estuary, Southern Vietnam. We discovered a rapid improvement for most of the considered water quality parameters (e.g., DO, NH4, and BOD) by step trend analysis, after the pollution abatement in 2008. Nevertheless, the nitrate concentration increased significantly at the upper and middle parts and decreased at the lower part of the estuary. Principal component (PC) analysis indicates that nowadays the water quality of the Thi Vai is influenced by point and diffuse pollution. The first PC represents soil erosion and stormwater loads in the catchment (TSS, PO4, and Fetotal); the second PC (DO, NO2, and NO3) determines the influence of DO on nitrification and denitrification; and the third PC (pH and NH4) determines point source pollution and dilution by seawater. Therefore, this study demonstrated the need for stricter pollution abatement strategies to restore and to manage the water quality of the Thi Vai Estuary

Determinants Influencing Accounting Quality of Transportation Service Firms

The study aimed to determine what determinants influencing the accounting of transportation service firms working the area of Da Nang of Vietnam. A study model was developed, investigated and analyzed with the involvement of 250 transportation service firms in Da Nang. The results show five determinants influencing the accounting works including industry characteristics; legal guidance; material facilities for accounting; interest in accounting of business owners; accountants’ qualifications. Among them, the two most important determinants influencing the quality of the accounting were legal guidance and interest in accounting of business owners. Based on the findings, some recommendations were made to improve the quality of accounting of transportation service firms. Keywords: Determinants, accounting, transportation services DOI: 10.7176/RJFA/11-4-08 Publication date: February 29th 202

Antibacterial, antioxidant and cytotoxic activities of different fractions of acetone extract from flowers of Dipterocarpus intricatus Dyer (Dipterocarpaceae)

This study has shown for the first time the antimicrobial, antioxidant and cytotoxicity of 3 fractions of acetone extract, including hexane, chloroform and ethyl acetate from flowers of Dipterocarpus intricatus. Antibacterial test using disc diffusion method showed that the chloroform and ethyl acetate fractions inhibited the growth of all the tested bacteria, including Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus and Staphylococcus aureus while the hexane fraction showed the antibacterial activity against B. cereus and S. enteritidis. Antioxidant activity and cancer cell resistance of those extracts were conducted using DPPH and MTT methods respectively. As a result, the DPPH radical scavenging activity of the hexane, chloroform and ethyl acetate fractions were determined with the IC50 values of 0.508, 0.22 and 0.075 mg/mL respectively while the cytotoxicity to HepG2 cell line of those fractions was 163.3 ppm, 106.7 ppm and 459.3 ppm. These results suggested the potential application of these fractions isolated from D. intricatus flowers as the natural antimicrobial, antioxidant and cytotoxic agents for medicine