Distributed optimisation for traffic management

This thesis reports on the development of a multi-agent approach to distributed traffic optimisation. In particular, I propose a solution to the dynamic traffic assignment problem in a decentralised manner and then I introduce the new infrastructurelessly decentralised traffic information system. By using this system, each vehicle agent is able to update the current traffic condition through vehicle-to-vehicle communication. For solving dynamic traffic assignment problem, I propose a novel completely decentralised multi-agent coordination algorithm, which is a synergy between dynamic distributed constraint optimisation problem (DynDCOP) algorithm and auction. Using this algorithm, vehicle agent is able to reduce its individual travel time as well as total travel time of overall system. This simulation is carried out in order to evaluate different traffic planning algorithms that include decentralised uncoordination, centralised coordination and decentralised coordination algorithms. Finally, the experimental results show that the performance of proposed decentalised coorindation algorithm is high in comparison to centralised coordination algorithm

Factors Influencing Online Booking Trial Decision in Ho Chi Minh City, Vietnam

Online booking has turned out to be increasingly prominent technique to offer travel items and is generally acknowledged in created nations. In spite of the fact that this idea has been presented in Vietnam for as long as couple of years, there are half of air tickets is sold online right now. There are different looks into directed concentrating on the elements affecting individuals aim to receive online booking. Be that as it may, there are relatively few explores concentrate on the aim to attempt online booking. This expectation to attempt is vital since individuals perfer to attempt initially, at that point they will assess their trial encounter, subsequently, embrace or reject web based booking innovation. In this manner, this exploration accentuates on discovering factors that impact individuals goal to attempt web based booking. The overview has been created in view of serious survey of literary works identified with web based booking, internet shopping, selection hypotheses, purchaser practices. The surveys have been conveyed and the information has been handled utilizing SEM-PLS to decide the connection between factors that impact Vietnamese expectation to attempt web based booking. Therefore, this exploration is required to have noteworthy commitment in both hypothesis and common sense. As far as hypothesis, this examination effectively proviced the model that exhibit the goal to attempt web based booking which is once in a while talked about in past explores. In term of common sense, this exploration gives a general bits of knowledge of Vietnamese online booker trademark for online travel organization working in Vietnam keeping in mind the end goal to enhance their business execution. Keywords: online booking trial, e-commerce trial, vietnam tourism industry, e-commerce, triability

WORK MOTIVATION AND PERFORMANCE OF ADMINISTRATORS IN SEDLECTED PRIVATE UNIVERSITIES OF HO CHI MINH CITY, VIETNAM

This article discusses the determination of the work motivation of administrators in selected private universities of Ho Chi Minh City, Viet Nam. It stresses the profile of the administrators, the impact of work motivation, the administrators’ perception of work motivation and performance, and the problems faced by the administrators. The findings of the study consist of personal professional profile of the administrators, the administrators’ perception of work motivation and performance, the impact of work motivation, the influence of work motivation on the profile of the administrators, the influence of the level of work motivation on the impact, and common problems encountered by the administrators. Based on the research findings and conclusions, some recommendations are forwarded.  Article visualizations

Biocompatible chitosan-functionalized upconverting nanocomposites

Simultaneous integration of photon emission and biocompatibility into nanoparticles is an interesting strategy to develop applications of advanced optical materials. In this work, we present the synthesis of biocompatible optical nanocomposites from the combination of near-infrared luminescent lanthanide nanoparticles and water-soluble chitosan. NaYF4:Yb,Er upconverting nanocrystal guests and water-soluble chitosan hosts are prepared and integrated together into biofunctional optical composites. The control of aqueous dissolution, gelation, assembly, and drying of NaYF4:Yb,Er nanocolloids and chitosan liquids allowed us to design novel optical structures of spongelike aerogels and beadlike microspheres. Well-defined shape and near-infrared response lead upconverting nanocrystals to serve as photon converters to couple with plasmonic gold (Au) nanoparticles. Biocompatible chitosan-stabilized Au/NaYF4:Yb,Er nanocomposites are prepared to show their potential use in biomedicine as we find them exhibiting a half-maximal effective concentration (EC50) of 0.58 mg mL–1 for chitosan-stabilized Au/NaYF4:Yb,Er nanorods versus 0.24 mg mL–1 for chitosan-stabilized NaYF4:Yb,Er after 24 h. As a result of their low cytotoxicity and upconverting response, these novel materials hold promise to be interesting for biomedicine, analytical sensing, and other applications

Secondary Network Throughput Optimization of NOMA Cognitive Radio Networks Under Power and Secure Constraints

Recently, the combination of cognitive radio networks with the nonorthogonal multiple access (NOMA) approach has emerged as a viable option for not only improving spectrum usage but also supporting large numbers of wireless communication connections. However, cognitive NOMA networks are unstable and vulnerable because multiple devices operate on the same frequency band. To overcome this drawback, many techniques have been proposed, such as optimal power allocation and interference cancellation. In this paper, we consider an approach by which the secondary transmitter (STx) is able to find the best licensed channel to send its confidential message to the secondary receivers (SRxs) by using the NOMA technique. To combat eavesdroppers and achieve reasonable performance, a power allocation policy that satisfies both the outage probability (OP) constraint of primary users and the security constraint of secondary users is optimized. The closed-form formulas for the OP at the primary base station and the leakage probability for the eavesdropper are obtained with imperfect channel state information. Furthermore, the throughput of the secondary network is analyzed to evaluate the system performance. Based on that, two algorithms (i.e., the continuous genetic algorithm (CGA) for CR NOMA (CGA-CRN) and particle swarm optimization (PSO) for CR NOMA (PSO-CRN)), are applied to optimize the throughput of the secondary network. These optimization algorithms guarantee not only the performance of the primary users but also the security constraints of the secondary users. Finally, simulations are presented to validate our research results and provide insights into how various factors affect system performance

Secondary Network Throughput Optimization of NOMA Cognitive Radio Networks Under Power and Secure Constraints

Recently, the combination of cognitive radio networks with the nonorthogonal multiple access (NOMA) approach has emerged as a viable option for not only improving spectrum usage but also supporting large numbers of wireless communication connections. However, cognitive NOMA networks are unstable and vulnerable because multiple devices operate on the same frequency band. To overcome this drawback, many techniques have been proposed, such as optimal power allocation and interference cancellation. In this paper, we consider an approach by which the secondary transmitter (STx) is able to find the best licensed channel to send its confidential message to the secondary receivers (SRxs) by using the NOMA technique. To combat eavesdroppers and achieve reasonable performance, a power allocation policy that satisfies both the outage probability (OP) constraint of primary users and the security constraint of secondary users is optimized. The closed-form formulas for the OP at the primary base station and the leakage probability for the eavesdropper are obtained with imperfect channel state information. Furthermore, the throughput of the secondary network is analyzed to evaluate the system performance. Based on that, two algorithms (i.e., the continuous genetic algorithm (CGA) for CR NOMA (CGA-CRN) and particle swarm optimization (PSO) for CR NOMA (PSO-CRN)), are applied to optimize the throughput of the secondary network. These optimization algorithms guarantee not only the performance of the primary users but also the security constraints of the secondary users. Finally, simulations are presented to validate our research results and provide insights into how various factors affect system performance

Investigating the leaching performance of ferric chloride solution for metallic alloys resulting from reduction smelting of spent lithium-ion batteries

Smelting reduction of spent lithium-ion batteries (LIBs) produces metallic alloys containing Co, Ni, Cu, Mn, and Fe. Finding suitable reagents in terms of efficiency, economics, and friendly environment for the dissolution of these metals from the alloys is very important for the recovery process of the metals. In this work, the employment of ferric chloride solution for the dissolution of the metals from the alloys was studied. The effect of parameters like FeCl3 concentration, temperature, time, and pulp density on the leaching efficiency of metals was investigated. Our results indicate that ferric ions in the leaching solutions act as oxidizing agents for the dissolution of the metals, while chloride anions as ligands for the formation of the complexes of the dissolved metal ions. The best conditions for the dissolution of full metals were 0.7 mol/L FeCl3, 12.5 g/L pulp density, 22oC, and 30 min. In comparison with HCl or H2SO4 leaching agents, ferric chloride shows some advantages like a decrease in the dosage of acids and oxidizing agents, fast reaction kinetics, and low energy consumption. With its advantages, ferric chloride solution is considered a potential leaching agent in the recovery process of valuable metals from spent LIBs

Robust Reflection Detection and Removal in Rainy Conditions using LAB and HSV Color Spaces

In the field of traffic monitoring systems, shadows are the main causes of errors in computer vision-based vehicle detection and classification. A great number of  research have been carried out to detect and remove shadows. However, these research works only focused on solving shadow problems in daytime traffic scenes. Up to now, far too little attention has been paid to the problem caused by vehicles’ reflections in rainy conditions. Unlike shadows in the daytime, which are homogeneous gray shades, reflection shadows are inhomogeneous regions of different colors. This characteristic makes reflections harder to detect and remove. Therefore, in this paper, we aim to develop a reflection detection and removal method from single images or video. Reflections are detected by determining a combination of L and B channels from LAB color space and H channel from HSV color space. The reflection removal method is performed by determining the optimal intensity of reflected areas so that they match with neighbor regions. The advantage of our method is that all reflected areas are removed without affecting vehicles’ textures or details

Throughput Optimization for NOMA Energy Harvesting Cognitive Radio with Multi-UAV-Assisted Relaying under Security Constraints

This paper investigates the throughput of a non-orthogonal multiple access (NOMA)-based cognitive radio (CR) system with multiple unmanned aerial vehicle (UAV)-assisted relays under system performance and security constraints. We propose a communication protocol that includes an energy harvesting (EH) phase and multiple communication phases. In the EH phase, the multiple UAV relays (URs) harvest energy from a power beacon. In the first communication phase, a secondary transmitter (ST) uses the collected energy to send confidential signals to the first UR using NOMA. Simultaneously, a ground base station communicates with a primary receiver (PR) under interference from the ST. In the subsequent communication phases, the next URs apply the decode-and-forward technique to transmit the signals. In the last communication phase, the Internet of Things destinations (IDs) receive their signals in the presence of an eavesdropper (EAV). Accordingly, the outage probability of the primary network, the throughput of the secondary network, and the leakage probability at the EAV are analyzed. On this basis, we propose a hybrid search method combining particle swarm optimization (PSO) and continuous genetic algorithm (CGA) to optimize the UR configurations and the NOMA power allocation to maximize the throughput of the secondary network under performance and security constraints

ĐẶC ĐIỂM SINH HỌC SINH SẢN CỦA NGÁN (AUSTRIELLA CORRUGATA) TẠI VÙNG TRIỀU VEN BIỂN TỈNH QUẢNG NINH

360 samples of mud clam (Austriella corrugata) were collected in the intertidal zone of Quang Ninh province city from January 2015 to December 2015 for this study. The results showed that the gonad of female is black, that of male is milky white. The spawning season is from mid April to early September and the peak of spawning occurs from early June to early August. In spawning season, ratio of male/female is toward balance. In other months, rate of male is dominant in the population. Hermaphroditism occurs in the mud clam with a small percentage (from 3.3% to 10%) in the breeding season, in group with size of more than 40 mm. The length of mud clam at first sexual maturity is over 30 mm and the weight is over 20 g. The average absolute fecundity (Fa) is 960,680 eggs/individual. Development of mud clam larvae goes through main stages: Veliger, Umbo and Spat. Our findings contribute information to the planning of the artificial seed production, conservation and sustainable development of mud clam native resource.Kết quả phân tích 360 mẫu ngán (A. corrugata) thu tại các khu vực nơi có ngán phân bố thuộc vùng triều ven biển tỉnh Quảng Ninh từ tháng 1/2015 đến tháng 12/2015 cho thấy: Tuyến sinh dục ngán đực có màu trắng sữa, ngán cái có màu đen thẫm. Mùa vụ sinh sản của ngán hàng năm được xác định từ giữa tháng 4 đến đầu tháng 9, mùa sinh sản tập trung từ đầu tháng 6 đến đầu tháng 8. Ở các tháng tromg năm, tỷ lệ con đực luôn chiếm ưu thế so với con cái trong quần đàn ngán. Vào mùa sinh sản tỷ lệ đực cái cân bằng. Ngán lưỡng tính xuất hiện với tỷ lệ nhỏ (3,3 - 10%) vào mùa sinh sản và ở nhóm kích thước lớn hơn 40 mm. Ngán thành thục sinh dục lần đầu khi chiều dài đạt trên 30 mm, khối lượng trên 20 g. Sức sinh sản tuyệt đối giao động từ 340.690  - 2.090.000 trứng/cá thể, trung bình đạt 960.680 trứng/cá thể. Ấu trùng của ngán phát triển trải qua các giai đoạn chính: Ấu trùng chữ D, ấu trùng đỉnh vỏ và ấu trùng chân bò. Sau đó, ngán phát triển thành con non. Kết quả nghiên cứu góp phần cung cấp cơ sở khoa học cho việc xây dựng kế hoạch sản xuất giống nhân tạo, bảo vệ và phát triển bền vững nguồn lợi ngán tại địa phương