MIMO無線伝送に適したスケーラブルビデオコーディングに関する研究

Because of the COVID-19 pandemic, a new normal has taken over. It affects the higher demand for using video traffic. H.264/SVC is the video compression standard with several advantages compared with the previous standard, such as a smaller storage space and scalability of video quality depending on network quality. The H.264/SVC bitstream includes one base layer (BL), the most important layer, and one or more enhancement layers (EL) which can be leveraged to optimize the video scalability depending on the network condition and user preferences. The method of transmission is powerful as the video coding method. The transmission of the good video quality will not be effective without a suitable transmission method. In this thesis, we study and research the H.264 scalable video coding transmission with IEEE 802.11ac standard MIMO wireless transmission. We focus on the suitable transmission method for H.264/SVC in a different environment. We divide the research focusing on two issues: 1. With the difference channel environment: The suitable H.264/SVC transmission technique in IEEE 802.11ac with the specific quantization parameter of video encoding was proposed. This aim is to compare three techniques in IEEE 802.11ac: STBC, SISO, and MIMO. In this focus, only the accuracy of the video was considered to measure the efficiency of the transmission technique. This part proposed to utilize STBC to improve the quality of H.264/SVC video transmission. We have shown the performance of H.264/SVC video transmission with three multiple antenna techniques. The results show that STBC is the best technique for H.264/SVC transmission under a low-quality channel environment. The best result shows that STBC in channel model D can improve the PSNR by 67 percent and 76 percent compared with SISO and MIMO, respectively, at low SNR of 20 dB. Due to STBC transmitting multiple copies of data, it can increase data reliability. We proved that STBC is the most suitable multiple antenna technique to improve the quality and realizability of video transmission in both PSNR and bit error rate (BER). 2. With the different transmission distance: H.264/SVC video transmission on MIMO with RSSI feedback was proposed. This aim to proposes the allocation of packetization in the transmission packet and the compromising of quantization parameter encoding both vary on the channel efficiency. This part proposed a MIMO transmission system for H.264 scalable video coding that does not require full CSI feedback. Instead of the CSI feedback, we have used the RSSI and table of encoding rules obtained via link simulation in MATLAB. The encoding rule takes the form of the encoding ratio between the base and enhancement layer, which was done by adjusting the quantization parameter. This proposed system has been shown to improve the PSNR by at least 16 dB and increase the effective distance of 6 meters above compared with the conventional method.九州工業大学博士学位論文 学位記番号：情工博甲第372号 学位授与年月日：令和4年12月27日1 Introduction|2 Video Transmission System Overview|3 H.264/SVC Video Transmission by IEEE 802.11ac Techniques|4 H.264/SVC Video Transmission on MIMO with RSSI Feedback|5 Conclusion and Future Work九州工業大学令和4年

Received Signal Strength Indication (RSSI) of 2.4 GHz and 5 GHz Wireless Local Area Network Systems Projected over Land and Sea for Near-Shore Maritime Robot Operations

The effect of the maritime environment on radio frequency (RF) propagation is not well understood. In this work, we study the propagation of ad hoc 2.4 GHz and 5 GHz wireless local area network systems typically used for near-shore operation of unmanned surface vehicles. In previous work, maritime RF propagation performance is evaluated by collecting RSSI data over water and comparing it against existing propagation models. However, the multivariate effect of the maritime environment on RF propagation means that these single-domain studies cannot distinguish between factors unique to the maritime environment and factors that exist in typical terrestrial RF systems. In this work, we isolate the effect of the maritime environment by collecting RSSI data over land and over seawater at two different frequencies and two different ground station antenna heights with the same physical system in essentially the same location. Results show that our 2.4 GHz, 2 m antenna height system received a 2 to 3 dBm path loss when transitioning from over-land to over-seawater (equivalent to a 25 to 40% reduction in range); but increasing the frequency and antenna height to 5 GHz, 5 m respectively resulted in no meaningful path loss under the same conditions; this reduction in path loss by varying frequency and antenna height has not been demonstrated in previous work. In addition, we studied the change in ground reflectivity coefficient, R , when transitioning from over-land to over-seawater. Results show that R remained relatively constant, −0.49 ≤ R ≤ −0.45, for all of the over-land experiments; however, R demonstrated a frequency dependence during the over-seawater experiments, ranging from −0.39 ≤ R ≤ −0.33 at 2.4 GHz, and −0.51 ≤ R ≤ −0.50 at 5 GHz

Shortest Route at Dynamic Location with Node Combination-Dijkstra Algorithm

Abstract— Online transportation has become a basic requirement of the general public in support of all activities to go to work, school or vacation to the sights. Public transportation services compete to provide the best service so that consumers feel comfortable using the services offered, so that all activities are noticed, one of them is the search for the shortest route in picking the buyer or delivering to the destination. Node Combination method can minimize memory usage and this methode is more optimal when compared to A* and Ant Colony in the shortest route search like Dijkstra algorithm, but can’t store the history node that has been passed. Therefore, using node combination algorithm is very good in searching the shortest distance is not the shortest route. This paper is structured to modify the node combination algorithm to solve the problem of finding the shortest route at the dynamic location obtained from the transport fleet by displaying the nodes that have the shortest distance and will be implemented in the geographic information system in the form of map to facilitate the use of the system. Keywords— Shortest Path, Algorithm Dijkstra, Node Combination, Dynamic Location (key words

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen