1,354 research outputs found
Performance enhancement solutions in wireless communication networks
In this dissertation thesis, we study the new relaying protocols for different wireless network systems. We analyze and evaluate an efficiency of the transmission in terms of the outage probability over Rayleigh fading channels by mathematical analyses. The theoretical analyses are verified by performing Monte Carlo simulations.
First, we study the cooperative relaying in the Two-Way Decode-and-Forward (DF) and multi-relay DF scheme for a secondary system to obtain spectrum access along with a primary system. In particular, we proposed the Two-Way DF scheme with Energy Harvesting, and the Two-Way DF Non-orthogonal Multiple Access (NOMA) scheme with digital network coding. Besides, we also investigate the wireless systems with multi-relay; the best relay selection is presented to optimize the effect of the proposed scheme. The transmission protocols of the proposed schemes EHAF (Energy Harvesting Amplify and Forward) and EHDF (Energy Harvesting Decode and Forward) are compared together in the same environment and in term of outage probability. Hence, with the obtained results, we conclude that the proposed schemes improve the performance of the wireless cooperative relaying systems, particularly their throughput.
Second, we focus on investigating the NOMA technology and proposing the optimal solutions (protocols) to advance the data rate and to ensure the Quality of Service (QoS) for the users in the next generation of wireless communications. In this thesis, we propose a Two-Way DF NOMA scheme (called a TWNOMA protocol) in which an intermediate relay helps two source nodes to communicate with each other. Simulation and analysis results show that the proposed protocol TWNOMA is improving the data rate when comparing with a conventional Two-Way scheme using digital network coding (DNC) (called a TWDNC protocol), Two-Way scheme without using DNC (called a TWNDNC protocol) and Two-Way scheme in amplify-and-forward(AF) relay systems (called a TWANC protocol).
Finally, we considered the combination of the NOMA and physical layer security (PLS) in the Underlay Cooperative Cognitive Network (UCCN). The best relay selection strategy is investigated, which uses the NOMA and considers the PLS to enhance the transmission efficiency and secrecy of the new generation wireless networks.V této dizertační práci je provedena studie nových přenosových protokolů pro různé bezdrátové síťové systémy. S využitím matematické analýzy jsme analyzovali a vyhodnotili efektivitu přenosu z hlediska pravděpodobnosti výpadku přes Rayleighův kanál. Teoretické analýzy jsou ověřeny provedenými simulacemi metodou Monte Carlo.
Nejprve došlo ke studii kooperativního přenosu ve dvoucestném dekóduj-a-předej (Two-Way Decode-and-Forward–TWDF) a vícecestném DF schématu s větším počtem přenosových uzlů pro sekundární systém, kdy takto byl získán přístup ke spektru spolu s primárním systémem. Konkrétně jsme navrhli dvoucestné DF schéma se získáváním energie a dvoucestné DF neortogonální schéma s mnohonásobným přístupem (Non-orthogonal Multiple Access–NOMA) s digitálním síťovým kódováním. Kromě toho rovněž zkoumáme bezdrátové systémy s větším počtem přenosových uzlů, kde je přítomen výběr nejlepšího přenosového uzlu pro optimalizaci efektivnosti navrženého schématu. Přenosové protokoly navržených schémat EHAF (Energy Harvesting Amplify and Forward) a EHDF(Energy Harvesting Decode and Forward) jsou společně porovnány v identickém prostředí z pohledu pravděpodobnosti výpadku. Následně, na základě získaných výsledků, jsme dospěli k závěru, že navržená schémata vylepšují výkonnost bezdrátových kooperativních systémů, konkrétně jejich propustnost.
Dále jsme se zaměřili na zkoumání NOMA technologie a navrhli optimální řešení (protokoly) pro urychlení datového přenosu a zajištění QoS v další generaci bezdrátových komunikací. V této práci jsme navrhli dvoucestné DF NOMA schéma (nazýváno jako TWNOMA protokol), ve kterém mezilehlý přenosový uzel napomáhá dvěma zdrojovým uzlům komunikovat mezi sebou. Výsledky simulace a analýzy ukazují, že navržený protokol TWNOMA vylepšuje dosaženou přenosovou rychlost v porovnání s konvenčním dvoucestným schématem používajícím DNC (TWDNC protokol), dvoucestným schématem bez použití DNC (TWNDNC protokol) a dvoucestným schématem v zesil-a-předej (amplify-and-forward) přenosových systémech (TWANC protokol).
Nakonec jsme zvážili využití kombinace NOMA a zabezpečení fyzické vrstvy (Physical Layer Security–PLS) v podpůrné kooperativní kognitivní síti (Underlay Cooperative Cognitive Network–UCCN). Zde je zde zkoumán výběr nejlepšího přenosového uzlu, který užívá NOMA a bere v úvahu PLS pro efektivnější přenos a zabezpečení nové generace bezdrátových sítí.440 - Katedra telekomunikační technikyvyhově
ベトナム・ハノイにおけるし尿腐敗槽からの温室効果ガスの排出
京都大学0048新制・課程博士博士(工学)甲第22768号工博第4767号新制||工||1745(附属図書館)京都大学大学院工学研究科都市環境工学専攻(主査)教授 田中 宏明, 教授 清水 芳久, 教授 藤井 滋穂学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA
TRADITIONAL THERAPY AND WESTERN MEDICINE FOR TREATING INSOMNIA
Objective: The herbs that have been used in Vietnam since ancient times for many different uses but not everyone recognize its great value. The paperaims to discover the preferred medicinal plants and the reasons why patients choose them. Although Western medicines play an important role intreatment and bring immediate effect, however, to treat insomnia in the long term, natural herbs account for significant importance. The paper wasconducted in early 2019 in different regions in South Vietnam to once again determine the role of medicinal plants use.Methods: This paper is completed with the support of 100 respondents who are from some places of Ho Chi Minh city and are suffering from insomnia.With the form of direct interviews, some questions are designed to examine patients’ opinions about the strategies that can to treat insomnia.Results: The results showed that herbal treatment still plays a rather important role even though people tend to choose Western medications in busydays because this medications are less time consuming. The paper also mentions that the importance of herbs in the treatment of insomnia needsmore attention.Conclusion: In the current medical methods, traditional methods are being trusted and used by many people because this therapy brings many healthbenefits, helps patients treat their illnesses well as well as improve their health much better. Traditional remedies which are all derived from naturalherbs are very good for health
Novel bioparticle vaccines against Chlamydia trachomatis
Chlamydia trachomatis, a sexually transmitted obligate intracellular bacterium, presents a significant global public health concern due to its high prevalence. Although C. trachomatis infection often remains undetected, it can lead to serious complications such as pelvic inflammatory disease, infertility, ectopic pregnancy, miscarriage, and even blindness. While antibiotics are effective against acute infection, they are believed to increase the risk of reinfection. Despite advances in understanding C. trachomatis-caused infectious diseases, a prophylactic vaccine against the bacterium is yet to be developed. The challenges lie in the safety risks associated with using weakened live vaccines and the limited efficacy of current alternative vaccination strategies. Protective immunity against C. trachomatis, like other intracellular pathogens, relies on both humoral and cellular immune responses, targeting the extracellular and intracellular stages of the bacterium, respectively. Many studies have focused on inducing protective CD4+ (Th1) T cell-mediated and humoral responses, but efforts to activate CD8+ T cells, responsible for monitoring and eliminating intracellular infections, are still in the early stages. Therefore, the development of innovative C. trachomatis vaccines, capable of inducing potent humoral and cellular (CD4+ and CD8+ T cell) responses, requires a complementary interdisciplinary approach with experts from various fields. The main objective of this thesis was to create and evaluate novel C. trachomatis bioparticle vaccines, using bacterial outer membrane vesicles (OMVs) and protein bodies (PBs) as delivery platforms. Several vaccine candidates based on LPS-detoxified Salmonella OMVs and E. coli PBs have been generated. Preclinical testing in a mouse model has shown that the OMV/PB-based vaccines are safe and immunogenic, inducing specific humoral and cellular immune responses against C. trachomatis antigens in both systemic and mucosal compartments. Currently, the protective efficacy of the most promising vaccine is being evaluated and compared to other vectored vaccines using a genital mouse challenge model
Macroeconomic effects of energy price shocks on the business cycle
This paper proposes a framework of endogenous energy production with convex costs to investigate the general equilibrium effects of energy price shocks on the business cycle. This framework explicitly models the consumption of durables and nondurables and implements a high complementarity between energy and the usage of durables and capital. The model predicts energy price elasticities of various consumption variables that fall within reasonable agreement with empirical estimates. Convex costs in energy production produce energy price and energy supply dynamics that tallies well with empirical behavior. Our analysis confirms in a theoretical setting recent observations that not all energy price shocks are the same. They can be distinct in terms of energy price dynamics and impact on the business cycle, as well as energy price elasticities of various macro variables that can be useful indicators for their underlying causes.</jats:p
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Giant cell myocarditis masquerading as orbital myositis with a rapid, fulminant course necessitating mechanical support and heart transplantation.
Giant cell myocarditis (GCM), a rapidly progressive inflammation of the myocardium, is associated with fulminant heart failure, refractory ventricular arrhythmias, and conduction system abnormalities. Few case reports have noted orbital myositis as the initial clinical presentation. Our case demonstrates a unique presentation of GCM with only ocular symptoms, which unlike prior studies, rapidly progressed to heart failure, tachyarrhythmias, and conduction disease. Our case necessitated quick recognition and treatment with mechanical support making this the first known case of GCM with successful placement of biventricular assist devices and ultimately with heart transplantation
Secrecy outage probability of a NOMA scheme and impact imperfect channel state information in underlay cooperative cognitive networks
Security performance and the impact of imperfect channel state information (CSI) in underlay cooperative cognitive networks (UCCN) is investigated in this paper. In the proposed scheme, relay R uses non-orthogonal multiple access (NOMA) technology to transfer messages e1, e2 from the source node S to User 1 (U-1) and User 2 (U-2), respectively. An eavesdropper (E) is also proposed to wiretap the messages of U-1 and U-2. The transmission's security performance in the proposed system was analyzed and performed over Rayleigh fading channels. Through numerical analysis, the results showed that the proposed system's secrecy performance became more efficient when the eavesdropper node E was farther away from the source node S and the intermediate cooperative relay R. The secrecy performance of U-1 was also compared to the secrecy performance of U-2. Finally, the simulation results matched the Monte Carlo simulations well.Web of Science203art. no. 89
Marine algal species and their distribution in Phu Quoc marine protected area
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