Hybrid beamforming for single carrier mmWave MIMO systems

Hybrid analog and digital beamforming (HBF) has been recognized as an attractive technique offering a tradeoff between hardware implementation limitation and system performance for future broadband millimeter wave (mmWave) communications. In contrast to most current works focusing on the HBF design for orthogonal frequency division multiplexing based mmWave systems, this paper investigates the HBF design for single carrier (SC) systems due to the advantage of low peak-to-average power ratio in transmissions. By applying the alternating minimization method, we propose an efficient HBF scheme based on the minimum mean square error criterion. Simulation results show that the proposed scheme outperforms the conventional HBF scheme for SC systems.Comment: IEEE GlobalSIP2018, Feb. 201

Crucial role of reactive oxygen species for targeting of cutaneous SCC cells

Cutaneous squamous cell carcinoma (cSCC) accounts for 20% of all skin cancers. Actinic keratoses (AK) is the precursors of cSCC, and there is still no effective way to stop its progression into cSCC. Effective medicines are needed to combat the current high incidence of of cSCC and AK. Non-steroidal anti-inflammatory drugs as celecoxib, indirubin derivatives or sinecatechins (Veregen, Polyphenon E, PE) represent promising candidates. Here, the efficacy and mode of action of celecoxib, three indirubin derivatives and PE were investigated in four cSCC cell lines. The indirubin derivatives caused loss of cell proliferation and viability as well as induced apoptosis. Celecoxib obtained a strong anti-proliferative effect in four representative cSCC cell lines. Apoptosis were further enhanced and loss of cell viability were increased, when the indirubin derivatives or celecoxib were combined with TRAIL (Tumor necrosis factor-related apoptosis inducing-ligand). In both combined treatments, pro-apoptotic caspase cascades were activated. Also, the TRAIL receptor DR5, the pro-apoptotic Puma and the p21 were up-regulated, whereas anti-apoptotic factors (survivin and XIAP) were down-regulated. PE also caused strong reduction in cell proliferation and cell viability but not apoptosis. For celecoxib and indirubin derivatives, a strong and early increase in reactive oxygen species (ROS) was characteristic, while for PE, ROS decreased early and increased later. For indirubin derivatives, the relation between high ROS and apoptosis could be shown by anti-oxidative pre-treatment, while for celecoxib, the production of ROS was strong so that it could not be prevented by anti-oxidants. For PE, the relation between low ROS and inhibition of cell proliferation and cell viability could be shown by anti-oxidative pre-treatment. Thus, high ROS may induce apoptosis, while low ROS may inhibit cell proliferation and cell viability in cSCC cells. These data illuminate the different mechanisms of ROS in the treatment of cSCC as well as provide the basis to understand how pro- and anti-tumorigenic ROS signalling pathways may be effectively used in cancer therapy.Das kutane Plattenepithelkarzinom (cSCC) macht 20 % aller Hautkrebserkrankungen aus. Aktinische Keratosen (AK) sind die Vorstufen von cSCC, und es gibt immer noch keine wirksame Methode, um ihr Fortschreiten zu cSCC zu verhindern. Es werden wirksame Arzneimittel benötigt, um die derzeit hohe Inzidenz von cSCC und AK zu bekämpfen. Nicht steroidale Entzündungshemmer wie Celecoxib, Indirubin-Derivate oder Sinecatechine (Veregen, Polyphenon E, PE) sind vielversprechende Kandidaten. Hier wurden die Wirksamkeit und die Wirkungsweise von Celecoxib, drei Indirubin-Derivaten und PE in vier cSCC-Zelllinien untersucht. Die Indirubin-Derivate führten zu einem Verlust der Zellproliferation und der Lebensfähigkeit und induzierten Apoptose. Celecoxib erzielte bei vier repräsentativen cSCC-Zelllinien eine starke anti-proliferative Wirkung. Die Apoptose und der Verlust der Lebensfähigkeit der Zellen wurden noch verstärkt, wenn die Indirubin-Derivate oder Celecoxib mit TRAIL (Tumor-Nekrose-Faktor-bezogener Apoptose-Induktions-Ligand) kombiniert wurden. Bei beiden kombinierten Behandlungen wurden pro-apoptotische Caspase-Kaskaden aktiviert. Außerdem wurden der TRAIL-Rezeptor DR5, das pro-apoptotische Bcl-2- Protein Puma und der Zellzyklusinhibitor p21 hochreguliert, während anti-apoptotische Faktoren (Survivin und XIAP) herunterreguliert wurden. PE führte auch zu einem starken Rückgang der Zellproliferation und der Lebensfähigkeit der Zellen, aber nicht zur Induktion der Apoptose. Für Celecoxib und Indirubin-Derivate war ein starker und früher Anstieg reaktiver Sauerstoffspezies (ROS) charakteristisch, während bei PE die ROS früh ab- und später zunahmen. Bei Indirubin-Derivaten konnte der Zusammenhang zwischen hohen ROS und Apoptose durch eine antioxidative Vorbehandlung aufgezeigt werden, während bei Celecoxib die Produktion von ROS so stark war, dass sie durch Antioxidantien nicht verhindert werden konnte. Bei PE konnte der Zusammenhang zwischen niedrigen ROS und der Hemmung der Zellproliferation und Zelllebensfähigkeit durch eine antioxidative Vorbehandlung nachgewiesen werden. Somit kann ein hoher ROS-Gehalt Apoptose auslösen, während ein niedriger ROS-Gehalt die Zellproliferation und Zelllebensfähigkeit von cSCC-Zellen hemmen kann. Diese Daten beleuchten die verschiedenen Mechanismen von ROS bei der Behandlung von cSCC und liefern die Grundlage für das Verständnis, wie pro- und antitumoröse ROS-Signalwege in der Krebstherapie wirksam eingesetzt werden könne

LRF-Net: Learning Local Reference Frames for 3D Local Shape Description and Matching

The local reference frame (LRF) acts as a critical role in 3D local shape description and matching. However, most of existing LRFs are hand-crafted and suffer from limited repeatability and robustness. This paper presents the first attempt to learn an LRF via a Siamese network that needs weak supervision only. In particular, we argue that each neighboring point in the local surface gives a unique contribution to LRF construction and measure such contributions via learned weights. Extensive analysis and comparative experiments on three public datasets addressing different application scenarios have demonstrated that LRF-Net is more repeatable and robust than several state-of-the-art LRF methods (LRF-Net is only trained on one dataset). In addition, LRF-Net can significantly boost the local shape description and 6-DoF pose estimation performance when matching 3D point clouds.Comment: 28 pages, 14 figure

Um estudo empírico sobre os fatores que influenciam a intenção comportamental de utilização dos consumidores relativamente às compras em livestreaming

Mestrado Bolonha em MarketingComo resultado do enorme impacto da Covid-19 na economia social nos últimos três anos, a economia de rede tem recebido ainda mais atenção de todos os lados, e cada vez mais empresários percebem que o desenvolvimento do marketing de rede será a tendência dominante no futuro. O surgimento desta nova forma de livestreaming nos meios de comunicação social também permite que as pessoas vejam novas oportunidades de negócio. Neste sentido, este estudo tem como objetivo identificar os fatores que motivam os consumidores a escolher as compras em livestreaming e explorar o impacto da confiança como fator mediador. Este estudo é de natureza quantitativa e a ferramenta de recolha de dados utilizada foi um questionário online em chinês e inglês. Obteve-se um total de 381 respostas válidas. Os dados foram analisados através regressões lineares múltiplas e simples. Este estudo conclui que quando os consumidores têm níveis mais elevados de perceção de facilidade de utilização, perceção de entretenimento, perceção de interatividade e confiança nas compras em livestreaming, a sua vontade de escolher as compras em livestreaming é maior. Além disso, o estudo também concluiu que, quando os consumidores experimentam níveis mais elevados de interatividade com as compras em livestreaming, a sua confiança nas compras em livestreaming é também aprofundada, e níveis mais elevados de confiança conduzem a uma maior de utilizar a plataforma. Este estudo fornece conhecimentos teóricos mais aprofundados sobre o processo de decisão dos consumidores, desde o que afeta a intenção de usar plataformas de livestreaming até intenção até ao comportamento efetivo na escolha das compras em livestreaming. Os conhecimentos adquiridos com este estudo são importantes para ajudar os operadores de lojas online e os profissionais de marketing online a compreender melhor as características dos clientes que preferem as compras em livestreaming e, assim, desenvolver estratégias de gestão e marketing mais eficazes.As a result of Covid-19's huge impact on the social economy over the last three years, the network economy has received even more attention from all sides, and more and more entrepreneurs realise that the development of network marketing will be the dominant trend in the future. The emergence of this new form of livestreaming in the media also allows people to see new business opportunities. With this in mind, this study aims to identify the factors that motivate consumers to choose livestreaming purchases and to explore the impact of trust as a mediating factor. This study is quantitative in nature and the data collection tool used was an online questionnaire in Chinese and English. A total of 381 valid responses were obtained. The data was analysed using multiple and simple linear regressions. This study concludes that when consumers have higher levels of perceived ease of use, perceived entertainment, perceived interactivity and trust in livestreaming purchases, their willingness to choose livestreaming purchases is greater. In addition, the study also concluded that when consumers experience higher levels of interactivity with livestreaming purchases, their trust in livestreaming purchases is also deepened, and higher levels of trust lead to greater willingness to use the platform. This study provides more in-depth theoretical knowledge about the consumer decision-making process, from what affects the intention to use livestreaming platforms to the actual behaviour when choosing livestreaming purchases. The knowledge gained from this study is important for helping online shop operators and online marketers to better understand the characteristics of customers who prefer livestreaming purchases and thus develop more effective management and marketing strategies.info:eu-repo/semantics/publishedVersio