Atrial fibrillation detection by heart rate variability in Poincare plot

© 2009 Park et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

RIS-Assisted Coverage Enhancement in Millimeter-Wave Cellular Networks

The use of millimeter-wave (mmWave) bandwidth is one key enabler to achieve the high data rates in the fifth-generation (5G) cellular systems. However, mmWave signals suffer from significant path loss due to high directivity and sensitivity to blockages, limiting its adoption within small-scale deployments. To enhance the coverage of mmWave communication in 5G and beyond, it is promising to deploy a large number of reconfigurable intelligent surfaces (RISs) that passively reflect mmWave signals towards desired directions. With this motivation, in this work we study the coverage of an RIS-assisted large-scale mmWave cellular network using stochastic geometry, and derive the peak reflection power expression of an RIS and the downlink signal-to-interference ratio (SIR) coverage expression in closed forms. These analytic results clarify the effectiveness of deploying RISs in the mmWave SIR coverage enhancement, while unveiling the major role of the density ratio between active base stations (BSs) and passive RISs. Furthermore, the results show that deploying passive reflectors is as effective as equipping BSs with more active antennas in the mmWave coverage enhancement. Simulation results confirm the tightness of the closed form expressions, corroborating our major findings based on the derived expressions.Comment: Accepted in IEEE ACCESS, Copyright (c) 2015 IEEE. Personal use of this material is permitted. However, permission to use this material for any other purposes must be obtained from the IEEE by sending a request to [email protected]

Gefährdungsabschätzung von Verdachtsflächen für koreanische Rahmenbedingungen

Gefährdungsabschätzung von Verdachtsflächen für koreanische Rahmenbedingungen vorgelegt von M. Sc. Jinho Park Zusammenfassung Bodenverunreinigungen werden zu Altlasten, wenn vom gesundheitlichen und ökotoxikologischen Gesichtspunkt aus ein Gefährdungspotential vorliegt. Solange kein Gefährdungspotential bestätigt worden ist, werden sie als Verdachtsflächen bezeichnet. Eine Altlast ist eine bewertete Verdachtsfläche, bei der ein Gefährdungspotential bestätigt worden ist. Obwohl der Kenntnisstand der Umweltbeeinträchtigung und das Ausmaß der Belastung im Einzelfall sehr unterschiedlich sein können, ist zur Bewertung und Behandlung von Altlasten ein einheitliches Verfahren zur systematischen und standortbezogenen Beurteilung des Gefährdungspotentials erforderlich. In Korea entstanden erstmals Anfang der sechziger Jahre als Folge der rasanten Entwicklung der Industrie Größere Umweltprobleme. Die intensive industrielle Bewirtschaftung ursprünglich vorwiegend landwirtschaftlich genutzter Gebiete hat regionale Bodenveränderungen hervorgerufen. 1994 wurde deshalb ein Bodenschutzgesetz im Parlament verabschiedet. Dieses Bodenschutzgesetz zielt darauf ab, durch Reduzierung der Umweltbelastung die Gesundheit der Bevölkerung und eine verbesserte Lebensqualität langfristig zu sichern. Das koreanische Umweltministerium hat eine Reihe von Sanierungsstrategien zusammengestellt und plant die stufenweise Verwirklichung dieser Maßnahmen. Zu diesem Zwecke sind geeignete landesspezifische Bewertungsverfahren zur Gefährdungsabschätzung für koreanische Verdachtsflächen zu entwickeln und anzuwenden. Aufgrund der aktuellen Situation der Altlastenproblematik in Korea, insbesondere wegen des dringenden Bedarfs an geeigneten und landesspezifischen Altlasten-Bewertungsverfahren, ergibt sich der Inhalt und die Bedeutung der vorliegenden Arbeit. Die Arbeit zielt darauf ab, unter Berücksichtigung der koreanischen rechtlichen Rahmenbedingungen, ein für die Gefährdungsabschätzung von Verdachtsflächen optimiertes Bewertungsverfahren zu entwickeln und durchgängig anzuwenden. Nach Anwendung dieses Verfahrens wird die Priorität der jeweils erforderlichen Sanierungsmaßnahmen festgelegt. Auf diese Weise wird bei vorgegebenem Sanierungsaufwand eine maximale Reduzierung der Umweltbelastung in Korea und eine bestmögliche Durchsetzung des koreanischen Bodenschutzgesetzes erreicht. Zur Entwicklung eines Bewertungsverfahrens ist es sehr wichtig, rechtliche und systematische Rahmenbedingungen zu berücksichtigen, die letztendlich die Grundlage für jedes Bewertungsverfahren bilden. Zur Berücksichtigung der Rahmenbedingungen in Korea werden die rechtlichen Instrumente Abfallmanagementgesetz, Wasserschutzrecht, Bodenschutzrecht und Chemikaliengesetz erörtert . Die von den jeweiligen Gesetzen abgeleiteten Grenzwerte werden zum Aufbau des Bewertungsalgorithmus angewandt. Beim Fehlen koreanischer Grenzwerte sind die bereits vorgeschlagenen Richtwerte aus internationalen Tabellenwerken zu übernehmen. In vorliegender Arbeit werden die Bewertungsmodelle der Industrieländer analysiert. Darüber hinaus wird auf den umweltpolitischen Hintergrund und die charakteristischen Merkmale von Bewertungsmodellen eingegangen. Bei der Beurteilung der von Altlastverdachtsflächen ausgehenden Gefährdungspotentiale werden die jeweiligen Belastungspfade Boden, Grundwasser, Oberflächengewässer und Luft sowie alle gefährdeten Schutzgüter berücksichtigt

Targeting Strategies for Multifunctional Nanoparticles in Cancer Imaging and Therapy

Nanomaterials offer new opportunities for cancer diagnosis and treatment. Multifunctional nanoparticles harboring various functions including targeting, imaging, therapy, and etc have been intensively studied aiming to overcome limitations associated with conventional cancer diagnosis and therapy. Of various nanoparticles, magnetic iron oxide nanoparticles with superparamagnetic property have shown potential as multifunctional nanoparticles for clinical translation because they have been used asmagnetic resonance imaging (MRI) constrast agents in clinic and their features could be easily tailored by including targeting moieties, fluorescence dyes, or therapeutic agents. This review summarizes targeting strategies for construction of multifunctional nanoparticles including magnetic nanoparticles-based theranostic systems, and the various surface engineering strategies of nanoparticles for in vivo applications

A Subspace Projection Approach to Autoencoder-based Anomaly Detection

Autoencoder (AE) is a neural network (NN) architecture that is trained to reconstruct an input at its output. By measuring the reconstruction errors of new input samples, AE can detect anomalous samples deviated from the trained data distribution. The key to success is to achieve high-fidelity reconstruction (HFR) while restricting AE's capability of generalization beyond training data, which should be balanced commonly via iterative re-training. Alternatively, we propose a novel framework of AE-based anomaly detection, coined HFR-AE, by projecting new inputs into a subspace wherein the trained AE achieves HFR, thereby increasing the gap between normal and anomalous sample reconstruction errors. Simulation results corroborate that HFR-AE improves the area under receiver operating characteristic curve (AUROC) under different AE architectures and settings by up to 13.4% compared to Vanilla AE-based anomaly detection.Comment: 5 pages, submitted to the IEEE for possible publicatio

Joint Design of Power Control and Access Point Scheduling for Uplink Cell-Free Massive MIMO Networks

This work proposes a joint power control and access points (APs) scheduling algorithm for uplink cell-free massive multiple-input multiple-output (CF-mMIMO) networks without channel hardening assumption. Extensive studies have done on the joint optimization problem assuming the channel hardening. However, it has been reported that the channel hardening may not be validated in some CF-mMIMO environments. In particular, the existing Use-and-then-Forget (UatF) bound based on the channel hardening often seriously underestimates user rates in CF-mMIMO. Therefore, a new performance evaluation technique without resorting to the channel hardening is indispensable for accurate performance estimations. Motivated by this, we propose a new bound on the achievable rate of uplink CF-mMIMO. It is demonstrated that the proposed bound provides a more accurate performance estimate of CF-mMIMO than that of the existing UatF bound. The proposed bound also enables us to develop a joint power control and APs scheduling algorithm targeting at both improving fairness and reducing the resource between APs and a central processing unit (CPU). We conduct extensive performance evaluations and comparisons for systems designed with the proposed and existing algorithms. The comparisons show that a considerable performance improvement is achievable with the proposed algorithm even at reduced resource between APs and CPU.Comment: 30 pages, 7 Figures. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Sequential Semantic Generative Communication for Progressive Text-to-Image Generation

This paper proposes new framework of communication system leveraging promising generation capabilities of multi-modal generative models. Regarding nowadays smart applications, successful communication can be made by conveying the perceptual meaning, which we set as text prompt. Text serves as a suitable semantic representation of image data as it has evolved to instruct an image or generate image through multi-modal techniques, by being interpreted in a manner similar to human cognition. Utilizing text can also reduce the overload compared to transmitting the intact data itself. The transmitter converts objective image to text through multi-model generation process and the receiver reconstructs the image using reverse process. Each word in the text sentence has each syntactic role, responsible for particular piece of information the text contains. For further efficiency in communication load, the transmitter sequentially sends words in priority of carrying the most information until reaches successful communication. Therefore, our primary focus is on the promising design of a communication system based on image-to-text transformation and the proposed schemes for sequentially transmitting word tokens. Our work is expected to pave a new road of utilizing state-of-the-art generative models to real communication systemsComment: 4 pages, 2 figures, to be published in IEEE International Conference on Sensing, Communication, and Networking, Workshop on Semantic Communication for 6G (SC6G-SECON23

On the Use of Bayesian Probabilistic Matrix Factorization for Predicting Student Performance in Online Learning Environments

Thanks to the advances in digital educational technology, online learning (or e-learning) environments such as Massive Open Online Course (MOOC) have been rapidly growing. In the online educational systems, however, there are two inherent challenges in predicting performance of students and providing personalized supports to them: sparse data and cold-start problem. To overcome such challenges, this article aims to employ a pertinent machine learning algorithm, the Bayesian Probabilistic Matrix Factorization (BPMF) that can enhance the prediction by incorporating background information on the side of students and/or items. An experimental study with two prediction settings was conducted to apply the BPMF to the Statistics Online data. The results shows that the BPMF with using side information provided more accurate prediction in the performance of both existing and new students on items, compared to the algorithm without using any side information. When the data are sparse, it is demonstrated that a lower dimensional solution of the BPMF would benefit the prediction accuracy. Lastly, the applicability of the BPMF to the online educational systems were discussed in the context of educational assessment.Kim, J.; Park, JY.; Van Den Noortgate, W. (2020). On the Use of Bayesian Probabilistic Matrix Factorization for Predicting Student Performance in Online Learning Environments. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):751-759. https://doi.org/10.4995/HEAd20.2020.11137OCS75175930-05-202