System Design And Motion Artifact Removal Algorithm Implementation For Ambulatory Women Ecg Measurement System:e-Bra System

Cardio Vascular Disease (CVD) leads to sudden cardiac death due to irregular phenomenon of the cardiac signal by the abnormal case of blood vessel and cardiac structure. For last three decades, there is an enhanced interest in research for cardiac diseases.. As a result, the death rate by cardiac disease in men has been falling gradually compared with relatively increasing the death rate for women due to CVD. The main reason for this phenomenon is due to the lack of seriousness to female CVD and different symptoms of female CVD compared with the symptoms of male CVD. Usually, because the CVDs for women accompany with ordinary symptoms not attributable to the heart abnormality signal such as unusual fatigue, sleep disturbances, shortness of breath, anxiety, chest discomfort, and indigestion dyspepsia, most women CVD patients do not realize that these symptoms are actually related to the CVD symptoms. Therefore, periodic ECG signal observation is required not only for women who have been diagnosed with heart disease but also for persons who want to examine their heart activity. Electrocardiogram (ECG) is used to diagnose abnormality of heart. Among the medical checkup methods for CVDs, it is very an effective method for the diagnosis of cardiac disease and the early detection of heart abnormality to monitor ECG periodically. This dissertation proposes an effective ECG monitoring system for woman by attaching the system on woman\u27s brassiere by using augmented chest lead attachment method. The suggested system called E-Bra system in this dissertation consists of an ECG transmission system and a computer installed program called E-Bra pro in order to display and analyze the ECG transmitted from the transmission module. The ECG transmission module consists of three parts such as ECG physical signal detection part with 3 stage amplifier and two electrodes, data acquisition with AD converter, and data transmission part with GPRS (General Packet Radio Service) communication, and it has very compact size that is attachable at the bottom layer of a brassiere for women. However, the ECG signal measured from the transmission module includes not only pure ECG components information; P waves QRS complex, and T wave, but also a motion artifact component (MA) due to subject movements. The MA component is one of the reasons for misdiagnosis. Therefore, the main purpose of the E-Bra system is to provide a reliable ECG data set identical to the quality of an ECG data set collected in hospital. Unfortunately, removing MA is a big challenge because the frequency range of the MA is duplicated on the frequency range of the pure ECG components, P-QRS-T. In this dissertation, two motion artifact removal algorithms (MARAs) with adaptive filter structure and independent component analysis concept are suggested, and the performance of the two MARAs will be evaluated by correlation values and signal noise ratio (SNR) values

고유 신축성 발광소자 제작을 위한 낮은 일함수의 고유 신축성 고분자 전극

학위논문(석사) -- 서울대학교대학원 : 공과대학 재료공학부, 2023. 2. 이태우.The poly (3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is a promising candidate for intrinsically stretchable electrodes to replace brittle and high-cost ITO. Previously, the study on stretchable PEDOT:PSS was only focused on electrical conductivity and mechanical stretchability. However, to be used as electrode in intrinsically stretchable light-emitting diode (ISOLED), energy level alingment is importnat for better charge injection. The work function (WF) of pristine PEDOT:PSS is around 5 eV. Therefore, the WF lowering must be conducted to use PEDOT:PSS as cathode in ISOLED. We use polyethyleneimine (PEI) which is widely used WF modifying layer to lower the WF of stretchable PEDOT:PSS. Commonly when PEI is directly coated on PEDOT:PSS, an undesired chemical reaction occurs where the PEI and PEDOT:PSS interacts. This reaction is called de-doping of PEDOT:PSS and the electrcial conductivity is significantly decreased. Especially in stretchable PEDOT:PSS with large fibril structure, PEI can diffuse into PEDOT:PSS film, therefore there are more de-doping of PEDOT:PSS. . Here, we introduce a PEDOT:PSS surface modification to tune the microstructure of stretchable PEDOT:PSS. The achieved smaller fibril structure effectively prevent the diffusion of PEI and chemical reaction can be suppressed only at the surface. Finally, we can achieve a PEDOT:PSS cathode with low WF (3.84 eV) without sacrificing any electrical conductivity. We succesfully fabricate ISOLED by based on low WF stretchable PEDOT:PSS.PEDOT:PSS는 높은 전도도와 우수한 안전성 특성을 가지며 이에 따라서 기존에 사용되고 있는 ITO 전극을 대체할 수 있는 신축성 전극의 후보군으로 연구되고 있다. 하지만 PEDOT:PSS의 높은 전기적 특성과 신축성을 유지한 상태로 일함수를 조절하는 것은 매우 도전적이다. 본 연구에서는, PEDOT:PSS의 표면처리를 통해 전도도와 신축성을 유지하면서 일함수를 조절할 수 있다. Polyethyleneimine (PEI)를 PEDOT:PSS 위에 코팅 시, 계면 사이에 원치 않은 화학적 반응이 일어난다. 이는 디도핑 반응이라 하며, 전도도가 급감하는 현상이 나타난다. 큰 피브릴 구조를 갖는 신축성 PEDOT:PSS에서는 PEI가 PEDOT:PSS film 내부로 더 깊게 확산 될 수 있으며, 이에 따라서 디도핑 현상이 더 강하게 나타난다. 본 연구에서는 미세구조를 조절함으로써, PEI의 확산을 방지했으며 디도핑 반응이 표면에서만 나타날 수 있도록 억제하는데 성공했다. 결과적으로 3.84 eV라는 낮은 일함수를 갖는 PEDOT:PSS 전극을 개발할 수 있었고 이를 적용한 고유 신축성 유기 발광 다이오드를 제작했다. 해당 연구를 통해서 신축성 전극과 신축성 LED 개발에 사용될 수 있는 다기능성을 확보한 PEDOT:PSS 전극을 개발했다.Chapter 1. Introduction 1 Chapter 2. Results and Discussions 2.1 Fabrication of Low Work Function Stretchable PEDOT:PSS 2.2 De-doping of PEDOT:PSS with PEI 2.3 The Mechanism of Selective Etching Post Treatment 2.4 The Effect of Selective Etching Post Treatment 2.5 The Stretchability after Selective Etching Post Treatment 2.6 Device Characteristics 2.7 Experimental Chapter 3. Conclusion석

RF SSSL by an Autonomous UAV with Two-Ray Channel Model and Dipole Antenna Patterns

Advancements in unmanned aerial vehicle (UAV) technology have led to their increased utilization in various commercial and military applications. One such application is signal source search and localization (SSSL) using UAVs, which offers significant benefits over traditional ground-based methods due to improved RF signal reception at higher altitudes and inherent autonomous 3D navigation capabilities. Nevertheless, practical considerations such as propagation models and antenna patterns are frequently neglected in simulation-based studies in the literature. In this work, we address these limitations by using a two-ray channel model and a dipole antenna pattern to develop a simulator that more closely represents real-world radio signal strength (RSS) observations at a UAV. We then examine and compare the performance of previously proposed linear least square (LLS) based localization techniques using UAVs for SSSL. Localization of radio frequency (RF) signal sources is assessed based on two main criteria: 1) achieving the highest possible accuracy and 2) localizing the target as quickly as possible with reasonable accuracy. Various mission types, such as those requiring precise localization like identifying hostile troops, and those demanding rapid localization like search and rescue operations during disasters, have been previously investigated. In this paper, the efficacy of the proposed localization approaches is examined based on these two main localization requirements through computer simulations.Comment: 7 Pages, submitted to 2023 PIMR

Impact of 3D Antenna Radiation Pattern in UAV Air-to-Ground Path Loss Modeling and RSRP-based Localization in Rural Area

Ensuring reliable and seamless wireless connectivity for unmanned aerial vehicles (UAVs) has emerged as a critical requirement for a wide range of applications. The increasing deployment of UAVs has increased the significance of cellular-connected UAVs (C-UAVs) in enabling beyond-visual line of sight (BVLOS) communications. To ensure the successful operation of C-UAVs within existing terrestrial networks, it is vital to understand the distinctive characteristics associated with air-to-ground signal propagation. In this paper, we investigate the impact of 3D antenna patterns on a UAV air-to-ground path loss model, utilizing datasets obtained from a measurement campaign. We conducted UAV experiments in a rural area at various fixed heights, while also characterizing the 3D antenna radiation pattern by using an anechoic chamber facility. By analyzing reference signal received power (RSRP) using path loss models that account for antenna patterns, we observed that our measurement results, obtained at different UAV heights, aligned well with the two-ray path loss model when incorporating the measured antenna pattern. we propose an RSRP-based localization algorithm at a UAV that takes into account antenna patterns in both offline and online scenarios. Through our experimentation dataset, we show that incorporating measured antenna patterns significantly enhances the source localization accuracy

비정형 축구경기 영상의 실시간 분석을 위한 최적화 방법

2

Algorithm-Hardware Co-Optimization for Cost-Efficient ML-based ISP Accelerator

In this paper, we present an advanced algorithm-hardware co-optimization method for designing an efficient accelerator architecture for image signal processing (ISP) with deep neural networks (DNNs). Based on the systolic-array structure, for performing the target network model, we newly introduce two evaluation metrics, each of which is dedicated to fairly representing either the processing speed or the energy consumption. Then, the overall evaluation metric is defined to test each systolic array, finding the initial array configuration for the given number of total multipliers. From the initial array, several array-scaling methods are then presented to find the most cost-efficient array structure. In addition, the original ML model is adjusted to further enhance the overall efficiency with subtle quality drops of image outputs. Implementation results in 28nm CMOS technology show that the proposed co-optimization method successfully finds the cost-efficient systolic accelerator architecture for ISP applications, improving the energy efficiency by 51% compared to the straightforward array design.1

Impact of 3-D Antenna Radiation Pattern in UAV Air-to-Ground Path Loss Modeling and RSRP-Based Localization in Rural Area

Ensuring reliable and seamless wireless connectivity for unmanned aerial vehicles (UAVs) has emerged as a critical requirement for a wide range of applications. The increasing deployment of UAVs has increased the significance of cellular-connected UAVs (C-UAVs) in enabling beyond-visual line of sight (BVLOS) communications. To ensure the successful operation of C-UAVs within existing terrestrial networks, it is vital to understand the distinctive characteristics associated with air-to-ground signal propagation. In this paper, we investigate the impact of 3D antenna patterns on a UAV air-to-ground path loss model, utilizing datasets obtained from a measurement campaign. We conducted UAV experiments in a rural area at various fixed heights, while also characterizing the 3D antenna radiation pattern by using an anechoic chamber facility. By analyzing reference signal received power (RSRP) using path loss models that account for antenna patterns, we observed that our measurement results, obtained at different UAV heights, aligned well with the two-ray path loss model when incorporating the measured antenna pattern. We propose an RSRP-based localization algorithm at a UAV that takes into account antenna patterns in both offline and online scenarios. Through our experimentation dataset, we show that incorporating measured antenna patterns significantly enhances the source localization accuracy

Fast Estimation of NTT/INTT Accelerator Costs for RNS-Based Homomorphic Encryption

This paper proposes a hardware estimator for accelerating number theoretic transform (NTT) for fast polynomial operations in the ring learning with error (RLWE) based homomorphic encryption (HE). By modifying the number of unit processing elements, modulus bit-width, and residue number system (RNS) parameters, we present a systematic way for rapidly calculating the hardware complexity without realizing the target accelerator. Compared with the actual synthesis results in 28nm CMOS technology, experimental results show that the proposed work successfully estimates the NTT accelerator area even under the large-valued parameters with acceptable errors, greatly relaxing the overheads for the design space exploration. Homomorphic encryption, residue number system, hardware accelerator2

Achieving Low-Voltage Operation of Intrinsically-Stretchable Organic Light-Emitting Diodes

A minimum operating voltage of intrinsically-stretchable organic light-emitting diodes (ISOLEDs) is always required for practical applications. However, the lack of protocols for the lamination complicates the task of attaining a reliable ISOLED without inducing degradation. Here, a solvent-vapor-assisted lamination (SVAL) method to reinforce the cathode interface is presented; this process lowers the operation voltage and increases the stretchability of ISOLEDs. Achieving a uniform contact and strong adhesion at the interface is the key to attaining reliable lamination. A cold-pressing (CP) treatment is applied first to reduce the surface roughness of silver nanowires before the surface embedding process. A subsequent solvent vapor treatment before the lamination partially solvated the surface of the active layer with an increase in the segmental motion of polymer chains, which substantially increases the interfacial adhesion after lamination. The combination of CP and SVAL treatments considerably reduces threshold voltage V-th (i.e., voltage at which current shows an abrupt increase for light-emission) from 6.7 to 2.7 V. The ISOLED also exhibts excellent mechanical stretchability, with no significant change in luminance under 30% strain. This study can assist in the development of practical applications of intrinsically-stretchable optoelectronic devices.N

Pratyush Rai e-Nanoflex Sensor System: Smartphone-Based Roaming Health Monitor

The growing need and market demand for point of care (POC