A polymer-based compliant force/torque and displacement sensor with creep compensation

Automation of assembly processes using robots remains challenging, requiring advanced capabilities in sensing for assembly state estimation and shock absorption to protect the robot from external forces. Traditional devices such as passive compliance devices and force/torque sensors provide only a subset of these functionalities. To integrate these capabilities into a single system, a polymer-based compliant force/torque and displacement sensor has been proposed. However, polymers classified as viscoelastic materials exhibit significant creep, degrading the sensing performance. Therefore, this paper addresses the development of a polymer-based compliance force/torque and displacement sensor with a creep compensation algorithm. The proposed sensor is made of viscoelastic materials to provide passive compliance, allowing it to adapt to external forces and protect the robot from shocks. Especially, it can achieve a remote center of compliance through a novel deformable structure. Moreover, it can measure the six-axis external forces and displacements generated by the passive compliance. In this process, the creep of the viscoelastic material is analyzed and compensated to improve the sensing performance. First, a stiffness analysis was conducted for the design of the sensor and finite element analysis was performed to verify that the sensor has a remote center of compliance. Then, a method for applying a creep compensation algorithm based on a viscoelastic model to the multi-axis force/torque and displacement sensor was proposed. The effectiveness of the creep compensation algorithm was evaluated through experiments, resulting in an 85.42 % reduction in creep error, a 63.52 % improvement in response time, and a 49.37 % reduction in hysteresis error. The proposed sensor can be utilized in various fields that require both flexibility and task state estimation such as robotic assembly, wearable robots, and medical robots. © 2025 Elsevier LtdFALSEsciescopu

Shortwave Infrared Imaging of a Quantum Dot-Based Magnetic Guidewire Toward Non-Fluoroscopic Peripheral Vascular Interventions

Peripheral vascular interventions (PVIs) offer several benefits to patients with lower extremity arterial diseases, including reduced pain, simpler anesthesia, and shorter recovery time, compared to open surgery. However, to monitor the endovascular tools inside the body, PVIs are conducted under X-ray fluoroscopy, which poses serious long-term health risks to physicians and patients. Shortwave infrared (SWIR) imaging of quantum dots (QDs) has shown great potential in bioimaging due to the non-ionizing penetration of SWIR light through tissues. In this paper, a QD-based magnetic guidewire and its system is introduced that allows X-ray-free detection under SWIR imaging and precise steering via magnetic manipulation. The QD magnetic guidewire contains a flexible silicone tube encapsulating a QD polydimethylsiloxane (PDMS) composite, where HgCdSe/HgS/CdS/CdZnS/ZnS/SiO2 core/multi-shell QDs are dispersed in the PDMS matrix for SWIR imaging upon near-infrared excitation, as well as a permanent magnet for magnetic steering. The SWIR penetration of the QD magnetic guidewire is investigated within an artificial tissue model (1% Intralipid) and explore the potential for non-fluoroscopic PVIs within a vascular phantom model. The QD magnetic guidewire is biocompatible in its entirety, with excellent resistance to photobleaching and chemical alteration, which is a promising sign for its future clinical implementation. © 2024 Wiley-VCH GmbH.FALSEsciescopu

Advances in gas sensors using screen printing

Gas sensing is crucial for detecting and monitoring hazardous, gases in various environments to ensure safety and prevent potential health risks. It helps in the early identification of gas leaks, air quality monitoring, and environmental protection, contributing to public health and industrial safety. Screen-printed gas sensors are trending nowadays due to their ability to fabricate electrodes or deposit functional components onto substrates and their cost-effective and scalable manufacturing process, making them suitable for mass production. This review provides an overview of screen printing and hybrid screen printing techniques utilizing different methods, such as spin coating, drop casting, spray coating, and inkjet printing (IJP), with screen printing for various gas sensing applications. The mechanism of each hazardous gas detection technique, their precision in the identification of hazardous gases, and their impact on sensor enhancement were thoroughly analyzed. Furthermore, the vital integration of screen-printed gas sensors with various futuristic technologies, such as artificial intelligence (AI), machine learning (ML), and Internet of Things (IoT) devices, supercapacitors (SCs), triboelectric nanogenerators (TENGs), and microheaters, was demonstrated to enhance sensor performance and broaden the application area. Moreover, this review highlighted the importance of sensors' sensitivity, selectivity, and environmental stability, which offer plenty of room for innovation. For future improvements, the integration of microfluidic, multi-sensor arrays, functional coatings, and nanomaterials into screen-printed gas sensor devices was proposed. In this context, gas sensing platforms can be refined by operating them using energy harvesting principles, improving their environmental stability, and making them wearable and flexible. This review paper would benefit many researchers and readers working in this field to familiarize themselves with the recent breakthroughs in the rapidly emerging field of screen-printed gas sensing. © 2025 The Royal Society of Chemistry.FALSEsciescopu

STSPhys: Enhanced Remote Heart Rate Measurement With Spatial-Temporal SwiftFormer

Estimating heart activities and physiological signals from facial video without any contact, known as remote photoplethysmography and remote heart rate estimation, holds significant potential for numerous applications. In this letter, we present a novel approach for remote heart rate measurement leveraging a Spatial-Temporal SwiftFormer architecture (STSPhys). Our model addresses the limitations of existing methods that rely heavily on 3D CNNs or 3D visual transformers, which often suffer from increased parameters and potential instability during training. By integrating both spatial and temporal information from facial video data, STSPhys achieves robust and accurate heart rate estimation. Additionally, we introduce a hybrid loss function that integrates constraints from both the time and frequency domains, further enhancing the model's accuracy. Experimental results demonstrate that STSPhys significantly outperforms existing state-of-the-art methods on intra-dataset and cross-dataset tests, achieving superior performance with fewer parameters and lower computational complexity. © IEEE.FALSEsci

Ni-based electrodes on 3D substrates: Development and performance for asymmetric supercapacitors

To produce high-performance supercapacitors, an easy hydrothermal method was utilized to fabricate the positive electrode employing transition metal nickel and carbonate, which exhibits good wettability and reacts well with aqueous electrolytes. In addition, electrodes without and with a 3D Ni foam substrate were compared, focusing on their surface area and electrochemical performance. The electrodes were fabricated using carbonate (CO32−) based compounds with high wettability. The Ni2(CO3)(OH)2 electrode without Ni foam substrates demonstrated higher electrochemical values at low current densities, while the Ni2(CO3)(OH)2 electrode with Ni foam substrates exhibited higher capacitance at increased current densities. As the current density increased from 3 A/g to 15 A/g, the capacitance of Ni2(CO3)(OH)2 without Ni foam and with Ni foam electrodes decreased by 58.1 % and 46.5 %, respectively. This indicates that higher electrochemical stability is possessed by electrodes directly deposited on Ni foam substrates. The significance of substrate selection for enhancing electrochemical performance is highlighted, with the Ni2(CO3)(OH)2 electrode deposited on Ni foam substrate showing a high capacitance of 101.5mAh/g at a current density of 3 A/g. Additionally, an asymmetric supercapacitor comprising Ni2(CO3)(OH)2 electrodes with Ni foam and graphene as positive and negative electrode, respectively, demonstrated a remarkable energy density of 22.1 W h kg−1 and power density of 673.1 W kg−1 at a current density of 2 A/g. Impressively, excellent cycling stability was exhibited by this asymmetric supercapacitor, with ∼83.4 % capacitance retention after 5000 cycles. © 2024 Elsevier B.V.FALSEsciescopu

FUST: 집속 초음파 변환기를 이용한 푸리에-웨이블렛 정규화 역컨볼루션 기반 실시간 영상화 기법

Focused Ultrasound(FUS), Deconvolution, Fourier-wavlet regularization deconvolution (ForWaRD)Ⅰ. INTRODUCTION 1 1.1 Focused Ultrasound 1 1.2 Image Guidance and Monitoring 2 1.3 System Integration for USgFUS 3 1.4 Objectives of Research 5 ⅠI. METHODS 6 2.1 Principles for Ultrasound Imaging with a FUS Transducer 6 2.2 Implementation Process 14 2.3 Simulation Study 16 2.4 Phantom Study 19 2.5 U-net based deep learning approach 21 ⅠII. RESULTS 25 3.1 Single wire Experiment in Water 25 3.2 Evaluation on Resolution 26 3.3 Evaluation on CNR 28 3.4 Evaluation Inference time 28 IV. CONCLUSION 30 V. REFERENCES 31MasterdCollectio

일주기 리듬을 통한 사회적 행동의 우선 순위 조절의 신경학적 기작

Circadian rhythm, Social prioritization, Suprachiasmatic nucleus, Vasoactive intestinal peptide, Nucleus reuniensⅠ. Introduction 1 1.1 Circadian rhythm 1 1.2 Cell atlas of the SCN 7 1.3 Neural network of the SCN 15 1.4 Circadian organization of behaviors 19 1.5 Circadian organization of social behaviors 21 1.6 Purpose 26 ⅠI. Materials and Methods 27 ⅠII. Results 34 3.1 Circadian profile of social prioritization 34 3.2 The role of SCN VIP neuron and its downstream projection on circadian rhythm in social prioritization 37 3.3 VIP-VIPR2 signaling in RE is necessary for circadian rhythm in social prioritization 39 3.4 In vivo responsiveness of RE VIPR2 neuron on circadian time information and social cues 41 3.5 Optogenetic manipulation of RE VIPR2 neuron and its downstream projection to mPFC is responsible for circadian rhythm in social prioritization 42 3.6 Behavioral consequences of functional VIPR2 expression in social and reproductive behavior during naturalistic interaction 43 ⅠV. Discussion 84 V. References 94 VI. Abstract in Korean 107DoctordCollectio

위성 엣지 컴퓨팅 환경에서의 안전한 코드 오프로딩을 위한 자원관리

LEO Satellite Edge Computing|Secure Code Offloading|Lyapunov Optimization|Physical Layer SecurityThe satellite edge computing (SEC) has recently received considerable attention thanks to its wide area service around the world. However, this also creates a risk of exposing private user data to eavesdroppers. Physical layer security can help prevent this, yet it requires extra usage of network resources. Hence, efficient management of these resources is essential for saving power and ensuring secure code offloading. Moreover, from the perspective of mobile devices that request services, the level of security demands is quite different for various services, yet current studies have not fully considered this aspect. In this paper, we propose a secure code offloading framework for an SEC system with a jam- ming strategy in the existence of eavesdropping satellite. We formulate an average power minimization problem of an LEO satellite, a gateway, and a mobile device while ensuring security and the stability of queues. This includes making decisions of code offloading, computing/network resource allocation, and jamming unit selection. As a solution of this problem, we propose an SOS algorithm by invoking stochastic optimization theory. Fi- nally, via extensive simulations, we demonstrate that the proposed SOS algorithm can save up to 60% of average power compared to existing algorithms while maintaining the same delay and zero leakage of information toward eavesdropper.|위성 엣지 컴퓨팅 (SEC)은 전 세계 넓은 영역에 끊김 없는 서비스를 제공할 수 있는 장점 덕분에 많은 주목을 받고 있다. 그러나 동시에 긴 통신 거리 및 높은 접근성에 의해 사용자 개인 데이터가 도청자에게 노출될 위험을 초래하기도 한다. 물리 계층 보안을 통해 이를 방지할 수 있으나, 추가적인 네트워크 자원 사용이 필요하기 때문에 최소한의 에너지로 안전한 코드 오프로딩을 수행하기 위해 효율적인 자원 관리가 필수적이다. 또한 서비스 요청을 하는 모바일 장치의 관점에서, 다양한 서비스에 대해 요구되는 보안 수준은 매우 다양하지만 기존 연구들은 이를 충분히 고려하지 않고 있다. 본 논문에서는 도청 위성이 존재하는 SEC 시스템에서 재밍을 사용하는 안전한 코드 오프로딩 프레임워크를 제안한다. 우리는 보안 정보의 유출이 없음과 모든 작업이 유한 시간 내에 처리됨을 보장하면서 저궤도 (LEO) 위성, 게이트웨이, 그리고 모바일 장치의 평균 전력을 최소화하는 문제를 정의한다. 이 문제에서는 매 타임 슬롯마다 코드 오프로딩 정책, 컴퓨팅/네트워크 자원 할당, 재밍 유닛 선택 등을 결정한다. 이를 해결하기 위해, 확률적 최적화 이론을 적용한 SOS 알고리즘을 제안한다. 마지막으로, 시뮬레이션을 통해 제안한 SOS 알고리즘이 기존 알고리즘과 비교하여 동일한 지연 시간에 대해 평균 전력을 최대 60%까지 절감할 수 있음을 입증한다.1 Dynamic Secure Code Offloading for Power Minimization in LEO Satellite Edge Computing 1 1.1 Introduction 1 1.2 Related Work 4 1.3 System Model 6 1.4 Problem Formulation and Algorithm 13 1.4.1 Problem Formulation 14 1.4.2 Algorithm Design 14 1.4.3 Dynamic Secure Code Offloading for Energy Minimization in LEO Satellite Edge Computing (SOS) 17 1.5 Simulation Result 19 1.5.1 Simulation Setup 20 1.5.2 Simulation Results 21 1.6 Conclusion 24 References 25MasterdCollectio