A5023637872- Wireless Body Area Networks
- Antenna Design and Analysis
- Microwave Engineering and Waveguides
- Electrical and Bioimpedance Tomography
- Photonic Crystals and Applications
- Body Composition Measurement Techniques
- Antioxidant Activity and Oxidative Stress
- Microfluidic and Bio-sensing Technologies
- Energy Harvesting in Wireless Networks
- Erythrocyte Function and Pathophysiology
- Wireless Power Transfer Systems
- Photonic and Optical Devices
- Bee Products Chemical Analysis
- Advancements in Semiconductor Devices and Circuit Design
- Thermal properties of materials
- Bluetooth and Wireless Communication Technologies
- Graphene research and applications
- Nutritional Studies and Diet
- Fern and Epiphyte Biology
- Antenna Design and Optimization
- Mobile Health and mHealth Applications
- Health Literacy and Information Accessibility
- Optical Coatings and Gratings
- RFID technology advancements
- Advanced MIMO Systems Optimization
Samsung (South Korea)
2012-2023
Yokohama National University
2006-2011
Abstract Bioelectrical impedance analysis (BIA) is used to analyze human body composition by applying a small alternating current through the and measuring impedance. The smaller electrode of BIA device, larger measurement error due contact resistance between skin. Therefore, most commercial devices utilize electrodes that are large enough (i.e., 4 × 1400 mm 2 ) counteract effect. We propose novel method compensating for performing 4-point 2-point measurements alternately such can be...
We experimentally demonstrate the light focusing by negative refraction in a photonic crystal slab superlens at wavelengths lambda of 1.26-1.42 microm. The was fabricated on silicon-on-insulator substrate with an interface structure optimized for low reflection and diffraction losses. clearly observed through intentional out-of-plane radiation or scattering guided slab. minimum focused spot width limited to 1.8 microm(1.4 lambda) owing aberrations. characteristics were good agreement those...
This paper presents a free access mat consisting of tightly coupled double layered microstrip resonator array to provide an easy for devices in short range wireless communications. While conventional system the electromagnetic wave is radiated from device another through space using built-in antennas, proposed uses propagate and proximate coupling between waveguide devices. The propagation loss small, which demonstrated by numerical simulation basic elements mat. We also demonstrate small...
This paper presents a novel concept data collecting device for body-centric wireless communications, smart robe or blanket. It couples to sensor units on human body wirelessly by just putting the body. is consisting of textile-based free access mat. The mat thin sheet-shaped waveguide which devices can couple at an arbitrary position it. We investigate transmission characteristics depending materials, folding bending, presence
Bioelectrical impedance analysis (BIA) is used to calculate the body fat percentage of a human by applying small amount alternating current through and measuring impedance. As electrode size BIA device becomes small, measurement error large due contact resistance between skin. Most commercial devices, therefore, utilize electrodes enough ignore effect resistance, e.g. 35×40 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> × 4EA. We...
There have been growing interests in body-centric wireless communications. As a new candidate to support on-body propagation, this paper proposes wear smart suit, subsidiary waveguide which devices couple to. Our proposal is called as free access mat limits the arrival domain of radio systems area around itself. Wireless it and electromagnetic wave transmits through it. Data power transmission therefore possible This presents experimental study using flexible conductive textile provides with...
Given the rapid growth of wearable healthcare device market, we examined associations among health-related and technology-related characteristics using devices demonstrated how differ between US Korean users.Online self-administered surveys were conducted with 4098 participants (3035 in 1063 Korea) who recruited through two online survey service providers based on quota sampling. The primary outcome was use devices. Seven health-related, technology-related, five socio-demographic factors...
Abstract Blood carotenoid concentration measurement is considered the gold standard for fruit and vegetable (F&V) intake estimation; however, this method invasive expensive. Recently, skin status (SCS) measured by optical sensors has been evaluated as a promising parameter F&V estimation. In cross-sectional study, we aimed to validate utility of resonance Raman spectroscopy (RRS)-assessed SCS biomarker in Korean adults. We used data from 108 participants aged 20–69 years who...
Current-voltage (I–V) characteristics of the graphene field effect transistors (GFETs) are measured by dc, fast I–V (FIV), and pulsed (PIV) methods analyzed. The hysteresis conductance in dc measurement affected sweeping bias range direction. curves FIV method show reduced enhanced at a faster rate, but still range. By applying PIV method, can be suppressed significantly while is improved controlling turn-on, turn-off times (t on t off) gate during off (V base) regardless With short on, long...
We present a useful design for free access mat which supports two frequency bands of 2.4 GHz and 5 GHz. The is sheet-shaped waveguide consists tightly coupled double-layered microstrip resonator array. It provides easy devices in short-range wireless communications. Interference common problem with conventional applications use space transmission. Our proposed system uses subsidiary waveguide, the mat. Wireless are proximately to through electromagnetic (EM) wave transmits. arrival domain EM...
We proposed a free access mat consisting of tightly coupled patch resonator array for an easy and low loss short range communications. By numerical simulation we obtained lower propagation than the space transmission one two dimensional models. measurement confirmed that this has in through even when antenna coupling to is considered. The gain was more 10 dB which large enough say available provide small wireless access.
Electrical methods are among the primarily studied non-invasive glucose measurement techniques; however, various factors affect accuracy of sensors used. Of these, temperature is a critical factor; hence, effects on electrical properties blood components investigated in this study. Furthermore, changes according to level corrected by considering properties. An impedance sensor developed and used measure whole 10 healthy participants at temperatures levels. Subsequently, conductivities plasma...
In this paper a free access mat for dual band operation is investigated. The consisting of tightly coupled patch array which provides an easy short range wireless communications proposed. conventional system, the electromagnetic wave radiated from device to another through space using built-in antennas so that propagation loss large. system mat, concentrated in and transmitted low loss. excitation devices obtained by proximate coupling. Design 2.4 5 GHz based on operating single GHz,...
Resonance Raman spectroscopy (RRS) has been used as a reference method for measuring skin carotenoid levels (SCL), which indicate vegetable and fruit intake. However, RRS is not an easy-to-use in SCL measurement due to its complicated implementation. In this study, commercial spectrophotometer based on reflection (RS), relatively simple inexpensive, was evaluated confirm usability compared with SCL. To investigate the agreement between RS RRS, eighty participants were randomly assigned...
Bio-impedance analysis provides non-invasive estimation of body composition. Recently, applications based on bio-impedance measurement in skin tissue such as cancer diagnosis and composition monitoring have been studied. For scanning the electrical properties along depth, relationship between electrode topologies depth sensitivity should be clarified. This work reports a systematic designing line to measure layer at specific using finite element method (FEM). Four electrodes consisting two...
The cause of drain current (ID) drift in graphene field-effect transistors is analyzed and a method to suppress the proposed. By analyzing ID-time characteristics, condition reasonable gate, source biases (VG, VD, VS) proposed ID drift. Based on this result, we find for VG during off-time (Vbase), VS pulsed I-V measurement obtain intrinsic ID-VG curves, analyze effect Vbase Dirac point shift. Through an analysis characteristics depending VG, according range explained.
‘건강한 삶’에 대한 소비자의 높은 관심이 지속됨에 따라 소비자들은 건강관리 활동을 삶의 필수적인 요소로 인식하기 시작하였다. 이에 본 연구는 소비자들이 건강한 삶에 니즈를 충족시키기 위해 실천하는 일상적이고 예방적인 활동으로 정의하여, 활동 수준을 살펴보고 소비자를 유형화하였다. 또한 활동에 인지ㆍ심리적 기제를 설명하기 보호동기이론(Protection motivation theory)을 적용하여 소비자 유형을 결정하는데 미치는 영향을 검증하였다. 이를 20-60대의 대상으로 설문조사를 실시하여 총 1,063명의 자료를 수집하였다. 연구의 결과는 다음과 같다. 첫째, 소비자들의 활동은 식이 활동, 보조기기 사용, 신체 순으로 수행되고 있으며, 구체적으로 걷기, 달리기 및 자전거타기, 건강기능 식품 섭취, 식단 관리, 식사량 조절의 수준이 편으로 나타났다. 둘째, 수준에 따른 유형화를 실시한 결과 활동의 모두 높고 고소득 비중이 ‘적극적 활동형(31.4%)’, 모든...
DNA sequencing using nanopore-based sensors attracts considerable interests because of the possibility ultimate sensitivity single-molecule resolution. Due to fast translocation speed on order microsecond, sensor requires a wide bandwidth exceeding megahertz. Such high frequency signal transmits through electrolyte and measures ionic current changes. The is essential dissolve sample into sensor. However, has not been considered yet. This study presents limitation we believe it should be when...