202 results match your criteria: "School of Integrated Technology[Affiliation]"

Differences in Interactions with a Conversational Agent.

Int J Environ Res Public Health

May 2020

Department of Future Design, Graduate School of Techno Design, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul 02707, Korea.

Recent technological advances introduced conversational agents into homes. Many researchers have investigated how people utilize and perceive them. However, only a small number of studies have focused on how older adults interact with these agents.

View Article and Find Full Text PDF

This letter proposes a radar interferometric survey system for the ground surface of helicopter landing sites. This system generates high-quality three-dimensional terrain surface topography data and estimates the slope of the site with the required accuracy. This study presents the processing algorithms of the radar system for safe helicopter landing using an interferometric method and also demonstrates the efficiency of the proposed approach based on computer simulation results.

View Article and Find Full Text PDF

3D MTF estimation using sphere phantoms for cone-beam computed tomography systems.

Med Phys

July 2020

School of Integrated Technology and Yonsei Institute of Convergence Technology, Yonsei University, 85, Songdo-gwahak-ro, Yeonsu-gu, Incheon, 21983, South Korea.

Purpose: For cone-beam computed tomography (CBCT) systems, we propose a sphere phantom based method to estimate the full three-dimensional (3D) modulation transfer function (MTF).

Methods: The FDK reconstruction of CBCT system in a local region was modeled by a triple convolution operator. Afterward, we calculated the directional projections of ideal and reconstructed sphere phantoms into a two-dimensional (2D) plane for multiple views.

View Article and Find Full Text PDF

For digital breast tomosynthesis (DBT) systems, we investigate the effects of the reconstruction filters for different data acquisition angles on signal detection. We simulated a breast phantom with a 30% volume glandular fraction (VGF) of breast anatomy using the power law spectrum and modeled the breast mass as a spherical object with a 1 mm diameter. Projection data were acquired using two different data acquisition angles and numbers of projection view pairs, and in-plane breast images were reconstructed using the Feldkamp-Davis-Kress (FDK) algorithm with three different reconstruction filter schemes.

View Article and Find Full Text PDF

Electrochemical local etching of silicon in etchant vapor.

Nanoscale

March 2020

School of Integrated Technology, Yonsei University, Incheon 21983, Republic of Korea. and Yonsei Institute of Convergence Technology, Incheon 21983, Republic of Korea.

Direct machining and imprinting of Si are beneficial for simplifying the fabrication of microelectromechanical systems, nanoelectromechanical systems, optical devices, and fin field-effect transistors, and for reducing process costs. Electrochemical micromachining has been introduced for highly doped Si, but complex structures cannot be imprinted directly. With chemical imprinting, complex nano/micropatterns can be imprinted even on low-doped Si, but the physical contact can damage the templates.

View Article and Find Full Text PDF

Ultra-low contact resistance at the interface between NiGe and p-Ge, i.e., NiGe/p-Ge was achieved by introducing terbium (Tb) as an interlayer in forming NiGe using Tb/Ni/TiN structure.

View Article and Find Full Text PDF

A convolutional neural network-based model observer for breast CT images.

Med Phys

April 2020

School of Integrated Technology and Yonsei Institute of Convergence Technology, Yonsei University, 162-1, Incheon, South Korea.

Purpose: In this paper, we propose a convolutional neural network (CNN)-based efficient model observer for breast computed tomography (CT) images.

Methods: We first showed that the CNN-based model observer provided similar detection performance to the ideal observer (IO) for signal-known-exactly and background-known-exactly detection tasks with an uncorrelated Gaussian background noise image. We then demonstrated that a single-layer CNN without a nonlinear activation function provided similar detection performance in breast CT images to the Hotelling observer (HO).

View Article and Find Full Text PDF

Recently, electronic skin that mimics human skin in measuring tactile stimuli, temperature, and humidity and having a self-healing function was developed. Furthermore, with the advances in the field of artificial intelligence and health monitoring, various materials and methods have been studied for e-skin. The limitations to work on actual human skin include device flexibility and large-area applications through array structures, and many studies are underway to overcome these problems.

View Article and Find Full Text PDF

Hands-Free User Interface for AR/VR Devices Exploiting Wearer's Facial Gestures Using Unsupervised Deep Learning.

Sensors (Basel)

October 2019

Seamless Transportation Lab (STL), School of Integrated Technology, and Yonsei Institute of Convergence Technology, Yonsei University, Incheon 21983, Korea.

Developing a user interface (UI) suitable for headset environments is one of the challenges in the field of augmented reality (AR) technologies. This study proposes a hands-free UI for an AR headset that exploits facial gestures of the wearer to recognize user intentions. The facial gestures of the headset wearer are detected by a custom-designed sensor that detects skin deformation based on infrared diffusion characteristics of human skin.

View Article and Find Full Text PDF

Anodic Imprint Lithography: Direct Imprinting of Single Crystalline GaAs with Anodic Stamp.

ACS Nano

November 2019

School of Integrated Technology , Yonsei University, 85 Songdogwahak-ro , Yeonsu-gu, Incheon 21983 , Republic of Korea.

Anodic imprint lithography patterns the GaAs substrate electrochemically by applying a voltage through a predefined anodic stamp. This newly devised technique performs anodic etching in a stamping manner. Stamps that serve as anodic electrodes are fabricated precisely, and the patterns can be imprinted continuously on GaAs substrates.

View Article and Find Full Text PDF

Hexagonal Boron Nitride for Surface Passivation of Two-Dimensional van der Waals Heterojunction Solar Cells.

ACS Appl Mater Interfaces

October 2019

School of Integrated Technology , Yonsei University, Incheon 21983 , South Korea.

Two-dimensional (2D) semiconductors can be promising active materials for solar cells due to their advantageous electrical and optical properties, in addition to their ability to form high-quality van der Waals (vdW) heterojunctions using a simple process. Furthermore, the atomically thin nature of these 2D materials allows them to form lightweight and transparent thin-film solar cells. However, strategies appropriate for optimizing their properties have not been extensively studied yet.

View Article and Find Full Text PDF

Fluorinated low-viscosity copolymer with enhanced release property for roll-to-plate UV nanoimprint lithography.

Nanotechnology

December 2019

School of Integrated Technology, Yonsei University, 85, Songdo-Gwahak-ro, Yeonsu-gu, Incheon, 21983, Republic of Korea. Yonsei Institute of Convergence of Technology, Yonsei University, 85, Songdo-Gwahak-ro, Yeonsu-gu, Incheon, 21983, Republic of Korea.

A new fluorinated low-viscosity copolymer resin with enhanced release properties has been developed to provide higher fidelity for roll-based ultraviolet (UV) nanoimprint lithography (NIL) and simplify the process. The properties are optimized by blending (2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl) oxirane (EP-F8) and 1,4-butanediol divinyl ether (BDDVE) with 3,4-epoxycyclohexylmethyl-3,4-epoxy cyclohexane carboxylate. The cured resin renders the hydrophobicity and allows demolding from the stamp mold without an anti-stick layer (ASL), as further verified by the contact angle and the work of adhesion measurements.

View Article and Find Full Text PDF

Magnetic nanoparticles (MNPs) that exhibit high specific loss power (SLP) at lower metal content are highly desirable for hyperthermia applications. The conventional co-precipitation process has been widely employed for the synthesis of magnetic nanoparticles. However, their hyperthermia performance is often insufficient, which is considered as the main challenge to the development of practicable cancer treatments.

View Article and Find Full Text PDF

The influence of thermal annealing on the properties of germanium grown on silicon (Ge-on-Si) has been investigated. Depth dependencies of strain and photoluminescence (PL) were compared for as-grown and annealed Ge-on-Si samples to investigate how intermixing affects the optical properties of Ge-on-Si. The tensile strain on thermally annealed Ge-on-Si increases at the deeper region, while the PL wavelength becomes shorter.

View Article and Find Full Text PDF

MacEtch allows subwavelength-structured (SWS) texturing on the GaAs surface without compromising crystallinity. The current density increases greatly, which is directly due to the reduction in the reflectance. Photons absorbed under reduced light reflectance are less affected by the charge recombination arising from crystal defects.

View Article and Find Full Text PDF

A performance comparison of convolutional neural network-based image denoising methods: The effect of loss functions on low-dose CT images.

Med Phys

September 2019

School of Integrated Technology and Yonsei Institute of Convergence Technology, Yonsei University, Incheon, 21983, South Korea.

Purpose: Convolutional neural network (CNN)-based image denoising techniques have shown promising results in low-dose CT denoising. However, CNN often introduces blurring in denoised images when trained with a widely used pixel-level loss function. Perceptual loss and adversarial loss have been proposed recently to further improve the image denoising performance.

View Article and Find Full Text PDF

Theoretical Analysis for Wireless Magnetothermal Deep Brain Stimulation Using Commercial Nanoparticles.

Int J Mol Sci

June 2019

Gwangju Institute of Science and Technology, School of Integrated Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Korea.

A wireless magnetothermal stimulation (WMS) is suggested as a fast, tetherless, and implanted device-free stimulation method using low-radio frequency (100 kHz to 1 MHz) alternating magnetic fields (AMF). As magnetic nanoparticles (MNPs) can transduce alternating magnetic fields into heat, they are targeted to a region of the brain expressing the temperature-sensitive ion channel (TRPV1). The local temperature of the targeted area is increased up to 44 °C to open the TRPV1 channels and cause an influx of Ca sensitive promoter, which can activate individual neurons inside the brain.

View Article and Find Full Text PDF

A performance comparison of anthropomorphic model observers for breast cone beam CT images: A single-slice and multislice study.

Med Phys

August 2019

School of Integrated Technology and Yonsei Institute of Convergence Technology, Yonsei University, 162-1, Incheon, South Korea.

Purpose: In this work, we investigate single-slice and multislice model observers which can predict human observer performance for simulated single-slice and multislice breast cone beam computed tomography (CBCT) images with a constant internal noise level.

Methods: Breast background is generated based on a power spectrum of mammograms, and breast mass is modeled by a spherical signal. Human observer performance is evaluated for detecting 1 and 2 mm signals in different noise structures stemming from different reconstruction filters and image planes in a Feldkamp-Davis-Kress reconstruction.

View Article and Find Full Text PDF

Low-Cost Curb Detection and Localization System Using Multiple Ultrasonic Sensors.

Sensors (Basel)

March 2019

School of Integrated Technology, College of Engineering, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Korea.

Curb detection and localization systems constitute an important aspect of environmental recognition systems of autonomous driving vehicles. This is because detecting curbs can provide information about the boundary of a road, which can be used as a safety system to prevent unexpected intrusions into pedestrian walkways. Moreover, curb detection and localization systems enable the autonomous vehicle to recognize the surrounding environment and the lane in which the vehicle is driving.

View Article and Find Full Text PDF

Resist-Free Direct Stamp Imprinting of GaAs via Metal-Assisted Chemical Etching.

ACS Appl Mater Interfaces

April 2019

School of Integrated Technology, Yonsei Institute of Convergence Technology , Yonsei University, 85 Songdogwahak-ro , Yeonsu-gu, Incheon 21983 , Republic of Korea.

We introduce a method for the direct imprinting of GaAs substrates using wet-chemical stamping. The predefined patterns on the stamps etch the GaAs substrates via metal-assisted chemical etching. This is a resist-free method in which the stamp and the GaAs substrate are directly pressed together.

View Article and Find Full Text PDF

Previous studies have used various external variables and parameters as well as moderator variables such as emotional intelligence have been to understand emotional labor and its related problems. However, a comprehensive model to study such variables' correlations with each other and their overall effect on emotional labor has not yet been established. This study used a structural equation model to understand the relationship between employees' expression of emotional labor and perception of customer feedbacks.

View Article and Find Full Text PDF

Magnetic drug targeting is a promising technique that can deliver drugs to the diseased region, while keeping the drug away from healthy parts of body. Introducing a human in the control loop of a targeted drug delivery system and using inherent bilateralism of a haptic device at the same time can considerably improve the performance of targeted drug delivery systems. In this paper, we suggest a novel intelligent haptic guidance scheme for steering a number of magnetic nanoparticles (MNPs) using forbidden region virtual fixtures and a haptic rendering scheme with multi particles.

View Article and Find Full Text PDF

Peptides have been overlooked for their use in the field of electronics, even though they are one of the most commonly found bio-induced materials, and are not only easy to mass-produce but also exhibit a high dielectric constant. Additionally, unlike proteins, which are gaining considerable interest with materials researchers, peptides are much simpler, rendering their original characteristics easier to maintain without significant alteration of their structure. On the other hand, proteins tend to deform due to their susceptibility to environmental changes.

View Article and Find Full Text PDF

As a means to overcome the limitation of installation space and to promote the utilization of the solar cell in various applications, a transparent thin-film solar cell has been studied by many researchers. To achieve a transparent solar cell, the choice of materials which are transparent enough and showing the photovoltaic property at the same time is the key. Here, we suggest a two-dimensional (2D) p-n heterojunction of WSe/MoS and an indium tin oxide electrode to fabricate a transparent thin-film photovoltaic cell.

View Article and Find Full Text PDF

Purpose: We evaluate the lesion detectability using human and model observer studies in single-slice and multislice cone beam computed tomography (CBCT) images with a breast anatomical background. The purposes of this work are (a) to compare human observer detectability between single-slice and multislice images for different signal sizes and noise structures, (b) to investigate the effect of different multislice viewing modes (i.e.

View Article and Find Full Text PDF