• Journal of Magnetics
• /
• v.10 no.3
• /
• pp.103-107
• /
• 2005

Magnetotransport is a prerequisite to realization of electronic operation of spintronic devices and it would be more useful if realized at room temperature. The effects of Be codoping on GaMnAs on magnetotransport were investigated. Mn flux was varied for growth of precipitated GaMnAs layers under a Be flux for degenerate doping via low-temperature molecular beam epitaxy. Magnetotransport as well as ferromagnetism at room temperature were realized in the precipitated GaAs:(Mn,Be) layers. Codoping of Be was shown to promote formation of MnGa clusters, and annealing process further stabilized the cluster phases. The room-temperature magnetic properties of the layers originate from the ferromagnetic clusters of MnGa and MnAs embedded in GaAs. The degenerately doped metallic GaAs matrix allowed the visualization of the magnetotransport through anomalous Hall effect.

• Journal of Magnetics
• /
• v.10 no.3
• /
• pp.99-102
• /
• 2005

Modification in exchange bias of a NiFe/FeMn/NiFe trilayer, on introduction of a nonmagnetic Al layer at the top FeMn/NiFe interface, is investigated in multilayers prepared by rf magnetron sputtering. The introduction of Al layer leads to vanishing of bias of the top NiFe layer. But the bias for the bottom NiFe layer increases steadily with increasing Al layer thickness and attains bias (230 Oe) which is greater than that of the trilayer without the Al layer (150 Oe). When the top NiFe layer thickness is varied, exchange bias has highest value at 12 nm thickness for 1 nm thicknes of Al layer. Ion beam etching of the top NiFe layer also leads to an enhancement in bias for the bottom NiFe layer.

• Current Optics and Photonics
• /
• v.5 no.5
• /
• pp.491-499
• /
• 2021

A scalar Fourier modal method for the numerical analysis of the scalar wave equation in inhomogeneous space with an arbitrary permittivity profile, is proposed as a novel theoretical embodiment of Fourier optics. The modeling of devices and systems using conventional Fourier optics is based on the thin-element approximation, but this approach becomes less accurate with high numerical aperture or thick optical elements. The proposed scalar Fourier modal method describes the wave optical characteristics of optical structures in terms of the generalized transmittance function, which can readily overcome a current limitation of Fourier optics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.371-374
• /
• 2016

In the digital business environment, digital trust has became a key element of business compete. With the Internet of Things(IoT) development, the success of businesses that participate in the world of connected devices depends on the level of digital trust consumers have in them. This paper introduced the definition and elements of digital trust, analyzed status of digital trust in IoT era, then puts forward the countermeasure of strengthening digital trust.

• Journal of information and communication convergence engineering
• /
• v.17 no.3
• /
• pp.221-226
• /
• 2019

In this work, a transmitter/receiver front-end module (T/R FEM) with an automatic Tx/Rx switching scheme for a 2.4 GHz microwave power transfer is developed for a retro-reflective beamforming scheme. Recently, research on wireless power transfer techniques has moved to wireless charging systems for mobile devices. Retro-reflective beamforming is a good candidate for tracking the spatial position of a mobile device to be charged. In Tx mode, the T/R FEM generates a minimum of 1 W. It also comprises an amplitude and phase monitoring port for transmitting RF power. In Rx mode, it passes an Rx pilot signal from a mobile device to a digital baseband subsystem to recognize the position of the mobile device. The insertion loss of the Rx signal path is 4.5 dB. The Tx and Rx modes are automatically switched by detecting the Tx input power. This T/R FEM is a design example of T/R FEMs for wireless charging systems based on a retro-reflective beamforming scheme.

• Journal of Internet Computing and Services
• /
• v.20 no.1
• /
• pp.67-75
• /
• 2019

The Android container is used for various purposes such as Bring Your Own Device (BYOD) solution and Android malware analysis. The strong point of android container than other technologies is it can simulate an android device like a real android phone on a hardware layer. Therefore, automatic management solutions for android container are necessary. This paper introduces a new design of cloud-based management solution for android containers. Through the proposal, android containers are managed automatically from a cloud platform - OpenStack with various tasks like: container configuration, deployment, destroy, android version, hardware device. In addition, the system monitoring and system statistics for android containers and hardware devices are also provided.

• Annual Conference of KIPS
• /
• 2013.05a
• /
• pp.728-730
• /
• 2013

스마트 모바일 기기의 발전으로 고성능, 고효율, 사용성이 급격하게 증가하고 있다, 또한 개인의 용도를 확장한 교육 분야 및 기타 산업분야에 전반적으로 사용되고 있다. 하지만 산업 및 교육 측면에서는 스마트 기기의 화면이 너무 작어서 활용성 및 교육적인 면에서 제약으로 대두되고 있다. 이에 본 연구에서는 스마트 모바일 기기의 화면을 실시간 HD 무선통신을 통한 대형 전자칠판으로 전달하고 또한 대형 전자칠판의 터치 데이터를 스마트 기기에 전달하여 대형 전자칠판에서 스마트폰 기능을 사용가능하게 하는 연구이다.

• Journal of Korean Academy of Dental Administration
• /
• v.8 no.1
• /
• pp.24-29
• /
• 2020

With the advancement of information technology, the application of augmented reality (AR) in dentistry is an emerging research field of image-guided surgery and dental education. In addition, the digital approach to incorporating AR in dental practice management is considered to be feasible. A prototype is developed to apply AR to dental daily clinical practice in order to help dentists to access electronic dental records. This prototype delivers patients' information and related clinical data to dental clinicians directly without the need to search for the appropriate patients. Wearable AR devices are considered to be a convenient tool for practicing dentists because dental practitioners are not always able to use a computer during active clinical sessions, such as implant placement, root canal treatment, and patient-doctor communication. The use of AR to visualize passive transferred patient data would be valuable for practicing dentists.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.5
• /
• pp.678-681
• /
• 2020

In this paper, we analyzed the noise figure of cascode low noise amplifier (LNA) based on the measured data of 65nm CMOS devices. By using the channel thermal noise model of transistors, we expanded noise figure equation and divided the equation into three parts to see its contributions to noise figure. We also varied design parameters such as bias point, transistor gate width, and operating frequency. Our results show that different noise sources dominate at the different operating frequencies. One can easily find the noise transition frequency with device models in ahead of the practical design. Therefore, this research provides a low noise design approach for different operating frequencies.

• Journal of Information Processing Systems
• /
• v.18 no.1
• /
• pp.12-25
• /
• 2022

In recent years, deep convolutional neural networks have made significant progress in the research of single image super-resolution. However, it is difficult to be applied in practical computing terminals or embedded devices due to a large number of parameters and computational effort. To balance these problems, we propose CSRNet, a lightweight neural network based on channel split residual learning structure, to reconstruct highresolution images from low-resolution images. Lightweight refers to designing a neural network with fewer parameters and a simplified structure for lower memory consumption and faster inference speed. At the same time, it is ensured that the performance of recovering high-resolution images is not degraded. In CSRNet, we reduce the parameters and computation by channel split residual learning. Simultaneously, we propose a double-upsampling network structure to improve the performance of the lightweight super-resolution network and make it easy to train. Finally, we propose a new evaluation metric for the lightweight approaches named 100_FPS. Experiments show that our proposed CSRNet not only speeds up the inference of the neural network and reduces memory consumption, but also performs well on single image super-resolution.