• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.282-285
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• 2019

A 100-nm gate-length metamorphic high electron mobility transistor(mHEMT) with a T-shaped gate was fabricated using a two-step gate recess and characterized for DC and microwave performance. The mHEMT device exhibited DC output characteristics having drain current($I_{dss}$), an extrinsic transconductance($g_m$) of 1,090 mS/mm and a threshold voltage($V_{th}$) of -0.65 V. The $f_T$ and $f_{max}$ obtained for the 100-nm mHEMT device were 190 and 260 GHz, respectively. The developed mHEMT will be applied in fabricating W-band monolithic microwave integrated circuits(MMICs).

• International Area Studies Review
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• v.18 no.3
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• pp.205-229
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• 2014

Global production networks (GPNs) emerged as multinational companies strategically relocated different stages of their value chain over many regions. Since GPNs require moving materials, parts, components and finished products across national borders multiple times, as well as coordinating it efficiently, they are intensified further within an integrated region. Within the region, developed countries which enjoy a comparative advantage in higher value-added tasks specialize in the production of ICT parts and components and exhibit high export RCA indices while developing countries show high import RCA indices. But, as developing countries upgrade technological capabilities and achieve industrial upgrading through participation in GPNs, their level of sophistication improves. East Asian countries have participated in GPNs to a greater degree when compared to countries in other regions because of a variety of factors. They have benefited much as shown by a significant increase in the level of ICT sophistication and export shares, which in turn led to uneven regional developments of GPNs in the ICT parts and components industry.

• Clean Technology
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• v.28 no.4
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• pp.278-284
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• 2022

This study presents an excellent planar heater based on low-dimensional composites. By optimizing the ratio of 1D carbon nanotubes (CNT) and 2D MXene (Ti₃C₂T_X), it is possible to create a planar heater that has superior electrical conductivity and high heat generation characteristics. Low-dimensional composites were prepared by mixing CNT paste and MXene solution with eco-friendly waterborne polyurethane (WPU). In order to find the optimal mixing ratio for the MXene-CNT-WPU composites, samples with MXene to CNT weight ratios of 3:1, 1:1, 1:3, 1:7, and 1:14 were investigated. In addition to these different weight ratios, 5 wt% WPU was equally applied to each sample. It was confirmed that the higher the weight ratio of CNT, the lower the sheet resistance and the higher the heating temperature. In particular, when the MXene-CNT-WPU planar heater was fabricated by mixing MXene and CNT at a weight ratio of 1:7 and 1:14, the heating temperature was higher than the heating temperature of a CNT-WPU planar heater. These characteristics are due to the optimized mixture of the 1D materials (CNT) and the 2D materials (MXene) causing the formation of a flat surface and a dense network structure. The low-dimensional composites manufactured with the optimized mixing ratios found in this study are expected to be applied in flexible electronic devices.

• 정보화사회
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• s.171
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• pp.22-29
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• 2004

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.2
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• pp.157-160
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• 2019

P(VDF-TrFE-CFE) (Poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)), which exhibits a high electrostriction of about 7%, can transmit tactile output as vibration or displacement. In this study, we investigated the applicability of P(VDF-TrFE-CFE) to wearable piezoelectric actuators. The P(VDF-TrFE-CFE) layers were deposited through spin-coating, and interspaced with patterned Ag electrodes to fabricate a two-layer $3.5mm{\times}3.5mm$ device. This layered structure was designed and fabricated to increase the output and displacement of the actuator at low driving voltages. In addition, a laser vibrometer and piezoelectric force microscope were used to analyze the device's vibration characteristics over the range of ~200~4,200 Hz. The on-off characteristics were confirmed at a frequency of 40 Hz.

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.81-93
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• 2018

Metamaterials are artificial media that can control the properties of waves at will. Active photonic metadevice technologies cover the device and material technologies that control the visible and IR light through an external signal (mainly an electrical signal). The application areas of active photonic metadevices are tremendous for example holography, active HOE, bio imaging, IR imaging, telecommunication, and optoelectronic devices. In this paper, the technical trends and prospects of active metamaterials, active meta holography, active meta devices, nano-optical telecommunication devices, and IR imaging meta devices are reviewed.

• 정보화사회
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• s.102
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• pp.13-16
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• 1996

우리나라의 산업정책은 대기업 중심의 대량생산에 의한 고도 성장정책으로 짧은 기간동안 산업분야별로 다소 차이는 있지만 눈부신 발전을 이룩하였다. 이러한 양적인 성장과정에서 가장 핵심이 되는 기술축적이나 핵심기술의 자체개발은 도외시되어 기초소재, 부품 및 주요기기의 수입의존율이 증가하는 현상이 발생하였고, 국내 생산제품의 개발은 주요국의 부품공급여하에 따라 좌우되는 기현상을 낳게 되었다.

• Electronics and Telecommunications Trends
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• v.37 no.2
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• pp.21-29
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• 2022

Cosmic radiation environments having extremely high-energy particles and photons cause severe malfunctions of electrical components in space and terrestrial regions. In this study, we revisit basic knowledge on radiation effects in ICT electrical devices, such as single event effect, total ionizing dose, and displacement damage. To avoid such soft errors and system failures, we introduce essential technical approaches from the perspectives of materials, layouts, circuits, and systems, including current research trends. By considering several techniques and Space EEE part standards, we suggest possible directions that can invoke New Space Era technology.

• Composites Research
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• v.34 no.1
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• pp.8-15
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• 2021

In the shipbuilding and marine industry, as a technology for reducing the weight of parts to reduce energy and improve operational efficiency of ships is required, a method of applying fibers-reinforced composites which is high-strength lightweight materials, as part materials can be considered. In this study, the possibility of applying fibers-reinforced composites to the pipe support clamps was evaluated to reduce the weight of LNGC. The fibers-reinforced composites were manufactured using carbon fibers and glass fibers as reinforcing fibers. Through the computer simulation program, the properties of the reinforcing materials and the matrix materials of the composites were inversely calculated, and the performance prediction was performed according to the change in the properties of each fiber lamination pattern. In addition, the structural analysis of the clamps according to the thickness of the composites was performed through the finite element analysis program. As a result of the study, it was confirmed that attention is needed in selecting the thickness when applying the fibers-reinforced composites of the clamp for weight reduction. It is considered that it will be easy to change the shape of the structure and change the structure for weight reduction in future supplementary design.

• Electronics and Telecommunications Trends
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• v.36 no.4
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• pp.110-117
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• 2021

The development of core technologies in the 4th Industrial Revolution, such as artificial intelligence, big data, and the intelligent Internet of Things, promote digital transformation and intelligence of the manufacturing industry. To realize them, there is an increasing demand for materials, components, and equipment needed for final goods. In particular, the expansion of global value chain instability due to changes in the external environment, such as the U.S.-China trade dispute, Japan's export regulations, and Covid-19 pandemic, increases the importance of strengthening the materials, components, and equipment industry in the global market. Thus, this study presents a strategic direction for securing global industrial competitiveness of materials, components, and equipment using Michael Porter's diamond model approach.