• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.255-257
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• 2006

This paper proposed a platform which includes both Network processor and DSP for flexible IED. The Network processor is one of the Intel's IXP4XX Product Line family and the DSP is one of the TI's C6000 family. An embedded Linux is ported in Network processor so that a DSP program can be downloaded to Network processor through ethernet and then downloaded to DSP. Using this method, various algorithms according to IED can be applied to the Network processor board. Maximum ten ADCs can be connected because there is a CPLD between DSP and ADC. That is, the network processor board which can measure maximum 40 channels is implemented. In DSP program, thread and double buffering methods are used not to miss voltage samples. The Network processor board is verified using a method that eight channel voltage signals converted to digital are transmitted to server through both DSP and IXP425.

• The Journal of Korea Robotics Society
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• v.11 no.3
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• pp.140-145
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• 2016

In this paper, we fabricate arrayed-type flexible capacitive touch sensor using liquid metal (LM) droplets (4 mm spatial resolution). Poly-4-vinylphenol (PVP) layer is used as a dielectric layer on the electrode patterned Polyethylene naphthalate (PEN) film. Bonding tests between hydroxyl group (-OH) on the PVP film and polydimethylsiloxane (PDMS) are conducted in a various $O_2$ plasma treatment conditions. Through the tests, we can confirm that non-$O_2$ plasma treated PVP layer and $O_2$ plasma treated PDMS can make a chemical bond. To measure dynamic range of the device, one-cell experiments are conducted and we confirmed that the fabricated device has a large dynamic range (~60 pF).

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.353-356
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• 2005

We have characterized the mechanical stability of the Pixel-Isolated Liquid Crystal (PILC) mode for plastic LC display applications. In our device, the LC molecules are fully isolated in the pixels by the phase-separated polymer walls. The experimental results of microscopic observation and electro-optic characterization show that our flexible PILC device has good mechanical stability against external point pressure or bending distortion due to the polymer walls in our structure.

• The Journal of Korea Robotics Society
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• v.3 no.4
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• pp.323-330
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• 2008

This work deals with a 4-DOF flexible continuum robot that employs a spring as its backbone. The mechanism consists of two modules and each module has 2 DOF. The special features of the proposed mechanism are the flexibility and the backdrivability of the whole body by using a spring backbone. Thus, even in the case of collision with human body, this device can ensure safety. The design and the kinematics for this continuum mechanism are introduced. The performance of this continuum mechanism was shown through simulation and experiment.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.129-129
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• 2003

전기변색(electrochromism)은 전기화학적 산화, 환원 과정을 통해 가역적인 광학특성의 변화를 갖는 현상을 말하며, 이를 이용한 전기변색소자(electrochromic device)는 전력 소모가 적고 변색효율이 크다는 장점으로 인해 smart window, display, mirror 등에 응용될 수 있다. 전기변색소자는 구조상 투명 기판, 투명 전도체, 환원 착색 물질 (cathodic coloration material), 산화 착색 물질(anodic coloration material), 그리고 투명 이온 전도체로 구성된다. 일반적으로 투명 기판으로는 열적 안정성이 좋은 유리기판을 사용하여 window에 응용할 수 있는 장점이 있는 반면 다양한 형태를 갖는 소자를 제작하기에는 그 한계가 있다.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.02a
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• pp.249.1-249.1
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• 2009

• Journal of the Microelectronics and Packaging Society
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• v.21 no.2
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• pp.1-11
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• 2014

Flexible transparent conductive electrodes (TCEs) have recently attracted a great deal of attention owing to rapid advances in flexible electronic devices, such as flexible displays, flexible photovoltanics, and e-papers. As the performance and reliability of flexible electronics are critically affected by the quality of TCE films, it is imperative to develop TCE films with low resistivity and high transparency as well as high flexibility. Indium tin oxide (ITO) has been the most dominant transparent conducting material due to its high optical transparency and electrical conductivity. However, ITO is susceptible to cracking and delamination when it is bent or deformed. Therefore, various types of flexible TCEs, such as carbon nanotube, conducting polymers, graphene, metal mesh, Ag nanowires (NWs), and metal mesh have been extensively investigated. Among several options to replace ITO film, Ag NWs and metal mesh have been suggested as the promising candidate for flexible TCEs. In this paper, we focused on Ag NWs and metal mesh, and summarized the current development status of Ag NWs and metal mesh. The several critical issues such as high contact resistance and haze are discussed, and newly developed technologies to resolve these issues are also presented. In particular, the flexibility and durability of Ag NWs and metal mesh was compared with ITO electrode.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.9-19
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• 2016

Accurate models of the characteristics of typical inverse-time overcurrent (OC) protective devices play an important role in the protective coordination schemes. This paper presents a novel approach to determine the OC protective device parameters. The approach is based on the Eigensystem Realization Algorithm which generates a state space model to fit the characteristics of OC protective devices. Instead of the conventional characteristic curves, the dynamic state space model gives a more exact fit of the OC protective device characteristics. This paper demonstrates the feasibility of decomposing the characteristic curve into smooth components and oscillation components. 19 characteristic curves from 13 typical and 6 non-typical OC protective devices are chosen for curve-fitting. The numbers of fitting components required are determined by the maximum absolute values of errors for the fitted equation. All fitted equations are replaced by a versatile equation for the characteristics of OC protective devices which represents the characteristic model of a novel flexible OC relay, which in turn may be applied to improve the OC coordination problems in the sub-transmission and distribution systems.

• Transactions of Materials Processing
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• v.25 no.3
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• pp.161-168
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• 2016

Sheet metals are often required to be formed into three dimensional curved shapes for use as skin structures. As a result various sheet metal forming methods, such as press die forming, stretch forming, and line heating have been used over the years in industrial production lines. Although they are extensively used in industry, these methods are not suitable for small quantity batch productions. Studies have been conducted to improve or replace these methods with plausible flexible forming technologies. As a part of these studies, we developed a new and more efficient forming device named flexibly-reconfigurable roll forming (FRRF). The current study presents the process development and experimental verification for the applicability of this device. To improve the efficiency of the FRRF apparatus, several hardware components were invented and a suitable operating program was developed using MFC of visual C++. The ways to make the FRRF apparatus fully functional are also described. Sheet metal was formed into three dimensional shapes using the FRRF apparatus and the final products are presented as evidence for the applicability of the developed device.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.262-263
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• 2011

Flexible electronics, a future technology of electronics, require a low cost integrated circuit that can be built on various types of the flexible substrates. As a potential candidate for this application, a single walled carbon nanotube network is studied as an active device with a scheme of thin film transistor. Transistors are formed on a plastic foil by the Roll-to-Roll (R2R) and the Roll-to-Device (R2D) printing method. For both printing methods, electrical transports for the transistors are presented with the temperature dependence of threshold voltage (V_Th) and mobility from the measured transfer curves at temperatures ranging from 10 K to 300 K. It is observed that ${\mu}=0.044cm^2/V{\cdot}sec$ and V_Th=7.28V for R2R and ${\mu}=0.025cm^2/V{\cdot}sec$ and V_Th=3.10V for R2D, both for the temperature at 300K. Temperature dependence of mobility and V_Th is observed. However for R2R, the temperature dependence of V_Th is constant. It is the difference between, R2R and R2D.