• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12S
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• pp.1237-1241
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• 2003

In this paper, we report a novel RF-MEMS packaging technology with lightweight, small size, and short electric path length. To achieve this goal, we used the ultra thin silicon substrate as a packaging substrate. The via holes lot vortical feed-through were fabricated on the thin silicon wafer by wet chemical processing. Then, via holes were filled and micro-bumps were fabricated by electroplating. The packaged RF device has a reflection loss under 22 〔㏈〕 and a insertion loss of -0.04∼-0.08 〔㏈〕. These measurements show that we could package the RF device without loss and interference by using the vertical feed-through. Specially, with the ultra thin silicon wafer we can realize of a device package that has low-cost, lightweight and small size. Also, we can extend a 3-D packaging structure by stacking assembled thin packages.

• Journal of Power Electronics
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• v.5 no.4
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• pp.247-256
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• 2005

In order to harvest power in an efficient manner from a micro piezoelectric (PZT) device for charging the battery of a remote system, a new AC/DC resonant pulse power converter is proposed. The proposed power converter has two stages in the power conversion process. The first stage includes N-type MOSFET full bridge rectifier. The second stage includes a boost converter having an N-type MOSFET and a P-type MOSFET. MOSFETs work in the $1^{st}$ or $3^{rd}$ quadrant region. A small inductor for the boost converter is assigned in order to make the size of the power converter as small as possible, which makes the on-interval of the MOSFET switch of the boost converter ultimately short. Due to this short on-interval, the parasitic junction capacitances of MOSFETs affect the performance of the power converter system. In this paper, the performance of the new converter is analytically and experimentally evaluated with consideration of the parasitic capacitance of switching devices.

• Journal of the Korea Society of Computer and Information
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• v.18 no.6
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• pp.1-8
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• 2013

In this paper, we design and implement a firmware for low-cost small PCR devices. To minimize machine code size, the proposed firmware controls real-time tasks simultaneously only with support of the hardware interrupt, but without support of the operating system program. The proposed firmware has the host-local structure in which the firmware receives operation commands from PC and sends operation results to PC through usb communication. We implement a low-cost small PCR device with the proposed firmware loaded on microchip PIC18F4550 chip, and verify that the implemented PCR device significantly reduces cost and volume size of existing commercial PCR devices with a similar performance.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.751-756
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• 2018

In smart factories and industrial IoT, all facilities in a factory are monitored over the Internet, thereby facility can reduce the downtime and increase the availiability by preventive maintenance before it breaks down. The abnormal conditions of the major facilities in the plant are caused by abnormal temperature rise, vibration, and variations in noise. Consequently, it is critical to develop a very small smart device that is easily installed in a small space to enable real-time monitoring of the vibration status of the facility. In this study, smart devices were developed for smart factory fault prediction and robustness management using ultra small micro-controllers with WiFi capabilities and MEMS acceleration sensors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2805-2810
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• 2010

The Passive Device called SAW Device of the ID Tag or a small sensor that can replace all of MEMS technology Micro Device. When using SAW Device will be able to replace that sensor control the power needed or separate space. Enlarge the scope of this advantage to use as a platform for various SAW Device is required. However, the current SAW Sensor development has many, but SAW Sensor that can leverage the platform's development is sketchy. Therefore, this paper implements SAW Reader can be measured in SAW Device Using an FPGA more simple and efficient Reader platform.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.35-41
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• 2018

Smart device has become an affordable main computing resource for robotic ap-plications in accordance with a fast growth of mobile internet environment. Since the computing power of smart device has been increased, smart device based ro-bot system attempts to replace traditional robot applications with laptop-based system. Methodologies for acquisition of remote sensory information and control of various types of robots using smart device have been proposed recently. In this paper, we propose a robot control system using a monitoring program and a communication protocol. The proposed system is a combination of an educa-tional programming oriented robot named EPOR-S. as small service robot plat-form and a smart device. Through a simulation study using image processing, the feasibility of combination of the proposed robot monitoring program and control system was verified.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.105-112
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• 2018

The purpose of this study is to develop an application that supports a user in the maintenance of small photovoltaic device. To this end, this study analyzed the maintenance status, related regulations and existing application contents in Korea. According to the analysis results, most users did not maintain device for themselves. In addition, the maintenance market has not been activated due to its low profitability. Regulations on the maintenance of photovoltaic device prescribed by the KESCO and Japanese counterpart were analyzed to establish the standards for photovoltaic device inspection, and an application was developed based on the existing applications and research results. In order to evaluate the completeness and satisfaction of the developed application, it surveyed 52 users and 22 experts. The survey results showed that the completeness was calculated to be 90 points, and the level of satisfaction was 93 points on a 100-point scale. Therefore, it is expected that the maintenance application developed in this study will be useful for users to maintain the photovoltaic device.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1481-1486
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• 2013

The small wind generator with existing mechanical control system has a frequent failure and malfunction, and its maintenance is difficult. In this paper, an electric control method using a boost converter for small wind generator was suggested. The suggested 2-level boost converter control device was manufactured and its experimental operation were conducted on a wind generator with 200 [W] capacity. As a result of experimental device, the control by a boost converter was executed at the point that the output voltage of a wind generator became 36 [V] so it could be identified that the output voltage of a wind generator diminished and then it became 0 [V] after 5 [sec]. Besides, in case of applying the method suggested in this paper to a small wind power generation facility for street lights, it is expected to reduce its maintenance by preventing a frequent failure of a generator and to improve its utilization rate.

• Journal of Korea Multimedia Society
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• v.10 no.2
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• pp.200-208
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• 2007

The noise induced hearing loss, which is one type of the hearing losses, is well known occupational diseases. The prevention of the noise induced hearing loss is very important, because it is unrecoverable. There are some kinds of devices for hearing protection, and those are effective in preventing the noise induced hearing loss. However, people often resist the use of hearing protection devices because they have some difficulties during conversation in wearing the devices. To solve the problem, a small acoustic filter can be used for a hearing protection device. In this paper, we designed several kinds of small acoustic filters and analyzed the characteristics of designed small acoustic filters using Finite Element Analysis (FEA). From FEA results, we proved the characteristics of designed small acoustic filters which vary according to length and diameter. And we found out that the general tendencies of modeled filters using FEA are same as acoustic experiment results of designed filters.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.336-336
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• 2011

Over the past decades, organic semiconductors have been investigated intensely for their potential in a wide range of optoelectronic device applications since the organic materials have advantages for very light, flexible and low cost device fabrications. In this study, we fabricated small-molecule organic solar cells (OSCs) based on chloro[subphthalocyaninato]boron(III) (SubPc) as an electron donor and $C_{60}$ as an electron acceptor material. Recently SubPc, a cone-shaped molecule with $14{\pi}$-electrons in its aromatic system, has attracted growing attention in small-molecule OSC applications as an electron-donating material for its greater open-circuit voltage (VOC), extinction coefficient and dielectric constant compared to conventional planar metal phthalocyanines. In spite of the power conversion efficiency (PCE) enhancement of small-molecule OSC using SubPc and $C_{60}$, however, the study on the interface between donor-acceptor heterojunction of this system is limited. In this work, SubPc thin films at various thicknesses were deposited by organic molecular beam deposition (OMBD) and the evolution of surface morphology was observed using atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM). We also investigated the influence of film thickness and surface morphology on the PCE of small-molecule OSC devices.