• Journal of Digital Contents Society
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• v.16 no.3
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• pp.355-363
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• 2015

In this paper, we propose a system for controlling the seat of the electric wheelchair depending on the slope of the terrain in real time by using the ATmega smart control based on the board. Smart control board includes a gyro sensor, an acceleration sensor and Tilt sensor, when the electric wheelchairs pass slope of the terrain, they use three sensors to identify terrain configuration in real time. We also applied the Complementary Filter in the gyro sensor and acceleration sensor, so the electric wheelchairs know the exact terrain by solving the interference during the movement. Based on this, the noise power wheelchair due to the movement will be reduced, the seat continues reliably movement without being vibration. In this paper, providing an application on the smart phone platform for the convenience of users who are not familiar with how to use electric wheelchairs, they can easily control wheelchairs. Control platform of the smart phone is able to monitor the electric wheelchair in real-time, with regard to pressure prevention, help the slope of the seat to be arbitrarily controlled.

• JOURNAL OF ELECTRICAL WORLD
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• no.11 s.83
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• pp.30-34
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• 1983

• JOURNAL OF ELECTRICAL WORLD
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• no.4 s.64
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• pp.25-31
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• 1982

• JOURNAL OF ELECTRICAL WORLD
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• no.5 s.65
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• pp.20-24
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• 1982

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1407-1417
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• 2009

Today is the Information age which Internet service acts a most important Information Source. So the Power Line Communication has been achieved to offer Internet service for Last-Mile area. And Research is achieved to frequence range from 30MHz to 80MHz for High-speed communication service. But, Power Line is not suitable for communication, So, electric wave is generated from flow of communication information. And the electric wave is interfered with Wireless Communication Service using the same frequence range. In this paper, a Notch Filter for reduce of interference between Power Line Communication and Wireless Communication Service is proposed. The proposed emulator is developed using TMS320C6416T DSP board of Texas Instruments.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.332-336
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• 2014

A non-electric water purification system using the Korean traditional ceramic ware Onggi, was demonstrated as an appropriate technology to solve water shortages in under developed regions. Generally, Onggi is produced using large size raw materials that are sintered at low temperature, resulting in a porous body that shows air and water permeability. An Onggi filter was prepared using a spinning wheel with the addition of rice bran to the body to increase porosity. The porosity of the obtained Onggi filter was 25.1%; the water permeability was 85.1 $L/m^2h$. Turbidity and TDS of the purified water using Onggi filter were decreased by 97.7% and 29.1%, respectively.

• Journal of the Korean Ceramic Society
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• v.54 no.2
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• pp.114-120
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• 2017

In underdeveloped countries, many people suffer from water shortage due to the absence of water supply service. Although water purifiers have provided support in such situations, it is not easy to maintain water filters without a continuous supply of consumable filters. To obtain a sustainable drinking water source, appropriate technology of water treatment is necessary. Herein, a low cost water purification system was developed using natural raw materials. A non-electric water treatment system was developed using filtration through an Onggi filter, which is a type of Korean traditional earthenware with a microporous surface. The porosity and flux of the prepared Onggi filter were 29.06% and 31.63 LMH, respectively. After purification of water with total dissolved solids of 10.4 mg/L and turbidity of 100 NTU, the total dissolved solids and turbidity of the water treated using the Onggi filter decreased by 12% and 99.8%, respectively.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.2
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• pp.158-165
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• 2012

In this paper, the test bed using three-phase PWM converter connected with single phase inverter in series is set up to configure an active AC electric load. Since the two topologies, three-phase PWM converter and single-phase inverter, can be operated bidirectionally, the system not only re-generates surplus power to grid but also prevents power dissipation. However, the construction of system has a drawback. That is, ripple components two times of inverter operation frequency occur at DC-Link due to cascade connection, it can be cause of three phase unbalance Since the operational characteristic of the active AC electric load, the power frequency entered into the electric load can be varied, and the ripple of DC-Link is changed as well. In this paper, the three-phase PWM converter using a variable notch filter is proposed, and the reduction of three-phase current unbalance is presented. the validity of the proposed PWM converter using a variable notch filter is verified by the simulation and experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.78-89
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• 2015

Conventional EMI filters have tried to use an active EMI filter as a series by the series connection of two EMI filters for CM and DM noise. However, the proposed filter is formed into one circuit by using the active EMI filter which is able to filter CM and DM noise components together. As a result, the active EMI filter showed the outstanding quality in mass and volume under 50% and electric characteristics have been compared to the passive EMI filter in approximately 150kHz~10MHz. Furthermore, the proposed circuit has simple circuit components by comparing with the series EMI filters, and electrical characteristics are similar. The noise have been attenuated to maximum 20dBuV.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.362-368
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• 2001

We study on the velocity matching algorithm for transfer alignment of inertial navigation system(INS) using a robust H$_2$ filter. We suggest an uncertainty model and a discrete robust H$_2$filter for INS and apply the suggested robust H$_2$ filter to the uncertainty model. The discrete robust H$_2$filter is shown by simulation to have better performance time and accuracy than Kalman filter.