• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1342-1344
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• 2002

Wind is a significant and valuable renewable energy resource. It is safe and abundant and can make an important contribution to future clean, sustainable and diversified electricity supplies. Unlike other sources of energy, wind does not pollute the atmosphere nor create any hazardous waste. In some countries wind energy is already competitive with fossil and nuclear power even without accounting for the environmental benefits of wind power. The cost of electricity from conventional power stations does not usually take full account of its environmental impact (acid rain, oil slick clean up, the effects of climate change, etc). In this paper, a transient phenomenon simulation method for Wind Power Generation System(WPGS) under real weather conditions has been proposed. The simulation method is expected to be able to analyze easily under various conditions with considering the sort of wind turbine, the capacity of system and the converter system. Wind turbine connected to the synchronous generator and power converter was simulated.

• Resources Recycling
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• v.20 no.1
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• pp.3-13
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• 2011

Taiwan's annual steel production reached 21.29 million tons. EAF accounted for about half of this total, or 11.2 million tons in 2008. The other 10.09 million tons came from blast furnace and converter process methods. The annual EAF carbon steel production is about 9.76 million tons, and the quantity of dust generated from the EAF process is 160 thousand tons, or about 16kg of dust per ton of steel was produced. In 2009, there is Walez process for carbon steel EAF dust recycling, and the capacity is about 70,000 tons per year; and there is RHF/SAF process for stainless steel EAF dust, the capacity is 60,000 tons per year which is enough to treat stainless steel EAF dust in Taiwan. There are many new treatment facilities processes will be that introduced to recycle the EAF dust in the near future, these processes will perform smoothly and successfully in Taiwan. The estimation of recycled crude ZnO is about 90,000 tons each year. The recycling and upgrading crude zinc oxide will be the next important issue in Taiwn zinc and steel industry.

• Journal of the Korean Ceramic Society
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• v.41 no.4
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• pp.323-327
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• 2004

This study has been carried out to use the municipal solid waste sewage sludge ash generated at sewage disposal field as the raw materials of Ordinary Portland Cement (OPC). Limestone, shale, converter slag, and fly ash were used as the main raw materials. After the raw materials were mixed, these were fired at 1,300, 1,350, 1,400, 1,450, and 1,500$^{\circ}C$ for 1 h and cooled rapidly in air. The properties of clinker synthesized were examined with XRD, SEM, and burnability index by polysius method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12C
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• pp.1131-1137
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• 2009

In this paper, a resource management technique for digital duplexing (DD) systems using orthogonal frequency division multiple access (OFDMA) is proposed. The proposed technique can reduce the dynamic range of the signal received at the subscriber station (SS) and minimize the effects of inter-symbol interference (ISI) and inter-carrier interference (ICI) due to the time difference of arrival (TDoA) without using a cyclic suffix. It is shown by computer simulation that the proposed technique can reduce the number of bits for an analog-to-digital converter (ADC) and increase the signal-to-interference and noise ratio (SINR) significantly.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.237-243
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• 2015

In this paper, we consider a cascaded type of control architecture for a multi motor-based feedback control system and propose an ADC (Analog to Digital Converter) resource allocation method to efficiently utilize the limited ADC resources. The purpose of the resource allocation method is to minimize both the motor position measurement error and the d-q current measurement error. The cascaded type of control architecture is applied in parallel to each motor to independently control the speed of a motor in the multi motor control system. All the control algorithms are implemented by software using a single microcontroller without using additional microcontrollers. It is illustrated by experiments that the speed and the torque of each motor are controlled precisely by the proposed control architecture with the efficient ADC allocation method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.71-77
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• 2015

In this paper, we propose a scheduling method for signal measurement and control algorithm execution in a multi-motor drive controller. The multi-motor controller which is used for vehicle control receives position/velocity command and performs position/velocity control and current control. Internal resource allocation and control algorithm execution timing are very important when one microcontroller is used for multi-motor drives. The control performance of the velocity control system is verified by varying ADC(Analog to Digital Converter) conversion timing and algorithm execution timing using real experiments.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1060-1068
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• 2018

Droop control schemes have been widely employed in the control strategies for Multi-Terminal Direct Current (MTDC) system for its high reliability. Under the conventional DC voltage-active power droop control, the droop slope applies a proportional relationship between DC voltage error and active power error for power sharing. Due to the existence of DC network impedance and renewable resource fluctuation, there is inevitably a DC voltage deviation from the droop characteristic, which in turn results in inaccurate control of converter's power. To tackle this issue, a piecewise droop control with DC voltage dead band or active power dead band is implemented into controller design. Besides, an advanced droop control scheme with versatile function is proposed, which enables the converter to regulate DC voltage and AC voltage, control active and reactive power, get participated into frequency control, and feed passive network. The effectiveness of the proposed control method has been verified by simulation results.

• Journal of Korea Multimedia Society
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• v.13 no.4
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• pp.609-617
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• 2010

Since Korean mobile communication companies each use different mobile platforms, developers must configure and translate their game contents to run under each of the platforms so that they can be serviced correctly. Nevertheless, such translation tasks require lengthy times and costs. This is one of the reasons why a variety of contents could not be provided. In order to mitigate such difficulty, this paper implemented an automatic mobile contents translating system that automatically translates mobile C game contents of the GNEX platform to mobile java contents of the WIPI platform. The GNEX C-to-WIPI Java automatic contents translation system helps minimize the amount of time and cost required in servicing contents to different mobile communication companies by promptly translating a platform-specific-content to run under other platforms. Also, the automatic translation and servicing of existing contents increases the reusability of these contents and also the productivity of new contents thereby offering users with a more variety of games.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.4
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• pp.520-526
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• 2006

Wave Energy is a derivative of the solar energy input to the earth, which is accumulated on open water surfaces by the action of the winds Waves are disturbances in the water surface. This paper is interested primarily in progressive waves, which carry energy from one place to another Waves are irregular in size and frequency. Moreover the surface of the sea is one of the most hostile environments for engineering structures and materials. The idea of harnessing the tremendous power of the ocean's waves is not new. Hundreds of wave energy conversion techniques have been suggested over the last two centuries. Although many WECS (Wave Energy Conversion Systems) have been invented, only a few systems have been tested and evaluated. This paper describes the characteristic of WES (Wave Energy System) in terms of, devices, resource and potential, etc.. Finally, this paper provides a summary of general and specific conclusions and recommendations concerning WECS potential in Korea.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.99-104
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• 2005

The CARB in USA has demanded OBD functions that detect any deterioration of performance of OTS as well as a simple defect of OTS which can affect emission to meet the reinforced emission regulation. In this paper, OTS plausibility monitoring functions to meet the demand from CARB are discussed. The output from OTS is used for the diagnostics of the torque converter clutch stuck and the gear ratio synchronous error. It is possible to diagnose the abnormality of OTS function by considering the oil temperature characteristics which changes according to the driving status of vehicles. In result, the OBD regulations of the CARB can be satisfied obligating car manufacturer to detect any problems in OTS functions which can affect emissions.