• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.809-810
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• 2006

An H.264 algorithm is commonly used for video compression applications. This algorithm requires a large number of data computations, for example, the sum of absolute difference (SAD) operation. We analyzed H.264 reference encoding workloads. The H.264 encoding program has 8.78% SAD operation. The SAD operation is to sum up 16 difference-values in H.264 $4{\times}4$ sub-blocks. In order to accelerate SAD operations, we implemented an application specific instruction-set processor (ASIP) that can execute SAD and data transfer instructions. The proposed coprocessor has an absolute value generator and a carry save adder (CSA) unit to sum up 8 difference-values per one clock cycle. We completed SAD operation in 2 clock cycles. Experimental results show that the performance is improved by 34% of total execution time.

• 대한전기학회논문지:전력기술부문A
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• 제48권5호
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• pp.517-523
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• 1999

The Start-up transformers or on-site stand-by transformers are installed for the start-up and shut-down of generator and emergency status in unclear power plant. The on-site power supply configuration using these transformers must be detemined by considering configuration requirements, site characteristics, reliability and availability severely because it is remarkably important for safety and benefit of plant. The start-up or stand-by power supply configuration has been determined considering only safety requirements and construction cost up to now in Korea. I study various reliability estimating methods for the prediction of availability, and estimate the unavailability for the start-up power supply system of two 1,000㎿ unclear power plants. I also detemine the reliability and unavailability and unavailavility of equipment, system and configuration using FTA method.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1038-1045
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• 2017

To address mounting concerns over global warming, the Paris Agreement was reached in December 2015, which aims to limit the increase in global average temperature. South Korea has set a highly ambitious target to reduce emissions and submitted an Intended Nationally Determined Contribution (INDC). Based on the INDC, we investigated the impact of limiting carbon emissions on the power system and the electricity market in Korea. Through detailed simulations on assumed plausible scenarios, this work highlights a) the effects of different carbon emission targets on the annual carbon emission volumes, generation costs, and carbon price; b) the generation mix changes induced by carbon emission limits; and c) the difference in system marginal price and payments for generator owners that carbon emission constraint creates in electricity markets under three different pricing rules.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.226-229
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• 1987

This paper was aimed to, using a new data structure, develop a set of algorithms to execute the output function of Digital System. These functions were represented as directed, acyclic graphs. by applying many restrictions on vertices on graph, the efficient manipulation of boolean function was accomplished. The results were as follows; 1. A canonical representation of a boolean function was created by the reduction algorithm. 2. The operation of two functions was accomplished using t he apply algorithm, according to the binary operator. 3. The arguments having 1 as the value nf function were enumerated using the satisfy algorithm. 4. Composing TTL 74181 4-bit ALU and 74182 look-ahead carry generator, the ALU having 4-bit and 16-bit as word size was implemented.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권2호
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• pp.82-89
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• 2004

In this paper, an active magnetic bearing(AMB) system is designed and controlled using a digital Proportional-Integral-Derivative(PID) control concept. The plant dynamics consisting of actuator and rigid rotor dynamics are described. A digital PID controller with a global control and a local control concept is designed and implemented using digital signal processor. Some experiments are conducted with each global control and local control concept. These include start-up test, impulse test, whirl response, and generator load test. The experimental results and comparison between those of a global control and a local control indicate that the global control of concept has impressive static and dynamic control performance for the prototype considered. From the whirl test, the developed system set can be controlled within about $\pm10\mu\textrm{m}$ gap variation at the rotational speed of 6000rpm and generate the AC power of frequency of $60\textrm{Hz}$, voltage of 100V and current of 0.8$\textit{A}$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3147-3149
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• 1999

In this paper, we develop a TMS320C31- 60 DSP board to generate spiral gradient waveforms for Spiral imaging, one of the ultra fast MRI methods. In Spiral imaging, accurate gradient waveforms are very important to acquire high quality image. For this purpose, sampling rate for generating the gradient waveforms is set twice as high as the data sampling rate. With the developed DSP board accurate gradient waveforms are obtained. Ultra fast MR image with the developed DSP board is currently under development.

• 한국항해학회지
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• 제20권2호
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• pp.97-107
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• 1996

The method of Electromagnetic Wave Immunity Test is continuously endeavored by IEC and CISPR as international unification, but it has not been established yet. The main reason is why it is difficult to obtain the measurement method and normalization of threshold to find out the complicated parameters for Electromagnetic Wave immunity Test. So far, thus, the Electromagnetic Wave Immunity Test is carried out case by case as the electromagnetic environment, which is set up Electromagnetic Wave Immunity Test. This study has developed an algorithm and measurement software suitable for IEC1000-4 Regulations, where a ready-made Amplifier, and Signal Generator have been used and an interconnecting Interface Board has been constructed for connecting with the other apparatuses, i.e., RF Switch, Power Meter, Field Sensor, Pre-Amp., etc. Therefore, we have achieved the aim to develop an automated software using OOP method and the measurement system.

• 전기학회논문지
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• 제57권4호
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• pp.617-624
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• 2008

This paper proposes design and implementation of wind turbine simulators which incorporate the turbine dynamic characteristics. At first, the turbine output characteristic in steady state is modelled as a function of wind speed and then dynamic characteristics are modelled such as pitch angle control, torsional vibration, tower shadow effect, wind shear effect, and inertia effect. In addition, a wind speed simulator is developed which can generate the real wind speed pattern. The wind turbine simulator is implemented with 3[kW] M-G set(cage-type induction motor coupled with doubly-fed induction generator) at laboratory.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.2953-2959
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• 2021

A new practical modeling of the Norton's power law creep is proposed and implemented to analyze the high temperature behaviors of Alloy 690 SG tube material. In the model, both the stress exponent n and the rate constant B are simply treated as the temperature dependent parameters. Based on the two-step optimization procedure, the temperature function of the rate constant B(T) was determined for the data set of each B value after fixing the stress exponent n value by using the prior optimized function at each temperature. This procedure could significantly reduce the numerical errors when using the power law creep equations. Based on the better description of the steady-state creep rates, the experimental rupture times could also be well predicted by using the Monkman-Grant relationship. Furthermore, the difference in tensile strengths at high temperatures could be very well estimated by assuming the imaginary creep stress related to the given strain rate after correcting the temperature effects on the elastic modulus.

• International Journal of Internet, Broadcasting and Communication
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• 제13권1호
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• pp.243-248
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• 2021

Although many different types of covert channels have been suggested in the literature, there are little work in directly applying game theory to building up covert channel. This is because researchers have mainly focused on tailoring game theory for covert channel analysis, identification, and covert channel problem solving. Unlike typical adaptation of game theory to covert channel, we show that game theory can be utilized to establish a new type of covert channel in IoT devices. More specifically, we propose a covert channel that can be constructed by utilizing the Nash Equilibrium with sensor data collected from IoT devices. For covert channel construction, we set random seed to the value of sensor data and make payoff from random number created by running pseudo random number generator with the configured random seed. We generate I × J (I ≥ 2, J ≥ 2) matrix game with these generated payoffs and attempt to obtain the Nash Equilibrium. Covert channel construction method is distinctly determined in accordance with whether or not to acquire the Nash Equilibrium.