• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.9
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• pp.398-405
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• 2001

The maximum and mean indicated pressure of two stroke low speed diesel engine has been continuously increased with a view of increasing engine power and also reducing fuel consumption. As a result, axial excitation has been increased comparing to that of the previous one. So the axial vibration damper in standard one is applied to all two stroke low speed diesel engine at the free end of crankshaft. Though many studies were carried out for marine use, few has been made for diesel power plant because there was little demand for power plant. Nowadays, diesel engine is much to be used for many benefits. In this paper, the optimum design of axial vibration on the 65 kW diesel power plant with tow 9K80MC-S engines of 9 cylinders was carried out. And the axial-torsional coupled vibration of this shafting system is identified by theoretical analysis and vibration measurement.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.5
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• pp.169-179
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• 2019

During the initial design stage of apartment complex, the photovoltaic(PV) system has been considered as an alternative of renewable energy system and planned to install at the rooftop floor level in general. The electric power generation characteristics can be influenced by the block layout, building orientation and roof top structure because of azimuth angle, tilt angle, and partial shading. This study aims to investigate power generation characteristics of photovoltaic system in apartment buildings by considering the partial shading conditions due to the block layout, building orientation and roof-top structures. For the photovoltaic module arrangement planning in rooftop floor level, shading areas were firstly analyzed due to the adjacent building structure. And the annual and seasonal power generation of PV system were analyzed through the PVsyst simulation results. The results show that shading period at the roof top surface can be increased due to the parapet and water tank. Initial design power capacity can be decreased by considering the daily insolation period and distance between PV modules through the shading simulation. As the number of PV modules decreases, the annual power generation can be decreased. However annual power generation per unit area of PV modules can be increased and performance ratio can be increased above 80%. Also the power generation of PV system can be critically affected by building orientation and the performance ratio can be drastically decreased in east-oriented buildings due to the shading problems caused by adjacent structures at roof top level such as parapet and water tank.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.49-51
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• 2012

In this paper, the integration issue, such as an air-side integration design between the gas turbine and air separation unit, is described and analyzed by the exergy and energy balance of the combined-cycle power block in an IGCC power plant. The results showed that the net power of the system was almost same, but that of the gas turbine was decreased as the integration degree increased. The highest exergy loss was occurred in the combustor of gas turbine, which was affected by the chemical reaction, heat conduction, mass diffusion, and viscous dissipation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.2
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• pp.141-146
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• 2009

In this paper, a novel harmonic control circuit has been proposed for the design of high-efficiency power amplifier with Si LDMOSFET. The proposed harmonic control circuit haying the short impedances for the second- and third-harmonic components has been used to design the in/output matching network. The efficiency enhancement effect of the proposed harmonic control circuit is superior to the class-F or inverse class-F harmonic control circuit. Also, when the proposed harmonic control circuit has been adapted to the input matching network as well as the output matching network, the of ficiency enhancement effect of the proposed power amplifier has increased all the more. The measured maximum power added efficiency (PAE) of the proposed power amplifier is 82.68% at 1.71GHz band. Compared with class-F and inverse class-F amplifiers, the measured maximum PAE of the proposed power amplifier has increased in $5.08{\sim}9.91%$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.151-152
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• 2018

In the domestic nuclear power industry, concern about safety of nuclear power plants is continuously increased with the Fukushima nuclear power plant accident. In order to enhance the safety of nuclear power plants, it is important to ensure that the power plants are operating with proper margin within the original design bases. Margin management is the process of ensuring that the NPP designer and operator are aware of the physical and operating limits, and potential and probability of failure, for each component in the plant. All components are subject to margin considerations, but the most important components by scope and attention are those related to safety-related systems and NPP safe shutdown.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.180-182
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• 1994

In an electron storage ring of Pohang Light Source (PLS), electrons lose their energy in every turn by the synchronous radiation. A high power RF amplifier is employed to compensate the electron energy that is lost by the synchronous radiation. The specification of RF amplifier is an continuous output power of 60 kW at 500.082 MHz operating frequency. The power is supplied to RF cavities in the storage ring tunnel. Total number of amplifier system currently required is three. Tile total number will be increased upto five as the operating condition of storage ring is upgraded. The RF amplifier is mainly consisted of a high voltage DC power supply, an intermediate RF power amplifier (IPA), and a klystron tube. In this article, the design of RF amplifier system and characteristics of the klystron tube will be discussed.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.172-180
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• 1999

The major subject of this paper is to develop the concept fur a Korea high speed train system and recommend to train configuration. High speed train configurations are basically concerned traction power(train configurations with concentrated; CPT or distributed Power system: DPT) and train design(single car as compared with articulated bogies). The result of configuration, a advantages and disadvantaged were necessitated by different train configurations; -distributed underfloor power have an increased length for the seats by 15% as compared with the concentrated power trait - articulated trainsets are characterised by less of number of bogies and reduced values of mass, train resistance, noise and vibration. from the result, the optimized train concept combining high seat capacity per train length with low weight and train resistance is 400m long, single -floor train composed of two symmetrically arranged half trainsets. Therefore, at this work recommended distributed train system However, the final decision of Korea high speed train configuration was concentrated power train and articulated bogie system. The configuration of trainset was 20cars included 2 power cars, 4 motorized cars and 14 trailer cars.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.4
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• pp.172-178
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• 2003

This paper examines the application of high voltage static var compensator(SVC) with cascade multilevel inverter which employs H-bridge inverter(HBI). This method has the primary advantage that the number of voltage levels can be increased for a given number of semiconductor devices when compared to the conventional control methods. The SVC system is modeled using the d-q transform which calculates the instantaneous reactive power. This model is used to design a controller and analyze the SVC system. From the mathematical model of the system, the design procedures of the circuit parameters L and C are presented in this thesis. To meet the specific total harmonic distortion(THD) and ripple factor of the capacitor voltage, the circuit parameters L and C are designed. Simulated and experimental results are also presented and discussed to validate the proposed schemes.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.4
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• pp.734-738
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• 1989

As a basic study of optimum design conditions of the heat engines, Curzon-Ahlborn cycle has been analyzed by considering the capacity of heat exchanger as a design parameter. The result shows that the maximum power output is just unity. In addition, the optimum ratio is slightly decreased from the unity as the irreversibility of the cycle is increased.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.186-192
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• 2014

Recently wind energy penetration into power systems has increased. Wind power, as a renewable energy source, plays a different role in the power system compared to conventional power generation units. As long as only single and small wind power units are installed in the power system, wind power does not influence power system operation and can easily be integrated. However, when wind power penetration reaches a significantly high level and conventional power production units are substituted, the impact of wind power on the power system becomes noticeable and must be handled. The connection of large wind turbines and wind farms to the grid has a large impact on grid stability. The electrical power system becomes more vulnerable to and dependent on wind energy production, and therefore there is an increased concern about the large wind turbines impact on grid stability. In this work, a new type of fuzzy logic controller for the frequency control of wind farms is proposed and its performance is verified using SimWindFarm toolbox which was developed as part of the Aeolus FP7 project.