• Journal of Digital Convergence
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• v.13 no.10
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• pp.33-40
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• 2015

Today the computerization in overall civil life is globally progressing, and software plays a central role in all interdisciplinary areas of society. These changes of information environments lead to the change of values and paradigm shift, and the change of Korean educational policies is also happening. As human-machine interaction is becoming ubiquitous, code literacy is going to play an important role before long. Despite these transitions, information education in universities in Korea focuses on just driving application programs. In this paper, we explore overall educational system and curriculum of universities in Korea. And we present educational factors corresponding to educational levels and contents. Presented five factors coupling three educational contents and three educational levels may be dedicated to design curriculum.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.46-51
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• 2012

Fuel Cell Hybrid Vehicles (FCHVs) have become a major topic of interest in the automotive industry owing to recent energy supply and environmental problems. Several types of power management strategies have been developed to improve the fuel economy of FCHVs including optimal control strategy based on optimal control theory, rule-based strategy, and equivalent consumption minimization strategy (ECMS). The ECMS is applied in this study. This strategy is based on the heuristic concept that the usage of the electric energy can be exchanged to equivalent fuel consumption. This strategy is known as one of the promising solutions for real-time control of hybrid vehicles. The ECMS for an FCHV is introduced in this paper as well as the equivalent fuel consumption parameter. The relationship between the battery final state of charge (SOC) and the fuel consumption while changing the equivalent fuel consumption parameter is obtained for three different driving cycles. The function of the equivalent fuel consumption parameter is also discussed.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.7-18
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• 2007

There are few studies on air pollution due to vehicle emissions in spite of the importance of this field. Therefore, this study describes trends and suggests implications through analysis relating to existing emissions research. This study has been divided into three areas. The first part is about estimating vehicle emissions. In this part, the authors analyze limits in ways of calculating emissions in the existing macroscopic view and then suggest the development of a model for calculating emissions considering velocity and acceleration. These variables are a function of traffic and individual driving behavior in the microscopic view. The second part is about management techniques for reducing vehicle emissions. The traffic management techniques for reducing vehicle emissions should conform to regional characteristics. The final part is about traffic operation for reducing vehicle emissions. The authors suggest the development of a micro-simulator and then the development of strategies for traffic operation. It is necessary to design better models estimating emissions and then, using real time data, to make a monitoring system simulating emission rates. This study serves as a literature review to make a foundation for further research about emissions research for transportation engineering.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1491-1496
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• 2009

This paper presents an digital based input/output interface circuit for controlling and monitoring the Diesel Engine Generator for emergency. In order to monitor and control of the Emergency Diesel Engine Generator, controlling and monitoring circuits need 5 analog input channels, 2 pick-up coil measuring circuits, 10 digital input channels containing Broken Wire Detect function, and 7 relay control signal output channels. This system performs signal processing of input signal taking advantage of simple filter circuit, photo-coupler and comparator circuit at analog input parts, and output signals for main relay is designed acting by double control, so it prevents malfunction completely. And it improves accuracy of speed input signal by applying digital circuit that processes rick-up coil signal.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.518-525
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• 2016

This paper presents the characteristics of non-fundamental multi-mode combustion instability and the effects of high-harmonic components on the Rayleigh criterion. Phenomenological observations of multi-harmonic-mode dynamic pressure waves regarding the intensity of harmonic components and the source of wave distortion have been explained by introducing examples of second- and third-order harmonics at various amplitudes. The amplitude and order of the harmonic components distorted the wave shapes, including the peak and the amplitude, of the dynamic pressure and heat release, and consequently the temporal Rayleigh index and its integrals. A cause-and-effect analysis was used to identify the root causes of the phase delay and the amplification of the Rayleigh index. From this analysis, the skewness of the dynamic pressure turned out to be a major source in determining whether multi-mode instability is driving or damping, as well as in optimizing the combustor design, such as the mixing length and the combustor length, to avoid unstable regions. The results can be used to minimize errors in predicting combustion instability in cases of high multi-mode combustion instability. In the future, the amount of research and the number of applications will increase because new fuels, such as fast-burning syngases, are prone to generating multi-mode instabilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1245-1255
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• 2009

Recently, to analyze the cause of the railway accident objectively and quickly and prevent the accident, many countries are legislating for the installation of the black box what we call an event recorder, which records information about the operation of railway vehicle. Thus, the study of the event recorder has been in progress. Moreover, the analysis software that can analyze and express the stored data in the event recorder is required for the correct decision on the accident. Therefore, in this paper, we presented a design of analysis software which analyzes the data, plays the audio and video in the event recorder system. This software can quickly and accurately identify the cause of the accident and recognize the driving patterns and habits of the driver according to the operating section. In addition, by analyzing the audio and video data simultaneously in the previous accident, we expect that it is possible to prevent accidents in advance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.53-60
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• 1996

The 8W hybrid MIC SSPA has been developed in the frequency range from 14.0 GHz to 14.5 GHz for uplink of KOREASAT's earth station. The whole system was designed of two parts with driving amplifier and high power amplifier to simplify the fabrication process. we reduced weight and volum of power amplifier through arranging the bias circuits in the same housing. The realized SSPA has a small signal gain of $26\pm1dB$within 500 MHz bandwidith, and the input and output return losses are over 7dB and 12dB respectively. The output power of 39.0 ~ 39.2dBm is achieved at the 1dB gain compression point of 14 GHz, 14.25 GHz, and 14.5 GHz. That reveals higher power than 8W of design target. The proposed SSPA manufacture techni- ques in this paper can be applied to the implementation of power amplifiers for some radars and SCPC.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.6
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• pp.383-389
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• 2016

Based on a surface design with rectangular cavities and channels, we investigated the effects of gravity and capillary pressure on pool-boiling Critical Heat Flux (CHF). The microcavity structures could prevent liquid flow by the capillary pressure effect. In addition, the microchannel structures contributed to induce one-dimensional liquid flow on the boiling surface. The relationship between the CHF and capillary flow was clearly established. The driving potentials for the liquid supply into a boiling surface can be generated by the gravitational head and capillary pressure. Through an analysis of pool boiling and visualization data, we reveal that the liquid supplement to maintain the nucleate boiling condition on a boiling surface is closely related to the gravitational pressure head and capillary pressure effect.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.5
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• pp.352-360
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• 2015

Squeal noise is a harsh, high-pitched sound that occurs when railways are running at sharp curve tracks. The cause of squeal noise is known to be the transient lateral traction force between wheel and rail. Field measurements are too difficult to control the parameters. Thus, the scaled test rig should have been made in order to investigate the generating mechanism of squeal noise. The unique feature of our test rig, HSTR(Hongik Squeal Testing Rig), is that DOFs of its wheelset are as close to as those of the real railway. The attack angle and running speed of the rail roller are controlled in real time for simulating a transient characteristic of driving curve. The environment conditions, such as given axle load, running speed, and wheel's yaw angle have been identified for generating squeal noise and the squeal noise itself has been measured. The relation between wheel creepage and creep force in lateral direction and the criteria for squeal noise have been investigated, which results has been verified by finite element method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.180-184
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• 2007

For driving a sinusoidal type permanent magnet synchronous motor with a maximum continuous torque, a $120^0$ delayed three phase sinusoidal current input which matched with the absolute rotor position is needed at a stator coil. So, the detection of absolute rotor position is required inevitably. Thus the right angle relationship between stator magnetic field and rotor magnetic field has to be preserved at a stator by this commutation action. The detection of a absolute position for the commutation can be made generally by the output signal analysis of the encoder attached at a motor shaft. This study purposes to design signal processing logic circuits which can detect the absolute position of motor with a modem encoder system and generate the three reference wave for making sinusoidal current input at a stator coil.