• Journal of Powder Materials
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• v.18 no.6
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• pp.517-525
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• 2011

In this study, the used DOCs, which could remove the air pollutants such as CO and HC in the exhaust gas from diesel vehicle, were remanufactured by various conditions. Their catalytic performances and characterization were also investigated. The remanufacturing process of the deactivated DOCs includes high temperature cleaning of incineration, ultrasonic cleaning for washing with acid/base solutions to remove deactivating materials deposited to the surface of the catalysts, and active component reimpregnation for reactivating catalytic activity of them. The catalytic performance tests of the remanufactured DOCs were carried out by the diesel engine dynamo systems and chassi dynamo systems in CVS-75 mode. All prepared catalysts were characterized by the optical microscopes, SEM, EDX, porosimeter and BET to investigate correlations between catalytic reactivity and surface characteristics of them. The remanufactured DOCs at various conditions showed the improved catalytic performances reaching to 90% of fresh DOC, which is attributed to remove the deactivating materials from the surface of the used DOC through the analysis of catalytic performance test and their characterization.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.216-218
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• 2006

The application of aluminium alloy is increasing for lightweight and high quality transport vehicle. In this study, therefore, it is intended to apply the high speed hybrid welding method for marine grade aluminium alloy(A5083) used for shipbuilding that consists of 3 kW CW Nd:YAG laser and MIG welding process. For this purpose, the characteristics of process parameters(laser & arc combine angle and focal position of hybrid head to specimen) are investigated for hybrid fillet joint. This study also describes determination of heat distribution using finite element model of the T-joint fillet weld using the in-house solver which has been validated for different type of welding problems.

• Electronics and Telecommunications Trends
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• v.35 no.5
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• pp.112-122
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• 2020

In 3D computer graphics, a depth map is an image that provides information related to the distance from the viewpoint to the subject's surface. Stereo sensors, depth cameras, and imaging systems using an active illumination system and a time-resolved detector can perform accurate depth measurements with their own light sources. The 3D image information obtained through the depth map is useful in 3D modeling, autonomous vehicle navigation, object recognition and remote gesture detection, resolution-enhanced medical images, aviation and defense technology, and robotics. In addition, the depth map information is important data used for extracting and restoring multi-view images, and extracting phase information required for digital hologram synthesis. This study is oriented toward a recent research trend in deep learning-based 3D data analysis methods and depth map information extraction technology using a convolutional neural network. Further, the study focuses on 3D image processing technology related to digital hologram and multi-view image extraction/reconstruction, which are becoming more popular as the computing power of hardware rapidly increases.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.54-58
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• 2006

There are many kinds of propellant tank for space systems, which should be designed and manufactured considering lots of conditions such as pressure of inside and outside, temperature and weight, etc. Among them, it is the one of the most important factors that the tanks could be designed to suspend and support the applied static and dynamic loads. Tank mounting, that installs and supports a tank in the structure, is a method that should be considered the rigid and tight jointing mechanism, including the manufacturing simplicity, the light weight and the economical budget. Methods and features for several propellant tank mountings are introduced in this paper with the applications for those in some foreign space program.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.104-117
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• 1999

The Composite materials has been used in the field of high technology industry because of high specific stiffness and high specific strength. Specially, the composite materials has been widely applied to the field of the aircraft and the transportation by the effectiveness of light weight due to low specific weight and reduction of the parts due to bonding, molding and so on. These advantages about the composite have led to study and apply in the transmission shaft for the aircraft and the drive shaft for the automobile. The composite material propeller shaft with the high vibrational stability was designed and analyzed. In order to verify the analysis, two types of experimental test which are the FFT analyzer with impact hammer and the rotational equipment were applied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.231-234
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• 2001

OBD-II regulations are already effective in many countries. The California Air Resources Board(CARB) first issued regulations in 1985 for the 1988 model year, known as OBD-I, and required the vehicle's engine management computer to warn the driver by means of a dash-mounted light if a malfunction occurred in either the oxygen sensor, the exhaust gas recirculation(EGR) valve or the evaporative emission system purge solenoid, and to store information on troubles that have no recurrent characteristics. This paper presents two methods of wireless monitoring OBD signal, which is one of the ECU output for self diagnostic measurement. RF module is used to monitor ECU's Self diagnostic signal remotely. Two kinds of measurement systems which are based on micro-controller(80C196KC) for portable detection and PC for sever are considered for receiving the RF signal. Therefore, possibility of real-time monitoring of ECU's self diagnostic signal remotely is verified on this paper.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.150-157
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• 2016

In this paper, a control system for E-bike based on IOT was developed, which collects and monitors information of states of E-bike and surrounding environments from several sensors and control devices in E-bike, and informs the possible dangers to rider when riding the E-bike. Developed electronic control system can manage battery efficiently, obtain battery's remaining power in real-time and provide possible riding distance to rider. It makes possible for rider to schedule near optimal riding route in terms of battery usage and respond quickly to battery discharge. Results of applying developed system to E-bike show that according to driving-mode, possible driving distance can be calculated efficiently and using user application App, real-time driver position marking and driving route searching functions lead to energy efficient E-bike driving. Later we will endeavor to integrate BMS, ECU, smart-phone and PC(server) to provide stable driving system based on various driving information of E-bike.

• Journal of Broadcast Engineering
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• v.20 no.6
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• pp.928-937
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• 2015

A portable head up display (HUD) using the optical combiner lens with a 0.47inch LCD panel for a portable multi-windows virtual display is proposed. The proposed system consists of several micro panels, optical devices, and RGB 3in1 light-emitting diodes (LED) for making the full color display, and video and audio format for the high definition multimedia interface (HDMI) for the connecting between HUD and mobile phone. The multi-windows HUD is designed as an alternative to conventional built-in type HUD targeting the mass volume aftermarket at an affordable price.

• Journal of Korea Foundry Society
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• v.30 no.1
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• pp.46-51
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• 2010

Recently, automotive industry is attempting to replace steels for automotive parts with light-weight alloys such as aluminum alloy, because of the growing environmental regulations governing exhaust gas and the engine effectiveness of a vehicle. The low cycle fatigue (LCF) and high cycle fatigue (HCF) properties as well as the microstructure and tensile property were investigated on the low pressure cast A356 aluminum alloy wheel, which was followed by T6 heat treatment. The cast microstructure of the alloy influenced significantly on the low cycle and high cycle fatigue behaviors. The rim part of cast aluminum alloy wheel showed higher low cycle and high cycle fatigue strength compared with the spoke part, which should be caused by higher cooling rate of rim part. The spoke part of the wheel showed coarser dendrite arm spacing (DAS) and wide eutectic zone in the microstructure, which resulted in the partial brittle fracture and lower fatigue life time.

• Advances in aircraft and spacecraft science
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• v.4 no.4
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• pp.487-501
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• 2017

The main purpose of the paper is to analyze effect of geometrical parameters of the reentry capsules such as radius of the spherical cap, shoulder radius, back shell inclination angle and overall length on the flow field characteristics. The numerical simulation with viscous flow past ARD (Atmospheric Reentry Demonstrator), Soyuz (Russian) and OREX (Orbital Reentry EXperimental) reentry capsules for freestream Mach numbers range of 2.0-5.0 is carried out by solving time-dependent, axisymmetric, compressible laminar Navier-Stokes equations. These reentry capsules appear as bell, head light and saucer in shape. The flow field features around the reentry capsules such as bow shock wave, sonic line, expansion fan and recirculating flow region are well captured by the present numerical simulations. A low pressure is observed immediately downstream of the base region of the capsule which can be attributed to fill-up in the growing space between the shock wave and the reentry module. The back shell angle and the radius of the shoulder over the capsule are having a significant effect on the wall pressure distribution. The effects of geometrical parameters of the reentry capsules will useful input for the calculation of ballistic coefficient of the reentry module.