• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.54-58
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• 2017

The vessels which are operated in ECA (Emission Control Area) after $1^{st}$ January 2016 shall be complied with revised NOx emission requirement (Tier III). Effective solutions for NOx emission requirement are SCR (Selective Catalytic Reduction), EGR (Exhaust Gas Recirculation) and Installation of LNG Dual Fuel Engine. This study is considered the design modification as per application of LNG Ready notation. In case of LNG Ready - S notation, the vessel shall be retrofitted the Main engine with Dual fuel engine and LNG Fuel system after delivery. On this paper, the entire process for design modification was explained to meet the requirement for LNG Ready notation.

• Journal of the Korean Society of Visualization
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• v.8 no.1
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• pp.25-30
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• 2010

The flow characteristics under recirculation cool vent mode is numerically studied using commercial fluid dynamic code(CFX). For the reliable analysis, real vehicle and human FE model is employed in grid generation process. The geometrical location and shape of panel vent, and exhaust vent is set as that of real vehicle model. The flowrate of the working fluid is determined as 330CMH which is equivalent to 70 percent of maximum capacity of HVAC system. The high velocity regions are formed around 4 each panel vent. Because of the non-symmetrically located exhaust, non-uniform flow and partial backflow near the door trim is observed. Streaklines start from each panel vent show the flow pattern of the airflow in the passenger's compartment very well.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.1
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• pp.29-39
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• 1986

The purpose of this study is to develop an exhaust gas recirculation valve for reduction of the NOx emission of the gasoline engine. In this study the back pressure modulated(BPM) EGR system was developed and tested for the 1.6$\ell$ gasoline engine. By this system 50% of NOx emission was reduced at 7% EGR rate. Fuel consumption and CO emission were not affected by EGR but HC was increased up to the level of allowable limit. Overall operation was satisfactory. As a result of this study, the technics for developing EGR valve and adjusting the engine for EGR have been established.

• Journal of Power System Engineering
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• v.6 no.1
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• pp.27-35
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• 2002

In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for direct injection diesel engine. It is tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenate blended fuel which has four kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission and brake specific fuel consumption rate have been investigated. Dimethyl carbonate(DMC) contains oxygen component 53.3% in itself, and it is a kind of effective oxygenated fuel of carbonate group that the smoke emission of DMC is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and EGR method.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.554-559
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• 2008

Most of vehicle manufacturers have applied exhaust gas recirculation (EGR) system to the development of diesel engines in order to obtain the high thermal efficiency without $NO_X$ and Particulate Matter (PM) emitted from the engine. EGR system, which reflow a cooled exhaust gas from vehicles burning diesel as fuel to a combustion chamber of engine, has been used to solve this problem. In order to confirm the safety of the EGR system, finite element analysis was carried out. The safety of EGR system against temperature variation in the shell and tubes was evaluated through the thermal and structural analysis, and the modal analysis using ANSYS was also performed. Finally, the performance of EGR system was verified through the experiment and numerical simulation using effectiveness-NTU method. Program for the estimation of the heat exchange efficiency of the EGR system with regard to the dimpled tube shape was developed.

• Environmental Engineering Research
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• v.7 no.3
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• pp.129-136
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• 2002

• Journal of Korea Multimedia Society
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• v.19 no.11
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• pp.1891-1899
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• 2016

Recently food problem and crop disaster have been increased continuously because of the meteorological changes. These cause rising cost for crops continuously and irregularly. Some researchers have studied straight structure of device for hydroponics and plant factory previously to solve a fundamental part of these problems. However, there are several problems such as limited crop cultivation space, providing irregular nutrients for crops, and lack of monitoring interfaces. For them, we propose an optimal growth and development crops management system using light source tracking and recirculation of nutrient solution method to supply nutrient continuously based on IoT. In order to evaluate the performance of our system, we compared and analyzed in terms of two viewpoints, the tracking analysis for natural light source measurement and the growth of crops through artificial light, LED, respectively. We confirmed that the higher the duty ratio of LED, the larger the crop's size, particularly. As well as, for about 1 month, we compared with the existing natural light growing environment and that of our system. It was confirmed that the size of the crops grown through our system is about three times larger than that of natural light natural crops.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.477-484
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• 2017

In the conventional recirculation fish farms, there is a lot of difficulties due to lack of professional manpower and high reliance on imported measurement equipment. In this paper, we implement an automatic water quality measurement system which can measure the pollution degree in a water tank of fish farms using an optical sensor(pH, DO) with the IoT technology. The problem with existing systems is that the fish tank should be checked by means of human, or put the measuring equipment into the water tank of fish farms and measurement directly. But, it has a bad influence on the growth of fish. In this paper, we propose a method of indirect measurement without immersing the measurement equipment in a water tank of fish farm and develop a sustainable measurement system in an environment containing salt and lots of pollutants without affecting the growth of fish within the water tank of fish farms.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.2
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• pp.139-148
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• 2013

In this study, an ejector was designed to recirculate the anodic off-gas of SOFC, and a parametric study of the system performance was conducted at various ejector entrainment ratios. Aspen Plus, a chemical engineering program, was used to calculate the operational conditions of the ejector. To minimize the calculation load of the CFD and to ensure the global optimum, a genetic algorithm and Kriging model were used for the optimization. The optimization results showed that the dominant design variables of the sonic ejector are the throat diameter and the first flow nozzle position. The designed ejector has enough flexibility for different operating conditions of a 1-kW SOFC system. When the ejector was applied to the SOFC, it reduced 56% of the steam and 8.4% of the fuel compared to the reference case.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.186-186
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• 2007