• Journal of Ocean Engineering and Technology
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• v.28 no.6
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• pp.566-573
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• 2014

This paper presents the results of an integrated navigation performance analysis for selecting the sensor of an unmanned underwater vehicle (UUV) using Monte Carlo numerical simulation. An inertial measurement unit (IMU) and Doppler velocity log (DVL) are considered to build the integrated navigation system. The position error and price of the sensor are selected as performance indices to evaluate the volunteer integrated navigation systems. Monte-Carlo simulation is introduced to analyze the circular error probability (CEP) and its variance. Simulation results provide the proper sensor combination for integrated navigation in relation to the performance and price.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.2
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• pp.22-26
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• 2006

This paper addresses the development of a laser interferometer to measure micro displacement for a micro system. The laser interferometer is able to measure micro displacement during a few micro seconds with non-contact. In order to employ the interferometer, the displacement calibration experiment should be required. For the experiment, a laser probe installed on the optical table with optical devices and a micro stage. The velocity decoding board is also added to calculate doppler shift frequency directly. The output signal is processed by LabView. Finally experiments are found out the relation between displacement and output signal.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.756-760
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• 1995

Optimal design of a hybrid parallel robot is investigated. In order to optimize the mechanism, new performance measures are introduced since use of the previous methods suffer form lack of the physical meaning due to the dimensional inhomogeneity. To overcome the problem, an Euclidean norm definition of each output space with homogeneous dimension is used to find input-output norm relation and derive new performance measures for each output spaces, that is, translational and rotational velocity, and derive new torque space. For illustion,the derived performance measures is applied to find the isotropic design of a Stewart platform robot which has condition number measures equal to one.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.140-147
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• 2000

Using lobed burner, flame visualization and measurements of NOx and CO concentration in the combustor exit were carried out to evaluate the relation between the lobed structure in a burner and pollutant emission characteristics. The flame stability is enhanced by the lobed burner compared to conventional circular one. The correlation on fuel discharge velocity for flame blowout should be included on a variable related to the wall effect of the burner, because the flame blowout is observed at the burner having large perimeter. The burner having lobed structure in fuel discharge side compared to conventional burner reduces by 5% NOx emission due to lower flame intensity through flame elongation. Meanwhile the burner having lobed structure in air discharge side and both fuel and air discharge side increase the NOx emission.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.24-30
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• 2013

This paper studies the comparative analysis on two different internal cushion devices (the types of needle and relief valve) used to absorb the energy which is generated when the pneumatic cylinder moves with the load at meter-out speed control system. The effect at varying the piston velocity under same driving condition is mainly investigated. The simulation results on pressure in the cushion chamber and the dynamic behavior of the relief valve type cushion device are compared with the needle valve type. Design and performance are improved with the cushion configuration of better quality at high-speed pneumatic cylinder. Based on the relation between absorbed energy and impact energy at cushion process, cushion performance at pneumatic cylinder is evaluated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.28-34
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• 2007

Recently, with the rapid growth of industry, environmental condition became worse. In addition to outdoor insulators in seashore are polluted due to salty wind. Also this pollution causes the flashover and failure of electric equipments. Especially the salt contaminant is one of the most representative pollutants, and known as the main source of the accident by contamination. As well known, the pollution has a close relation with meteorological factors such as wind velocity, wind direction, temperature, relative humidity, precipitation and so on. In this paper we have statistically analyzed the correlation between the pollution and the meteorological factors. The multiple regression analysis was used for the statistical analysis; daily measured equivalent salt deposit density(dependent variable) and the weather condition data(independent variable) were used. Also we have developed an expert program to predict the pollution deposit. A new prediction system using this program called SPPP(salt pollution prediction program) has been used to model accurately the relationship between ESDD with the meteorological factors.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.46-51
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• 2002

The measurement of velocity and stain rate field has been conducted in opposed impinging jet combustion. When a smaller diameter (5mm) orifice of pre-chamber was used, previous studies had reported that the combustion phase showed a shift from weak turbulent combustion to moderate turbulent combustion in the modified Borghi Diagram. In the case with smaller orifice diameter (5mm), NOx emission was substantially reduced by a factor 1/2 while the combustion pressure remains at the same as that in the conventional combustion. Hence, in this study, the experiment setup using PIV technique was designed to identify the relation of the strain rate distribution and NOx reduction associated with moderate turbulent combustion.

• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.379-385
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• 2011

One of main catalysts for De-NOx in SCR is a $V_2O_5/TiO_2$, and this work formulated powdery catalysts focusing ultimately on corrugate catalytic support. The prepared catalyst consisted of anatase $TiO_2$. Amount of the added vanadium oxide determined the viscosity of catalyst slurry, which is important for washcoat for a final corrugate type catalytic reactor. The test showed a proportional relation between adsorption amount of ammonia and specific surface area. De-NOx efficiency could be obtained up to 96.3 % at $400^{\circ}C$ with a spacial velocity of $4,000hr^{-1}$.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.3
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• pp.137-143
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• 2003

The degree of contamination on outdoor insulator is ons of the most importance factor to determine the pollution level of outdoor insulation, and the sea salt is known as the most dangerous pollutant. As shown through the preceding study, the generation of salt pollutant and the pollution degree of outdoor insulator have a close relation with meteorological conditions, such as wind velocity, wind direction, precipitation and so fourth. So, in this paper, we made an investigation on the prediction method, a statistical estimation technique for equivalent salt deposit density of outdoor insulator with multiple linear regression analysis. From the results of the analysis, we proved the superiority of the prediction method in which the variables had a very close(about 0.9) correlation coefficient. And the results could be applied to establish the Pollution Prediction System for power utilities, and the system could provide an invaluable information for the design and maintenance of outdoor insulation system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.3
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• pp.160-166
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• 2001

A numerical analysis has been performed for natural convection in an air conditioner duct system. The governing equations were solved a finite volume method using a SIMPLE algorithm. In the calculation mode of duct, the room temperature was preserved at $25.0^{\circ}C$ and duct wall temperature had a temperature of 15, 20.0, 22.5, 23.75, 26.25, 27.5 30 and $35^{\circ}C$. The results of velocity vectors and contours have been represented for various parameters. Based on the numerical data, the relationships between temperature difference and flow rate into room was represented. In the case of $T_\gamma>T_\omega$, the equation for temperature difference and flow rate was $Q=0.0285\triangleT^0.4005$, and in the case of $T_\gamma>T_\omega$, the equation was $Q=0.0099\triangleT^0.4752$. The duct system has an important relation to room temperature and duct wall temperature.