• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.530-533
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• 1999

During the last decade, high quality digital audio has essentially replaced analog audio. During this period, digital audio have applied many application areas of the info-industry. These applications have created a demand for high quality digital audio. In audio compression, the methods using human auditory nervous properties are used and introduced from psychoacoustical model utilized perceptual audio coding unable to code above the limitation of human perception. The discussion concentrates on architectures and applications of those techniques which utilize psychoacoustical models to exploit efficiently masking characteristics of the human receiver. In this paper, the designed MDCT/IMBCT as a standard of current MPEG is implemented onto FPGA.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.592-595
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• 2011

A numerical investigation on a suction vortices, free vortices and subsurface vortices behavior in the model sump system with multi-intakes is performed A test model sump and piping system were designed based on Froude similitude for the prototype of the recommended structure layout by HI-9.B Standard for Pump Intake Design of the Hydraulic Institute. A numerical analysis of three dimensional multiphase flows through the model sump is performed by using the finite volume method of the CFX code with multi-block structured grid systems. A ${\kappa}-{\omega]$ ShearStressTransportturbulencemodelandthe Rayleigh-Plesset cavitation model are used for solving turbulence cavitating flow. From the numerical analysis, several types of vortices are reproduced and their formation, growing shedding and detailed vortex structures are investigated. To reduce abnormal vortices, an anti-vortex device is considered and its effect is investigated and discussed.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1019-1021
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• 1999

In this paper, we describe the design and appliance of the preventive diagnostic expert system of gas in oil for power transformer. This expert system is developed to use expert system development tool; Element Expert (NEURON DATA Inc.) Analysis is developed by four diagnose methods. In first, the standard of KEPCO is applied. It classifies the state of transformer by four level: Normal, warning, abnormal and danger. And the others are gas pattern methods, IEC code method, and Dornen & Roger Ratio method and applied later. These latter methods analyse the cause of result. Inference engine was designed with Element Expert. In last, we operate the system with sample data and we can obtain the correctly inferred result for the state of transformer.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.215-222
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• 2002

It has been well acknowledged that intake system plays great role in the performance of reciprocating engine. Well-designed intake system is expected to not only increase engine efficiency but also decrease engine emission, which is one of the most urgent issues in the automotive society. Thorough understanding of the flow in intake system helps great to design adequate intake system. Even though both experimental and numerical methods are used to study intake flow, numerical analysis is more widely used due to its merits in time and economy. Intake system of In-line 6-Cylinder CNG engine was chosen for the analysis ICEM CFD HEXA was used to create 3-D structured grid and FIRE code was used for the flow analysis in the intake system. Due to the complexity of the geometry standard ${\kappa}-{\varepsilon}$ turbulence model was applied. Numerical analysis was performed for various inlet and outlet boundary conditions under both steady and transient flow. Inlet mass flow rate and outlet pressure variation were changing parameters with respect to engine speed. Flow parameters, such as velocity, pressure and flow distribution, were evaluated to provide adequate data of this intake system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.42-47
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• 2014

In this paper, fatigue life analysis of each structure was performed through theoretical analysis method at design stage in order to verify the success or failure of the store's acoustic noise durability according to the Method 515.5 standard of MIL-STD-810F. In addition, experimental analysis was carried out through the ground and flight test by manufacturing the measuring store, and verification of the sound durability was completed through the flight test after manufacture of the actual store. Furthermore, the commercial FEM code through the PSD calculation method applying measured SPL enables verify the durability of new store components development for the future.

• ETRI Journal
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• v.32 no.1
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• pp.163-165
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• 2010

A trend in 3D mesh compression is codec design with low computational complexity which preserves the input vertex and face order. However, this added information increases the complexity. We present a fast 3D mesh compression method that compresses the redundant shared vertex information between neighboring faces using simple first-order differential coding followed by fast entropy coding with a fixed length prefix. Our algorithm is feasible for low complexity designs and maintains the order, which is now part of the MPEG-4 scalable complexity 3D mesh compression standard. The proposed algorithm is 30 times faster than MPEG-4 3D mesh coding extension.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.189-196
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• 2002

According to the Korean Design Code for port and harbor facilaties, bearing capacity of rubble mound under eccentric and inclined load is calculated by the simplified Bishop method, and strength parameters are recommended to be c=0.2kg/$\textrm{cm}^2$ and ø=35$^{\circ}$for standard rubble if the compressive strength of parent rock is greater than 300kg/$\textrm{cm}^2$, quoting from research results by Jun-ichi Mizukami(1991), But this facts have never been certified in Korea because there was not large-scale triaxial test apparatus until 2000 in Korea. Firstly in Korea, the large-scale triaxial test (sample diameter, 30cm and height, 60cm) on the rubble originated from porous basalt rock in North-Cheju was accomplished. Then strength parameters for basalt rubble produced in North-Cheju are recommended to be c=0.3kg/$\textrm{cm}^2$ and ø=36$^{\circ}$if the compressive strength of parent rock is greater than 400kg/$\textrm{cm}^2$.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.274-278
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• 2006

An upgraded algorithm that in proves the performance of existing interfacing software for parsing HL7 messages is introduced. It incorporates stack operations on objects to guarantee segment order while parsing messages. This object-oriented design greatly facilitates the complicated process of validating, parsing, and creating HL7 messages in the clinical setting. The new interface engine can manage all HL7 messages corresponding to admission and registration, discharge and transfer, laboratory results, clinical images, and clinical reports. The international version of this engine, currently under development, will be tested in Asian countries using standard character code such as Unicode (ISO 10646).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.49-54
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• 2005

This paper describes the result of structure analysis and load test of body structure. The purpose of the analysis and test is to evaluate an safety which body structure shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load and operating condition. Material of body structure applied an aluminum alloy. Body structure consist of side frame, under frame, roof frame, end frame. Both FEM analysis and load test are based on 'Performance Test Standard for Electrical Multiple Unit, noticed by Ministry of Construction & Transportation, in 2000' and reference code is JIS E 7105. The test results have been very safety and stable fer design load conditions.

• Journal of the Korean Society of Visualization
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• v.17 no.1
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• pp.26-33
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• 2019

The rapid increase in the usage of energy in the fast-changing industries has led to resource depletion and environmental conflicts. Many types of research are available on heat exchangers that undergo simple energy conversion processes. The impingement rods discussed in this study improves the durability of the heat exchanger and ensure the stability of the operation. However, it is uncertain about selecting the installation location of the impingement rods. The commercially available CFD code, ANSYS CFX, is used for the impingement rods installation.