• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.302-307
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• 2010

본 연구는 최적설계 기법의 하나인 다구찌 방법을 이용하여 소방용 스프링클러 배관용 밀봉부에 대한 유한요소해석을 수행하고, 이를 통하여 소방용 배관의 밀봉안전성을 확보하고자 한다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.7-11
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• 2010

본 논문에서도 유한요소해석과 최적설계 기법의 하나인 다구찌 방법을 이용하여 나선모양을 갖는 소방용 배관의 최적설계를 통하여 배관의 강도 안정성을 확보하고자 한다.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.06a
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• pp.232-237
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• 2004

Anatahan Volcano in the Commonwealth of the Northern Mariana Islands (CNMI) erupted for the first time in recorded history on 10 May 2003. The underwater acoustic records of earthquakes, explosions, and tremor produced during the eruption were recorded on a sound-channel hydrophone deployed in February 2003. Acoustic propagation models show the seismic to acoustic conversion at Anatahan is particularly efficient, aided by the slope of the seamount toward the hydrophone. The hydrophone records confirm the onset of earthquake activity at 01:53Z on 10 May, as well as the onset (at ${\~}$06:20Z) of continuous, low-frequency (5-40 Hz) acoustic energy that is likely volcanic tremor related to magma intrusion. The hydrophone recorded a total of 458 earthquakes associated with the eruption. To predict the character of acoustic signals generated from Anatahan, we developed a moment-tensor representation of a volcano-seismic source that is governed by the geometry of the source and the physical properties of the magma. A buried magmatic pipe model was adopted, and numerically modeling source parameters such as the pipe radius and magma viscosity enable us to grasp the inward nature of Anatahan Volcano.

• Journal of Korea Foundry Society
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• v.28 no.5
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• pp.231-236
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• 2008

H-NCM(Hong-Nanocast Method)has several benefits such as a lower porosity defect and high quality casting comparing to conventional die casting. Influence of casting parameters of hybrid-lower arm in rheocasting process on the slurry flow and the amount of porosity defect was investigated using experimental and simulation methods. In the present study, the Carreau model was adopted to simulate the pattern of rheological flow. Optimal casting paremeters such as injection speed and stroke variations were established. Sound products with integral microstructure and sound shape of joinning different materials of Al and steel pipe without deforming the steel pipe were obtained by the H-NCM slurry and X-ray analysis also showed integral condition throughout the entire parts.

• Plant Journal
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• v.13 no.3
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• pp.30-35
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• 2017

Module can be categorized as PAS(Pre-Assembled Steel structure), PAR(Pre-Assembled pipe Rack), PAU(Pre-Assembled Unit), VAU(Vendor Assembled Unit) and VPU(Vendor Package Unit). At the stage of design and fabrication of module, the condition of land and ocean transportation is considered and these conditions are reflected on the module division design. The control of the module's center of gravity is important to transport and install modules safely and the steel structure should have the strength enough to resist the sea acceleration force during the ocean transportation. The transportation condition and the installation method influence the size and weight of module. The size and weight of module are considered for the design of module division.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.49-55
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• 2007

Polyethylene pipes have been widely used as they are easy to construct and suitable for economical efficient when they are compared with metal pipelines. This paper studies the effect of various external loadings on stress and deflection of the buried PE pipes using Finite Element Method(FEM). For this purpose, stresses of buried PE pipes are calculated according to the loading condition such as pipe types (pipe diameter $50{\sim}400mm$), burial depths ($0.6{\sim}1.2m$) and internal pressures ($0.4{\sim}4bar$). As a result, it is founded the effect and relation with each of loading conditions under the buried condition.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.33-38
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• 2000

When fire and explosion accidents have occurred due to a leak of the flammable gas involving the LNG & LPG in an industrialized society, it is a very important problem. Accordingly, in this paper, we have compared and analyzed the occurrence transition and the electrostatic energy according to dust supplies and pressure variations for the electric charge due to the gas-solids of pipe flow. As the experimental results, if dust amounts and the initial pressure increased, electric charge in the pipe and the exit increased. The Specific charge of $Fe_2O_3$ increased proportionally if the initial pressure increased but if the quantity of dust increased, the specific charge decreased. Energy increased significantly as the dust amounts and the initial pressure increased. The possibility of fire and explosion exist in the measuring point(M 1) and the Faraday cage if natural gas and LPG were used.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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• pp.61-68
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• 2004

Recently, there has been an increasing demand for computer-vision based inspection and/or measurement system as a part of factory automation equipment. Existing manual inspection method can inspect only specific samples and has low measuring accuracy as well as it increases working time. Thus, in order to improve the objectivity and reproducibility, computer-aided analysis method is needed. In this paper, front and side profile inspection and/or data transfer system are developed using computer-vision during the inspection process on three kinds of pipes coming from a forming line. Straight line and circle are extracted from profiles obtained from vision using Laplace operator. To reduce inspection time, Hough Transform is used with clustering method for straight line detection and the center points and diameters of inner and outer circle are found to determine eccentricity and whether good or bad. Also, an inspection system has been built that each pipe's data and images of good/bad test are stored as files and transferred to the server so that the center can manage them.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.10
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• pp.776-782
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• 2006

A new district cooling system using ice slurry for the uncertain cooling load of the future is presented. The chilled water produced by the absorption chillers is used for the base cooling load. The temperature of the chilled water is reduced by mixing of ice slurry depending on increasing of the cooling load. Finally, IF of the ice slurry is increased up to 10% at the peak load. The transporting mass flow rate is decreased down to 44.7%, and the diameter of the main pipe is decreased down to 66.7%, but the diameter of the branched pipe is designed as the same size of the chilled water.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.561-572
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• 2019

In the design criterion for the nuclear power plant piping system, the limit state of the piping against an earthquake is assumed to be plastic collapse. The failure of a common piping system, however, means the leakage caused by the cracks. Therefore, for the seismic fragility analysis of a nuclear power plant, a method capable of quantitatively expressing the failure of an actual piping system is required. In this study, it was conducted to propose a quantitative failure criterion for piping system, which is required for the seismic fragility analysis of nuclear power plants against critical accidents. The in-plane cyclic loading test was conducted to propose a quantitative failure criterion for steel pipe elbows in the nuclear power plant piping system. Nonlinear analysis was conducted using a finite element model, and the results were compared with the test results to verify the effectiveness of the finite element model. The collapse load point derived from the experiment and analysis results and the damage index based on the stress-strain relationship were defined as failure criteria, and seismic fragility analysis was conducted for the piping system of the BNL (Brookhaven National Laboratory) - NRC (Nuclear Regulatory Commission) benchmark model.