• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.172-179
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• 2004

Average Bi-directional flow tube was suggested to measure single and two phase flow rate. Its working principle is similar with Pilot tube, however, it makes it possible to eliminate the cooling system which is normally needed to prevent from flashing in the pressure impulse line of Pilot tube when it is used in the depressurization condition. The suggested instrumentation was tested in the air-water vertical test section which has 80mm inner diameter and 10m length. The flow tube was installed at 120 of L/D from inlet of test section. From the test, single air and water flow rate was measured successfully. For the emasurement of two phase flow rate, Chexal drift-flux correlation was used. In the test a new correlation of momentum exchange factor was suggested. The test result shows that the suggested instrumentation using the measured void fraction and Chexal drift-flux correlation can predict the mass flow rates within $10\%$ error of measured data.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.11-18
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• 2022

In this research, curium oxide (CmO₂) is studied as fuel for VVER-1200 reactor to get an attention to its energy value and possibilities. For this purpose, CmO₂ is used in fuel rods or integrated burnable absorber (IBA) rods with and without UO₂ and then compared with the conventional fuel assembly of VVER-1200 reactor. It is burned to 60 GWd/t by using SRAC-2006 code and JENDL-4.0 data library. From these studies, it is found that CmO₂ is competent like UO₂ as a fuel due to higher fission cross-section of ²⁴³Cm and ²⁴⁵Cm isotopes and neutron capture cross-section of ²⁴⁴Cm and ²⁴⁶Cm isotopes. As a result, when some or all of the UO₂ of fuel rods or IBA rods are replaced by CmO₂, we get a similar k-inf like the reference even with lower enrichment UO₂ fuels. These studies show that the use of CmO₂ as IBA rods is more effective than the fuel rods considering the initially loaded amount, power peaking factor (PPF), fuel temperature and void coefficient, and the quality of spent fuel. From a detailed study, 3% CmO₂ with inert material ZrO₂ in IBA rods are recommended for the VVER-1200 reactor assembly from the once through concept.

• American Studies
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• v.34 no.1
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• pp.181-202
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• 2011

The purpose of this paper is to examine Paul Auster's Leviathan according to Slavoj Žižek's theory. Analyzing the characters in Leviathan, this paper chiefly discusses the postmodern subject's anxiety and obsessive repetition that the lack of the big Other led to. Section II explains the disintegration of the big Other and the subject's anxiety and obsessive repetition by the interpretation of the characters: Peter Aaron, Maria Turner, and Benjamin Sachs. Aaron wants to write on Sachs's life to overcome his uneasy subject's condition, and to establish the consistent and whole world. But his writing fails to meet his desire, owing to uncertainty of his understanding, and the incompleteness of his writing. In case of Maria, her uneasy subject's condition led to her obsessively repetitive picture-shooting herself and others, which proved to be a meaningless struggle for filling the void of the big Other and herself. Although Sachs already knows the lack and inconsistency of the big Other, he also repetitively tries to establish the consistent and whole Other. In Section III, this paper examines Sachs's terror as he struggles for the preservation of the big Other. His extreme striving also fails to reestablish the big Other as it loses its symbolic effectiveness in the postmodern era because he does not grasp the big Other as an empty Symbolic order, and rejects the premise of the big Other itself.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2C
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• pp.109-117
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• 2010

Gas hydrate dissociation can generate large amounts of gas and water in gas hydrate bearing sediments, which may eventually escape from a soil skeleton and form voids within the sediments. The loss of fine particles between coarse particles or collapse of cementation due to water flow during heavy or continuous rainfall may form large voids within soil structure. In this study, the effect of void formation resulting from gas hydrate dissociation or loss of some particles within soil structure on the strength of soil is examined. Glass beads with uniform gradation were used to simulate a gas hydrate bearing or washable soil structure. Glass beads were mixed with 2% cement ratio and 7% water content and then compacted into a cylindrical sample with five equal layers. Empty capsules for medicine are used to mimic large voids, which are bigger than soil particle, and embedded into the middle of five equal layers. The number, direction, and length of capsules embedded into each layer vary. After two days curing, a series of unconfined compression tests is performed on the capsule-embedded cemented glass beads. Unconfined compressive strength of cemented glass beads with capsules depends on the volume, direction and length of capsules. The volume and cross section formed by voids are most important factors in strength. An unconfined compressive strength of a specimen with large voids decreases up to 35% of a specimen without void. The results of this study can be used to predict the strength degradation of gas hydrate bearing sediments in the long term after dissociation and loss of fine particles within soil structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.113-116
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• 2008

In recent the construction of bridges having hollow sectional piers is gradually increasing since the hollow section is more effective than solid section in resistance against seismic load. It is, therefore, very important to understand the behavior of columns with hollow sections in seismic design. However, many past researches were concentrated only on the flexural deformability of them. In this study the shear characteristics of them have been studied with scale model tests. 7 models having different void and aspect ratios were designed and tested to investigate the effect of them on shear capacities. And then the validity of empirical equations to predict shear capacity was investigated compared with the test results. The test result 80 percent of the valid area of cross section should be adequate. And compared to the proposed four model the experimental shear capacities are in good agreement with the UCB.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2C
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• pp.59-69
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• 2009

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in crystalline rocks like gneiss, granite, and so on, a prediction model was developed by the use of a decision tree model. The classification standard of the selected prediction model is composed of the slope angle, the coefficient of permeability and the void ratio in the order. The computer program, SHAPP ver. 1.0 for prediction of slope hazards around an important national facilities using GIS technique and the developed model. To prove the developed prediction model and the computer program, the field data surveyed from Jumunjin, Gangneung city were compared with the prediction result in the same site. As the result of comparison, the real occurrence location of slope hazards was similar to the predicted section. Through the continuous study, the accuracy about prediction result of slope hazards will be upgraded and the computer program will be commonly used in practical.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1465-1468
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• 1997

In this study we investigated the aging characteristic such as leakage current, dielectric loss, contact angle, of EPDM for outdoor use by thermal treatment. And also observed the color change of surface, changing of chemical ingredient of the marterials by optical microscope. SEMI, FTIR and EDX at the section and surface. The test result show that leakage current is increased with thermal aging time. contact angle and dielectric loss is slightly decreased. Moreover, micro-void or crack in bulk is severely increased with aging time. However, the result affect to the tan $\delta$ at bulk of EPDM. It seems that carrier sources are removed by degassing with heat treatment.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2121_2122
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• 2009

In this paper, we analyzed carbonization pattern of Ligth Emitting Diode(LED) lamp that become burnout by outside flame. Surface side can know that void is formed greatly than central part in section analysis of electric wire that is carbonized by outside flame. Chared globe displayed special quality that lump of abnormal carbonization falls was formed, and becomes melting among carbonization process. The LED resistance of forward direction is about 1.74 [$M{\Omega}$], and backward resistance is about 140 [$M{\Omega}$]. We can know progress direction of flame through measurement of the LED resistance.

• Journal of computational fluids engineering
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• v.15 no.3
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• pp.73-80
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• 2010

In this paper, we present the exact Riemann solver for the compressible liquid-gas two-phase shock tube problems. We hereby consider both isentropic and non-isentropic two-phase flows. The shock tube has a diaphragm in the mid-section which separates the liquid medium on the left and the gas medium on the right. By rupturing the diaphragm, various waves are observed on the phasic field variables such as pressure, density, temperature and void fraction in the form of rarefaction wave, shock wave and material interface (contact discontinuity). Both phases are treated as compressible fluids using the linearized equation of state or the stiffened-gas equation of state. We solve several shock tube problems made of a high/low pressure in the liquid and a low/high pressure in the gas. The wave propagations are well resolved by the exact Riemann solutions.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.151-156
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• 2009

Forward modelling of ground penetrating radar (GPR) data is implemented using a new finite element ray tracing technique. The method is different from conventional ray tracing techniques in that the radar cross section of buried targets, the effective area of the receiving antenna, and the attenuation along the raypath are computed. The forward models are used to understand radar signatures measured across various ground structures which are important in detecting engineering hazards at construction sites, void spaces beneath simulated road beds, as well as a learning tool to avoid pitfalls in radargram interpretation. Forward modelling of radar data also can be used in predicting possible structures present at cultural property sites.