• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.4
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• pp.274-286
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• 2003

Numerical simulations are performed to investigate the turbulent convective heat transfer of the supercritical carbon dioxide flows in vertical and horizontal square ducts. The gas cooling process at the supercritical state experiences a sudden change in thermodynamic and transport properties. This results in the extraordinary variations of the heat transfer coefficients in the supercritical state, which are much different from those of single or two phase flows. Algebraic second moment closure which can include the effects of large thermophysical property variations of carbon dioxide and of buoyancy is employed to model the Reynolds stresses and turbulent heat fluxes in the governing equations. The previous correlations for the turbulent heat transfer coefficient for the supercritical carbon dioxide flows couldn't reflect the buoyancy effect. The present results are used to establish a new heat transfer coefficient correlation including the effects of large thermophysical property variation and buoyancy on in-duct cooling process of supercritical carbon dioxide.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.3
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• pp.63-69
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• 1998

In this paper, a new input method is proposed to improve shift-invariant property of a photorefractive correlator andwe implemented real-time optical pattern recognition system using it. In the conventional photorefractive correlator, it is vrey difficult to satisfy the Bragg condition in the pattern recognition process. So, correlation peak is decreased heavily for the shift of input image. If a liquid crystal television(LCTV) without an anlyzer is used as input device, we can get the correlation result regardless of shift of input image because beam path is not changed during storage of holographic filter and correlation process. Also recording time of a holographic matched filter in photorefractive crystal is reduced and the correlation peak is increased because incident beam on the LCTV is transmitted completely. Therefore total optical efficiency is improved. We compared and analyzed the correlation results of proposed photorefractive correlator by computer simulation and optical experiment. We used a BaTiO$_{3}$ single crystal which has high diffraction efficiency in optical experiment.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1705-1708
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• 2002

Spreading codes with ZCD(zero-correlation duration) property have the MAI(multiple access interference) rejection ability in the CDMA systems. A class of multi-level spreading codes, i.e., Zero padded ternary ZCD codes are introduced in this paper. By the selected zero-padding method to the binary ZCD codes, ternary ZCD codes are generated and they have enhanced ZCD property and family size than the binary ZCD codes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.225-228
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• 2010

It is an social issue that is various claim related on the defect of apartment house. The cost of defect repair is the most important matter that residents dispute constructers with the huge time wasting and cost loss. For resolve the matter of defect claim, it must to be analyze to the cost property that study and find to pending issue about the cost of defect repair. Therefore this study is investigated the cost property of defect repair relation on correlation analysis and regression analysis around the judgement cost. Consequently, cost of the judgment is associated with cost of the accusation and cost of the defect repair, is recognizable as them that is closely connected. Meanwhile, the more time of take effect and time of lawsuit increase, the more cost of the judgment decrease by draw the regression equation. On the contrary, there are same aspects in the case on the cost of the accusation and cost of the defect repair.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1C
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• pp.9-14
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• 2009

In this paper, using the binary (N,M,L,1) low correlation zone(LCZ) sequence set with specific property, we propose the construction method of a quaternary LCZ sequence set with parameters (2N,2M,L,2). The binary LCZ sequence using this method must have period $N{\equiv}3$ mod 4, balance property, and specific correlation property. The proposed method is modified from the construction method of binary LCZ sequence set by using binary LCZ sequence with specific condition proposed by Kim, Jang, No, and Chung[4].

• Journal of Biomedical Engineering Research
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• v.42 no.4
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• pp.143-149
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• 2021

In order to predict and prevent the disease of the abdominal aorta, which is the largest artery in the human body and the most common aneurysm, the normal arterial blood flow operation should be considered. To this end, we are trying to solve problems that may arise in the future by executing FSI based on the data obtained from 4D flow MRI. However, to match the similarity between the 4D flow MRI flow and the FSI flow, correlation was used in previous papers, but the correlation did not show the degree of agreement. Therefore, in this paper, we analyzed the correlation between the 4D flow MRI flow velocity of the human abdominal aorta and the two-way FSI flow velocity in which the three physical properties used for the aortic FSI were added to the CT abdominal aorta 3D model and the interclass correlation coefficient. As a result, the physical property M2 showed the highest similarity in correlation and intraclass correlation coefficient, and this property is intended to be helpful in the future study of the abdominal aortic two-way FSI flow rate.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4
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• pp.49-57
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• 1992

This study was conducted to evaluate physical property change of asphalt cement chromatograms (by HP-GPC) were experimentally obtained from 3 types of AC-20 virgin ACs, 5 and 24-hour artificially aged ACs, and naturally aged 4 ACs that were recovered from 4 different roads. Absolute viscosity, kinematic visoosity and penetration were the physical properties tested. THF was used for mobil phase and RI detector was used as a detector for Hp-GPC testing. Correlation between each physical property change and the chromatogram variation was evaluated. Each chromatogram was divided into ten-equal-time slices. The percentage areas of 10 slices and each physical property were used for statistical correlation evaluation. Statistical analysis results showed that eaoh physical property had a strong correlation with the chromatogram characteristics. Aging was identified as a mechanism of change of molecular size distribution - increasing large size molecules and reducing coresponding samll size molecules.

• Proceedings of the Korea Crystallographic Association Conference
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• 2000.05a
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• pp.28-28
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• 2000

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1985.10a
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• pp.79-83
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• 1985

• 한국전기화학회:학술대회논문집
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• 2003.04a
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• pp.55-55
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• 2003