• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1495-1507
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• 2022

The improvement of thermal-hydraulic analysis techniques is essential to ensure the safety and reliability of nuclear power plants. The one-dimensional two-fluid model has been adopted in state-of-the-art thermal-hydraulic system codes. Current constitutive equations used in the system codes reach a mature level. Some exceptions are the partition method of wall friction in the momentum equation of the two-fluid model and the interfacial drag force model for a horizontal two-phase flow. This study is focused on deriving the partition method of wall friction in the momentum equation of the two-fluid model and modeling the interfacial drag force model for a horizontal bubbly flow. The one-dimensional momentum equation in the two-fluid model is derived from the local momentum equation. The derived one-dimensional momentum equation demonstrates that total wall friction should be apportioned to gas and liquid phases based on the phasic volume fraction, which is the same as that used in the SPACE code. The constitutive equations for the interfacial drag force are also identified. Based on the assessments, the Rassame-Hibiki correlation, Hibiki-Ishii correlation, Ishii-Zuber correlation, and Rassame-Hibiki correlation are recommended for computing the distribution parameter, interfacial area concentration, drag coefficient, and relative velocity covariance of a horizontal bubbly flow, respectively.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.6
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• pp.736-744
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• 2005

Statement of problem. Initial stability of implant is an important factor for predicting osseointegration. It requires a rapid, non-invasive, user-friendly technique to frequently assess the implant stability and the degree of osseointegration. Purpose. The aim of this study was to evaluate the correlation between the resonance frequency analysis (RFA) and the radiographic method for peri-implant bone change under in vitro conditions. Material and Method. Twenty implants of 3.75 mm in diameter(Neoplant, Neobiotech, Korea) were used. To simulate peri-implant bone change, 2 mm-deep $45^{\circ}$ range horizontal defect and 2 mm-deep $90^{\circ}$ range horizontal defect area were serially prepared perpendicular to the X-ray beam after conventional implant insertion. Customized film holding device was fabricated to standardize the projection geometry for serial radiographs of implants and direct digital image was obtained. ISQ values and gray values inside threads were measured before and after peri-implant bone defect preparation. Results. Within a limitation of this study, ISQ value of resonance frequency analysis was changed according to peri-implant bone change (p<0.05) and gray value of radiographic method was changed according to peri-implant bone change (p<0.05). There was no correlation between the ISQ value and the gray value for peri-implant bone change (p>0.05). But, in horizontal defect condition, relatively positive correlation were between ISQ and gray values(r=0.663). Conclusion. This results provided a possibility that peri-implant bone change may be evaluated by both RFA and radiographic method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.4
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• pp.727-738
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• 2015

Until recently, power analysis is one of the most popular research issues among various side channel analyses. Since Differential Power Analysis had been first proposed by Kocher et al., various practical power analyses correspond with software/hardware cryptographic devices have been proposed. In this paper, we analyze vulnerability of countermeasure against power analysis exploiting single power trace of public cryptographic algorithm. In ICICS 2010, Clavier et al. proposed Horizontal Correlation Analysis which can recover secret information from a single exponentiation trace and corresponding countermeasures. "Blind operands in LIM", one of their countermeasures, exploits additive blinding in order to prevent leakage of intermediate value related to secret information. However, this countermeasure has vulnerability of having power leakage that is dependant with the message known by an adversary. In this paper, we analyzed vulnerabilities by three attack scenarios and proved them by practical correlation power analysis experiments.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.503-518
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• 2012

Models estimating carbon budget at land surface are mainly interested in vertical flux of carbon. On the other hand, studies on horizontal flux are obviously lacked to confirm that relationship between the hydrological flux of organic carbon discharged from catchment and terrestrial carbon production, a relation between Total Organic Carbon(TOC) and Gross Primary Production(GPP) tried analysis through cross correlation. The best correlation structure is correlation between GPP and TOC of flow-weighted mean concentration from watershed without delay. Furthermore, cross correlation analysis was performed by consider periodicity. The correlation between TOC and GPP in summer was similar to correlation without periodicity. Therefore, correlation between GPP and TOC was most regulated by the correlation between GPP and TOC at summer. As a result, the vegetation carbon and organic carbon from watershed is recognized a close relationship on the seasonal. Therefore, future research is correlation analyzing between vegetation variables according season, GPP and TOC, we are expected to use quantitative understanding that horizontal flux flow of carbon from the surface.

• Journal of the Korean Home Economics Association
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• v.33 no.4
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• pp.149-155
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• 1995

In this study, the formative property of flare skirts is carry out by the shape horizontal sections of hem line. Flare skirts was made by 10 kinds of fabrics with different physical properties. the length of flare skirts was 60cm. The main results obtained are as follows ; 1, The shape horizontal sections of hem line has differed with number of nodes and fabrics properties, in direction of texture. 2. According to the fabrics analysis of drapability decreased in order from Polyester/nylon(20/80)>Polyester(twill, thickness 0.2441)>Polyester(plain, thickness0.3760)>Polyester(plain, thickness 0.3687)>Polyester(plain, thickness 0.3101). 3. The correlation between the number of nodes and wave-height of modes and breadth showed a high negative correlation with the drapability of fabrics.

• Geomechanics and Engineering
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• v.33 no.4
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• pp.393-400
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• 2023

Displacements near crack and stress intensity factor (SIF) are key parameters to solve rock failure issue when using fracture mechanics. In order to study the horizontal displacement and stress intensity factor of the mode I fracture, a series of three-point bending tests of granite specimens with central notch were carried out. The evolution of horizontal displacements of precast notch and crack tip opening displacements (CTOD) were analyzed based on the digital image correlation (DIC) method. Stress intensity factors for three-point bending beams with arbitrary span-to-width ratios(S/W) were calculated by using the WU-Carlsson analytical weight function for edge-crack finite width plate and the analytical solution of un-cracked stress by Filon. The present study provides a high efficient and accurate method for fracture mechanics analysis of the three-point bending granite beams.

• Journal of Mechanical Science and Technology
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• v.15 no.10
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• pp.1451-1460
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• 2001

The critical condition of the onset of buoyancy-driven convective motion of uniformly heated horizontal fluid layer was analysed by the propagation theory which transforms the disturbance quantities similarly. The dimensionless critical time, $\tau$$\sub$c/, is obtained as a function of the Rayleigh number and the Prandtl number. Based on the stability criteria and the boundary-layer instability model, a new heat transfer correlation which can cover whole range of Rayleigh number was derived. Our theoretical results predict the experimental results quite reasonably.

• Journal of Conservation Science
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• v.34 no.4
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• pp.283-293
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• 2018

This study involved a comparative analysis of the correlation between meteorological elements and the concentration of airborne fungi(CFU) in relation to biological damage to two temples on piedmonts, which is a cultural heritage building. The work compared Beopjusa temple in Boeun(Chungcheongbuk-do Province) and Seonamsa temple in Suncheon(Jeollanam-do Province). Twelve meteorological elements and the CFU were measured and the Pearson correlation analysis was used to determine the degree of the relationship between them. The results showed that Beopjusa temple had high wind speed, high total horizontal radiation, high evaporation, and large number of days with precipitation. Seonamsa temple had high air temperature, high relative humidity, high dew point temperature, high sea level pressure, high precipitation, and high CFU. The CFU at Beopjusa temple did not have a linear correlation with meteorological elements, but at Seonamsa temple it was highly positive correlated with the number of days with precipitation, relative humidity, and precipitation, and was highly negative correlated with total horizontal radiation. In addition, Beopju and Seonamsa temple had a common linear relationship between factors not affected by the topographical conditions, and had a individual linear correlation between factors affected by the topographical conditions.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.115-115
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• 1999

To demonstrate the applicability of RELAP5 to the prediction of the onset offlooding in the hot leg at the reflux condensation phase during mid-loop operation, numerical analysis is performed for the counter-current flow in a horizontal pipe with the inclined riser using the RELAP5/MOD3.2.2b code. It is found that the RELAP5, simulating the CCFL phenomena using interfacial friction along with the flow regime map in the horizontal pipe, produces unsatisfactory results. Under the CCFL condition, it is observed that large oscillation exists in the flow rate, void fraction, and etc. and the liquid flow rate is much lower than that predicted by the CCFL model measured in the experiment. The CCFL model of RELAP5 for the vertical volume is extended to the model for the horizontal and inclined volumes. The horizontal volume flow regime map and interfacial friction model coupled to the CCFL model are modified. And a new correlation developed from Kang's experiment is implemented to the CCFL model of RELAP5. With this modified RELAP5, the analysis of CCFL phenomena in the horizontal pipe and hot leg geometry is performed, and produces reasonable results in comparison with experimental data.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.8
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• pp.21-29
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• 2013

The functional behaviors of human standing postural control were investigated when they were exposed to long-term horizontal vibration in the sagittal plane. For complexity of human postural control, a useful alternative method that has been based on a black-box approach was taken; that is, where the feedback mechanism was lumped into a single element. A motor-driven support platform was designed as a source of vibration. The AC Servo-controlled motors produced continuous anterior/posterior (AP) motion. The data were analyzed both in the time and frequency domain. The cross-correlation and coherency functions were estimated. Subjects behaved as a non-rigid pendulum with a mass and a spring throughout the whole period of the platform motion, as consistent with the plan chosen for this study.