• International Journal of Aerospace System Engineering
• /
• v.7 no.1
• /
• pp.21-27
• /
• 2020

Quasi steady stall is a phenomenon to characterize the aerodynamic behavior of aircraft at high angle of attack region. Generally, it is exercised from a steady state level flight to stall and its recovery to the initial flight in a calm weather. For a theoretical study, such maneuver is demonstrated in the form of aerodynamic model which consists of aircraft's stability and control derivatives. The current research paper is focused on the appropriate selection of aerodynamic model for the maneuver and estimation of the unknown model coefficients using least-square method. The statistical accuracy of the estimated parameters is presented in terms of standard deviations. Finally, the validation has been presented by comparing the measured data to the simulated data from different models.

• Journal of Mechanical Science and Technology
• /
• v.16 no.4
• /
• pp.522-531
• /
• 2002

In order to study the thermal-hydraulic behavior of the cable-in-conduit-conductor (CICC), a numerical model has been developed. In the model, the high heat transfer approximation between superconducting strands and supercritical helium is adopted. The strong coupling of heat transfer at the front of normal zone generates a contact discontinuity in temperature and density. In order to obtain the converged numerical solutions, a moving mesh method is used to capture the contact discontinuity in the short front region of the normal zone. The coupled equation is solved using the finite element method with the artificial viscosity term. Details of the numerical implementation are discussed and the validation of the code is performed for comparison of the results with thse of GANDALF and QSAIT.

• 유체기계공업학회:학술대회논문집
• /
• 2005.12a
• /
• pp.233-239
• /
• 2005

In the present study, numerical simulation has been performed to investigate the characteristics of the mist flow through the fire suppression nozzles. The commercial CFD software, FLUENT with the proper modeling was applied in both the internal and external flow region of the spray nozzles. Applications were done to the full cone nozzle for the operation range of the low pressure and high flow-rate. Numerical validation was proved by the comparison of the experimental data. Parametric study of the key design factors was tried to improve the performance.

• Tribology and Lubricants
• /
• v.11 no.5
• /
• pp.93-98
• /
• 1995

To increase the information storage density in magnetic disk files, the head, the headdisk spacing must be reduced. This has motivated the investigation of alternatives to the conventional air-lubricated head-disk interface (HDI), which operates at a spacing of about 100 nm. One such alternative under consideration is the liquid-lubricated bearing. To properly model the HDI with a liquid bearing it is necessary to incorporate the theological properties of liquid lubricants at high shear rates. These rheological properties themselves are most easily measured within the HDI. Recently, some question has arisen in the literature concerning the interpretation of the frictional data acquired in this manner. In this study analytical and numerical solutions of the Reynolds eqn. are applied to the starved, liquid lubricated HDI to provide some validation of the rheological data reported the author and coworkers (Streator et al., 1994). Results of the analysis highlight the importance of the inlet taper region in determining the equilibrium configuration of the starved HDI even when only a small fraction of its length is wetted by the lubricant.

• The Plant Pathology Journal
• /
• v.36 no.1
• /
• pp.98-105
• /
• 2020

Venturia nashicola is a fungal pathogen causing scab disease in Asian pears. It is particularly important in the Northeast Asia region where Asian pears are intensively grown. Venturia nashicola causes disease in Asian pear but not in European pear. Due to the highly restricted host range of Venturia nashicola, it is hypothesized that the small secreted proteins deployed by the pathogen are responsible for the host determination. Here we report the whole genome based phylogenetic analysis and predicted secretomes for V. nashicola isolates. We believe that our data will provide a valuable information for further validation and functional characterization of host determinants in V. nashicola.

• New & Renewable Energy
• /
• v.3 no.2 s.10
• /
• pp.3-10
• /
• 2007

Tidal regime change with general hydrolic condition change is examined, according to Garolim Tidal Power Plant (TPP) operation. Numerical model has been developed for the Yellow and East China Seas region, in order to consider the tidal regime change by the TPP operation. The changes of tidal elevation and tidal current inside the Garolim bay are also investigated in details, along with examining the change of the tidal flat area with operation. The field measurement for the tide and current have been carried out for the validation of the numerical model and for understanding the state of current system in the present state.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.2
• /
• pp.150-160
• /
• 2002

The free vibration characteristics of the triple cylindrical shells filled with fluid are investigated. The triple cylindrical shells are filled with compressible fluid. The boundary condition is clamped at both ends. Analytical method is developed to evaluate natural frequencies of triple cylindrical shells using Sanders' shell theory and courier series expansion by Stokes' transformation. Their results are compared with those of finite element method to verify the validation of the method developed. The modal characteristics of shells filled with fluid at region 1, 2 and 3 are evaluated.

• Journal of the Korean Home Economics Association
• /
• v.29 no.1
• /
• pp.189-201
• /
• 1991

The purpose of this study was to validate the KMBI(Korean Maternal Behavior Inventory). Subjects were 1179 mothers of 4th-6th graders in the elementary schools from 5 small and medium cities and 5 urban cities in Korea. Pearson's γ, Cronbach's α, Cramer'sν, one-way ANOVA were conducted for the statistical analyses. The major findings were as follows. 1. The reliability coefficient of the scale (α) were ranged 0.62-0.79 and 0.70-0.82. 2. The discriminant coefficients(ν)of the item were ranged 0.40-0.83. 3. By the analysis of multitrait-multimethod matrix, convergent validity coefficients(γ) were ranged 0.28-0.66: and discriminant validity coefficients(γ) were ranged 0.28-0.66. 4. Significant sex differences were found in the scores of Affection, Overprotection, Achievement, and Achieve Involvement: significant SES differences were found in the scores of Reasoning Guidance, Affection, Overprotection, Achievement, & Active Involvement: and significant region differences were found in the scores of Authoritarian Control and Achievement.

• Journal of the Korean Society of Safety
• /
• v.11 no.3
• /
• pp.66-74
• /
• 1996

Numerical simulations were carried out using standard Reynolds stress turbulence model(LRR model) and modified RSM(Janicka model ) to validate these models in combustion flow fields. Two flames were selected for use as a benchmark data for model testing. One is a conventional jet diffusion flame that has the effect of suppression of turbulence by combustion. The other is a triple jet diffusion flame that designed to give high turbulence to the periphery of the flame and to remove the low Reynolds-number flow fields. As a result, it was found that the modification of standard RSM model is indispensable in the modelling of flames with low turbulence region. And it is also necessary to improve the existing modified models for the universal use.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.331-333
• /
• 2003

KMA successfully began to receive and utilize the GOES-9 GVAR data since May 22nd 2003 when GOES-9 replaced the long-lived GMS-5 for Western Pacific and East Asian region until operation of MTSAT-1R in 2004. To take advantage of improvements of the GOES-9 data over the GMS-5 data, such as the increase of the temporal and spat ial resolution and addition of 3.9${\mu}$m channel, we have improved several algorithms to derive the meteorological products. Here we show two examples of algorithms, sea surface temperature and atmospheric motion vector, and preliminary results of validation of the improved algorithm.