• The KSFM Journal of Fluid Machinery
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• v.19 no.6
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• pp.14-18
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• 2016

Multi-MW wind turbines have very large blades over 40~50 m in length. Some factors like wind shear and tower shadow make an effect on asymmetric loads on the blades. Larger asymmetric loads are produced as the length of blade is getting longer. In this paper, a 2 MW on-shore wind turbine is considered and variations of thrust on 3 blades and rotor hub under wind shear are calculated by using a commercial Bladed S/W and dynamic properties of the thrust variations are investigated. It is shown that the amplitude of the asymmetric thrust on each blade under wind shear is getting larger as the wind speed increases, the frequency of the thrust variation on each blade is same as the one of rotor speed, and the frequency of the thrust variation at rotor hub is 3 times as high as the one of rotor speed.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.10a
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• pp.7-12
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• 1993

Preparation of asymmetric polyimide membranes by the phase inversion process was investigated to develop ultrafiltration, reverse osmosis and pervaporation membranes for organic solutions, using a commercially available solvent-soluble polymaide. The influences of the various factors such as the composition of a cast solution, casting conditions, gelating solutions and others on membrane structure and performance were studied in detail, and it was made clear that a wide variety of asymmetric polyimide membranes ranging from UF to RO for organic solutions could be prepared from the aromatic polyimide used. It was also found that the chemical stability and separation performance of the asymmetric polyimide membranes could be improved by annealing in a liquid or a vacuum at above 200$\circ$. The membrane annealed at 300$\circ$ in a vacuum exhibited the separation factor $\alpha(H_2O/EtOH)$ of 900 with the flux of 1.0 kg/$m^2\cdot h$ at 60$\circ$C for an aqueous ethanol solution of 95 vol%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3231-3244
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• 2016

As processor design has been transiting from homogeneous multicore processor to heterogeneous multicore processor, traditional Amdahl's law cannot meet the new challenges for asymmetric multicore system. In order to further investigate the impact factors related to the Overhead of Data Preparation (ODP) for Asymmetric multicore systems, we evaluate an asymmetric multicore system built with CPU-GPU by measuring the overheads of memory transfer, computing kernel, cache missing and synchronization. This paper demonstrates that decreasing the overhead of data preparation is a promising approach to improve the whole performance of heterogeneous system.

• The Korean Journal of Financial Management
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• v.6 no.2
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• pp.33-69
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• 1989

The Purpose of this study is to test empirically the determinants of capital structure of the Korea Listed Firms. In order to accomplish the purpose of this study, both literature survey and empirical test have been made. For the empirical test, agency and asymmetric information factors as well as traditional ones have been throughly reviewed. Traditional factors tested in this study include firm-size, collateral value of the assets, business risk, tax, non-debt tax shields, and industry effects. Agency and asymmetric information factors include growth opportunities, the percentage of outstanding equity held by inside stockholders, and the number of inside stockholders. From the results of the cross-sectional regression analysis, the adjusted R-square is 1931%, and the overall F-value indicates significance. For the analysis period, the signs of the variables except business risk are as predicted. Firm-size, collateral value of the assets, and business risk significant at the.01-.05 level. In order to determine the influence of industry factors on the financial leverage, a total of 8 dummy variables are added to the regression model. The adjusted R-square inclosed by 4.2% for the first analysis period(1983-1985) and 6% for the second analysis period(1986-1987). This suggests that industry factors are significant in explaining the variations in financial leverage across firms. In order to pursue the influence of agency and asymmetric information factors on the financial leverage, again the cross-sectional regression analysis is done for the middle size firms gruop(n=40). The adjusted R-square increased by 9.8% for the first analysis period(1983-1985) and 6.1% for the total analysis period(1983-1987), and all the signs was as predicted. But both the variables except the number of inside stockholders was not significant.

• Journal of the Korean Geosynthetics Society
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• v.15 no.4
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• pp.17-23
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• 2016

This study assessed the behavior of rock pillar in tunnel asymmetric diverging area by using a three dimensional numerical analysis. The stability of pillar is very important for the ensure the stability of the tunnel asymmetric diverging area. Based on parameters affecting the behavior of rock pillar, this study evaluated different safety factors according to pillar width, depth and rock conditions. It turned out that as the rock pillar width increases, the change curve of safety factors in accordance with depth and rock conditions shows more of the nonlinear behavior. By the assessment of the minimum safety factor, a safety factor chart on the behavior of rock pillar in tunnel asymmetric diverging area was suggested.

• The Journal of Asian Finance, Economics and Business
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• v.10 no.1
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• pp.79-89
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• 2023

The paper aims to investigate the asymmetric long-run and short-run relationships between inflation and remittance outflows in the Kingdom of Saudi Arabia (hereafter KSA) over the period 1971-2019 by using the Nonlinear Autoregressive Distributed Lag (NARDL) model. The statistical tests have supported the validity and stability of the model. The Wald F-test statistics confirm the existence of a long-run equilibrium relationship among the model variables; remittance outflows, positive (negative) shocks in inflation rates, investment, real GDP, and trade openness. Moreover, the empirical results confirm the existence of an asymmetric effect of the inflation rate on remittance outflows. The response of foreign workers to an increase in inflation rates differs from their response to a decrease in inflation rates. However, this asymmetric relationship between the increases/decreases in inflation and remittance outflows is significantly weak. The weakness of this relationship is due to the high marginal remittance propensity of migrant workers, which is explained by the low consumption propensity of foreign workers and their ability to adjust to the high cost of living due to inflation and the imposition of accompanying fees. Finally, the change in the inflation rate is not among the main factors influencing foreign remittance decisions in Saudi Arabia.

• Transactions of Materials Processing
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• v.23 no.2
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• pp.82-87
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• 2014

The plastic strain ratio is one of the factors that affect the deep drawability of Al alloy sheet. The deep drawability of Al alloy sheet is limited because of its low plastic strain ratio. Therefore an increase in the plastic strain ratio to improve the deep drawability of Al alloy sheet is needed. The current study investigated the increase of the plastic strain ratio and the change in texture of AA5083 Al alloy sheet after a 2 step asymmetric rolling with heat treatments. The average plastic strain ratio of initial AA5083 Al alloy sheets was 0.83. After the first asymmetric rolling step of 88% deformation and subsequent heat treatment at $320^{\circ}C$ for 10 minutes the value was still 0.83. After the second asymmetric rolling of 14% reduction and subsequent heat treatment at $330^{\circ}C$ for 10 minutes the plastic strain ratio rose to 1.01. The average plastic strain ratio after the 2 step asymmetric rolling and heat treatment is 1.2 times higher than that of initial AA5083 Al alloy sheet. This result is related to the development of ND/<111> texture component after the second asymmetric rolling and heat treatment.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.87-97
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• 2010

The purpose of this study was to evaluate the validity of the second-order analysis for asymmetric unbraced frame using the load amplification factor suggested by design codes. For this purpose, the first-order analysis with the B1 and B2 factors suggested by KBC 2005 and the direct analysis with the load amplification factors suggested by KBC 2009 were performed for five story - two bay and five story - four bay asymmetric unbraced steel frames. The results of the analyses were compared with the results of the second-order inelastic analysis to evaluate the validity of the suggested methods. The main parameters of the analysis were the shape of the frame, the axial load ratio of the column, the methods of analysis and the location of column. The research results show that the asymmetric shape of the frame deteriorates the validity of the factor B2 and the suggested methods. The range of error is increased in case of irregular or inclined column.

• Structural Engineering and Mechanics
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• v.9 no.1
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• pp.17-35
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• 2000

Dynamic response of a three span continuous bridge has been determined by full scale experiments on the bridge. In the experiments, a heavy vehicle was driven across the bridge at different speeds and along different lanes of travel and the strains were recorded at different locations. The bridge was made of reinforced concrete and was asymmetric in plan and in elevation. Frequencies and modes of vibration excited by the vehicle were determined. The dependence of the dynamic amplification on bridge location and vehicle speed was investigated and dynamic amplifications up to 1.5 were recorded, which was higher than values predicted by bridge design codes. It was evident that when this asymmetric bridge was loaded by an asymmetric forcing function, higher modes, which are lateral and/or torsional in nature, were excited. Dynamic modulus of elasticity and the support stiffness influenced the natural frequencies of the bridge, which in turn influenced the dynamic amplifications. Larger than anticipated dynamic amplification factors and the excitation of lateral and/or torsional modes should be of interest and concern to bridge engineers.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.567-576
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• 2020

One of the main challenges receiving much attention in the Rwandan agriculture and food industry in recent decades is the increases in maize prices. Indeed, a rise in maize prices causes higher living expenses for households because maize, which is a major staple food crop, constitutes a significant share of total food consumption among households in Rwanda. The aim of this study was to assess the extent of integration and how prices are transmitted between retail and wholesale markets of domestic maize in Rwanda. This study used monthly data of retail and wholesale prices of maize from January 1995 to December 2019. This empirical investigation was based on a linear cointegration approach and an asymmetric error correction model framework. Using the augmented dickey-fuller residual-based test and the Johansen Maximum Likelihood cointegration test, the results revealed that the retail and wholesale markets of maize are integrated. Hence, prices in these markets do not drift apart in the long run. The results of the Granger causality test revealed that there is a unidirectional causal relationship flowing from wholesale prices to retail prices, i.e., wholesale prices influence retail prices. Accordingly, the results from the asymmetric error correction model confirmed the presence of a positive asymmetric price transmission between wholesale and retail prices of maize in Rwanda. Thus, we suggest that policymakers take a critical look at the causes and factors that may influence asymmetry price transmission.