• Geomechanics and Engineering
• /
• v.22 no.4
• /
• pp.339-348
• /
• 2020

The uncertain geotechnical properties of frozen soil are important evidence for the design, operation and maintenance of the frozen ground. The complex geological, environmental and physical effects can lead to the spatial variations of the frozen soil, and the uncertain mechanical properties are the key factors for the uncertain analysis of frozen soil engineering. In this study, the elastic modulus, strength and Poisson ratio of warm frozen soil were measured, and the statistical characteristics under different temperature conditions are obtained. The autocorrelation distance (ACD) and autocorrelation function (ACF) of uncertain mechanical properties are estimated by random field (RF) method. The results show that the mean elastic modulus and mean strength decrease with the increase of temperature while the mean Poisson ratio increases with the increase of temperature. The average values of the ACD for the elastic modulus, strength and Poisson ratio are 0.64m, 0.53m and 0.48m, respectively. The standard deviation of the ACD for the elastic modulus, strength and Poisson ratio are 0.03m, 0.07m and 0.03m, respectively. The ACFs of elastic modulus, strength and Poisson ratio decrease with the increase of ratio of local average distance and scale of fluctuation. The ACF of uncertain mechanical properties is different when the temperature is different. This study can improve our understanding of the spatial autocorrelation variations of uncertain geotechnical properties and provide a basis and reference for the uncertain settlement analysis of frozen soil foundation.

• The Journal of Information Technology
• /
• v.4 no.4
• /
• pp.51-63
• /
• 2001

Residue Number System has carry free operation and parallelism each modulus, So it is used for special purpose processor such as Digital Signal Processing and Neuron Processor. Magnitude comparison and sign detection are in need of Mixed Radix Conversion, and these operations are impediment to improve the operation speed. So in this Paper, MRC(Mixed Radix Converter) is designed using modified partitioned residue to speed up the operation of MRC, so it has progressed maximum twice operation time but increased the size of converter comparison to other converter.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.1
• /
• pp.79-84
• /
• 2018

This paper relates with the performance improvement of SE-MMA (Signed Error-Multiple Modulus Algorithm) adaptive equalization algorithm that is used for the reduction of the intersymbol interference due to the distortion which occurs in the communication channel for the transmission of 16-QAM nonconstant modulus signal.. In the conventional MMA, the fixed modulus value that is second order statistics of transmitting signal were used, and the SE-MMA was introduced in order to the simplification of the algorithm's arithmetic operation. The SE-MMA have a fast convergence speed than MMA, but it has a problem of degradation of equalization performance in the steady state due to the arithmetic simplification. In this paper, we propose the new algorithm AV-SE-MMA (Adaptively Varying-SE-MMA) that uses the adaptive varying modulus in order to obtain the error signal for updating the adaptive equalizer coefficient, and its equalization performance were confirmed by simulation. In this paper, the performance of SE-MMA and proposed algorithm were compared, and the equalizer output signal constellation, residual isi, MSE and SER in order to confirm the robustness of noise were used as performace index. As a result of performance comparison, the AV-SE-MMA has better performance in output signal constellation, residual isi and MD compared to the SE-MMA, but it was confirmed that the AV-SE-MMA has similar in the SER performance that means the robustness to the noise.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.131-134
• /
• 2007

In this paper, we propose the 1D-CZP pattern for FPGA verification. The algorithm that was implemented by Verilog-HDL on FPGA board is verified before the chip is producted. Input through the external sensor might not be enough to verify the algorithm on FPGA board. Hence, both external input and internal input can lead the verification of the algorithm. This paper suggests the hardware implementation of compact 1D-CZP pattern that has the random input. It is useful to analyze the characteristics of the filter frequencies and organized as ROM Table which is efficient to Modulus operation.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.2
• /
• pp.596-603
• /
• 1991

Fatigue life prediction of pressure vessel is studied analytically using cumulative damage models and linear elastic fracture mechanics method. The stresses are analyzed by finite element method. During operation, the maximum stress occurs at the outside of neck region while fatigue analysis indicates that the bottom of nozzle part has the shortest fatigue life. Previously proposed fatigue life prediction equation and cumulative damage model are modified successfully by introducing reference fatigue modulus. It is found that the modified life prediction equation and damage model are useful for lower stress level application.

• Journal of the Korean Society of Combustion
• /
• v.20 no.2
• /
• pp.46-53
• /
• 2015

The relationship between mass transfer and reaction within the washcoat is investigated in a monolith type micro-scale Pt-catalytic combustor. Nondimensionalized balance equation of butane is applied in a simplified washcoat geometry having the shape of slab. Both Thiele modulus and effectiveness factor are considered to compare reaction rate and diffusion rate according to the operation temperature and the diameter of alumina nano-pores. The effect of reaction becomes stronger as the temperature increases, while the effect of diffusion becomes relatively dominant as the diameter of nano-pores increases. From the analysis of butane distribution within the washcoat, design criterion for the thickness of washcoat is discussed.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.48 no.4
• /
• pp.59-66
• /
• 2006

In this study, construction modulus, void ratio and settlement characteristics of 38 CFRD in domestic and foreign countries were investigated from monitoring data. The effect of field dry density and void ratio to dam body was analyzed. The standard void ratio of CFRD that can be easily used by dam designers and field engineers was proposed from the monitoring data. It was confirmed that we can get the degree of compaction needed for reasonable compaction of dam body by calculating the field dry density from inverse operation of the standard void ratio. It was thought that the void ratio of CFRD depends on shape coefficient and in case of a high shape coefficient, the void ratio was high with its void ratio 0.17 -0.38.

• Journal of Drive and Control
• /
• v.14 no.4
• /
• pp.17-22
• /
• 2017

In this study, the back-drivability of the single-rod and double-rod type EHAs (Electro-Hydrostatic Actuators) was compared by computer simulation and experiments. The back-drivability of EHAs exhibit non-linear behavior like their force tracking performance. In case of the double-rod type EHA, the back-drivability was mostly influenced by the bulk modulus of oil that changes with the working pressure due to entrapped air. The back-drivability of the single-rod type EHA was directly affected by the operation states of its pilot-operated check valves, while the asymmetrical piston geometry and the non-linear bulk modulus of oil also made the dynamic response in building up the cylinder pressure dependent on the operating conditions.

• Proceedings of the IEEK Conference
• /
• 2002.06b
• /
• pp.285-288
• /
• 2002

In this paper, a new structure of 1024-bit high-speed RSA cryptosystem has been proposed and implemented in hardware to increase the operation speed and enhance the variable-length operation in the plain text. The proposed algorithm applied a radix-4 Booth algorithm and CSA(Carry Save Adder) to the Montgomery algorithm for modular multiplication As the results from implementation, the clock period was approached to one delay of a full adder and the operation speed was 150MHz. The total amount of hardware was about 195k gates. The cryptosystem operates as the effective length of the inputted modulus number, which makes variable length encryption rather than the fixed-length one. Therefore, a high-speed variable-length RSA cryptosystem could be implemented.

• Journal of the Korean Society for Railway
• /
• v.14 no.3
• /
• pp.256-261
• /
• 2011

Recently a limited section of trackbed with ballast at KTX railway were reported to have settled down and led to problems such as reduced speed and passenger discomfort. Therefore, an urgent remedy for the settled trackbed is required to recover normal operation of KTX trains. In this paper, a new technique is proposed to visualize the elastic modulus of cross sections at railway trackbeds under ballast for practical identification of potential settlement. The proposed technique is based on ICSW technique, enabling use of impact source and overcoming inherent limitations of CSW method. To verify validity and feasibility of the proposed method, the method was employed to construct cross-sectional images of elastic modulus of two railway trackbeds and compared with other tests such as SASW, PBT, DCP and portable FWD tests.