• Journal of Korean Society of Steel Construction
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• v.19 no.4
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• pp.383-393
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• 2007

A simplified model which incorporates the moment-axial tension interaction of the double-span beams in a column-removed steel frame is presented in this paper. To this end, material and geometric nonlinear parametric finite element analyses were conducted for the double-span beams by changing the beam span to depth ratio and the beam size within some practical ranges. The beam span to depth ratio was shown to be the most influential factor governing the catenary action of the double-span beams. Based on the parametric analysis results, a simplified piece-wise linear model which can reasonably describe the vertical resisting force versus the beam chord rotation relationship was proposed. It was also shown that the proposed method can readily be used for the energy-based progressive collapse analysis of steel moment frames.

• Transactions of Materials Processing
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• v.19 no.8
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• pp.508-516
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• 2010

Thickening process in sheet metal forming is being increased to improve the strength as well as to reduce manufacturing process such as welding. This process can make it possible to obtain part locally thicker than that of initial sheet thickness. In this study, design method for manufacturing the component which has double sinks with local thickened wall is proposed. Deep drawing and upsetting processes are applied in order to form double sinks and thicken its walls. Used material is SPHC440 with the thickness of 2.0mm and initial blank size is determined on the basis of the final product. Distance between the center of double sinks and first drawing ratio to avoid fracture are the most significant factors during deep drawing. FE-analysis is implemented in order to determine the appropriate values. Progressive die is designed based on the proposed method and FE-analysis. As a result of experiment, locally thickened component can be manufactured, which has double sinks with the thickness about 3mm at the corner and wall.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.6
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• pp.621-628
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• 1992

This paper proposes a progressive Image transmission method with a variable magnification hierarchical structure for image processing system. As Introduced in the literature, the progressive image transmission method, uses a fixed magnification rates of either 4 or 1/4. Thus, a sudden in-crease In resolution Is obtained due to a sudden Increase in information. By adapting a variable magnification hlerarchical structure In this research, a gradual increase in resolution Is possible by slowly inrireasing information between hierarchical levels. The simulation results show that a 5.7dB SNR improvemr'nt Is obtained with an Improved compression rate by 0.7 Ult /pel compare to the LP method. It also gives about 1 dB SNR improvement compare to the PCS method at intermediate hierarchical levels.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.349-356
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• 1997

In this paper, we propose the lossless coding: scheme for progressive transmission of medical images. The input image is decomposed by the proposed fast adaptive subband decomposition method which is suited for a lossless coding. The decomposed images are coded by an arithmetic coder with two conditioning pixels, and the conditioning pixels are selected differently according to the property of the subbands. The conditioning contexts are usually quantized to reduce the conditional state, and the optimization method of quantization is proposed For the purpose of improving compression ratio in this paper. The proposed lossless coding scheme provides the asymmetric structure of cosec and results in better compression ability than the JPEC lossless coding[ 1 ].

• Structural Engineering and Mechanics
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• v.58 no.2
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• pp.327-345
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• 2016

Many experimental and analytical studies have been conducted with beam-column subassemblages composed of a two-span beam to investigate the progressive collapse resistance of RC frames. Most study results reveal a strength-decreased transition phase in the nonlinear static load-deflection curve, which may induce dynamic snap-through response and increase the chord rotation demand for effective catenary action (ECA). In this study, the nonlinear static response is idealized as a piecewise linear curve and analytical pseudo-static response is derived for each linearized region to investigate the rotation demands for the ECA of the two-span RC beams. With analytical parameters determined from several published test results, numerical analysis results indicate that the rotation demand of 0.20 rad recommended in the design guidelines does not always guarantee the ECA. A higher rotation demand may be induced for the two-span beams designed with smaller span-to-depth ratios and it is better to use their peak arch resistance (PAR) as the collapse strength. A tensile reinforcement ratio not greater than 1.0% and a span-to-depth ratio not less than 7.0 are suggested for the two-span RC beams bridging the removed column if the ECA is expected for the collapse resistance. Also, complementary pseudo-static analysis is advised to verify the ECA under realistic dynamic column loss even though the static PAR is recovered in the nonlinear static response. A practical empirical formula is provided to estimate an approximate rotation demand for the ECA.

• 한국해양학회지
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• v.21 no.4
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• pp.259-264
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• 1986

The problem of the formation of steady stream of flat bottom boundary is revisited by applying a progressive finite amplitude wave as an external flow. A solution for the boundary layer is found by expanding the boundary equation into double Fourier series. A vertical profile of the stream is obtained as a function of the ratio, h/L, where h and L are the water depth and the wave length. For the best applicable range of the external wave, it is shown that the boundary stream is independent of the fluid viscosity, but a function of the wave parameters and the water depth. The stream velocity of the steady boundary layer flow is proportional to the wave phase velocity and the square of the ratio, H/h, where His the wave height. The magnitude of the velocity is insignificant when h/L is greater than 1/5.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.245-252
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• 2011

Currently, the design guidelines for the prevention of progressive collapse are not available in Korea due to the lack of study efforts in progressive collapse resistance evaluation of RC flat plate system. Therefore, in this study, three types of analysis were conducted to evaluate the progressive collapse resistance of a RC flat plate system. A linear static analysis was carried out by comparing the demand-capacity ratio (DCR) differences of the systems using the alternate load path method, which is the guideline of GSA. A dynamic behavior was investigated by checking the vertical deflection after removal of the column using the linear dynamic analysis. Lastly, a maximum load factor was investigated using the nonlinear static analysis. The finite element (FE) analyses were conducted using various parameters to analyze the results obtained using effective beam width (EB) model and plate element FEM (PF) model. This study results showed that the strength contributions of the slab in the EB models are underestimated compared to those obtained from the PF models. Therefore, a detailed FE analysis considering the slab element is required to thoroughly estimate the progressive collapse resisting capacity of flat plate system. The scenario of the corner column (CC) removal is the most dangerous conditions where as the scenario of the inner column (IC) removal is the least dangerous conditions based on the consideration of various parameters. The analysis results will allow more realistic evaluations of progressive collapse resistance of RC flat plate system.

• Korean Journal of Animal Reproduction
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• v.10 no.2
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• pp.182-187
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• 1986

As a fundamental study to increase the fertility and to modify the sex ratio in cattle, highly motile sperm were separated by bovine serum albumin gradients. The pregnancy rates of Korean native cow and Holstein cow, and the sex ratio between AI and natural mating were also investigated. The results obtained were as follows. 1. First service pregnancy rate of Korean native cow in artificial insemination was higher than that of Holstein. 2. At secondary sex ratio in artificial insemination and natural mating, male ratio in artifical insemination was slightly higher than that in natural mating. 3. The sperm separated from marketed frozen semen using 6%, 10% and 20% bovine serum albumin showed significantly high value in motility, percent of normal sperm and progressive motility as compared with control sperm.

• Animal Bioscience
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• v.37 no.2
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• pp.203-209
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• 2024

Objective: This study aimed to assess the impact of the dilution ratio of Tris diluent, storage at 0℃, and long-distance transportation on the spermatozoa of Simmental cattle. It also validated the feasibility of the regional distribution of fresh semen. Methods: In experiment 1, semen was diluted at four dilution ratios (1:6, 1:9, 1:12, and 1:15) to determine the optimal dilution ratio of Tris diluent. In experiment 2, we assessed sperm viability, progressive motility (objectively assessed by computer-assisted sperm analyzer), and acrosome intactness in Tris dilutions kept at constant 0℃ for 1, 3, 6, 9, and 12 days. We compared them to Tianshan livestock dilutions (Commercial diluent). In experiment 3, semen was diluted using Tris diluent, and sperm quality was measured before and after long-distance transport. Artificial insemination of 177 Simmental heifers compared to 156 using Tianshan Livestock dilution. Results: The outcomes demonstrated that 1:9 was the ideal Tris diluent dilution ratio. The sperm viability, Progressive Motility, and acrosome integrity of both Tris and Tianshan dilutions preserved at 0℃ gradually decreased over time. sperm viability was above 50% for both dilutions on d 9, with a flat rate of decline. The decrease in acrosome integrity rate was faster for Tianshan livestock dilutions than for Tris dilutions when stored at 0℃ for 1 to 6 days. There was no significant difference (p>0.05) in sperm viability between semen preserved in Tris diluent after long-distance transportation and semen preserved in resting condition. The conception rates for Tris dilution and Tianshan livestock dilution were 49.15% and 46.15% respectively, with no significant difference (p>0.05). Conclusion: This shows that Tris diluent is a good long-term protectant. It has been observed that fresh semen can be successfully preserved for long-distance transport when stored under 0℃ conditions. Additionally, it is feasible to distribute semen regionally.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1318-1321
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• 1997

A method for two-dimensional position measurement using an enclosing field has been studied and reported. The feature of this mehtod is zooming functional measurement by operating both the initial phase shift and the brightness ratio of the lighting function. An experimental system was developed and the experimental results on zooming effects are shown in this paper. This system is also an example of a "progressive learning measurement system".tem".uot;.