• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.149-154
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• 1993

In heavy grinding that is on of the high efficient grinding method, meaningful deformation is generated by high temperature. So, after machining, geomeric error generated od the workpiece. The most important factor on the geometric error is temperature difference between upper layer and lower layer (T $_{d}$) . Relations between Td and grinding condition and maximum geometric error and grinding condition are obtained by experiment. This relations are used in fuzzy algorithm for improvement geometric accuracy. The main results are follows : (1) The linear relation between maximum geometric error and grinding condition is ovtained by experiment. (2) The linear relation between maximum temperature difference between upper layer and lower layer and grinding condition is ovtained by experiment. (3) Control peth of wheel for improvement geometric accuracy is obtained by using the fuzzy algorithm.m.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.137-140
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• 1996

This study investigated the length-tension and velocity-force relations of the torso erectors. A myoelectric based approach was used wherein a dynamic biomechanical model incorporating active and passive tissue charactreistics provided music kinematic estimates during controlled sagittal plan extension motions. A double linear optimization formulation from the literatured provided muscle tension estimates. The data supported a linear length-tension relation toward full flexion for both the erector spinae and latissimus muscles. Velocity trends agreed with that predicted by Hill's exponential relation. The results have implications for muscle tension estimation in biomechanical torso modeling, and suggest a possible low back pain injury mechanism.

• Economic and Environmental Geology
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• v.17 no.3
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• pp.163-169
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• 1984

A linear inversion of heat flow values using heat production data with reliable value is studied in this work. To evaluate 2-D problem, a thin vertical sheet model is considered. Making use of a relation based on potential theory, a new relation between $q_{rad}$ and $A_0$ is derived. The forward calculations with noise and without noise are shown. The inversion of random search is comparable to that of ridge regression method. The agreements between the computed and best fit after inversion suggest the importance of random search method in the inversion technique.

• Journal of The Korean Astronomical Society
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• v.11 no.1
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• pp.31-36
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• 1978

Although Serkowski used a single value K=1.15 in representing all the observed interstellar linear polarization curves by his empirical relation $p({\lambda})/P_{max}$=exp (-K $1n^2({\lambda}_{max}/{\lambda})$), where $p_{max}$ is the maximum polarization at wavelength ${\lambda}_{max}$, we have noticed a meaningful variation in K from observations of 72 stars. By comparing K's with $P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$, we have examined how the shape of the polarization curve is related with the degree of grain alignment on one hand, and with grain sizes on the other. We have shown that correlations between K, $P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$, are consistent with the idea of Davis-Greenstein mechanism for grain alignment.

• Journal of the Korean housing association
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• v.27 no.6
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• pp.45-55
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• 2016

This study focused on the changes of residential area around the linear park. The goal of this study is to determine the value of linear park at the view of residents and discover the interaction between the linear park and the residential area around it. To investigate this goal, the researcher chose case sites, the regenerated linear park and the uncovered stream park. This study analyzed the site around the linear parks with four points of view, the organization of urban Fabric, architecture, the economic value of the site and the behavior of residents. This research adopted several research methodologies like aerial photograph analysis, road-view analysis, paper research, and field study, observation, and expert interview to approach as both quantitative and qualitative analysis. With that variation characteristic, the researcher determines the influence of linear park through the residential area around them. As the result, linear park gives positive effects of running sustainable residential area around them and acting as the pivot for the residential area. Also for the future, designers must consider this interactive relation between the linear park and residential area with the wide point of view.

• Journal of Welding and Joining
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• v.27 no.5
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• pp.42-48
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• 2009

Pipe welding is used in various ranges such as civil engineering and ship building engineering. Until now, many technicians work for pipe welding manually under harmful, dangerous and difficult conditions. So it is necessary to install automation process. For automation pipe welding, relation between welding parameters & bead shape should be considered. Using this relation, bead shape could be expected from welding parameters. FCAW was used in this study. Instead of pipe workpiece, fillet joint plate is used, which were inclined 0,45,90,135,180 degree. By analyzing between welding parameters (current, welding speed, voltage) and bead shape parameters with non-linear multiple regression, bead shape parameters could be expected. Piecewise Cubic Hermite Interpolation was used to expect smooth curved bead shape with bead shape parameters. From these processes, bead shape could be expected from welding parameters.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1563-1571
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• 2003

A fast response NO analyzer was applied to investigate the relation between cycle-by-cycle NO emissions and combustion chamber pressure. NO emissions were sampled at an isolated exhaust manifold of 4-stroke spark ignition engine to avoid the interference of exhaust gas from other cylinders. The linear correlation analysis was performed with collected data of NO emissions and combustion chamber pressure with respect to the various air-fuel mixture ratios and engine loads. The sampled data sets were obtained during 200 cycles at each operating condition. The results showed that there was a typical pattern in NO emissions from an exhaust port through a cycle. It was possible to set a block of crank angle in which the linear correlation coefficient between NO emissions and combustion chamber pressure was high. As the engine load increased, NO emissions were more dependent on combustion chamber pressure after TDC. It was also analyzed that the correlation between two parameters with respect to air-fuel mixture ratio tended to increase as mixture went leaner. Furthermore, this correlation coefficient for the mixture near the lean limit seemed to be kept high even though combustion was unstable.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.21-33
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• 2007

The study investigates the effects of luminance contrast, which is the contrast between text color and background color, on readability in VDT environments. Our research goals are to prove that the relationship between luminance contrast and readability is not linear and to explore the best luminance contrast level for optimal readability. We conducted two pretests before the main experiment to determine the operational readability and luminance contrast levels. We also conducted a controlled main experiment, in which luminance contrast, reading amount and screen size were tested in terms of its relation with readability. The results of the main experiment indicate that the readability has a non-linear relation with luminance contrast, and the optimal readability is obtained when the contrast is equal to 0.951. Furthermore, the non-linear function and optional point stay constant regardless of screen size and reading amount. The paper ends with implications of the results that maximal contrast does not always mean the optimal readability.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.5
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• pp.69-77
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• 2012

Relative density, used to express dynamics condition of sand quantitatively, is measured by RI Test, Standard Penetration Test and Cone Penetration Test. Each measurement method has demerits, which is complicated or needs a specific analysis instrument and an analysis of expert. Also the ground is in wet condition commonly because of an unsaturated zone between a saturated zone and a surface, so the behaviour of the ground has different engineering properties unlike the dry ground and it diminishes accuracy of measuring relative density. In this study, the correlation between relative density and penetration of fall cone test in dry condition and wet condition with variation of water content was analyzed and a simple measuring method for relative density was suggested. As a result, there were difference of penetration between dry sands and wet sands, the correlation between relative density and penetration showed linear expression and relative density could be measured by the linear relation.

• International journal of steel structures
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• v.18 no.5
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• pp.1654-1665
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• 2018

In an irregular prism tensegrity, the number of force equilibrium equations is less than the number of unknown parameters of nodal coordinates and member force ratios. As a result, the form-finding process normally becomes nonlinear with additional conditions or needs to be carried out with the use of iterative procedures. For cases of irregular prism tensegrity which involves large number of members, it was found that previously proposed methods of form-finding are not practical. Moreover, there is a need for a form-finding approach which is able to cater to different requirements on final configuration. In this paper, the length relation condition is introduced to be used in combination with the force equilibrium equation. With the combined use of length relation and equilibrium conditions, a linear form-finding approach for irregular prism tensegrity was successfully formulated and developed. An easy-to-use interactive form-finding tool has been developed which can be used for form-finding of irregular prism tensegrities with large number of elements as well as under diverse specific requirements on their configurations.