• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.1
• /
• pp.42.4-43
• /
• 2017

We investigate the long-period radial velocity (RV) variations for M giant HD 18438 and K giant HD 158996 using the high-resolution Bohyunsan Observatory Echelle Spectrograph at the 1.8m telescope of Bohyunsan Optical Astronomy Observatory in Korea. These two target stars are important because HD 18438 is the largest star and HD 158996 is the brightest star for exoplantary system candidate so we can understarnd how evolved stars affect planets by researching these stars. We calculated precise RV measurements of 38 and 24 spectra from November 2010 to January 2017 and June 2010 to January 2017, respectively. We dreived the RV variation period for 719.0 days of HD 18438, 775.6 days for HD 158996. We conclude that the RV variation of HD 158996 is caused by planetary companion which has the mass of 14.7 MJup, semi-major axis of 2.2 AU, and eccentricity of 0.27 assuming the stellar mass of $2.34M{\odot}$. On the other hand, the origin of RV variation of HD 18438 with period of 719.0 days is still uncertain. It might be caused by stellar chromospheric activity or planetary companion, so more observations and tests are required.

• Structural Engineering and Mechanics
• /
• v.30 no.5
• /
• pp.603-617
• /
• 2008

Three dimensional coupled bending-torsion dynamic vibrations of thin-walled open section beam subjected to moving vehicle are investigated by transfer matrix method. Through adopting the idea of Newmark-${\beta}$ method, the partial differential equations of structural vibration can be transformed to the differential equations. Then, those differential equations are solved by transfer matrix method. An iterative scheme is proposed to deal with the coupled bending-torsion terms in the governing vibration equations. The accuracy of the presented method is verified through two numerical examples. Finally, with different eccentricities of vehicle, the torsional vibration of thin-walled open section beam and vertical and rolling vibration of truck body are investigated. It can be concluded from the numerical results that the torsional vibration of beam and rolling vibration of vehicle increase with the eccentricity of vehicle. Moreover, it can be observed that the torsional vibration of thin-walled open section beam may have a significant nonlinear influence on vertical vibration of truck body.

• Structural Engineering and Mechanics
• /
• v.27 no.4
• /
• pp.439-456
• /
• 2007

Reinforced concrete (RC) joint shear strength models are constructed using an experimental database in conjunction with a Bayesian parameter estimation method. The experimental database consists of RC beam-column connection test subassemblies that maintained proper confinement within the joint panel. All included test subassemblies were subjected to quasi-static cyclic lateral loading and eventually experienced joint shear failure (either in conjunction with or without yielding of beam reinforcement); subassemblies with out-of-plane members and/or eccentricity between the beam(s) and the column are not included in this study. Three types of joint shear strength models are developed. The first model considers all possible influence parameters on joint shear strength. The second model contains those parameters left after a step-wise process that systematically identifies and removes the least important parameters affecting RC joint shear strength. The third model simplifies the second model for convenient application in practical design. All three models are unbiased and show similar levels of scatter. Finally, the improved performance of the simplified model for design is identified by comparison with the current ACI 352R-02 RC joint shear strength model.

• The Research Journal of the Costume Culture
• /
• v.28 no.3
• /
• pp.330-343
• /
• 2020

This study defines the concept of the fashion meme, which has recently emerged as a fashion trend, influential fashion keyword. After analyzing the concepts and characteristics of traditional memes from prior studies, examples of fashion memes were collected from online community and social network services, while a literature study and case study analysis were conducted in parallel drawing on related articles and journals. Modern fashion memes refer to fashion-related symbols and fashion images that are spread online by word-of-mouth, together with fashion styles and items that spread as a result of being worn. Fashion memes in cyberspace are mainly spread through social network or message services, and sometimes combine text, images, videos, hashtags, and emoticons. Fashion memes are a type of collective action of the people in response to social problems in the world, and often involve humorous antics, satire, shock, and eccentricity. Shared fashion memes reflect the expression of personality expression and fun, and at the same time are used as an expression of designer and brand creativity and are integral to marketing. Fashion memes are classified into four types, based on two central axes as follows: non-commercial/commercial and anti-fashion/fashion-friendly. Unlike traditional memes, Internet-based fashion memes emphasize elements of transformation through creativity as well as imitation, which has become a persisting contemporary trend beyond temporary phenomena.

• Journal of Advanced Marine Engineering and Technology
• /
• v.30 no.5
• /
• pp.623-628
• /
• 2006

Laser material processing is a very fast advancing technology for various industrial applications. because of many advantages. Its major advantage of less and controlled heat input has been exploited successfully for the very critical application of aluminium alloy welding. This study suggested the occurrence source of weld-defects and its solution methods in a welding of lithium ion battery by pulsed Nd:YAG laser. In experiment. battery case has changed over joint geometry from welding of side position to flat one. In the case of a electrolyte injection hole in order to seal it. welding is carried out after pressing Al ball. At this time. an eccentric degree. contact length and gap are worked as a major parameters. As improving the method of Al ball pressing. it was able to reduce an eccentricity. increase the contact length and decrease gap. As a results of a experiment. a sound weld bead shape and crack-free weld bead can be obtained.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.06a
• /
• pp.339-343
• /
• 2005

Laser material processing is a very fast growing technology for various industrial applications, because of many advantages. Its major advantage of less and controlled heat input has been exploited successfully for the very critical application of aluminium alloy welding. This study suggested the occurrence source of weld-defects and its solution methods in a welding of lithium ion battery by pulsed Nd:YAG laser. In experiment, battery case has changed over joint geometry from welding of side position to flat one. In case of a electrolyte injection hole in order to seal it, welding is carried out after pressing Al ball. At this time, an eccentric degree, contact length and gap are worked as a major parameters. As improving the method of Al ball pressing, it was able to reduce an eccentricity, increase the contact length and decrease gap. As a results of a experiment, a sound weld bead shape and crack-free weld bead can be obtained.

• Journal of Astronomy and Space Sciences
• /
• v.17 no.2
• /
• pp.173-180
• /
• 2000

All times of minimum light of V651 Cas, which is still less studied so far, were analyzed. From our analysis, it was found that the orbital period of the system may have varied in a periodic manner. After assuming that the period change is produced by the light-time effect due to a third body in the system, attempts to derive the orbital elements of the light-time orbit were made. The resultant values for the period, semi-amplitude, and eccentricity of the light-time orbit were 6.${y}^{25}$, 0.${d}^{0013}$, and 0.77, respectively. The future observations of times of minimum light of V651 Cas are needed to confirm the existence of the third body we suggested in this paper.

• Journal of Astronomy and Space Sciences
• /
• v.14 no.2
• /
• pp.381-385
• /
• 1997

A long-term prediction algorithm of geostationary orbit was developed using the analytical method. The perturbation force models include geopotential upto fifth order and degree and luni-solar gravitation, and solar radiation pressure. All of the perturbation effects were analyzed by secular variations, short-period variations, and long-period variations for equinoctial elements such as the semi-major axis, eccentricity vector, inclination vector, and mean longitude of the satellite. Result of the analytical orbit propagator was compared with that of the cowell orbit propagator for the KOREASAT. The comparison indicated that the analytical solution could predict the semi-major axis with an accuracy of better than $pm35$ meters over a period of 3 month.

• Journal of Korean Society of Steel Construction
• /
• v.13 no.6
• /
• pp.609-619
• /
• 2001

It is almost impossible to evaluate the ultimate strength theoretically, because the behavior of Gusset-Tube connection stiffened with rib-plate is considerably complicate. Therefore in this study a finite element model of gusset-tube connection stiffened with rib-plate was established. The validity of finite element analysis was examined through comparing with previous experimental result and the behavior and strength of the connection was examined. From the parametric study considering lateral force ratio, eccentricity, gusset length based on finite element model, the stiffened effect was estimated and stiffening method was proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.04a
• /
• pp.663-670
• /
• 2011

In this study, the design and verification of 6kW class lift-type vertical-axis wind turbine (VAWT) has been conducted using advanced CAE technique based on computational fluid dynamics (CFD), finite element method (FEM), and computational structural dynamics (CSD). Designed aerodynamic performance of the VAWT model is tested using unsteady CFD method. Designed structural safety is also tested through the evaluation of maximum induced stress level and resonance characteristics using FEM and CSD methods. It is importantly shown that the effect of master eccentricity due to rotational inertia needs to be carefully considered to additionally investigate dynamic stress and deformation level of the designed VAWT system.