• Smart Structures and Systems
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• v.20 no.5
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• pp.525-537
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• 2017

This paper explores different vibration control strategies for the cancellation of human-induced vibration on a structure with time-varying modal parameters. The main motivation of this study is a lively urban stress-ribbon footbridge (Pedro $G\acute{o}mez$ Bosque, Valladolid, Spain) that, after a whole-year monitoring, several natural frequencies within the band of interest (normal paring frequency range) have been tracked. The most perceptible vibration mode of the structure at approximately 1.8 Hz changes up to 20%. In order to find a solution for this real case, this paper takes the annual modal parameter estimates (approx. 14000 estimations) of this mode and designs three control strategies: a) a tuned mass damper (TMD) tuned to the most-repeated modal properties of the aforementioned mode, b) two semi-active TMD strategies, one with an on-off control law for the TMD damping, and other with frequency and damping tuned by updating the damper force. All strategies have been carefully compared considering two structure models: a) only the aforementioned mode and b) all the other tracked modes. The results have been compared considering human-induced vibrations and have helped the authors on making a decision of the most advisable strategy to be practically implemented.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.232-238
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• 2001

Experimentally it is well known that the magnetic properties significantly deteriorate when nanocomposite bonded magnet are made from nanocomposite ribbon. A decrease in maximum energy product of F $e_3$B+N $d_2$F $e_{14}$B nanocomposite from 14 MGOe in nanocomposite ribbon to 6.5 MGOe in powder compact was fecund to be general. Thus, the present study is focused on finding out the root of exchange decoupling of N $d_4$F $e_{73.5}$ $Co_3$H $f_{0.5}$G $a_{0.5}$ $B_{18.5}$ nanocomposite powder compacts. The exchange decoupling behavior of the powder compact of F $e_3$B+N $d_2$F $e_{14}$B composition was studied by measuring DC demagnetization and isothermal remanent demagnetization curves, which are essential for plotting produced $\delta$M curve. From the $\delta$M plot the deterioration in the magnetic properties resulted from the fact that the magnetostatic interaction became dominant rather thanthe exchange interaction in powder compact. It is concluded that the demagnetization behavior governed by the dominant magnetostatic interaction reduced the remanence magnetization, which caused the reduction of maximum energy Product of the powder compact. We also found that the elimination of residual stress which is unavoidably accumulated during grinding process enhanced the magnetic properties considerably.bly.bly.

• Journal of the Korea Fashion and Costume Design Association
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• v.19 no.2
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• pp.15-28
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• 2017

Today, modern people are exposed to various environmental pollutants such as harmful substances and stress, which can compromise health. Therefore, a healing culture that seeks to enjoy human life based on the healing of body and mind is attracting great attention. The purpose of this study is to develop environmentally friendly natural dyeing considering a healing concept with four elements: color, dye, material, and pattern. The research methods and scope are based on a theoretical review of healing and research on the literature of bedding related to natural dyes, national and international books, the Internet, etc., and naturally dyed bedding. This paper presents actual production research. The results of this study are as follows. First, the elements of color, dyeing, material and pattern were developed through the process of a bedding design development model that applies a healing concept and can be commercialized as a healing bedding product. Second, a healing color proposal was expressed in an intermediate color system of pink, ocher, lavender, and indigo colors for emotional stability, warmth, calmness, comfort and softness. Third, eco-friendly bedding using natural dyes with medicinal efficacy can obtain the healing effect of the natural treatment method, which can aid healthy sleep. Fourth, the pattern used in the bedclothes was a motif of Sarasa embroidery, flower embroidery, ribbon embroidery, and wave quilting motifs to provide psychological stability as a healing concept in the sleeping environment. The natural healing bedding with the healing concept proposed in this study has natural treatment that is beneficial to human health and the development of bedding with natural dyes will lead to an increase of demand for the sleeping environment.

• Journal of the Korean Society of Costume
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• v.27
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• pp.163-171
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• 1996

As the current stage of the fashion begins to follow the styles of the past the study on he past costume is getting more importance and as the methodology of the study the accurately ap-proached study through the rehabilitation of the past costume is more needed than the simple re-arrangement of the historical documents. By this methodology this study can be positioned as a re-creation activity. The results of the study are as follows. 1) Style: The S-line silhouette remains be-cause of the straight silhouette or the blossom style bodice. This dress has various types of sil-houette but generally it forms one silhouette and is one-piece. 2) color and Material: The material varies hile the color is divided as the main color of ivory and the stress color of brown. This shows not only that the material has been varied but also that they tried to reduce the monotony. 3) Pattern and Sewing: The simple external figure and the previous stage typically shows the movement to the simplicity of the contemporary and the num-ber of patterens is plenty and the sewing method is also complex. 4) Detail. To overcome the simplicity of the style and to show the characteristics of the afternoon dress the skunk fur the net the sash, and the bow are used. 5) Structural Characteristics: The front open-ing the back opening and the side opening coexists in one-pieced dress and this forms unique structure and complex fastening device. The ribbon tape and casing not only finish the seam but also fix the shape of the dress. Synthetically the 1913-14 afternoon dress has the characteristics of transitional stage in which the characteristics of the costume of 1910s and the remnants of the characteristics of the pre-vious costume style and shows the character-istics of afternoon dress well in terms of the ma-terial the structure and the detail.

• Journal of the Korean Magnetics Society
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• v.2 no.2
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• pp.91-98
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• 1992

In a $Co_{67}Fe_{4.5}Nb_{2}Si_{10}B_{15}$ amorphous alloy ribbon the effect to two-step annealing on the soft magnetic properties has been studied. By two-step annealing method which the second annealing at low temperature of $310^{\circ}C$ for 2 hours is undertaken after the primary annealing at high temperature above $480^{\circ}C$ for 20 minutes at the vacuum state, the coercive force and the squareness are not changed nearly but the initial permeability at d.c. and the effective permeability at a.c. are remark-ably increased compared with the one-step annealing. The maxima of the initial permeability and the effective permeability at 1 kHz after the two-step annealing are 290,000 and 41,000, respectively, which are 30% higher than those of the one-step annealing. The change of magnetic properties with annealing temperature is discussed in terms of the residual stress, the domain size, the cluster and the crystalline phase.