• Journal of the Korean Society of Clothing and Textiles
• /
• v.40 no.5
• /
• pp.910-920
• /
• 2016

This study is to understand the problems of current police raincoats for professional policemen and conscripted policemen. Interviews and a survey were completed to investigate the wearing conditions of current police raincoats. The questionnaire was composed of questions on current wearing conditions of raincoat, motional adaptability, dimensional compatibility, design suitability and demographic information on the research target. The results indicated that the wearing frequency of raincoats had significant difference according to duty and age range. The main reason for the low wearing frequency was the uncomfortableness of working while wearing the raincoat, followed by the inconvenience of managing the raincoat after use and feeling hot while wearing the raincoat. The three most important factors when wearing a raincoat was pleasantness, activity capability and the functionality of the fabric. The satisfaction on body parts during motions tended to be evaluated lower as the raincoat size increased. The results of the dissatisfaction factors indicated that the raincoat hood had the most problems. There was inconvenience when using the equipment belt because officers have to wear their belts inside the raincoat. In regards to the fabric satisfaction level, respondents were less satisfied with ventilation, hygroscopicity, and drying time. Therefor it appeared that the current raincoat had problems due a lack of functionality in regards to ventilation, hygroscopicity, and quick drying; in addition, the satisfaction on motional adaptability had a significant difference according to raincoat size.

• Steel and Composite Structures
• /
• v.26 no.4
• /
• pp.513-531
• /
• 2018

In this article, static, buckling and free vibration analyses of a sinusoidal micro composite beam reinforced by single-walled carbon nanotubes (SWCNTs) with considering temperature-dependent material properties embedded in an elastic medium in the presence of magnetic field under transverse uniform load are presented. This system is used at micro or sub micro scales to enhance the stiffness of micro composite structures such as bar, beam, plate and shell. In the present work, the size dependent effects based on surface stress effect and modified strain gradient theory (MSGT) are considered. The generalized rule of mixture is employed to predict temperature-dependent mechanical and thermal properties of micro composite beam. Then, the governing equations of motions are derived using Hamilton's principle and energy method. Numerical results are presented to investigate the influences of material length scale parameters, elastic foundation, composite fiber angle, magnetic intensity, temperature changes and carbon nanotubes volume fraction on the bending, buckling and free vibration behaviors of micro composite beam. There is a good agreement between the obtained results by this research and the literature results. The obtained results of this study demonstrate that the magnetic intensity, temperature changes, and two parameters elastic foundations have important effects on micro composite stiffness, while the magnetic field has greater effects on the bending, buckling and free vibration responses of micro composite beams. Moreover, it is shown that the effects of surface layers are important, and observed that the changes of carbon nanotubes volume fraction, beam length-to-thickness ratio and material length scale parameter have noticeable effects on the maximum deflection, critical buckling load and natural frequencies of micro composite beams.

• Earthquakes and Structures
• /
• v.8 no.5
• /
• pp.1215-1240
• /
• 2015

In this paper, the Theory of Plastic Mechanism Control (TPMC) is applied to the seismic design of dual systems composed by moment-resisting frames and Chevron braced frames. The application of TPMC is aimed at the design of dual systems able to guarantee, under seismic horizontal forces, the development of a collapse mechanism of global type. This design goal is of primary importance in seismic design of structures, because partial failure modes and soft-storey mechanisms have to be absolutely prevented due to the worsening of the energy dissipation capacity of structures and the resulting increase of the probability of failure during severe ground motions. With reference to the examined structural typology, diagonal and beam sections are assumed to be known quantities, because they are, respectively, designed to withstand the whole seismic actions and to withstand vertical loads and the net downward force resulting from the unbalanced axial forces acting in the diagonals. Conversely column sections are designed to assure the yielding of all the beam ends of moment-frames and the yielding and the buckling of tensile and compressed diagonals of the V-Braced part, respectively. In this work, a detailed designed example dealing with the application of TPMC to moment frame-chevron brace dual systems is provided with reference to an eight storey scheme and the design procedure is validated by means of non-linear static analyses aimed to check the actual pattern of yielding. The results of push-over analyses are compared with those obtained for the dual system designed according to Eurocode 8 provisions.

• Earthquakes and Structures
• /
• v.6 no.1
• /
• pp.71-87
• /
• 2014

Interaction between closely-spaced buildings subject to earthquake induced strong ground motions, termed in the literature as "seismic pounding", occurs commonly during major seismic events in contemporary congested urban environments. Seismic pounding is not taken into account by current codes of practice and is rarely considered in practice at the design stage of new buildings constructed "in contact" with existing ones. Thus far, limited research work has been devoted to quantify the influence of slab-to-slab pounding on the inelastic seismic demands at critical locations of structural members in adjacent structures that are not aligned in series. In this respect, this paper considers a typical case study of a "new" reinforced concrete (R/C) EC8-compliant, torsionally sensitive, 7-story corner building constructed within a block, in bi-lateral contact with two existing R/C 5-story structures with same height floors. A non-linear local plasticity numerical model is developed and a series of non-linear time-history analyses is undertaken considering the corner building "in isolation" from the existing ones (no-pounding case), and in combination with the existing ones (pounding case). Numerical results are reported in terms of averages of ratios of peak inelastic rotation demands at all structural elements (beams, columns, shear walls) at each storey. It is shown that seismic pounding reduces on average the inelastic demands of the structural members at the lower floors of the 7-story building. However, the discrepancy in structural response of the entire block due to torsion-induced, bi-directionally seismic pounding is substantial as a result of the complex nonlinear dynamics of the coupled building block system.

• Earthquakes and Structures
• /
• v.5 no.5
• /
• pp.499-526
• /
• 2013

Seismic isolation is an effective method for the protection of buildings and their contents during strong earthquakes. This research work aims to assess the appropriateness of the linear and nonlinear models that can be used in the analysis of typical low-rise base isolated steel buildings, taking into account the inherent nonlinearities of the isolation system as well as the potential nonlinearities of the superstructure in case of strong ground motions. The accuracy of the linearization of the isolator properties according to Eurocode 8 is evaluated comparatively with the corresponding response that can be obtained through the nonlinear hysteretic Bouc-Wen constitutive model. The suitability of the linearized model in the determination of the size of the required seismic gap is assessed, under various earthquake intensities, considering relevant methods that are provided by building codes. Furthermore, the validity of the common assumption of elastic behavior for the superstructure is explored and the alteration of the structural response due to the inelastic deformations of the superstructure as a consequence of potential collision to the restraining moat wall is studied. The usage of a nonlinear model for the isolation system is found to be necessary in order to achieve a sufficiently accurate assessment of the structural response and a reliable estimation of the required width of the provided seismic gap. Moreover, the simulations reveal that the superstructure's inelasticity should be taken into account, especially if the response of the structure under high magnitude earthquakes is investigated. The consideration of the inelasticity of the superstructure is also recommended in studies of structural collision of seismically isolated structures to the surrounding moat wall, since it affects the response.

• Journal of Sasang Constitutional Medicine
• /
• v.19 no.1
• /
• pp.127-136
• /
• 2007

1. Objectives It is necessary to find the psychological methods to treat not only physical but also mental problems. Because the Sasang Constitutional medicine is based on Mind-Body Medicine, so that the Nature and Emotion-Happiness, Anger, Sorrow, Pleasantness- have to be controlled properly. 2. Methods We analysed the characters of each constitutions, drama therapy and meditation and tried to find the suitable application of one for Sasangin. 3. Results and Conclusions Soeumin is feminine, easy to worry, pessimistic and non-active so they need to express their problems, be encouraged and participate to be one of a group having relationship with other people. Soyangin is out-going, easy to start, not enough to be aware of themselves so they need to relax, calm and try to have an insight into themselves. Taeumin is stable, easy to keep something so they need to communicate well with the exterior. Taeyangin is going forward, masculine and necessary to avoid being angry so they need to calm down and relax. Drama therapy is group work with actors, staffs and audiences so it is useful to express their negative feelings through motions, dances and sounds unless they talk. So it is supposed to be useful far Soeumin and Taeumin. And we can apply it to heal the Emotion because it is based on the relationship and the contact with other people. Meditation is helpful to not only concentrate, relax, have insight into themselves but also calm down anxiety, depression an anger. So it could be the best psychotherapy for Soyangin and Taeyangin. And we can apply it to reflect oneself alone to express their Nature adequately.

• International Journal of Fluid Machinery and Systems
• /
• v.9 no.3
• /
• pp.194-204
• /
• 2016

Floating ring seals offer an opportunity to reduce leakage flows significantly in rotating machinery. Accordingly, they have been applied successfully to rotating machinery within the last several decades. For rocket turbopump applications, fundamental behavior and design philosophy have been revealed. However, further work is needed to explore the rotordynamic characteristics associated with rotor vibrations. In this study, rotordynamic forces for floating ring seals under rotor's whirling motions are calculated to elucidate rotordynamic characteristics. Comparisons between numerical simulation results and experiments demonstrated in our previous report are carried out. The three-dimensional Reynolds equation is solved by the finite-difference method to calculate hydrodynamic pressure distributions and the leakage flow rate. The entrance loss at the upstream inlet of the seal ring is calculated to estimate the Lomakin effect. The friction force at the secondary seal surface is also considered. Numerical simulation results showed that the rotordynamic forces of this type of floating ring seal are determined mainly by the friction force at the secondary seal surface. The seal ring is positioned almost concentrically relative to the rotor by the Lomakin effect. Numerical simulations agree quite well with the experimental results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.341-342
• /
• 2008

The dynamics of nano particles in LC medium under an external electric field is of theoretical and technological interest. In this work, the dynamical characteristics of fullerene $(C_{60})$ particles in liquid crystal (LC) medium under dc electric field have been investigated. This effect was studied for homogeneously aligned nematic LC cells driven by in-plane field. The $C_{60}$ was found to be aggregated in a form of cluster inside the LC medium. Hence polystytene was used to protect the aggregation of $C_{60}$ in LC medium. When the electric field was applied, the fullerenes start to move in direction of applied electric field. The density of $C_{60}$'s particles at the electrodes increase with increase in the value of applied electric field. The dynamical motions of fullerene $(C_{60})$ particles in liquid crystal (LC) suggest that fullerene can be designed for electrophoretic displays (i.e., electronic ink).

• Journal of the Korean Magnetics Society
• /
• v.23 no.5
• /
• pp.173-177
• /
• 2013

This work describes the experimental investigations on sloshing characteristics of water and ferrofluid as working fluids in the spherical container with the horizontal oscillation motion and compared the results obtained by two working fluids. In order to Investigate the sloshing characteristics of the sphere container with the horizontal oscillation, experiments are performed with the magnetic intensities from 0 mT to 50 mT and horizontal oscillation motions from 5 mm to 15 mm. As results, Ferrofluid without magnetic field in the sphere container showed a similar liquid surface movement with water. The resonance point of the ferrofluid in the sphere container happened at higher value than that of the theoretical resonance frequency with the rise of the magnetic field. In addition, the sloshing characteristics of the ferrofluid in the sphere container can be controlled with the resonance frequency with the magnetic intensity and the liquid surface displacement could be also controlled.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.7
• /
• pp.135-141
• /
• 2009

For more reliable estimation of soil-structure interaction and seismic source and attenuation properties, site amplification function should be considered. This study use the Nakamura's method (1989) for estimating site amplification though various methods for the same purpose have been proposed. This method was originally applied to the surface waves of background noise and therefore there are some limitation for applications to general wave energy. However, recently this method has been extended and applied to the S wave energy successfully. This study applied the method to the coda wave energy which is equivalent to the backscattered S wave energy. We used more than 60 observed ground motions from 5 earthquakes which occurred recently, with magnitude range from 3.6 to 5.1 Each station showed characteristic site amplification property in low-, high- and resonance frequency ranges. In the case of comparing these results to those from S wave energy, lots of information to the site classification work can be gained. Moreover, removal of site amplification can give us more reliable seismic source parameters.