• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.105-110
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• 2011

Catwalk structures are temporary walk ways for erection of main cables in suspension bridge. The aerodynamic characteristics of the catwalk structures are not well studied even though the catwalk structures are sensitive to wind action because of its flexibility. Present study demonstrates technical results obtained from wind tunnel tests of various catwalk structures. To obtain the aerostatic force coefficients of the floor system of catwalk, 1/14 and 1/4 scaled partial rigid models were fabricated and tested at the wind tunnel. In order to investigate the Reynolds number effects, the aerostatic force coefficients were measured at various wind velocities ranged from 5m/s to 30m/s. The test results revealed that the Reynolds number effects on aerostatic coefficients were not significant for the catwalk floor systems. An empirical equation for aerostatic force coefficients of catwalk are proposed based on the measured results.

• Wind and Structures
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• v.10 no.4
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• pp.367-382
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• 2007

A nonlinear numerical method was developed to assess the stability of suspension bridge catwalks under a wind load. A section model wind tunnel test was used to obtain a catwalk's aerostatic coefficients, from which the displacement-dependent wind loads were subsequently derived. The stability of a suspension bridge catwalk was analyzed on the basis of the geometric nonlinear behavior of the structure. In addition, a full model test was conducted on the catwalk, which spanned 960 m. A comparison of the displacement values between the test and the numerical simulation shows that a numerical method based on a section model test can be used to effectively and accurately evaluate the stability of a catwalk. A case study features the stability of the catwalk of the Runyang Yangtze suspension bridge, the main span of which is 1490 m. Wind can generally attack the structure from any direction. Whenever the wind comes at a yaw angle, there are six wind load components that act on the catwalk. If the yaw angle is equal to zero, the wind is normal to the catwalk (called normal wind) and the six load components are reduced to three components. Three aerostatic coefficients of the catwalk can be obtained through a section model test with traditional test equipment. However, six aerostatic coefficients of the catwalk must be acquired with the aid of special section model test equipment. A nonlinear numerical method was used study the stability of a catwalk under a yaw wind, while taking into account the six components of the displacement-dependent wind load and the geometric nonlinearity of the catwalk. The results show that when wind attacks with a slight yaw angle, the critical velocity that induces static instability of the catwalk may be lower than the critical velocity of normal wind. However, as the yaw angle of the wind becomes larger, the critical velocity increases. In the atmospheric boundary layer, the wind is turbulent and the velocity history is a random time history. The effects of turbulent wind on the stability of a catwalk are also assessed. The wind velocity fields are regarded as stationary Gaussian stochastic processes, which can be simulated by a spectral representation method. A nonlinear finite-element model set forepart and the Newmark integration method was used to calculate the wind-induced buffeting responses. The results confirm that the turbulent character of wind has little influence on the stability of the catwalk.

• Wind and Structures
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• v.19 no.6
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• pp.665-686
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• 2014

This study presents a comprehensive investigation of the aerostatic and buffeting response characteristics of a suspension bridge catwalk. The three-dimensional aerostatic response analysis was carried out taking into account the geometric nonlinearity and nonlinear dependence of wind loads on the angle of attack. The buffeting response analysis was performed in the time domain. The aerostatic and buffeting responses of the catwalk show strong coupling of vertical and lateral vibrations. The lateral displacement is the main component of the wind-induced static and buffeting response of the catwalk.

• Wind and Structures
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• v.25 no.3
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• pp.215-232
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• 2017

Wind tunnel tests and numerical aerodynamic analyses were conducted for an integrated catwalk structure under strong winds. From the wind tunnel tests, it is found that the aerodynamic coefficients were different from those of the typical type. The drag coefficient was larger than typical and was sensitive to number of vertical meshes installed rather than the solidity ratio. Comparing with typical catwalk, the integrated one showed larger deformation under strong wind, and the large torsional deformation are mainly caused by drag force. It did not show aerodynamic divergence even the torsional deformation reaching $20^{\circ}$. The reason could be that the stiffness is smaller and thus the catwalk is able to deform to the shape compactable with higher loading. Considering safety for construction, storm rope system is introduced to the catwalk to reduce the deformation to acceptable level.

• Journal of Korean Society of Steel Construction
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• v.27 no.4
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• pp.371-376
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• 2015

This study was conducted for the torsional behavior of catwalk system which is a temporary structure on a suspension bridge. The torsional deformation of the catwalk structure has a significant effect on the workability and safety of workers during main cable erection. For this reason, the torsional deformation of catwalk is controlled to be acceptable levels below by adjusting the cross bridge interval in design stage. This study analyzed the effect of separation between cross bridge associated with twist safety of catwalk system. For the analytical approach, a detailed analysis model was created including cross bridge. Both wind load within the wind velocity range that allows the construction and eccentric load of Prefabricated Parallel Wire Strand were analyzed by analysis model. Result of study shows that separation between cross bridges has a significant effect on the torsional behavior of the catwalk.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.683-686
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• 2007

This paper investigates acoustical characteristics of open-type ceilings using 1:25 scale model. The field survey in the existing 15 halls was carried out to figure out the ceiling structure. The components of the open-type ceiling were mainly steel truss structures, duct, catwalk and finishing surfaces. In order to investigate the absorption characteristics of the equipped ceiling, the absorption coefficient measurements were made using 1:25 reverberation chamber based on ISO 354. Results showed that the absorption coefficient of the empty ceiling structure (6m-height) with 50%-perforated covering plate was 0.2-0.3 at above 500 Hz. When steel structure was added inside the empty ceiling, absorption coefficient increased by 0.16 at 250-1kHz. Adding catwalk did not increase the absorption, but adding duct increased the absorption at 1-2kHz. NRC of the equipped ceiling was 0.39, and the absorption characteristics were mainly found at high frequencies. In addition, the opening size of the covering plate did not change the absorption coefficient of the equipped ceiling meaningfully.

• Journal of the Korean Society of Costume
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• v.51 no.4
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• pp.71-80
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• 2001

Since the beginning of the 90's, Fashion shows appear to be a type of performance form of art combining with other areas to visually entertain the viewers. This can be explained by the modern tendency to escape from society which requires formality and complicated lifestyles. Fashion shows take place in a scene Influenced by the idea of post-modernism which redefines the definition of space. A church, old factory, unoccupied ground, subway stations, or even place like a waste disposal are used as a setting. The stage set is no longer the T shape run way and the procinium arch has disappeared. The gap between audience and stage has diminished and theatrical element is added to the fashion performance by using viewers living and working environments as setting of the show. The human relation with machine based on the cutting edge technology such as the stage automation, robots and mist making sprinkler system introduces new elements with spontaneity and detailed planning in the stage performance. Music also plays an Important role in attracting viewers. The sound track covers house music to techno music. Instead of music being abstract, folks orchestral music, choirs, piano. even live concert performed by pop artist provide the liveliness of the fashion show. And the catwalk itself is a performance. Model needs to be well trained as the capable talent who can handle sensitive gestures, facial expressions, dancing and choreography. The improvisatorial interaction between audience and model lead to audience participation. Models now range from pop star, ordinary people, handicapped people, to elderly and so on. John Galliano introduced the theatrical factors for the fashion show and Alexander Mcqueen approached the fashion show as the visual art of communication. Hussein Chalayan utilized high technology skewing futurism as if in a magic show. Today the Fashion show tends to be a total performance which includes audience participation, impromptu, and that break the limitation that fashion shows previously had. This will lead the fashion industry in opening new horizon of its own.

• Korean Journal of Acupuncture
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• v.32 no.1
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• pp.30-38
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• 2015

Objectives : The aim of the study is to investigate the effects of low level laser treatment (LLLT) on the gait behavior in the rat model of arthritis. Methods : Knee arthritis was induced by the injection of $125{\mu}l$ of Complete Freund's Adjuvant(CFA) into the right hind knee joint cavity. Arthritic rats were divided 3 groups; arthritis group was used for control(CON), 10 min of laser treated group(LSR10), and 30 min of laser treated group(LSR30). LLLT was applied to KI 1 for 11 times under gaseous anesthesia. We performed several analyses under catwalk test including stand and swing time, duty cycle of paw steps, intensity and print area of steps, and stride length. Results : Stand and duty cycle of paw steps were increased significantly at 12 days after arthritis induction in LSR30 group. Swing time was decreased significantly at 12 days after arthritis induction in LSR10 group. In the analysis of intensity, print area and stride length, however, results did not show statistical significance during the time point of experiments. Conclusions : The data suggest that LLLT on the rat model of CFA induced arthritis showed beneficial effects by increase of stand time and duty cycle of paw steps and decrease of swing time. Therefore, LLLT could be useful option to improve gait discomfort in arthritis patients.

• The Research Journal of the Costume Culture
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• v.5 no.3
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• pp.77-95
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• 1997

The purpose of this is to investigate the relation between Graffiti techniques and the contemporary dress. Graffiti is the internal expression of human potential desires which is composed of informative signs. As Graffiti have become the cross-cultural condition under the Hiphop culture, it makes the meaningless space into the characteristic space, and proposes the identities of graffiti ‘writes’. In the contemporary dress, Graffiti look has become means of communication and playfulness. Through the external forms like icon, index, and symbol, graffiti look expresses individual, social, and political identities, and aesthetic values of satirement and playfulness. It would be define graffiti look as postmodern characteristics, as it wee, which has collapsed between the mainstream, and anti-mainstream, and it contributes to spread streetstyle to catwalk.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.3
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• pp.502-515
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• 1997

The purpose of this thesisis to show that, on the basis of a reconstructed theoretical framework of postmodernisuL the seemingly chaotic phenomena in recent fashion specta ole- i.e. extensive eclecticism and deconstruction of styles - can be systematically explained and that it is by no means a transient anomaly. The main task of this thesis is to distill out from the apparently chaotic scene in the Catwalk such distinctive features as 1. the bona fide postmodern subculture fashion as a non-mainstream,2. the subculture elements introduced in the mainstream, pastiche a la Jameson. Our theoretical framework enables us to establish these features as the necessary outcomes and tendencies of postmodern logic.