• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.2
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• pp.144-150
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• 2003

Pleasantness or quietness becomes one of the most important factors for residential and office building designs recently. Especially for apartments, the noise generated by falling objects becomes a sensitive issue these days. To overcome the problem of the impact noise in apartments, the floor design has been changed. To reduce the transmissibility of the noise. composite floor structures ate devised and implemented for the construction of apartments. In this paper. the noise reduction) performance of a composite floor plate with holes is analyzed. Computational models for the structures are developed and its Performance is evaluated by using the finite element method. The results show that the noise can be significantly reduced with the multi-layer composite floor plates with holes.

• KIEAE Journal
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• v.8 no.1
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• pp.105-110
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• 2008

Most high rise buildings have been constructed with steel structure systems with metal deck floors and concrete topping. Since the mass of the metal deck floor system is relatively thinner than that of the concrete floor system and due to the larger span compared to other floor systems, vibration serviceability problems are frequently occurred. Most of vibration problems are induced by the movement of humans. A walking load function was proposed for the better estimation of composite deck floor vibration based on site measurements in this paper.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.60-65
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• 2015

This study is to explore floor impact sound and sound insulation of reinforced concrete structure with void-deck slab system which combines polystyrene void foam and T-shaped steel deck plate. A void-deck slab system can effectively reduce the amount of concrete used and hence the mass of a reinforced concrete slab. Also void slab system has dynamically favorable for bending. Three-bay 2-story building was constructed as a mock up test specimen using void-deck slab system and floor impact sound was measured to valuate sound insulation performance. Light weight floor impact and heavy weight floor impact were investigated. Light weight floor impact pressure levels were 32dB, 28dB, and 29db at representative locations which are $1^{st}$ level in the floor impact sound insulation performance grading system. The heavy-weight floor impact pressure levels were 44dB, 45dB, and 43dB at representative locations which are $2^{nd}$ level in the floor impact sound insulation performance grading system. Therefore void-deck slab system can be used in public housing apartment building in terms of not only effectively reduced construction materials but also floor impact sound insulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1152-1155
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• 2007

Lately concerns about structure have been increased by advantages of floor impact noise, poilitical induction and changeability. Hence, Flat Plate Structure has been constructed increasingly. This study shows the comparison of the performance of sound insulation of Flat Plate Structure System and the existing Wall Structure. For this study, taking the same level organization of Daelim Architectural Environmental Research Center, I found the performance of sound insulation between the upper and lower floors about Wall Structure and Flat Plate Structure. Consequently, the performance of sound insulation between upper and lower floors of Flat Plate Structure was 3-5dB higher was approximately 3-5dB higher than one of Wall Structure. Especially, the performance of sound insulation on the upper floor was 1-3dB higher than on the lower floor. In addition, as the result of comparing radiation sound which radiates from the wall of lower floors with each structure system, Flat Plate Structure was about 4dB higher with Rw than Wall Structure. As we see totally, the performance of sound insulation of Flat Plate Structure is highter than one of the Wall Structure. It is 3-5dB higher and the main reason for this result depends on the existence of the wall which can radiate sound and nonexistence.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.609-613
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• 2004

An economic analysis is one of the most dominant factors to determine the project feasibility of super tall building. In economic considerations, it is very important toadopt optimum structural floor systems because these are dependent on both the cost and the duration of construction. The economics affected by structural floor systems are more distinct athigher story. As the story increases, the construction cost of floor system. is accumulated linearly, while the cost of lateral resisting system is increased geometrically. The purpose of this study is to investigate the economical effects of super tall buildings through application of optimum structural floor systems. Three types of structural systems(RC beam-column frame, RC flat plate frame, and Steel frame) of super tall buildings having 50-stories are considered in this study and compared to RC flat plate slab with other systems. Analytical result shows that RC flat plate slab using lightweight concrete ismost effective in both the cost and the duration of construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.189-190
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• 2015

Slim Floor construction method has to increase the available surface area thereby reducing the depth beams and slab. In addition, In this study compostie beam assembly of plates, square-shape steel pipe and deck plate. So workabiltiy is superior to the upper concrete possible without formwork. In the present study is strength test in progress in development slim floor composite beam used plate and perforated square shape steel pipe and obtained anlysis and conclustion of the experimental results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1320-1325
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• 2009

The sources of the vibration of railway vehicles in the cabin are usually bogie, axle, and wheel. The vibrations are transmitted through the floor structures of railway vehicle. The floor structure is the combination of bottom plate, plywood, and rubber. In this research the vibration transmission is measured experimentally and analyzed numerically to find the transmission characteristics of the vehicle floor structures. The result shows that the vibration characteristic of soft rubber is better than hard rubber or wood as the connecting material between the bottom plate and the plywood.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.659-662
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• 2003

Recently, the floor thickness in residence may not be satisfied with the floor vibration criteria although the thickness is evaluated by the serviceability requirements in current design provisions. Thus it is necessary to develop the procedure to determine slab thickness satisfied with the floor vibration criteria. In this study, We proposed the methods to determine the slab thickness satisfied with the vertical floor vibration criteria for several concrete compressive strength of flat plate floor systems. For this purpose Monte Carlo simulation procedure was adopted and both randomness inherent in young modulus of concrete and heel drop intensity were accounted.

• Structural Engineering and Mechanics
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• v.69 no.3
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• pp.283-291
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• 2019

Accurately determining the natural frequencies and mode shapes of a structural floor is an essential step to assess the floor's human-induced vibration serviceability. In the theoretical analysis, the prestressed concrete floor can be idealized as a multi-span continuous anisotropic plate. This paper presents a new analytical approach to determine the natural frequencies and mode shapes of a multi-span continuous orthotropic plate. The suggested approach is based on the combined modal and perturbation method, which differs from other approaches as it decomposes the admissible functions defining the mode shapes by considering the intermodal coupling. The implementation of this technique is simple, requiring no tedious mathematical calculations. The perturbation solution is validated with the numerical results.

• Archives of Craniofacial Surgery
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• v.19 no.4
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• pp.264-269
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• 2018

Background: Orbital resorbable mesh plates are adequate to use for isolated floor and medial wall fractures with an intact bony buttress, but are not recommended to use for large orbital wall fractures that need load bearing support. The author previously reported an orbital wall restoring surgery that restored the orbital floor to its prior position through the transnasal approach and maintained temporary extraorbital support with a balloon in the maxillary sinus. Extraorbital support could reduce the load applied on the orbital implants in orbital wall restoring surgery and the use of resorbable implants was considered appropriate for the author's orbital wall restoring technique. Methods: A retrospective review was conducted of 31 patients with pure unilateral orbital floor fractures between May 2014 and May 2018. The patients underwent transnasal restoration of the orbital floor through insertion of a resorbable mesh plate and maintenance of temporary balloon support. The surgical results were evaluated by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR) values. Results: The OVR decreased significantly, by an average of 6.01% (p<0.05) and the preoperative and postoperative Hertel scale measurements decreased by an average of 0.34 mm with statistical significance (p<0.05). No complications such as buckling or sagging of the implant occurred among the 31 patients. Conclusion: The use of resorbable mesh plate in orbital floor restoration surgery is an effective and safe technique that can reduce implant deformation or complications deriving from the residual permanent implant.