• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.6 s.111
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• pp.574-581
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• 2006

Flat plate slab systems are more economical rather than reinforced concrete frame systems because flat plate slab system reduces story height. Furthermore flat plate systems are more popularly needed in construction practice due to flexibility of plan. Korean Concrete Provisions 2003 provide the minimum thickness of the slab that satisfies serviceability requirement to the static displacement. However, floor thickness in residence buildings may not satisfy the floor vibration criteria although the thickness satisfies the serviceability requirements in current design provisions. This study estimates the dynamic properties of floor vibration for existing flat plate slabs, and proposes the slab thickness satisfying the floor vibration criteria. The dynamic response analysis using finite element method and reliability analysis are carried out for this Purpose.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.408-411
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• 2008

As to this research is new structure of the semiconductor substrate heating apparatus. The fast thermoresponsive according to the direct heating structure of the heating plate layer adhering closely to the floor side of a substrate and the fast heat loss minimization can be accomplished. Moreover, the contact area of the sheath heater, which is the heating plate layer built-in heating apparatus, is increased, so that it has more heating valid area. For this, it adheres closely to the substrate, in which the photosensitive film is coated and the heating plate layer, adhering closely to the floor side of a substrate the mica layer which adheres closely to the floor side of the upper heating plate layer in order to minimize an insulation and heat loss, and the lower part of the mica layer and it is comprised of the floor plate layer. The heating plate layer forms the continued groove portion over the floor side whole. The sheath heater for heating a substrate is inserted with the groove portion and the heating plate layer is comprised. It is confirmed that by using the new substrate heating structure, the temperature change of the heating plate against the time is observed. Then, there is the electric power saving effect of about 40% in comparison with the existing method.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.600-603
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• 2003

The floor thickness in residential buildings may not satisfy the floor vibration criteria even though the thickness is determined by the serviceability requirements in current design provisons. Thus it is necessary to develop the procedure to determine slab thickness that satisfies the floor vibration criteria. In this study provide the methods to determine the slab thickness that satisfies the vertical floor vibration criteria for several sizes of flat plate floor system. Randomness inherent in young modulus of concrete and heel drop intensity was accounted. For this purpose Monte Carlo simulation procedure was adopted.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.35-39
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• 2009

Recently, the flat-plate structure is widely used because it has many advantages such as reduction of story height, long span etc than the RC rahmen structure. Furthermore, application of the flat-plate is on the increase because of flexible plan unlike wall structure. Long span have been at a disadvantage for vibration serviceability evaluation, however studies about vertical direction vibration of flat-plate structure has not been carried out. This study analysis the characteristics according to slab structure to make an experiment on vibration and floor impact noise for the flat-plate structure in construction performance laboratory in Kolon E&C R&D center, the flat-plate structure applied to the post-tension method, and the wall structure in apartment houses.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.9 s.114
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• pp.949-957
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• 2006

In this Paper, reduction of noise and vibration in ship cabins by using floating floor is studied. Two theoretical models are presented and predicted insertion losses of floating floor are compared to experimental results, where measurements have been done in mock-up built for simulating typical ship cabin structures. In ships, mineral wool is usually used as the impact absorbing materials. The first model (M-S-Plate Model) is that upper plate and mineral wool are assumed as a one-dimensional mass-spring system, which is in turn attached to the simply supported elastic floor. The second model (Wave-Plate Model) is that mineral wool is assumed as an elastic medium for wave propagation. The comparisons show that M-S-Plate model is in good agreement with experimental results when density of mineral wool is 140K, and fiber direction is horizontal. For higher density and vertical fiber direction, Wave-Plate model shows good agreements with measurements. It is found that including the elastic behavior of the floor is essential in improving accuracy of the prediction for low frequency ranges below $100{sim}200Hz$.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1204-1208
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• 2000

Objectives : At the closure of the transsphenoidal approach(TSA), the proper sellar floor reconstruction plays an important role in preventing postoperative complications. The septal cartilage, perpendicular plate of nasal septum, and the sphenoid sinus bone are usually used to repair the sellar floor as a bone splint. The authors evaluate the usefulness of a silicone plate as a substitute for bone splint to close a defect of the sellar floor. Materials and Methods : A silicone plate was used to repair the sellar floor in 7 patients with sellar lesions which included four pituitary adenomas, two Rathke's cleft cysts and one metastatic tumor. Among seven cases, five cases underwent a standard TSAs and two received a extended TSAs. The trajectories of the approach were sublabial in four cases and endonasal routes in three cases. The silicone plate for implantation was cut to a size of slightly larger than that of bone window and inserted with a three-pronged fork, and then adjusted precisely. Results : In six patients, there were no complications which related to sellar floor reconstruction. A postoperative cerebrospinal fluid(CSF) rhinorrhea was observed in one patient with pituitary macroadenoma. Conclusions : From the authors' experience, the advantages of the silicone plate are its simplicity of molding to fit any size of sellar floor defects, and easy detection of previously created bone window at reoperation.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.451-457
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• 2008

The aim of the sturdy is for the development of Bridge plate installing on floor for SETPA Sliver line V. SEPTA train have pocket sliding door which is similar with domestic trains. typically In the USA railway market, Portable type and standing type bridge plate used, easily hiding the bridge plate in stowed position and convenience operation, Bridge plate installed on floor is designed. relative regulation Like CFR APTA, and EN, UIC is reviewed and compared.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.619-625
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• 2010

Purpose: Trapdoor orbital blowout fracture is most common in orbital blowout fracture. Various materials have been used to reconstruct orbital floor blowout fracture. Absorbable alloplastic implants are needed because of disadvantages of nonabsorbable alloplastic materials and donor morbidity of autogenous tissue. The aim of the study is to evaluate usefulness of absorbable mesh plate as a reconstructive material for orbital blowout fractures. Methods: From December 2008 to October 2009, 18 trapdoor orbital floor blowout fracture patients were treated using elevator fixation, depressor fixation, or elevatordepressor fixation techniques with absorbable mesh plates and screw, depending on degree of orbital floor reduction, because absorbable mesh plates are less rigid than titanium plates and other artificial substitutes. Results: Among 18 patients, 5 elevator fixation, 4 depressor fixation, and 9 elevator and depressor fixation technique were performed. In all patients, postoperative computed tomographic (CT) scan showed complete reduction of orbital contents and orbital floor, and no displacement of bony fragment and mesh plate. Mean follow-up was 10 months. There were no significant intraoperative or postoperative complications. Conclusion: Three different techniques depending on the degree of orbital floor reduction are useful for open reduction and internal fixation of trapdoor orbital floor blowout fracture with absorbable mesh plates.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.731-738
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• 2001

The conventional techniques for the prediction of natural frequency are often used to estimate the floor vibration. However. the predicted frequency differs significantly from the measured one since the predicted equation is not able to proper1y treat various material type. Transformation of slab section is necessary to predict natural frequency of composite deck plate, and this effort is complicated due to the various shape of each deck plate. In this study, a new simplified methodology to transform slab section is proposed, which treats effective depth as the distance from the top of a concrete topping to neutral axis of each deck plate. Finally proposed equation with fairly reasonable result compared to the measured values is obtained. based on the modification of vibration equation from LRFD theory. This efforts enhance errors in predicting frequency up to 15％.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.665-670
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• 2002

Pleasantness or quietness becomes one of the most important factors for residential 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 are 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 modelings for the structures are developed and its performance is evaluated by using the finite element method. The results show that the noise can be well reduced with the multi-layer composite floor plates with holes.