• Computers and Concrete
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• v.25 no.3
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• pp.273-282
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• 2020

A new seismic design methodology for precast concrete diaphragms has been developed and incorporated into the current American seismic design code. This design methodology recognizes that diaphragm inertial forces during earthquakes are highly influenced by higher dynamic vibration modes and incorporates the higher mode effect into the diaphragm seismic design acceleration determination using a first mode reduced method, which applies the response modification coefficient only to the first mode response but keeps the higher mode response unreduced. However the first mode reduced method does not consider effects of diaphragm flexibility, which plays an important role on the diaphragm seismic response especially for the precast concrete diaphragm. Therefore this paper investigated the effect of diaphragm flexibility on the diaphragm seismic design acceleration for precast concrete shear wall structures through parametric studies. Several design parameters were considered including number of stories, diaphragm geometries and stiffness. It was found that the diaphragm flexibility can change the structural dynamic properties and amplify the diaphragm acceleration during earthquakes. Design equations for mode contribution factors considering the diaphragm flexibility were first established through modal analyses to modify the first mode reduced method in the current code. The modified first mode reduced method has then been verified through nonlinear time history analyses.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.1
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• pp.25-33
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• 2019

PURPOSE: This study examined the effective impact of self and resistive and ultrasound-biofeedback diaphragm breathing on the pulmonary function and diaphragm thickening ratio of young adults. METHODS: Thirty normal adults were assigned randomly to three experimental groups (self- diaphragm breathing (n=9), resistive-diaphragm breathing (n=11), ultrasound-biofeedback diaphragm breathing (n=10)). Each group participated for 15 minutes for times with a two minute rest between two sets. The subjects were assessed using the pre- and post- diaphragm thickening ratio and the pulmonary function (forced vital capacity, forced expiratory volume at one second, maximal voluntary ventilation, and respiratory rate) on the thirty subjects. A paired t-test was to determine the difference between before and after the experiment in each group of diaphragm breathing before and after the exercises. One-way ANOVA was used to determine the differences between the groups. RESULTS: The forced vital capacity and maximal voluntary ventilation measurements revealed a significant difference in the resistive-diaphragm breathing group than the other two groups. On the other hand, there was no significant difference between the self-diaphragm breathing and ultrasound-biofeedback breathing groups. CONCLUSION: The resistive-diaphragm breathing group showed greater improvement in the pulmonary function than the other two groups. Therefore, resistive-diaphragm breathing will improve the pulmonary function on normal young adults.

• Journal of radiological science and technology
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• v.30 no.4
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• pp.335-341
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• 2007

General anatomy classifies diaphragm as muscle of boundary between chest and abdomen, while radiology divides it into right and left hemidiaphragm, because it is more advantageous in radiological diagnosis on chest and abdomen. Based on these anatomic characteristics of diaphragm, this study aimed to measure the height and curvature of right and left diaphragm in simple chest radiography. As a result, this study came to the following conclusions : 1. For all subjects who joined this study, it was found that their mean transverse diameter in internal diameter of thorax(ID) amounted to 293.3 mm(min. 221.0 mm, max 335.3 mm). 2. For the right and left height of diaphragm, it was found that 81.4% showed higher right diaphragm ; 16.2% showed equivalent height between right and left diaphragm ; and only 2.4% showed higher left diaphragm. 3. For higher right diaphragm, it was found that the mean height of right diaphragm amounted to 15.2 mm(min. height = 2.0 mm, max. height = 41.7 mm). 4. For higher left diaphragm, it was found that the mean height of left diaphragm amounted to 11.5 mm(min. height = 4.7 mm, max. height = 30.4 mm). 5. The mean curvature of right diaphragm amounted to 22.9 mm(min. curvature = 10.4 mm, max. curvature = 37.3 mm). 6. The mean curvature of left diaphragm amounted to 22.4 mm(min. curvature = 11.3 mm, max. curvature = 42.2 mm). 7. For possible associations between ID and right/left diaphragm curvature, it was noted that ID was in significantly positive correlations with right diaphragm curvature(r= .427, p<.001) and left diaphragm curvature(r= .425, p<.001) on statistical level. 8. For possible associations between right and left diaphragm curvature, it was found that right diaphragm curvature was in significantly positive correlations with left diaphragm curvature(r= .403, p<.001).

• Journal of Chest Surgery
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• v.25 no.9
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• pp.916-920
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• 1992

Bilateral traumatic rupture of diaphragm is very rare. One case due to car accident is reported. Preoperative chest X-ray revealed the diaphragm rupture in the left side and the hemothorax in the right side. During the completion of left diaphragm repair through left thoracoabdominal incision, right diaphragm rupture was found incidentally. Left diaphragm was repaired using pledgets which were anchored at the thoracic wall. Right diaphragm was also repaired by interrupted Halsted sutures through seperated right thoracotomy. Postoperative course was uneventful.

• Journal of Sensor Science and Technology
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• v.22 no.3
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• pp.227-232
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• 2013

In this research, fiber-optic pressure sensors were fabricated with rugate-structured porous silicon (RPS) diaphragms coated with PMMA (Polymethyl-Methacrylate). The reflectance spectrum of the PMMA/RPS diaphragm was almost the same as that of uncoated RPS diaphragm. However the mechanical strength of the PMMA/RPS diaphragm increased more than that of the uncoated diaphragm. As a result, the fiber-optic sensor fabricated with PMMA/RPS diaphragm could successfully detect more high pressure difference without diaphragm damage than the highest detectable pressure difference of the sensor with normal RPS diaphragm. The response data of the fiber-optic sensor recorded as a function of pressure difference were fitted by theoretical curves. During this process, elastic moduli of the used PMMA/RPS diaphragms were obtained numerically. The dynamic response properties of the fiber-optic sensor were also investigated under continuous variation of the pressure difference conditions.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.564-571
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• 1998

The function of diaphragms at abutments and piers of prestressed concrete (PSC) box girder train bridge is to transfer forces from the superstructure onto bearings or column and to stiffen the superstructure cross-section against in-plane deformation. Due to large stress disturbance at diaphragm, the design for the diaphragm using conventional design method is relatively irrational than designs for other structual members. And, due to contribution to boundary condition of deck slab by the diaphragm, the behavior of deck slab near the diaphragm is different from behavior of the deck slab obtained from two dimensional analysis of the bridge, which is basis far the design of deck slab. In this paper, three dimensional behavior of deck slab near diaphragm of PSC box girder train bridge constructed by the precast span method are analyzed by using three dimensional finite element modeling. Then, strut-and-tie model is applied to design the diaphragm of PSC box girder train bridge. The modeling techniques in this paper can be applied effectively to examine the causes of cracks at deck slab near diaphragm and to design diaphragm rationally.

• Journal of Sensor Science and Technology
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• v.30 no.5
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• pp.273-278
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• 2021

Here, we studied the change in the mechanical stiffness of a diaphragm according to the corrugation pattern. The diaphragm consists of a silicon oxide and nitride double layer; a corrugation pattern was formed by dry etching, and the diaphragm was released by wet etching. The fabrication of the thin film was verified using focused ion beam and scanning electron microscopy images. The mechanical stiffness of the diaphragm was obtained by measuring the surface vibration using a laser Doppler vibrometer while applying external sound pressure. Flat squares, diaphragms with square corrugations, and circular corrugation patterns were measured and compared. The stiffness of the diaphragm with a corrugation structure was found to be smaller than that without a corrugation structure; in particular, circular corrugation showed a better effect because of the high symmetry. Furthermore, the effect of corrugation was theoretically predicted. The proposed corrugated diaphragm showed comparable flexibility with the state-of-the-art MEMS microphone diaphragm.

• Annals of Clinical Neurophysiology
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• v.19 no.2
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• pp.131-135
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• 2017

Background: Neuromuscular ultrasound can be used to assess the diaphragm. Before it can be used clinically, the reference ranges of diaphragm thickness and contractility must be determined. Methods: We measured the thickness of the diaphragm and the diaphragmatic thickening fraction (DTF) in 80 healthy volunteers with ultrasound and collected their demographic information to determine if age, sex, and body mass index (BMI) influence these measures. Results: The thickness of the diaphragm at resting end expiration was $0.193{\pm}0.044cm$ on the right side and $0.187{\pm}0.039cm$ on the left. The DTF was $104.8{\pm}50.6%$ on the right side and $114.9{\pm}49.2%$ on the left. Sex, weight, height, and BMI significantly affected the thickness of the diaphragm, but had little effect on the DTF. Conclusions: Normal reference values for the diaphragm should be helpful when evaluating the diaphragm. The DTF appears more useful than resting diaphragm thickness because it is affected less by individual variation.

• Journal of the Korean Society for Railway
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• v.1 no.1 s.1
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• pp.30-39
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• 1998

The functions of diaphragms at abutments and piers of PSC box girder railway bridge are to transfer forces from the superstructure onto bearings or columns and to stiffen the superstructure cross-section against in -plane deformation. Due to stress disturbance at diaphragm, the design for the diaphragm using conventional design method is relatively irrational than those for other structural members. And, due to contribution to boundary condition of deck slab by the diaphragm, the behavior of deck slab near the diaphragm is different from that of the deck slab obtained from two dimensional analysis of the bridge, which is basis for the design of deck slab. In this paper, three dimensional behavior of deck slab near the diaphragm of prestressed concrete (PSC) box girder railway bridge constructed by the precast span method are analyzed by using three dimensional finite element modeling and using the strut-and-tie model design of the diaphragm are presented. The modeling techniques used in this paper can be applied effectively to examine the causes of cracks at deck slab near diaphragm and to design diaphragm rationally.

• 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.919-925
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• 2006

An accurate mathematical model for complex stiffness of the pneumatic spring would be necessary for an efficient design of a pneumatic spring used in vibration isolation tables for precision instruments such as optical devices or nano-scale equipments. A diaphragm, often employed for prevention of air leakage, plays a significant role of complex stiffness element as well as the pressurized air itself Therefore, effects of the diaphragm need to be included in the dynamic model for a more faithful description of dynamic behavior of pneumatic spring. But the complex stiffness of diaphragm is difficult to predict In an analytical way, since it is a rubber membrane of complicated shape in itself. Moreover, the diaphragm should be expandable in response to pressurization inside a chamber, which makes direct measurement of complex stiffness of diaphragm extremely difficult. In our earlier research, the complex stiffness of diaphragm was indirectly measured, which was just to eliminate the theoretical stiffness of pressurized air from the measured complex stiffness of the pneumatic spring. In order to reflect complex stiffness of inflated diaphragm on the total stiffness at the initial design or design improvement stage, however. it is required to be able to predict beforehand. In this paper, how to predict the complex stiffness of inflated rubber diaphragm by commercial FE codes (e.g. ABAQUS) will be discussed and the results will be compared with the indirectly measured values.