• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.270-274
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• 2015

Purpose: The purpose of this study was to examine the electromyographic (EMG) activity of the abdominal muscles and to compare the activity ratios of the bilateral rectus abdominis (RA) to oblique abdominal muscles during shoulder abduction in opposite directions with single leg raising (SLR) performed in the supine position on a foam roller. Methods: Fifteen healthy subjects were recruited to the study. Each subject lay on the foam roller and performed left single leg raising with right or left shoulder $90^{\circ}$ abduction (Abd); performed in a random order. Surface EMG recordings of selected abdominal muscles (i.e., the RA, external oblique abdominis [EO], internal oblique abdominis [IO], and transverse abdominis [TrA]) were normalized to maximum voluntary isometric contraction. EO/RA and IO and TrA/RA ratios were determined with surface EMG. Data were analyzed by Independent t-test. The statistical significance level was p<0.05. Results: The results were as follows: (1) the right RA, left EO, and right IO and TrA muscle activities increased significantly at the left SLR with left Abd compared to the left SLR with right Abd (p<0.05); and (2) the ratio of right EO/RA activity increased significantly at the left SLR with right Abd compared to left Abd (p<0.05). Conclusion: These findings suggest that left SLR with left Abd on a foam roller is an appropriate exercise for activation of specific oblique abdominal muscles.

• The KSFM Journal of Fluid Machinery
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• v.11 no.3
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• pp.14-21
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• 2008

A numerical simulation on the flow field of a valveless bidirectional piezoelectric micropump has been performed. In this type of micropump, the oscillation of the piezoelectric diaphragm generates the blowing and suction flow through the oblique channel from the pumping chamber. The angle between the oblique and main channel causes the variation of flow distribution through upstream and downstream channels in suction and blowing modes. In the suction flow mode, the working fluid flows from both the upstream and downstream of the main channel to the pumping chamber through the oblique channel. However, in the blowing flow mode, the fluid pushed out of the pumping chamber flows more toward the downstream of the main channel due to the inertia of the fluid. In the present study, the effects of geometries such as the angle of oblique channel and the shape of main channel on the flow rate of the up/downstream were investigated. The flow rate obtained from the pump and the energy required to the pump were also analyzed for various displacements and frequencies of the oscillation of the diaphragm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.928-933
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• 2004

The vibration characteristic is a primary design factor. The cylindrical shells are used as a primary components of complex structure. also, The cylindrical shells have oblique angle. In this study, The vibrational characteristics of steel and plain wave GFRP cylindrical shell with an oblique end are given by experimental and finite element method. To be find characteristic of the oblique end, the mass of the cylindrical shell is maintained. Natural frequency and mode shapes of isotropic and plain weave composite shells are obtained by modal test. The results are compared with those of the finite element method. The simply supported boundary conditions with bolts along the circumferential direction of the GFRP shell are well achieved. Also, The clamped boundary conditions is applied to the steel specimen. Those are shown to agree well with the analytical results and finite element analysis results.

• The Journal of Korean Physical Therapy
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• v.31 no.5
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• pp.298-303
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• 2019

Purpose: This study examined the effects of slashpipe exercise on reducing the thickness of the left and right external oblique, internal oblique, transverse abdominis, erector spinae, and multifidus muscles. Methods: A total of 29 healthy adult men and women were included in the study. They performed trunk flexion in the supine position and trunk extension in the prone position with a slashpipe and weight bar. The external oblique, internal oblique, and transverse abdominis muscles were measured in the supine position, while the erector spinae and multifidus muscles were measured in the prone position. The data were analyzed using the SPSS ver 21.0 statistical program. The difference in thickness between the right and left sides of the trunk muscle was analyzed by repeated measures analysis. The statistical significance level was set to p<0.05. Results: The results showed that the slashpipe exercise reduced significantly the difference in thickness of the oblique internus and erector spinae muscles compared to the weight bar exercise. Conclusion: The chaotic fluidity of the fluid filled inside the slashpipe could be used as sensory feedback information on body mal-alignment, which would have positively affected the symmetrical contraction of the trunk muscles as a trigger for self-correction. Therefore, it will have a useful effect not only on the health of the general public, but also on low back patients and athletes with muscle asymmetry.

• Journal of Korean Physical Therapy Science
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• v.29 no.1
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• pp.55-63
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• 2022

Background: This study investigated the effect of erector spinae and quadratus lumbar kinesio taping and support surface conditions on abdominal muscle activity during plank exercise. Design: Within-Group design. Methods: A total of twenty-three healthy men and women participated in this study. Abdominal muscle (both external obliques and internal oblique muscle) contraction was analyzed through EMG measurement with the presence or absence of kinesio taping applied to the erector spinae muscle and quadratus lumborum muscle during plank exercise and the difference between the support surfaces (stable surface and unstable surface) as variables. Abdominal EMG was attached to the right external oblique, left external oblique, right internal oblique, and left internal oblique. Results: The results showed that Abdominal left and right external obliques and internal obliques showed significant increases in activity when kinesio taping was applied to the erector spinae and quadratus lumborum muscles and unstable ground (p<0.05). Conclusion: In this study, we confirmed that the activity of the abdominal muscles was significantly increased during the plank operation in the state where the kinesio tape was attached. In addition, it was confirmed that the activity of the abdominal muscles was significantly increased during the plank operation on the unstable surface. These results suggest that in the state of kinesio tape attached and instability, plank motion has a positive effect on abdominal muscle activity.

• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.119-126
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• 2022

Objective: This study aimed to investigate the effect of the application of abdominal brace techniques on muscle activity of the trunk and lower extremities when walking. Design: Cross-sectional study Methods: This study was conducted on 26 healthy adults in their 20s, and the subjects performed two conditions in random order: walking with the abdominal bracing technique and walking in an abdominal relaxation state (normal gait). Muscle activity was measured on the dominant side of all subjects using surface electromyography, and the attachment sites were the erector spinae, external oblique, internal oblique, vastus lateralis, and vastus medialis oblique muscles. Each condition was measured three times to calculate and analyze the average value. Results: When walking using the abdominal brace technique, the muscle activity of the erector spinae, external oblique, internal oblique, and vastus lateralis increased significantly (p<0.05), and the muscle activity of the vastus medialis increased as well but was not significant. Conclusions: The results of this study indicate that it is possible to be used as an effective guide to increasing the muscle activity and stability of the trunk and lower extremities through the application of the abdominal bracing technique during walking.

• Advances in aircraft and spacecraft science
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• v.11 no.2
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• pp.195-213
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• 2024

This article deals with the changes in flow air properties across an oblique shock wave for a real gas. The flow through is investigated to find a general form for oblique shock waves. The main objective of this work will result in the development of a new numerical algorithm to determine the effect of the stagnation pressure on supersonic flow for thermally and calorically imperfect gases with a molecular dissociation threshold, thus giving a better affinity to the physical behavior of the waves. So, the effects of molecular size and intermolecular attraction forces are used to correct a state equation, emphasizing the determination of the impact of upstream stagnation parameters on oblique shock waves. As results, the specific heat pressure does not remain constant and varies with the temperature and density. At Mach numbers greater than 2.0, the temperature rise considerably, and the density rise is well above, that predicted assuming ideal gas behavior. It is shown that caloric imperfections in air have an appreciable effect on the parameters developed in the processes is considered. Computation of errors between the present model based on real gas theory and a perfect gas model shows that the influence of the thermal and caloric imperfections associated with a real gas is important and can rise up to 16%.

• Structural Engineering and Mechanics
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• v.91 no.5
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• pp.503-516
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• 2024

The present research examines the primary resonance (PR) behaviors of oblique stiffened multilayer functionally graded (OSMFG) shallow shells featuring an FG porous (FGP) core under an external excitation. The research considers two distinct types of FGP cores: one characterized by uniform porosity distribution (UPD) and the other by non-uniform porosity distribution (NPD) along the thickness direction. Furthermore, the study explores two types of shallow shells: one with external oblique stiffeners and one with internal oblique stiffeners, which might have angles that are similar or different from each other. Using the stress function alongside the first-order shear deformation theory (FSDT), the research establishes a nonlinear model for OSMFG shallow shells. The strain-displacement relationships are obtained utilizing FSDT and von-Kármán's geometric assumptions. The Galerkin approach is utilized to discretize the nonlinear governing equations, allowing for the analysis of stiffeners at varied angles. To validate the obtained results, a comparison is made not only with the findings of previous research but also with the response of PR obtained theoretically with the method of multiple scales, using the P-T method. Renowned for its superior accuracy and reliability, the P-T method is deemed an apt selection within this framework. Additionally, the study investigates how differences in material characteristics and stiffener angles affect the system's PR behaviors. The results of this study can be used as standards by engineers and researchers working in this area, and they can offer important information for the design and evaluation of the shell systems under consideration.

• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.1207-1214
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• 2008

We give an elementary proof of one of the main results in [H.O. Kim, R.Y. Kim, J.K. Lim, The infimum cosine angle between two finitely generated shift-invariant spaces and its applications, Appl. Comput. Har-mon. Anal. 19 (2005) 253-281] concerning the existence of an oblique projection onto a finitely generated shift-invariant space along the orthogonal complement of another finitely generated shift-invariant space under the assumption that the generators generate Riesz bases.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.3 no.1
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• pp.23-28
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• 2000

A numerical investigation was made to examine characteristics of rectangular pontoon type floating breakwaters in oblique waves. Sway and heave wave exciting forces, roll moment acting on the floating breakwater and three motion reponses decrease as the incident wave angle increases for the most of the wave ranges. There exists a minimum wave transmission coefficient which is a function of wave frequency. In short wave range wave transmission coefficient increases as the incident wave angle increases. In long wave range, however, wave transmission coefficient decreases as the wave incident angle increases.