• International Journal of Internet, Broadcasting and Communication
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• 제16권1호
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• pp.156-162
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• 2024

The purpose of this study was to investigate the muscle activity of internal oblique, rectus femoris, and multifidus according to knee posture and foot bar angle during pilates reformer high flank exercise. Twelve women in their 20s were recruited within six months of their experience as pilates instructors. The subjects performed six types of high flanks according to knee posture and foot bar angle. EMG signals of internal oblique, rectus femoris, and multifidus during exercise were measured and analyzed by integral EMG. The collected data were processed by repeated measures two-way ANOVA. In this paper it shows the following results. First, internal oblique iEMG was not significantly different according to knee posture and foot bar angle. Second, the rectus femoris had an interaction effect according to knee posture and foot bar angle. Third, there was no significant difference in multifidus according to knee posture and foot bar angle. In conclusion, according to the exercise method, the activity of the rectus femoris was the highest in the knee bending and high foot-bar angle high plank exercise, and there was no difference between the internal oblique and multifidus.

• 한국정밀공학회지
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• 제29권12호
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• pp.1368-1375
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• 2012

In this paper, a method for prediction of spread is proposed to design proper roll profile taking into account spread in shape rolling of angle bar. The effect of the process variables on spread, such as draught ratio, bending angle and aspect ratio, is analyzed by FE-analysis and response surface method (RSM). Roll profiles for equal angle bar are designed with the spread predicted by the regression equation. Effectiveness of the designed roll profiles are verified by FE-analysis in which the flange length, strain distribution, mean strain and roll torque are compared with those by Geuze. Finally, the proposed method is applied to the design of roll profile for unequal angle bar. As a result, the final product can be obtained within the allowable tolerance of ${\pm}0.5mm$ in length. Therefore, it is found that the prediction of spread can improve the efficiency of design roll profile in shape rolling of angle bar.

• 대한수학회보
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• 제24권1호
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• pp.13-17
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• 1987

Let S denote the class of nivalent functions normalized so that f(0)=f'(0)-1=0 in vertical bar z vertical bar <1. Let $S_{\alpha}$$^{*}$, -.pi./2<.alpha.<.pi./2, denote the subclass of S that satisfies Re $e^{i{\alpha}}$zf'(z)/f(z).geq.0 in vertical bar z vertical bar <1; then f is called .alpha.-spiral-like and the case .alpha.=0 is the class of normalized starlike functions [6, pp.52]. Let T denote the class of functions f normalized as above and satisfying Im z[Im f(z)]..geq.0 in vertical bar z vertical bar <1; then f is called typically real and T contains those functions of S whose coefficients are real [6, pp.55]. Also, in view of [6, pp.231], let B(.lambda.) be the class of function normalized as above and map vertical bar z vertical bar <1 onto the complement of an arc with radial angle .lambda.(0<.lambda.<.pi./2). The radial angle is meant to be the angle between the tangent and radial vectors to the arc. This note includes a sharp version for Corollary 1 of [2] when f.mem. $S_{\alpha}$$^{*}$ as well as a logarithmic coefficient estimate.nt estimate.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.414-417
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• 2003

A copper-clad aluminium composite bar is lighter and less expressive than a commercial copper alloy bar. Copper-clad aluminium composite bar can be fabricated by hot hydrostatic extrusion process. In this work, the effect of die angle on the compressive properties of copper-clad aluminium composites fabricated using hydrostatic extrusion process was investigated experimentally. The results showed that optimum half die angle was in the range of 40$^{\circ}$ to 50$^{\circ}$ for an extrusion ratio of 19. The results also showed that the half die angle had little influence on the compressive strength of copper-clad aluminium composites. A diffusion layer increased with increasing die angle.

• 한국기계가공학회지
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• 제6권4호
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• pp.76-80
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• 2007

Two roll straightener showed the remarkable improvement in straightness betterment of the bar compared with other types of straightener. So, in this study we designed a two-cross straightener curvature for the straightness improvement of a bar and contact sections with respect to the variation of the gap between two-cross roll using nonlinear contact analysis. The Displacement in terms of a intersection angle between roll and bar was predicted on with the effect of a straightness and plastic deformation behaviors of the bar according to the roll drive of a two cross-roll straightener.

• 대한기계학회논문집A
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• 제32권2호
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• pp.170-176
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• 2008

Anti roll bar model for real time multibody vehicle dynamics model has been proposed using kinematic constraint. Anti roll bar have been modeled by kinematic relationship, and mass properties are neglected. Relative angle of torsion bar spring is computed by constraint about drop-link using Newton-Raphson iteration, and then the torque of torsion bar spring can be computed with the angle and torsion spring stiffness. Finally anti roll bar force acting on both knuckle can be calculated. To validate the proposed method, half car simulations of McPherson strut suspension and full car simulations are also carried out comparing with the ADAMS vehicle model with anti roll bar. CPU times are also measured to see the real-time capabilities of the proposed method.

• 한국건축시공학회지
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• 제15권5호
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• pp.465-471
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• 2015

철근콘크리트 기둥에서 횡 보강근의 시공성 및 구속효과를 향상시키기 위하여 본 연구에서는 내부 크로스타이의 대체로서 V형 띠철근의 배근방법을 제시하였다. 제시된 V형 띠철근의 부착응력-미끄러짐 관계를 파악하기 위하여 콘크리트 강도 및 V형 띠철근의 절곡각도와 묻힘길이를 주요변수로 35개의 직접인발 실험체를 제작하였다. V형 띠철근의 부착강도는 절곡각도가 $60^{\circ}$ 이하에서 CEB-FIP 기준 식보다 높게 있었다. V형 띠철근의 시공성 및 부착거동을 고려하면, V형 띠철근의 최적 절곡각도 및 묻힘길이는 각각 $45^{\circ}$와 $6d_b$ 이상으로 제시될 수 있었는데, 여기서 $d_b$는 띠철근 직경이다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.37-40
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• 2009

본 연구에서는 케로신/과산화수소 점화용 분사기의 설계/제작하여 분무특성에 관한 연구를 수행하고자 하였으며, 이에 앞서 촉매점화방식으로 적용할 때 가장 적합한 분사기를 설계하고자 하였다. 설계/제작된 분사기를 수류시험을 통해 질량 유량 및 분산각을 측정하였다. 그 결과 케로신의 목표 질량유량(12.88 g/s)은 설계 차압과 같은 차압인 3 bar에서 측정되었으며, 이 때 분산각은 $40^{\circ}$을 확인하였다. 또한 과산화수소의 목표 질량 유량(94.39 g/s)은 설계 차압(3 bar) 보다 작은 1 bar에서 측정됨을 확인하였다.

• 국제물리치료학회지
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• 제6권1호
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• pp.809-814
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• 2015

This study was conducted to identify how a flexi-bar exercise influences body alignment and balance in adults who have asymmetry in their right or left body. In total, 20 participants were separated into the experimental group and the comparison group. Those in the experimental group participated in a flexi-bar exercise for 6 weeks and based on the coronal plane before and after exercise, their body alignment and balance were measured behind the body. The result was those who had participated in a flexi-bar exercise significantly improved their angle of acromion on both sides, the difference in the angle and height of the posterior superior iliac spine on both sides(p<.05), and the balance of the center sagittal plane(p<.05). Through this study, it could be said that participating in a flexi-bar exercise would improve postural alignment and balance of the shoulder and pelvis in adults with asymmetric posture.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.1017-1022
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• 2001

The bend resistance of coated reinforcing bar is greatly influenced by adhesion strength of bar and coating materials and transformation of coating materials to the bar. Expecially, tearing state or a limited microscopic cracks are predicted on the inside and outside of bending angle because of adhesion strength and elongation is very different with types of polymer materials using bar coating, and these parts are accelerated corrosion as penetration of bar corrosion effects factor. In this study, cement modified polymer are prepared four types and differ from polymer cement ratio of 50% and 100%, coating thickness of 250$\mu$m and 450$\mu$m, coating number, curing age of 3, 7, 14 and 280days, and then tested bend resistance as bending angle $90^{\circ}$, $135^{\circ}$ and $180^{\circ}$ for observe the microscopic demage effect according as bar bend. From the test results, when is used cement modified polymer as coating materials of bar, St/BA is showed excellent bend resistance than a polyacrylic emulsion and SBR because of softness. But it is to need attention because as coating parts are pressed down and tearing, also experimental study is proceeded to corrosion potential on the inside and outside of coated reinforcing bar.