• Title/Summary/Keyword: cushion

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Analysis Method of Module Type Crash Cushion (모듈형태의 충격흡수장치 해석방법)

  • Ko, Man-Gi;Kim, Kee-Dong;Sung, Jung-Gon;Yun, Duk-Geun
    • International Journal of Highway Engineering
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    • v.10 no.1
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    • pp.97-104
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    • 2008
  • Many atypical structures on the roadside are exposed to traffics unshielded posing great danger. One way to shield an atypical structure to secure the occupant safety is to stack energy absorbing material modules in front of the structure. This paper presents the analysis method of module type crash cushion made of EPS blocks using simple energy balance of the car and crash cushion and numerical examples for 0.9ton-500km/h, 0.9ton-60km/h and 0.9ton-70km/h impact are presented. This method gives simple estimation of maximum acceleration, time of crash, whether or not the vehicle stops completely before whole cushion is being crushed. However, since the acceleration and velocity data from the analysis is so crudely spaced that calculation of safety indices such is RA and OIV is not possible. Problem is overcome by using data interpolation. The spline and linear interpolation is introduce and safety analysis is made and the results are compared.

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The Effects of Lower Limb Muscle Activity on Postural Stability and Ground Type During Gait in Elderly Women (보행 시 여성노인의 자세안정성과 지면형태가 하지 근활성도에 미치는 영향)

  • Woo, Byung-Hoon;Park, Yang-Sun
    • Korean Journal of Applied Biomechanics
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    • v.25 no.1
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    • pp.77-84
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    • 2015
  • Objective : The purpose of this study was to analyze the effects of lower limb muscle activity on postural stability and ground type in elderly women subjects. Method : Forty two subjects participated in the experiment (high group - age: $74.29{\pm}4.13yr$, height: $152.44{\pm}5.54cm$, weight: $57.43{\pm}6.16kg$, BMI: $24.77{\pm}2.99$, low group - age: $77.67{\pm}5.16yr$, height: $151.40{\pm}3.93cm$, weight: $60.92{\pm}6.40kg$, BMI: $26.59{\pm}2.57$). Wireless EMG with eight channels was used. Ground types were classified as flat and cushion. Results : In the double-support phase, left and right rectus femoris, left biceps femoris, left and right tibialis anterior, and left gastrocnemius did not show a significant difference in postural stability according to ground type. However right biceps femoris and gastrocnemius showed higher muscle activity in the elderly women group with lower postural stability. In the single-support phase, left and right rectus femoris, right biceps femoris, and left and right tibialis anterior did not show a significant difference in postural stability according to ground type. In addition, left biceps femoris had higher muscle activity in the elderly women group with lower postural stability. Left gastrocnemius had higher muscle activity in the elderly women group with higher postural stability and right gastrocnemius had higher muscle activity in the elderly women group on cushion ground. Conclusion : In a dynamic postural stability and cushion ground, biceps femoris and gastrocnemius muscle activity were high. As a result, biceps femoris and gastrocnemius muscle strengthening exercise on cushion ground could be beneficial in the prevention of falling.

A Study on Accalerated Vocous Condition in Siphon Spillway (싸이폰식 여수토의 진공촉진에 대한 연구)

  • 김시원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.6 no.2
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    • pp.816-825
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    • 1964
  • 1. Outline: The flow of the siphon spillway is very intricate and affected by vacuous condition. It is an intresting problem to make vacuum rapidly in_siphon, i.e, to provoke the perfect siphonaoge with the lowest water-level of overflow. The hydraulic experiments of siphon spillway have practiced at the Masan Lake, Haenam, the province of Junnam and gained rational and economical results which cannot be odtained by calculation. 2. Experiment: The model scale was a half of that of the prototype. 3. Results and discussion: In the experiments of 14 runs, washing, overflow water level, outlet, water level of cushion, phenomenon of water flying and water pressure of every part, etc. were studied. a) The relation of overflow water-level at siphon inlet and deflector When the elevation of the deflector is 10. 65m and the form of deflector O.4m long is the hypotenuse of an $45^{\circ}$ isosceles triangle, the over flow water-level is the minimum, i. e. the siphonage was excellent. There is no effect by the rising of overflow water-Ievel between 11.95m to 1O.65m of deflector elevation (in the first plan, it is 11.05m). But the overflow water-level rises remarkably in the outside region of the above limits. b) The relation of overflow water-level, the length of cushion and standard height of the base. The reduction of the length of cushion brings the rising of overflow waterlevel, and the rising of the standard height of the base brings the rising of overflow water level. For the long cushion length and low standard height of the base, it cannot be expeted to have the falling of overflow water-level. The most satisfactory data were obtained at 5.20m of the base standard height and 6.1m of the length of cushion. The first vah,le planned was 5.70 m and 4.30m.

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Air-containing Multi-functional Jacket Design Utilizing Modular Systems - Focused on Cushioning, Heat Insulation and Portability - (모듈러 시스템을 이용한 공기주입형 다기능 재킷 디자인 - 쿠션, 보온, 휴대 기능을 중심으로 -)

  • Son, Sue-Min
    • The Research Journal of the Costume Culture
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    • v.20 no.2
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    • pp.222-237
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    • 2012
  • Air-containing fashion, which can offer diverse functions through the inflow and outflow of air, is highly relevant in today's mobile society, where people are experiencing a wider range of environments. This study attempts to suggest the possibility of air-containing multi-functional fashion that could continuously be utilized by developing a design for an air-containing jacket using modular systems. In this research, the modular systems in architecture and furniture design were referenced through a review of the literature for the purpose of establishing modular systems in fashion. Functions relevant to the mobility of today's society are derived from the results of advanced research and applied to the design of modules of the jacket. The modules are integrated through the modular systems. The folding and unfolding structure in architecture and furniture is applied as a folding system in fashion, the vertical accumulation structure as a layering system, and the horizontal integration structure as a combining system, and in addition, the containing system has emerged in fashion. Each module is designed to fulfill certain functions, such as cushioning, heat insulation, and portability. The folding system is utilized in designing the cushion module to support the neck and back of a wearer by making its hood and hem fold in the back. The application of a layering system was suggested by making the vest, combined with the neck cushion and back cushion via the combining system, layered with its insulation module. By applying the combining system, the hood that includes the neck cushion, the skirt that includes the back cushion, the body that includes the insulation module, and the sleeves can be connected and separated by a zipper. The applicability of this concept was proven by applying a developed design to an actual item.

Cushioning Efficiency Evaluation by using the New Determination of Cushioning Curve in Cushioning Packaging Material Design for Agricultural Products (농산물 포장용 지류완충재의 새로운 완충곡선 구현을 통한 완충성능 평가)

  • Jung, Hyun Mo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.19 no.1
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    • pp.51-56
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    • 2013
  • From the time the product is manufactured until it is carried and ultimately used, the product is subjected to some form of handling and transportations. During this process, the product can be subjected to many potential hazards. One of them is the damage caused by shocks. In order to design a product-package system to protect the product, the peak acceleration or G force to the product that causes damage needs to be determined. When a corrugated fiberboard box loaded with products is dropped onto the ground, part of the energy acquired due to the action of the gravitational acceleration during the free fall is dissipated in the product and the package in various ways. The shock absorbing characteristics of the packaging cushion materials are presented as a family of cushion curves in which curves showing peak accelerations during impacts for a range of static loads are shown for several drop heights. The new method for determining the shock absorbing characteristics of cushioning materials for protective packaging has been described and demonstrated. It has been shown that cushion curves can be produced by combining the static compression and impact characteristics of the material. The dynamic factor was determined by the iterative least mean squares (ILMS) optimization technique in which the discrepancies between peak acceleration data predicted from the theoretical model and obtained from the impact tests are minimized. The approach enabled an efficient determination of cushion curves from a small number of experimental impact data.

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Time effect of pile-soil-geogrid-cushion interaction of rigid pile composite foundations under high-speed railway embankments

  • Wang, Changdan;Zhou, Shunhua;Wang, Binglong;Guo, Peijun
    • Geomechanics and Engineering
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    • v.16 no.6
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    • pp.589-597
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    • 2018
  • Centrifuge model tests were used to simulate pile-raft composite foundation and pile-geogrid composite foundation with different pile spacing for researching the time effect of negative skin friction of rigid piles in high-speed railways. The research results show that the negative skin friction has a significant impact on the bearing capacity of composite foundation. Pile-raft composite foundation has higher bearing capacity compared to pile-geogrid composite foundation to reduce the effect of negative skin friction on piles. Both the foundation settlement and negative skin friction have significant time effect. The distribution of skin friction can be simplified as a triangle along the pile. The neutral point position moves deeper in the postconstruction stage at larger pile spacing. For pile-geogrid composite foundation, the setting of pile-cap affects the position of neutral point in the post-construction stage. Reinforced cushion with geotextile may promote the better performance of cushion for transmitting the loads to piles and surrounding soils. Arching effect in the cushion of the composite foundation is a progressive process. The compression of the rigid piles contributes less than 20% to 25% of the total settlement while the penetration of the piles and the compression of the bearing stratum below the pile tips contribute more than 70% of the total settlement. Some effective measures to reduce the settlement of soils need to be taken into consideration to improve the bearing capacity of pile foundation.

The Effect of Cushion Insole on the Flexibility and Exercise Ability of Lumbar Spinal Stenosis (쿠션인솔이 요추 척추관협착증 환자의 유연성 및 운동능력에 미치는 영향)

  • Kim, Hyun Taeg;Moon, Sang Ho;Kim, Kyung Chul;Kwon, Byong An
    • Journal of Digital Convergence
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    • v.17 no.1
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    • pp.423-432
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    • 2019
  • The purpose of this study was to investigate the effect of cushion insole on lumbar flexibility and motor fitness in patients with lumbar spinal stenosis. 26 patients with lumbar spinal stenosis were randomly assigned to the experimental group 13 and the control group 13. Volunteers were allowed to wear cushioned insoles for two hours a day for six weeks. The experimental group was 8 mm and the control group was 4 mm, wearing a cushion insole as a blinded experiment. There was a significant increase(p<0.05) in the flexion test of the experimental group ($3.38{\pm}3.12$), but not statistically significant in the other tests(p>0.05). In conclusion, cushion insole was not suitable for intervention for lumbar spinal stenosis. There is a need to study the height and material of the insoles in the future.

Model Tests on a Plastic Pipe Pile for the Analysis of Noise, Energy Transfer Effect and Bearing Capacity due to Hammer Cushion Materials (해머 쿠션 재질에 따른 모형말뚝의 소음, 에너지 전달효율 및 지지력 분석)

  • Lim, Yu-Jin;Hwang, Kwang-Ho;Park, Young-Ho;Lee, Jin-Gul
    • Journal of the Korean Geotechnical Society
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    • v.22 no.12
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    • pp.33-43
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    • 2006
  • Driving tests using model plastic piles with different hammer cushion materials were performed in order to evaluate the efficiency of energy transfer ratio from the hammer, degree of vibration of the surrounding ground and noise due to impacting. A small pile driving analyzer (PDA) was composed using straingages and Hopkinson bar which is measuring force signal and pile-head velocity. The hammer cushion (cap block) materials used for the model driving tests were commercial Micarta, plywood, polyurethane, rubber (SBR) and silicone rubber. The highest energy transfer ratio was obtained from Micarta in the same soil and driving conditions. Micarta was followed by polyurethane, plywood, rubber and silicone in descending order. The more efficient energy transfdr ratio of the hammer cushion materials became, the bigger average noisy (sound) level was found. In addition, Micarta and polyurethane provided bigger bearing capacities than other materials compared in the same soil and driving conditions in which the static loading tests were performed at the end of driving.

Partial Endocardial Cushion Defect with Unusual Clinical Course (부분 심내막상 결손증의 치험 1예)

  • 이철주
    • Journal of Chest Surgery
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    • v.13 no.3
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    • pp.237-242
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    • 1980
  • This is a case report of spontaneous regression of elevated pulmonary vascular resistance after the age of 6 years in a patient with partial endocardial cushion defect. The patient was first evaluated and considered to be highly risky for surgical correction because of obstructive type of pulmonary hypertension and presisting congestive heart failure at the age of 6 years, during which time medical treatment for congestive heart failure and sufferring from respiratory infection were only provided. Finally the patient was reevaluated at the age of 16 years, in January of 1980 when cardiac catheterization was revealed markedly reduced pulmonary vascular resistance and pulmonary hypertension as well. The patient was operated upon with uneventful postoperative recovery. So we report this case with review of the literatures regarding natural history regarding natural history of partial endocardial cushion defect.

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A Deformation Model of a Bag-Finger Skirt and the Motion Response of an ACV in Waves

  • Lee, Gyeong-Joong;Rhee, Key-Pyo
    • Selected Papers of The Society of Naval Architects of Korea
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    • v.2 no.1
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    • pp.29-46
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    • 1994
  • In this paper, the effect of a skirt deformation on the responses of an Air Cushion Vehicle in waves is investigated. The air in the bag and plenum chamber is assumed to be compressible and to have a uniform pressure distribution in each volume. The free surface deformation is determined in the framework of a linear potential theory by replacing the cushion pressure with the pressure patch which is oscillating and translating uniformly. And the bag-finger skirt assumed to be deformed due to the pressure disturbance while its surface area remained constant. The restoring force and moment due to the deformation of bag-finger skirt from equilibrium shape is incorporated with the equations of heave and pitch motions. The numerical results of motion responses due to various ratios of the bag and cushion pressure or bag-to-finger depth ratios are shown.

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