• Title/Summary/Keyword: System Rigidity

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Muscle Tone and Somatosensory System acting on This (근육긴장도와 이에 영향을 미치는 체성감각계에 관한 고찰)

  • Kim Joong-Hwi;Kwon Yong-Hyun;Park Jung-Mi;Kim Chung-Sun
    • The Journal of Korean Physical Therapy
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    • v.15 no.2
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    • pp.85-99
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    • 2003
  • Muscle tone is the force with which a muscle resists being lengthened. Muscle tone is often tested clinically by passively extending and flexing a relaxed patient's limbs and feeling the resistance offered by the muscle. Both nonneural and neural mechanism contribute to muscle tone. Muscle tone is the mechanisms that contribute to the generation of tone in individual muscles when a person is in a relaxed state. This background level of activity changes in a certain antigravity posture muscle when we stand upright, thus counteracting the force of gravity. This increased level of activity in antigravity muscles is known as postural tone. The evidence from experiments showing that lesions of the dorsal(sensory) roots of the spinal cord reduced muscle(postural) tone is influenced by inputs from the somatosensory system. Patients with neurological damage have several state of muscle(postural) tone, which display from flaccidity to rigidity. This review article deal with muscle tone and somatosensory system acting on this. The understanding about this contribute to a better therapeutic approach for the rehabilitation of patients to have an abnormal muscle(postural) tone due to neurological damage.

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Mechanical Properties and Garment Formability on Breathable Fabrics for Sports-wear Garment (스포츠 의류용 투습직물의 역학특성과 의류형성성능 특성)

  • Kim, Hyun Ah
    • Fashion & Textile Research Journal
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    • v.19 no.5
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    • pp.626-634
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    • 2017
  • This study investigated garment formability of the 73 breathable fabrics for sports-wear garment and their fabric mechanical properties were measured using KES-FB and FAST systems. Predicted garment formability from the mechanical properties measured using KES-FB and FAST systems was compared and discussed with fabric structural parameters. In addition, virtual 3D simulation silhouette by I-designer CAD system wear appearance by simulation using 3D CAD system. And compared with FAST finger chart by mechanical properties of FAST system. The correlation coefficients of extensibility and shear modulus between KES-FB and FAST systems were high, however, bending rigidity and compressibility showed relatively low correlation coefficients. The correlation coefficient of garment formability of breathable fabrics between KES-FB and FAST systems was 0.82. It revealed that garment formability can be predicted from fabric mechanical properties by KES-FB and FAST systems. The garment formability of nylon breathable fabric was higher than that of PET one, and the garment formability of laminated breathable fabric showed the highest value compared to coated, dot and hot melt laminated breathable fabrics. It revealed that garment formability of breathable fabrics for sports-wear can be predicted from fabric mechanical properties and garment formability was dependent on the materials, finishing method and fabric structural parameters.

A Development of Platforms for Boiler of Thermal Power Plant (화력발전소 보일러 수퍼히트부 안전발판 개발 연구)

  • Lee, Jung Seok;Lee, Dong Lark;Kim, Hee Kyung;Jeong, Byeong Yong;Oh, Tae Keun
    • Journal of the Korean Society of Safety
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    • v.32 no.3
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    • pp.34-40
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    • 2017
  • The catastrophic collapse of the in-boiler scaffolding system in the two thermal power plants occurred in March and April 2012. After site investigation and document review, it was found that the specialized scaffolding system was imported for overhaul & maintenance and that the system did not get the safety certification at the import. In this regard, this study developed & proposed an access platform and a support for the vertical tube section of the super heat as well as a variable-length platform for the horizontal tube section, satisfying the domestic certification standards. The access platform was developed to be easy to handle by the worker with a weight of about 0.069 kN, which could reduce the risk of falling accidents and workers' musculoskeletal diseases. For the variable-length platform, it is possible to cope with various changes in length between the horizontal tubes associated with the increase of rigidity in the overlapping and the elimination of the protrusion.

Establishment of Roadside Tree Planting System in Kangnung (가로수 식재체계 수립)

  • 박용진;김태경
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.5
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    • pp.93-103
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    • 2000
  • This research is to propose a rational criterion of the selection and the management f the roadside trees, and to establish the planting design and system with the objective of improving the roadside environment. All of the roadside trees in each objective courses in Kangnung, and the soil disposition, hardness of the soil in the planting areas have been investigated. Also, we have surveyed the kinds of the trees which kandgnung inhabitants want. The conclusion is as follows Most of roadsides have trees, but they need the introduction of shrubs or ground covering plants according to the locations and the environmental conditions. We have selected nineteen species in regard to the roadside tree criterion and the growing conditions living in Kangnung. It is desirable that we make banding style planting space between each roadside tree to improve the low ratio of green coverage. We have found out that Ligustrum obtusifolium, Buxus micropnylla, Euonymus japonica, Rhododendron schlippenbachii, Phyllostachys nigro and Rosa rugosa, ect. are suitable. In order to soften and weaken the rigidity of the hard substances on a paved roadside, the climbers such as the perennial herbaceous flowering and hedera rhombea should be preferred rather than annual herbaceous flowering because of curtailment of expenditure. To posses a systematical greenery frame in kangnung, we have planned a planting design system that would expand the greenery space every year. Moreover, we have to make a plan to overcome space restrictions. We have established a flexible plan considering the roadside conditions and the improved standard planting methods with an ultimate aim to create a special roadside view.

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A Study on the Performance Evaluation of Cycloid Reducer (사이클로이드 감속기의 성능평가에 관한 연구)

  • Park, Jin-Seok;Kim, Ki-Hun;Kim, Lae-Sung;Qin, Zhen;Lyu, Sung-Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.3
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    • pp.113-118
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    • 2017
  • In this paper, a study on the performance evaluation of a cycloid reducer for remote weapons systems is presented. Reduction gears applied to remote weapons vehicles need to be compact and capable of large torque transmissions as well as require structural optimization, high load capacity, and high precision position control. To meet these requirements, a cycloid reducer with low backlash, high precision, high overload capability, high rigidity, and high efficiency is required. Thus, a cycloid reducer with a reduction ratio of 127:1, backlash of 1 arcmin (1/60 deg) or less, and reduction gear efficiency of 70% or more, which are the design requirements for a remote weapons system, was designed utilizing a design and analysis program (HEXAGON) for gear engineering. To confirm the performance of the cycloid reducer, the hardness of the main components of the manufactured cycloid reducer, reduction ratio, and efficiency were measured.

Structural Analysis of 800Ton Hot Stamping Press (800톤 핫스탬핑 프레스의 구조해석)

  • Choi, Byeong-Keun;Lee, Jeong-Hoon;Lee, Jong-Myeong;Ha, Jeong-Min;Gu, Dong-Sik;Kim, Won-Chul
    • Journal of Power System Engineering
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    • v.17 no.1
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    • pp.97-103
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    • 2013
  • Press machine has advantages over other manufacturing machine which can produce large quantities of products in short time so it is widely used in lots of industrial sectors. To obtain the vehicle's weight lightening and rigidity of the body-frame by applying 'Hot stamping' technique is increasing in the automotive field. In this paper, to improve the irregular vibration arose by 800Ton hot stamping press, the research was continued. Bed, slide and main frame are the key part of working precision, so perform structural analysis was conducted, and based on the analyzing results, structural changes were done on the parts where structural deformation occurred.

The Characteristics of Elasto-Plastic Behaviour for the Latticed Dome Structures (래티스 돔 구조물의 탄소성 거동 특성에 관한 연구)

  • Park, Chul-Ho;Han, Sang-Eul;Yang, Jea-Guen
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.53-62
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    • 2004
  • A single layer latticed dome is one of the most efficient structures because of its low specivic gravity. For easily analyzing of a single layer latticed dome, joint system is assumed to be pin or rigid joint. However, its joint uses ball whose system has intermediate properties of pin and rigid joint. Therefore this study has a grasp of bending rigidity, stress and mechanical properties through experimental and analyzing method of the bolt inserted ball joint. To analyze the stress of bolt and sleeve, this study uses through 3D elastic contact and cubic element, and then the ball and the bolt are perfectly connected for easily analyzing Compared experimental results to F.E.M, each specimen has an error of less than 12 percent. In the results of stress distribution through F.E.M, stress occurs from bottom of bolt to top of sleeve, and most of tension appears on the bolt, also compression occurs from upper parts of the bolt to the sleeve. The assumption of bending stiffness in ball joint is well known that bolt resists only tension and upper sleeve resiss compression. The results of experiment and analysis have $7{\sim}56%$ error, assuring that upper part of bolt occurs of partial compression. In the result of modified assumption have $4{\sim}20%$ error.

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Seismic Response Evaluation of Seismically Isolated Nuclear Power Plant with Stiffness Center Change of Friction Pendulum Systems (마찰진자시스템의 강성중심 변화에 따른 면진된 원전 구조물의 지진응답평가)

  • Seok, Cheol-Geun;Song, Jong-Keol
    • Journal of the Earthquake Engineering Society of Korea
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    • v.21 no.6
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    • pp.265-275
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    • 2017
  • In order to improve the seismic performance of structures, friction pendulum system (FPS) is the most commonly used seismic isolation device in addition to lead rubber bearing (LRB) in high seismicity area. In a nuclear power plant (NPP) with a large self weight, it is necessary to install a large number of seismic isolation devices, and the position of the center of rigidity varies depending on the arrangement of the seismic isolation devices. Due to the increase in the eccentricity, which is the difference between the center of gravity of the nuclear structure and the center of stiffness of the seismic isolators, an excessive seismic response may occur which could not be considered at the design stage. Three different types of eccentricity models (CASE 1, CASE 2, and CASE 3) were used for seismic response evaluation of seismically isolated NPP due to the increase of eccentricity (0%, 5%, 10%, 15%). The analytical model of the seismic isolation system was compared using the equivalent linear model and the bilinear model. From the results of the seismic response of the seismically isolated NPP with increasing eccentricity, it can be observed that the effect of eccentricity on the seismic response for the equivalent linear model is larger than that for the bilinear model.

Large Eddy Simulation on the Aerodynamic Performance of Three-Dimensional Small-Size Axial Fan with the Different Depth of Bellmouth (벨마우스 깊이가 다른 3차원 소형축류홴의 공력특성에 대한 대규모 와 모사)

  • Kim, Jang-Kweon;Oh, Seok-Hyung
    • Journal of Power System Engineering
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    • v.19 no.6
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    • pp.19-25
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    • 2015
  • The unsteady-state, incompressible and three-dimensional large eddy simulation(LES) was carried out to analyze the aerodynamic performance of three-dimensional small-size axial fan(SSAF) with the different depth of bellmouth. The static pressure coefficients analyzed by LES predict a little bit larger than measurements except stall region regardless of the installation depth between SSAF and bellmouth. Moreover, static pressure efficiencies analyzed by LES show about maximum 30% at the actual operating point ranges, but measurements do not. Therefore, if the blades of conventional SSAF have some more rigidity and complete dynamic balance, the aerodynamic performance of SSAF will be some more improved. In consequence, LES shows the best prediction performance in comparison with any other Reynolds averaged Navier-Stokes(RANS) method.

Behavior Analysis and Empirical Relation for a Flexible Disk with High Speed Rotation (고속회전 유연디스크의 거동해석과 경험식)

  • Lee, Ho-Ryul;Rhim, Yoon-Chul
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.4
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    • pp.245-250
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    • 2006
  • Organizations such as broadcasting stations and libraries which deal with huge amount of information require high-capacity storage systems for archiving their materials and information. It is necessary and urgent for the storage people to develop a compact, high capacity, and low-cost data storage systems. Even though the Blue-ray technology is commercialized and now it is on the market, demand for the compact and low-cost system is still increasing. A flexible disk system has been introduced recently to satisfy above mentioned requirements. The system uses multiple of thin disks and is expected to achieve technical requirements. However, decreasing the disk thickness makes it difficult to read and write data because it decreases the disk rigidity so that the transverse vibration of the rotating disk increases easily due to both the interaction with surrounding air and the vibration characteristics of thin flexible disk itself. In this study, flat-type stabilizer is proposed to suppress the transverse vibration of a $95{\mu}m$-thick polycarbonate disk. Characteristics of disk vibration have been studied through the results of numerical analysis from the fluid mechanics point of view. Numerical simulation is verified through the experiment by measuring the gap between the rotating disk and the stationary flat stabilizer. The axial deflections of the disk are computed for various rotating speeds and reference gap sizes and then a method of regression is applied to those data. As a result, an empirical relation is proposed for the steady deformation shape of the rotating disk.

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