• Title/Summary/Keyword: eccentric

Search Result 897, Processing Time 0.026 seconds

Papers : Snap - through Phenomena on Nonlinear Thermopiezoelastic Behavior of Piezolaminated Plates (논문 : 압전적층판의 비선형 열압전탄성 거동에서의 스냅 - 스루 현상)

  • O,Il-Gwon;Sin,Won-Ho;Lee,In
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.30 no.1
    • /
    • pp.36-43
    • /
    • 2002
  • Thermopiezoelastic snap-through phenomena of piezolaminated plates are investigated by applying an are-length scheme to Newton-Raphson method. Based on the layerwise displacement theory and von Karman strain-displacement relationships, nonlinear finite element formulations are derived for the thermopiezoelastic composite plates. From the static and dynamic viewpoint, nonlinear thermopierzoelastic behavior and vibration characteristicx are stuied for symmetric and eccentric structural models with various piezoelestric actuation modes. Present results show the possibility to enhance the performance, namely thermopiezoelastic snapping, induced by the excessive piezoelectric actuation in the active suppression of thermally buckled large deflection piezolaminated paltes.

The Investigation of effect of Physical Therapy for Delayed Onset Muscle soreness according to difference of experimental designs (실험방법의 차이에 따른 지연 발생 근육통의 물리치료 효과에 대한 연구)

  • Chae Yun-Won;Nam Ki-Seok;Choi Jin-Ho;HwangBo Gak;Kim Jin-Sang
    • The Journal of Korean Physical Therapy
    • /
    • v.11 no.3
    • /
    • pp.37-44
    • /
    • 1999
  • Delayed onset muscle soreness is a sensation of discomfort that occurs 24h after exercise, and it is associated with the performance of unfamiliar and high force muscle wor, such as eccentric contractions. The injury to the muscle has been well described but the mechanism underlying the injury is not fully understood. Although the pathophysiological processes underlying delayed onset muscle soreness are not completely understood, many researchers have investigated various treatments in a attempt to reduce the soreness. These treatments have focused on reducing the inflammation, or edema, consequent to tissue damage, and breaking up the cycle which is thought provoke tonic muscle spasm or pain. Physical therapy is the most importance thechniques to reduce delayed onset muscle soreness. Physical therapy on delayed onset muscle soreness includes massage, exercise, therapeutic ultrasound, TENS, stretching and cryotherapy, this investigation should encourage physical therapists to experiment further with various techniques to reduce delayed onset muscle soreness.

  • PDF

The role of calpain in skeletal muscle

  • Pandurangan, Muthuraman;Hwang, Inho
    • Animal cells and systems
    • /
    • v.16 no.6
    • /
    • pp.431-437
    • /
    • 2012
  • Calpains are a class of proteins that belong to the calcium-dependent, non-lysosomal cysteine proteases. There are three major types of calpains expressed in the skeletal muscle, namely, ${\mu}$-calpain, m-calpain, and calpain 3, which show proteolytic activities. Skeletal muscle fibers possess all three calpains, and they are $Ca^{2+}$-dependent proteases. The functional role of calpains was found to be associated with apoptosis and myogenesis. However, calpain 3 is likely to be involved in sarcomeric remodeling. A defect in the expression of calpain 3 leads to limb-girdle muscular dystrophy type 2A. Calpain 3 is found in skeletal muscle fibers at the N2A line of the large elastic protein, titin. A substantial proportion of calpain 3 is activated 24 h following a single bout of eccentric exercise. In vitro studies indicated that calpain 3 can be activated 2-4 fold higher than normal resting cytoplasmic [$Ca^{2+}$]. Characterization of the calpain system in the developing muscle is essential to explain which calpain isoforms are present and whether both ${\mu}$-calpain and m-calpain exist in differentiating myoblasts. Information from such studies is needed to clarify the role of the calpain system in skeletal muscle growth. It has been demonstrated that the activation of ubiquitous calpains and calpain 3 in skeletal muscle is very well regulated in the presence of huge and rapid changes in intracellular [$Ca^{2+}$].

Practical second-order analysis and design of single angle trusses by an equivalent imperfection approach

  • Cho, S.H.;Chan, S.L.
    • Steel and Composite Structures
    • /
    • v.5 no.6
    • /
    • pp.443-458
    • /
    • 2005
  • Steel angles are widely used in roof trusses as web and chord members and in lattice towers. Very often angle members are connected eccentrically. As a result, not only an angle member is under an axial force, but it is also subject to a pair of end eccentric moments. Moreover, the connection at each end provides some fixity so neither pinned nor the fixed end represents the reality. Many national design codes allow for the effects due to eccentricities by modifying the slenderness ratio and reducing the compressive strength of the member. However, in practice, it is difficult to determine accurately the effective length. The concept behind this method is inconsistent with strength design of members of other cross-sectional types such as I or box sections of which the buckling strength is controlled by the Perry constant or the initial imperfection parameters. This paper proposes a method for design of angle frames and trusses by the second-order analysis. The equivalent initial imperfection-to-length ratios for equal and unequal angles to compensate the negligence of initial curvatures, load eccentricities and residual stresses are determined in this paper. From the obtained results, the values of imperfection-to-length ratios are suggested for design and analysis of angle steel trusses allowing for member buckling strength based on the Perry-Robertson formula.

Effects of Propeller Forces on the Propeller Shaft Bearing during Going Straight and Turning of Ship (선박의 직진과 선회 시의 프로펠러 하중이 프로펠러 축 베어링에 미치는 영향)

  • Shin, Sang-Hoon
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.52 no.1
    • /
    • pp.61-69
    • /
    • 2015
  • In the beginning of the 1990's, numerous shaft bearing damages, especially in aft stern tube bearing, were reported. The main reasons of bearing damages were estimated that hull deflections have been increased by more flexible hulls and propeller dynamic loads have not been considered in shaft alignment. After that time, studies to take into account hull deflections in shaft alignment have been actively carried out, but for the latter leave much to be desired. In this study, the effects of the propeller forces on the propeller shaft bearing have been investigated by estimating thrust eccentricity as reasonable as possible although some assumptions to simulate turning of ship were introduced. Three dimensional nominal wake to estimate thrust eccentricity have been calculated by using CFD analysis and model test in the towing tank. This study presents the procedure to estimate the propeller eccentric forces and their influence on the stern tube bearing for a container carrier. As a result, it has been found that the lateral propeller forces in turning condition should be considered in shaft alignment to prevent shaft bearing damages.

Clinical Application of Combination of Isotonic in Proprioceptive Neuromuscular Facilitation (고유수용성 신경근 촉진법중 등장성수축 결합의 임상적용)

  • Bae Sung-soo;Hwang-bo Gak;Kim Mi-hyun;Kim Jae-Hun;Choi Jae-Won
    • The Journal of Korean Physical Therapy
    • /
    • v.16 no.3
    • /
    • pp.205-216
    • /
    • 2004
  • The purpose of this study is to find application of combination of insotonic(CI) in clinical approach. This is a literature study with books and clinical experience. CI was developed after Margaret Knott that is very useful in clinically. CI has two lever system. It has class II lever system for eccentric contraction and class III lever system for concentric contraction. Therefore it make two different contraction that is not only magnitude of motion and speed increase of motion but also biomechanical advantage. Application of CI has much variety by patient position and treatment position. Especially, it is very effectable on mat activities and training for mid stance period. CI apply in supine position on treatment table, mat or high mat activities, bridging activities, all fourth activities and sit on chair activities. CI apply serially with different techniques. These are rhythmic initiation, dynamic reversal, approximation, rhythmic stabilization and replication.

  • PDF

Cutaneous smooth muscle tumors in 3 dogs

  • Jung, Ji-Youl;Kang, Sang-Chul;Park, Dae-Sik;Lee, Eun-Sung;Bae, Jong-Hee;Kim, Jae-Hoon
    • Korean Journal of Veterinary Research
    • /
    • v.49 no.1
    • /
    • pp.63-66
    • /
    • 2009
  • Cutaneous leiomyomas (leiomyosarcomas) are smooth muscle tumors that occur single or as multiple lesions. They usually arise from the arrector pili muscles (piloleiomyomas) and less commonly from the muscle of veins (angioleiomyomas). This report describes histologic and immunohistochemical features of one cutaneous piloleiomyoma and two angioleiomyosarcomas. Three 7-12-year-old female dogs were presented with single or double cutaneous nodules. Histologically, the neoplastic masses were composed of densely or loosely arranged interlacing bundles. The neoplastic cells were ovoid to elongate, and had eosinophilic cytoplasms and perinuclear cytoplasmic vacuolation. Nuclei were central to eccentric, cigar shaped, oval to elongate. In two cases, high mitotic index in high power field, multifocal necrosis and local invasion were also noted. Masson's trichrome and van Gieson staining revealed muscle origin tumors in these cases. Immunohistochemically, the tumor cells were strongly positive for smooth muscle actin. In our best knowledge, this is the first report of cutaneous smooth muscle tumors in dogs in Korea.

Input Impedances of PWM DC-DC Converters: Unified Analysis and Application Example

  • Pidaparthy, Syam Kumar;Choi, Byungcho
    • Journal of Power Electronics
    • /
    • v.16 no.6
    • /
    • pp.2045-2056
    • /
    • 2016
  • The input impedances of pulse width modulated (PWM) dc-to-dc converters, which dictate the outcomes of the dynamic interaction between dc-to-dc converters and their source subsystem, are analyzed in a general and unified manner. The input impedances of three basic PWM dc-to-dc converters are derived with both voltage mode control and current mode control. This paper presents the analytical expressions of the 24 input impedances of three basic PWM dc-to-dc converters with the two different control schemes in a factorized time-constant form. It also provides a comprehensive reference for future dynamic interaction analyses requiring knowledge of the converters' input impedances. The theoretical predictions of the paper are all supported by measurements on prototype dc-to-dc converters. The use of the presented results is demonstrated via a practical application example, which analyzes the small-signal dynamics of an input-filter coupled current-mode controlled buck converter. This elucidates the theoretical background for the previously-reported eccentric behavior of the converter.

A Study on the semantic network system of the line of flow appearing on the residential space of super high-rise apartments (초고층아파트 주거공간에 나타난 동선의 의미적 네트워크 체계에 관한 연구)

  • Yoon, Jae-Eun;Kim, Joo-Hee
    • Korean Institute of Interior Design Journal
    • /
    • v.16 no.3 s.62
    • /
    • pp.58-65
    • /
    • 2007
  • The residential space of super high-rise buildings, having a form of a huge three-dimensional vertical city, affect the residents psychologically and qualitatively according to the line of flow. Because of these affects, the system of the line of flows is a very important factor. In this study, we recognize the super high-rise apartment's line of flow as a semantic network system based on case studies. And we also understand the mutual relationship by analyzing each space to recognize what effect it does on the residential environment. Furthermore, to bring up a better semantic network system for super high-rise apartment's line of flows is our goal. According to the case studies, the semantic network of the line of flow consists of 3 parts: the functional network, economical network and unit network. The functional network is composed of the 'need' and 'has', while the economical network includes variable walls that can be changed following the user's taste and eccentric positioned living rooms that protect personal privacy. Therefore the economical network started to appear while the personal value changed according to the improvement of the social condition. Finally, the unit network is a network that effects each unit that has ambiguous boundaries due to the appropriate arrangement between transitional spaces. And the unit network is based on the functional network.

Search for dormant comets in AcuA

  • Kim, Yoonyoung;Ishiguro, Masateru;Usui, Fumihiko
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.38 no.1
    • /
    • pp.62.2-62.2
    • /
    • 2013
  • It is considered that comets near the ecliptic plane have been injected into inner solar system from Kuiper-belt. Some of them are still active while others are dormant with no detectable tails and comae. These dormant comets have eccentric and/or inclined orbits, which are parameterized by Tisserand parameter TJ<3. In addition, dormant comets can be differentiated from asteroids based on the albedo, because they have low albedo (the geometrical albedos pv<0.1). The conditions of TJ<3 and pv<0.1 have been used as a criteria to discriminate dormant comets from asteroids. However, we must be more careful because there are 'contaminations' from the outer region, i.e. Jovian Trojans (5.05

  • PDF