• Title/Summary/Keyword: Wedge Structure

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MATROID BASE POLYTOPES FOR SERIES-PARALLEL EXTENSIONS

  • Kim, Sangwook
    • Honam Mathematical Journal
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    • v.38 no.2
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    • pp.393-401
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    • 2016
  • In this article, we study the matroid base polytope for a matroid obtained from another matroid by a series or parallel extension of an element. We express this polytope as a wedge of a polytope. In particular, we provide the facial structure of the matroid base polytope corresponding to a series-parallel matroid.

Effect of Medial Wedge on Muscle Activity of Lower Limb in Healthy Adults During One Leg Standing (한 다리 서기 시 내측 쐐기(wedge)의 적용이 하지 근활성도에 미치는 영향)

  • Hong, Ji-A;Kim, Min-Hee;Jung, Doh-Heon;Lim, One-Bin;Yi, Chung-Hwi
    • Physical Therapy Korea
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    • v.18 no.2
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    • pp.60-66
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    • 2011
  • Foot posture is important in the development of the musculoskeletal structure in the lower limbs because it can change the mechanical alignment. Although foot orthotics are widely used for the correction of malalignments in the lower extremities, the biomechanical effects of wedges have not yet been cleared. The aim of this study was to investigate whether medial wedges affect the electromyographic (EMG) activity of the knee and hip joints in healthy adults that are performing one leg standing. Seventeen healthy volunteers performed the one leg standing under two foot conditions: A level surface, and a $15^{\circ}$ medial wedge. The subjects' EMG data for the gluteus maximus (Gmax), gluteus medius (Gmed), tensor fasciae latae (TFL), biceps femoris (BF), vastus lateralis (VL), and vastus medialis oblique (VMO) were recorded, along with the surface EMG, and all were analyzed. The EMG activity of the Gmed and TFL had significantly decreased under the medial wedge condition during one leg standing. Further study is needed in order to investigate whether medial wedges influence the EMG activity and kinematic data of the knee and hip joints as well as the ankle joints in adults with flexible flatfoot, while they are performing one leg standing.

Design and Performance Evaluation of Shear Wave Phased Array Ultrasonic Transducer (횡파 위상배열 초음파 탐촉자 설계 및 성능 평가)

  • Yoon, Byung-Sik;Lee, Hee-Jong;Braconnier, Dominique
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.2
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    • pp.185-191
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    • 2012
  • Typically, a wedge is involved to generate effectively high inspection angle in pipe weld inspection using phased array ultrasonic technique. But the usage of this wedge for weld or access limited area can cause coverage limitation for the examination volume because of the wedge front length. Therefore, the shear wave phased array probe which can generate high inspection angle without wedge is essentially necessary. In this paper, the shear wave phased array ultrasonic probe which can generate high inspection angle designed by modeling and manufactured from the modelling result. And this shear wave probe tested whether it can detect and sizing for EDM test block that contains various depth. As results, the experimental results show that the designed shear wave phased array probe can detect and size with reliable accuracy. Therefore if this phased array probe apply in field inspection, it is expected that it show more reliable inspection result for plant structure having access limitation.

An Analysis of Design Parameters and Optimal Design for Anchors with Wide CFRP Plate (대형 CFRP Plate용 정착구의 설계요소분석 및 최적설계)

  • Kim, Hyung-Joon;Chung, Heung-Jin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.102-112
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    • 2020
  • In this study, in order to design a wedge-type anchor that can hold an wide carbon plate with a width of 100 mm or more that can be used in a bridge structure, the mechanical behaviors are evaluated based on the main design variables such as the angle of the wedge and the coefficient of friction between the guide and the wedge. The stress state of the carbon plate was calculated by numerical analysis method for each design variable, and the performance of the anchor in the critical state was evaluated according to the failure criteria for composite material, and the optimal design specifications of the anchor were determined based on numerical results. The performance of the optimally designed anchor was verified through actual experiments, and the results of this study are considered to be useful for the optimal design of the CFRP plate anchor to reinforce large structures.

Right-Angle-Bent CPW for the Application of the Driver-Amplifier-Integrated 40 Gbps TW-EML Module

  • Yun, Ho-Gyeong;Choi, Kwang-Seong;Kwon, Yong-Hwan;Choe, Joong-Seon;Moon, Jong-Tae;Lee, Myung-Hyun
    • ETRI Journal
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    • v.28 no.5
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    • pp.648-651
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    • 2006
  • In this letter we present a right-angle-bent coplanar waveguide (CPW) which we developed for the application of the driver amplifier-integrated (DAI) 40 Gbps traveling wave electroabsorption modulated laser module. The developed CPW realized parallel progression of the radio frequency (RF) and light using a dielectric overlay structure and wedge bonding on the bending section. The measured $S_{11}$ and $S_{21}$ of the developed CPW were kept below-10 dB up to 35 GHz and -3 dB up to 43 GHz, respectively. These measured results of the CPW were in good agreement with the simulation results and demonstrated the applicability of the CPW to the 40 Gbps communication module.

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A Study on the Rock Pressure Wedge Failure During Ground Excavation (대규모 지하굴착시 쐐기파괴로 인하여 발생하는 토압에 관한 연구)

  • 이승호
    • The Journal of Engineering Geology
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    • v.11 no.1
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    • pp.1-11
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    • 2001
  • The geological characteristics of Korea are that we can encounter the rock layer only after 10m of excavation, methods to presume the rock pressure distribution of the rock layer is urgently needed. When using the existing empiric science of Terzaghi-Peck, Tschebotarioff to measure the rock pressure of the rock layer, underestimate the real strength because of the cohesion is ignored. Therefore calculating the horizontal sliding force of wedge block, which includes the dips and shear strength of discontinuities and surcharge load etc., think to be to getting a closer rock stress of the real rock pressure acting upon the earth structure in rock mass. This research use Coulomb soil pressure theory assuming that the backfill soil will yield wedge failure when it has cohesion, applying Prakash-Saran(l963), and then it uses equilibrium of force and shear strength $\tau$=c+$\sigma$tan $\Phi$ of the cliscontinuities. Analyzing shear strength and dips of cliscontinuities using calculated theory according to the status of discontinuities aperture, we were able to find out that because the cohesion and friction angle of the rock layer itself is large enough, how the dip directions and dips facing the excavation face is the only factor deciding whether or not the rock stress is applied. The evaluated theory of this research should be strictly estimated, so that the many parameters such as c, $\Phi$value, types and structures of rock class, excessive lateral pressure, dynamic load, earthquake, needed later when calculating shear strength of discontinuities and especially the ground water effect acting on rock layer should be coumpted with many measuring data achieve at the insite to study the application.

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The Study of noise and vibration on application of the method breaking & excavating rock(Super wedge) (암파쇄굴착공법(Super wedge) 적용에 따른 소음.진동에 대한 고찰)

  • Won, Yeon-Ho;Kang, Choo-Won;Ryu, Chang-Ha
    • Proceedings of the KSEE Conference
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    • 2006.10a
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    • pp.167-184
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    • 2006
  • There is cattle shed and house structure of a country village in the vicinity of the construction site. that is why the environmental effect evaluation on blasting had been done in advance to prevent any harm to those from the work. As the result, it is impossible to apply to the blasting method, and the Super wedge method, a kind of a rock-splitting method which there is no secondary breaking by a breaker of the methods breaking &excavating rock according to the classification of the blasting method by the ministry of construction & transpotation, applied to decrease noise and vibration, and to the work classification, the extent of noise and vibration measured with the instrument only for noise(SC-310c) and with the instrument only for vibration(BLASTMATE) respectively. A drilling, splitting, collecting, loading works at the closest point(about 10m) is barely possible on the consideration of vibration to the result of measurement, but carefulness needs on moving of equipment. On the case of noise, even drilling, collecting, loading work except splitting at the comparatively close point(about 20m) is difficult. So, the method breaking &excavating rock according to the classification of the blasting method by the ministry of construction & transpotation has to apply in consideration of noise level in accordance with the work processing.

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An Experimental Study on the Flow Characteristics around Wedge Type Structure by Slamming (슬래밍에 의한 쐐기형 구조물 주위의 유동특성에 관한 실험적 연구)

  • Oh, Seung-Jin;Cho, Dae-Hwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.2
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    • pp.213-218
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    • 2013
  • This paper presents are experimental investigation to figure out slamming impact pressure and flow characteristics of a wedge type structure in free fall. The flow field has been obtained by 2-frame grey level cross correlation PIV(Particle Image Velocimetry) method, the impact presure of free fall structure by a pressure acquisition system apply to Dewetron system. The angles between a model and the free surface are adapted $15^{\circ}$, $25^{\circ}$, $35^{\circ}$ and $45^{\circ}$ respectively. Velocity field of water exit has higher better than water entry. The impact pressure under the bottom of the model ha been appeared higher values at 15 degrees than 45 degrees, and also at P1.

Korean Phonetic Characteristics reflected in the Pronunciation of French (한국인의 불어발음에 나타나는 음성학적 특징)

  • Park Hay-Jeanne
    • Proceedings of the KSPS conference
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    • 1996.10a
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    • pp.252-257
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    • 1996
  • La structure syllabique est un facteur important dan la prononciation d'une langue. Dans cette these, on a essaye de montrer que les caracteristiques de la syllabe varie d'une langue a une autre, et que les regles qui regissent la syllabe dan la langue maternelle a le dessue et done fait appliquer ses regles a la langue etrangere. Premierement, l'accentuation du coreen depend de la structure syllabique (qu'elle soit consonne-voyelle(CV) ou consonne-voyelle-consonne(CVC) et de la longueur de la voyelle. Ce qui fait que bien que le francais soit oxyton, et que la longueur et la qualite de la voyelle dependent de la structure syllabique, le francais, le francais parle par les coreens suit les regles du coreen. Autre caracteristique est que le coreen n'admet pas de suite de consonnes avant et apres la voyelle centrale comme dans "premier"[$pr{\partial}mje$] "autre"[o:tR]. D'ou l'insertion de voyelle superflue comme [${\varpi},{\;}{\wedge},{\;}{\partial}$]. Troisiemement, il existe une difference dans la coupe de la chaine parlee: en coreen la coupe ecrite(le blanc) egale a peu pres a la coupe orale(la pause) alors qu'en francais, c'est en groupe de mots que se fait la coupe. A l'interieur du groupe, les mots sont lies entre eux, soity par liaison, soit par enchainement. On peut remarquer donc une nette influence du coreen, ou la regle est de prononcer correctement par unites ecrites (equivalent des mots en francais) : la chaine parlee devient saccadee, avec un accent sur tous les mots, et des coups de glotte entre les mots, et l'une des voyelles [${\varpi},{\;}{\wedge},{\;}{\partial}$] inseree entre un mot se terminant par une consonne suivi d'un mot qui commence par une consonne.

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