• Title/Summary/Keyword: notch type

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On geometry dependent R-curve from size effect law for concrete-like quasibrittle materials

  • Zhao, Yan-Hua;Chang, Jian-Mei;Gao, Hong-Bo
    • Computers and Concrete
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    • v.15 no.4
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    • pp.673-686
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    • 2015
  • R-curve based on the size effect law previously developed for geometrically similar specimens (geometry type III) is extended to geometries with variable depth (geometry type I) as well as with variable notch (geometry type II), where the R-curve is defined as the envelope of the family of critical strain energy release rates from specimens of different sizes. The results show that the extended R-curve for type I tends to be the same for different specimen configurations, while it is greatly dependent on specimen geometry in terms of the initial crack length. Furthermore, the predicted load-deflection responses from the suggested R-curve are found to agree well with the testing results on concrete and rock materials. Besides, maximum loads for type II specimen are predicted well from the extended R-curve.

The Experimental Study on GCM(General Coordinative Manipulation) which has been studied on the basis of Spine & Limb Extremity (인체 사지 및 척추관절의 운동증감패턴에 따른 전신교정치료에 관한 실증적 연구)

  • Moon, Sang-Eun
    • Journal of Korean Physical Therapy Science
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    • v.6 no.2
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    • pp.1041-1062
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    • 1999
  • This study is to stimulate the model of which top notch muscle stimuli physical therapy has been made on the basis of GCM. GCM has been studied on the hypermobility & hypomobility pattern on the part of spine & extremity, and the body characteristics of four body types, which is the tilting of seal scapular & ilium. The purpose of this study is to analysize the type of GCM which has been focused on the spine & extremity for the patients having dysfunctions of neuromuscular system, being analysized the movement. The result of this study is as following; 1) The First hypothesis: The hypermobility & hypomobility pattern assorted by the tilting of scapular & ilium, as does the former study analysize was claimed that it would be in line with the pattern for hypermobility hypomobility and physical characteristics according to each body type at the percentage of at least 60(p<.001). 2) The 2nd hypothesis : Stimuli therapy of muscle dealing with physical characteristics and joint hypermobility hypomobility has the important role in restoring the deformity and keeping anatomical postural plumb alignment also it would a highly effects on correcting the body even though the stimuli area was limited to four areas and it was lack of time compared with those applied by general physical therapy(p<.001). As above the result, the top-notch type for physical therapy based on hypermobility hypomobility pattern by 4 body types which has been studied on tilting of scapular & ilium is more specificed and specialized than those of general physical therapy technologies. So this study will be believed to dedicate to restoration ideal anatomical postural plumb alignment based on spinal Manipulation and the concept of whole person as well as to being simple and effective to apply.

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A Study on the Characteristics of Volumetric Efficiency of an Axial Piston Pump considering Piston Tilting

  • Park, In-Kyu;Rhim, Yoon-Chul
    • KSTLE International Journal
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    • v.10 no.1_2
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    • pp.37-42
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    • 2009
  • This paper presents the characteristics of volumetric efficiency of an axial type piston pump considering the piston tilting. A numerical analysis is carried out in order to obtain the pressure distribution considering the fluid inertia at the notch of the valve plate. The cylinder pressure variation and the discharge flow rate are measured experimentally according to the operating conditions such as supply pressure, rotational speed, and viscosity of the working fluid by using the cam type test apparatus. Leakage is also measured considering piston tilting. The characteristics of the volumetric efficiency are analyzed with respect to various operating conditions and leakage is also analyzed according to the piston tilting angle. Results are applicable to improve the design of an axial type piston pump.

Performance Improvement of IPM-type BLDC Motor Using the Influx Method of Spatial Harmonic in Air-gap Flux Density (공극 자속밀도의 공간 고조파 유입 방법을 통한 IPM type BLDC Motor의 성능 개선)

  • Lee, Kwang-Hyun;Reu, Jin-Wook;Hur, Jin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.4
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    • pp.739-745
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    • 2011
  • This paper proposes a method for reducing the negative spatial harmonics of the radial flux density of an interior-type permanent magnet (IPM) motor. The reliability of the motor is increased by minimizing its vibrations under dynamic eccentricity (DE) state and normal state due to reduction of a negative spatial harmonics component through the influx of a zero spatial harmonics component in the radial flux density. To minimize the vibrations, optimal notches corresponding to the distribution shape of the magnetic field are designed on the rotor pole face. The variations of vibration computation by finite element method (FEM) and the validity of the analysis and rotor shape design are confirmed by vibration and performance experiments.

A Study on the Trapezoidal Cutthroat Flumes for Measuring Flow in Open-Channels (개수로의 유량 측정을 위한 제형 Cutthroat Flume에 관한 연구)

  • 윤주상;정하우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.19 no.4
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    • pp.4533-4543
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    • 1977
  • The purpose of this study was to investigate and compare flow discharges of rectangular, V-notch and trapezoidal type of cutthrooat flumes, and the published data for trapezoidal parshall flumes. And the trapezoidal cutthroat flumes were also compared in their accuracy of discharge measurements for various convergence ratios in the inlet section and divergence ratios in the outlet section. Five flumes were studied, and all the flumes were 45cm long with flat-bottom and were made of well-finished transparent acryl plate of 3mm thickness. One rectangular, one V-notch and three trapezoidal types were numbered 1 to 5 as shown in Fig. III-1. The measured depth of water was ranged from 5 to 20cm. The results obtained in this study are summarized as follows: 1. The general discharge equations for tested prototypes are listed for free flow in Table IV-1 and for submergence flow in Table IV-4. 2. In both free and submerged flow, the accuracy of the discharge formula obtained by this test is highly significant at 1% level as shown in Table IV-2 and Table IV-6. The accuracy of disharges measured depends upon the convergence and divergence ratios in the trapezoidal types: the less the ratios of convergence as well as divergence, the lower the accuracy. 3. Submergence ratios tend to increase in the order of flume number except flume No. 4. This implies that trapezoidal cutthroat flumes are more acceptable than rectangular or V-notch ones for free flow. 4. The transition submergence for the trapezoidal Parshall flumes ranges from 80-85 percent, which is slightly higher than the tested flume. However, the trapezoidal cutthroat flume No. 5 has higher transition submergence ratio, ranging from 73-78 percent, than other trapezoidal ones. The difference between the trapezoidal Parshall flumes and the trapezoidal cutthroat flumes in transition submergence seems small enough to be ignored in their field use. 5. Trapezoidal cutthroat flume is simple and economical to construct in existing openchannels whose shapes are generally trapezoidal. In order to obtain the best rating accuracy, flume No. 3 among the tested trapezoidal types is recommended, because it shows the highest accuracy for both free and submerged flow.

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Design and implementation of Broadband Antenna/Diplexer for dual-band handsets (이중대역 단말기용 광대역 안테나 및 다이플렉서 설계 및 구현)

  • 김재호;김영태;박준석;천창율;임재봉;신재완;강현규;정중성;황희용
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2002.11a
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    • pp.149-152
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    • 2002
  • In this paper, We have designed an internal chip type-ceramic antenna and diplexer for dual-band handset applications. for increasing bandwidth, antennas used a meander line structure with L, C matching network. The designed diplexer is based on the multi-layered structure for the purpose of the LTCC applications. We have given a notch using resonator for elevated attenuation characteristics.

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Crack Propagation Behavior for Variable Load in Cantilever Beam under Bending Load (굽힘하중의 받는 외팔보의 변동하중에 대한 균열진전 거동)

  • 김엽래
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.03a
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    • pp.178-183
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    • 1998
  • This paper examines the crack growth behavior of 7075-T651 and 5052-H32 aluminum alloys for variable load within tensile load range condition. The cantilever beam type specimen with a chevron notch is used in this study. The crack growth and closure are investgated by compliance method. The applied initial stress ratio is R=0.3 and variable load are R=0.65, 0.46. Crack length, stress intensity factor range, ratio of effective stress intensity factor range and crack growth rate etc. are inspected with fracture mechanics estimate.

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The Design of a Wideband E-plane Phased Array Antenna using W/G Simulator (도파관 시뮬레이터를 이용한 광대역 E-평면 넛치 위상 배열 안테나 설계)

  • 김준연;소준호;임중수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.2
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    • pp.111-118
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    • 2003
  • Notch Antenna is a travelling wave type antenna and can provide multioctave operation in phased arrays that scan over wide angle. In this paper, we designed a wideband E-plane phased array antenna using E-plane waveguide simulator which has a bandwidth of 3 : 1 and a scan volume of $\pm$45$^{\circ}$ in E-plane. We compared impedance of single antenna and infinite array antenna using equivalent circuit modeling. We analyzed full structure of 1$\times$9 phased array antenna and we evaluated active reflection coefficient with variation of beam scan angle through mutual coupling coefficient acquired from simulation and investigated the variation of antenna gain with variation of active element pattern as beam scan angle is varied.

Study on the Precise Controlling of Fracture Plane in Smooth Blasting Method (SB발파에서 파단면 제어의 고도화에 관한 연구)

  • Cho, Sang-Ho;Jeong, Yun-Young;Kim, Kwang-Yum;Kaneko, Katsuhiko
    • Tunnel and Underground Space
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    • v.19 no.4
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    • pp.366-372
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    • 2009
  • Recently, in order to achieve smooth fracture plane and minimize the excavation damage zone in rock blasting, controlled blasting methods which utilize new technologies such as electronic delay detonator (EDD) and a notched charge hole have been suggested. In this study, smooth blastings utilizing three wing type notched charge holes are simulated to investigate the influence of explosive initial density on the resultant fracture plane and damage zone using dynamic fracture process analysis (DFPA) code. Finally, based on the dynamic fracture process analyses, novel smooth blasting method, ED-Notch SB (Electronic Detonator Notched Charge Hole Smooth Blasting) is suggested.

The Defect Detection and Evaluation of Austenitic Stainless Steel 304 Weld Zone using Ultrasonic Wave and Neuro (초음파와 신경망을 이용한 오스테나이트계 스테인리스강 304 용접부의 결함 검출 및 평가)

  • Yi, Won;Yun, In-Sik
    • Journal of Welding and Joining
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    • v.16 no.3
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    • pp.64-73
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    • 1998
  • This paper is concerned with defects detection and evaluation of heat affected zone (HAZ) in austenitic stainless steel type 304 by ultrasonic wave and neural network. In experiment, the reflected ultrasonic defect signals from artificial defects (side hole, vertical hole, notch) of HAZ appears as beam distance of prove-defect, distance of probe-surface, depth of defect-surface on CRT. For defect classification simulation, neural network system was organized using total results of ultrasonic experiment. The organized neural network system was learned with the accuracy of 99%. Also it could be classified with the accuracy of 80% in side hole, and 100% in vertical hole, 90% in notch about ultrasonic pattern recognition. Simulation results of neural network agree fairly well with results of ultrasonic experiment. Thus were think that the constructed system (ultrasonic wave - neural network) in this work is useful for defects dection and classification such as holes and notches in HAZ of austenitic stainless steel 304.

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