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THE STUDY OF THE EFFECT OF DENTAL ARCH FORM ON CHEWING MOVEMENT II. THE ANALYSIS OF CHEWING MOVEMENT (저작운동에 미치는 치열궁형태의 영향에 관한 연구 II. 저작운동의 분석에 대하여)

  • Jo Byung-Woan
    • The Journal of Korean Academy of Prosthodontics
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    • v.32 no.4
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    • pp.553-564
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    • 1994
  • Using Sirognathograph Analyzing System, the patterns of chewing movement were analyzed into opening phase and closing phase, each phase to frontal plane, horizontal plane, and sagittal plane by maruyama's classification. In opening phase, the chewing patterns of frontal plane were classifed into Chopping Opening, Grinding Opening, Concave Opening, Lateral Shift Opening, Vertical Guide Opening, Convergence Opening. Those of horizontal plane were classified into Chopping Opening, Grinding Opening, Concave Opening, Protrusive Shift Opening, Posterior Guide Opening, Convergence Opening. Those of sagittal plane were classified into Normal Opening, Protrusive Shift Opening, Vertical Guide Opening, Convergence Opening. In closing phase, the chewing patterns of frontal plane were classified into Normal Closure, Concave Closure, Lateral Shift Closure, Lateral Guide Closure, Vertical Guide Closure, Convergence Closure, Those of horzontal plane were classified into Normal Closure, Concave Closure, Lateral Shift Closure, Protrusive Shift Closure, Lateral Guide closure, Posterior Guide Closure, Convergence Closure. Those of sagittal plane were classified into Normal Closure, Protrusive Shift Closure, Vertical Guide. Closure, Convergence Closure. Results were summarized as follows : 1. Opening phase in chewing movement The Normal Openings in 3 planes(frontal, horizontal, sagittal), the Concave Openings in frontal plane and horizontal plane, the Vertical Guide Opening in frontal plane and the Posterior Guide Opening in horizontal plane were many observed. 2. Closing phase in chewing movement The Concave Closure in frontal and horizontal plane, the Normal Closure in 3 planes (frontal, horizontal, sagittal), the Concave Closure in horizontal plane were many observed.

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Opening Spring Modeling of Current Circuit Breaker Mechanism with respect to Opening Speed using Energy Method (전류 차단기 메커니즘에서 에너지방법을 이용한 차단 속도에 따른 스프링 모델링)

  • Kwon, Byung-Hee
    • Proceedings of the KSME Conference
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    • pp.688-692
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    • 2000
  • This study proposed design parameters of opening spring of circuit breaker that cut off the over-current in order to protect the electric device about opening speed using the energy method. We simulated the opening kinetic energy, the potential energy of opening spring and the design parameters of opening spring with respect to opening speed of VCB (Vacuum Circuit Breaker)'s moving contactor which has 24kV 25kA break capacity. From the result of simulation the initial tensional force and the final tensional force of the opening spring chose 107kgf and 282kgf respectively. Through the dynamic analysis using ADAMS, We verified that the opening speed of moving contactor satisfied break capacity of VCB and analyzed opening dynamic characteristics of VCB such as the opening displacement, the opening velocity and the opening acceleration of moving contactor in time domain.

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Ultimate strength of simply supported plate with opening under uniaxial compression

  • Yu, Chang-Li;Lee, Joo-Sung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.4 no.4
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    • pp.423-436
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    • 2012
  • Unstiffened plates are integral part of all kinds of structures such as ship and offshore oil platforms. Openings are unavoidable and absolutely reduce the ultimate strength of structures. In this study, the finite element analysis package, ABAQUS, is used to analyze the behavior of unstiffened plate with rectangular opening. The rectangular opening form is divided into two cases. In case1, opening depth is constant, but opening width is varied. Meanwhile, in case2 opening width is fixed and opening depth is varied. Besides, for the two different form opening, the effect of plate slenderness parameter (${\beta}$), opening area ratio (AR) and opening position ratio (PR) on the ultimate strength of plate with opening under axial compression are presented. It has been found that the ultimate strength of plate ofcase1is much more sensitive to the plate slenderness parameter (${\beta}$) and opening area ratio (AR) than that of case2. However, for case1, opening position (PR) almost has no effect on the ultimate strength, whereas, regardingcase2, the influence of opening position (PR) depends on the plate slenderness parameter (${\beta}$). Based on nonlinear regression analysis, three design formulae are not only developed but also approved reasonably for the practical engineering design.

Helium-Air Exchange Flours Through Partitioned Opening and Two-Opening

  • Kang, Tae-il
    • Nuclear Engineering and Technology
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    • v.29 no.3
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    • pp.251-259
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    • 1997
  • This paper describes experimental investigations of helium-air exchange flows through partitioned opening and too-opening. Such exchange flows may occur following rupture accident of stand pipe in high temperature engineering test reactor. A test vessel with the too types of small opening on top of test cylinder is used for experiments. An estimation method of mass increment is developed to measure the exchange now rate. Upward flow of the helium and downward flow of the air in partitioned opening system interact out of entrance and exit of the opening. Therefore, an experiment with too-opening system is made to investigate effect of the fluids interaction of partitioned opening system. As a result of comparison of the exchange flow rates between too types of the opening system, it is demonstrated that the exchange flow rate of the two-opening system is larger than that of the partitioned opening system because of absence of the effect of fluids interaction.

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A STUDY ON THE RELATIONSHIPS BETWEEN MAXIMUM OPENING AND MAXIMUM CAPACITY OPENING DISTANCE (최대개구와 최대용양개구에 관한 연구)

  • Chin, Yong-Whan;Lee, Cheol-Hoon;Kim, Yung-Soo;Koo, Ok-Kyung
    • The Journal of the Korean dental association
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    • v.10 no.2
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    • pp.109-113
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    • 1972
  • The measuring tests on the maximum opening distance and the maximum capacity opening distance were conducted on the one hundred normal dental college students and staffs o Seoul National University in order to study the relationships between the maximum opening distance and maximum capacity opening distance. The results were as follows: 1. The maximum opening distance and maximum capacity opening distance were not coincided. 2. The distance of the maximum opening was higher than that of the maximum capacity opening. 3. Physiologic reflex was caused by the water injected into the mouth. 4. The correlation between the maximum opening distance, and maximum capacity opening distance was hardly recognized. 5. Each correlation of the weight height and cheek thickness to maximum opening distance and maximum capacity opening distance was not recognized.

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Finite Element Analysis for the Prediction of Fatigue Crack Opening Behavior Using Cyclic Crack Tip Opening Displacement (되풀이 균열 선단 열림 변위를 이용한 피로 균열 열림 거동 예측을 위한 유한 요소 해석)

  • Choi, Hyeon-Chang
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.11
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    • pp.1455-1460
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    • 2006
  • The relationship between fatigue crack growth behavior and cyclic crack tip opening displacement is studied. An elastic-plastic finite element analysis (FEA) is performed to examine the growth behavior of fatigue crack, where the contact elements are used in the mesh of the crack tip area. We investigate the relationship between the reversed plastic zone size and the changes of the cyclic crack tip opening displacement along the crack growth. We investigate the effect of the element size when predict fatigue crack opening behavior using the cyclic crack tip opening displacement obtained from FEA. The cyclic crack tip opening displacement is related to fatigue crack opening behavior.

An Experimental Study on the Engineering Characteristics of Perforated Reinforced Concrete Beams containing Shells (패각을 사용한 철근콘크리트 유공보의 공학적 특성에 관한 연구)

  • Koo, Hae-Shik
    • KIEAE Journal
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    • v.15 no.1
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    • pp.139-146
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    • 2015
  • This is an experimental study on the engineering characteristics of perforated reinforced concrete beams with shells. In the material matter of this study, the water cement ratio put 60%, the ratio of substitution of oyster shells to fine aggregate 30%. And in the structural matter, the form of opening put circle and square, the size of opening as the radius and the length of it changed from one to three times of the beam depth with a change presence and absence of reinforced steel around opening. All thirteen reinforced concrete beam tests composed one standard beam and twelve six beams with the circle and square opening were tested in shear strength under two points loading and compared and analyzed the characteristics of test beams under the same conditions one another. The results of the study showed as followed. 1) The initial crack load value of the opening test beams is similar the standard beam but the maximum load value decreased with increase in proportion of the opening size, in the square opening than the circle opening and in the absence than the presence of reinforced steel. 2) As the difference between the circle opening and the square opening beams is represented 2.17~9.8% in the maximum load value and the load capacity of the square opening suddenly decrease than it of the circle opening, it is judged because of the shortage of concrete section, the concentration of the stress in the corner of the square opening and material influence of shell substitution. 3) The failure figure such as the pattern of the crack and so on is represented brittle failure as the opening size is the bigger and the ratio of substitution is higher because of the lack material properties.

Hysteretic Behavior of Composite Beam with Web Opening (웨브 개구부를 가진 합성보의 이력거동)

  • 박노웅
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.173-179
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    • 1998
  • This research investigates the hysteretic behavior of composite beams with web opening near the beam end. The objective of this research is to intend a ductile failure around the web opening subjected to cyclic loading prior to the potential brittle failure at the beam-to-colum connection. Experimental tests of two specimens having different location of opening were conducted resulting in better performance of strength and ductility at the specimen of middle opening compared with that of upper opening. Also, comparisons of experimental and theoretical results were carried out.

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Helium-Air Exchange Flow Through Openings with Vertical Partitions (수직평판을 삽입한 개구부의 헬륨 및 공기 치환류)

  • 강태일
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.3
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    • pp.79-87
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    • 2000
  • This paper describes experimental investigations of helium-air exchange flow through openings with vertical partitions. Such exchange flows may occur following rupture accident of stand pipe in high temperature gas cooled reactor. Exchange flow rates are investigated experimentally by using partitioned opening and opening with extended partition to assess fluids interference of the exchange flow at the stand pipe rupture accident. A tests vessel with the two types of opening on top of test cylinder is used in the experiments. An estimation method of mass increment is developed and applied to measure the exchange flow rate. A technique of flow visualization by Mach-Zehnder interferometer is provided to recognize the exchange flows. Amplitude and progress of interference fringes of the flows are observed and used as a support in comparison with the exchange flow rates. Flow passages of upward flow of the helium and downward flow of the air for both two types of the opening are separated by inserted partition within the opening, but in the case of partitioned opening, unseparated flow is formed at the opening entrance and the two flows interface. The exchange flow rate for the partitioned opening is not greater than that of the opening with extended partition because of the fluids interference at the entrance of opening. Finally, the fluids interference at the opening entrance is found to be one of important factors on the helium-air exchange flow rate.

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A Study on Sewing Methods of the Joseon Period -Focusing on Reinforcing the Opening of Clothes- (조선시대 복식에 나타난 바느질기법에 대한 연구 I - 트임 보강을 중심으로 -)

  • Ku, Nam-Ok
    • Journal of the Korean Society of Costume
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    • v.58 no.8
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    • pp.120-136
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    • 2008
  • This study examined sewing methods used to reinforce the opening of clothes of the Joseon period. Through the analysis of a total of 117 clothing items of the Joseon period, the following results were obtained. 1. Most costumes of the Joseon period had the opening. The purpose of the opening was to allow one to put on and take off a costume, act comfortably, and turn a costume Inside out. The opening was located on the Side, Conte. Back, fgwi(Side opening of pants), Wristband, Armhole, and Godae(the bark part of the collar). 2. As the opening tended to get easily worn out, it was often reinforced. The 1911owing three methods were used to reinforce the opening of clothing items of the Joseon period: a method to attach a cloth such as Dang, Binding, and Badae; a method using a variety of knots; and a method by sewing stitches such as a sort of cross stitch called Satteugi, Prick stitch, and Loop. 3. The most frequently used reinforcing method was the one that used a knot(34 items), followed by the one by sewing Satteugi(27 items), and the one using Dang(25items). The most frequently detected location of the opening was Side(59 items), followed by Agui(37 items), Wristband(19 items), and Center Back(13 items). 4. The reinforced opening made a costume more endurable and elastic, decorative and neat.