• Title/Summary/Keyword: Handle

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Study on Vibration Characteristic Improvement of Aircraft Landing Gear Handle (항공기용 착륙장치 핸들의 진동 특성 개선에 관한 연구)

  • Kang, Gu Heon;Ahn, Jong Moo
    • Journal of Aerospace System Engineering
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    • v.12 no.2
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    • pp.59-65
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    • 2018
  • The landing gear (L/G) handle of an aircraft is an essential piece of equipment for aircraft take-off and landing. The bracket in the landing gear handle was fractured during a vibration test when developing the landing gear handle. This paper summarizes the vibration test procedures performed during landing gear handle development. A cause analysis, design improvements, and verification results of the fault in the vibration test are also provided.

Equation for handle assessment of cotton and polyester fabrics using nozzle extraction testing method (노즐시험법을 이용한 면/폴리에스터 직물의 촉감 방정식)

  • Yoon, Chang-Hyun;Chun, Dae-Yeop;Hong, Cheol-Jae
    • Science of Emotion and Sensibility
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    • v.14 no.2
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    • pp.191-196
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    • 2011
  • Fabric extraction force measured through nozzle tester reflects a comprehensive fabric handle. Nozzle tester takes advantage of low cost, and simple and fast operating procedure compared with KES system. The paper is to develop the semi-emprical equation for assessment of the fabric handle measured with nozzle tester on the basis of friction law. The variables considered in the equation arc fabric's frictional coefficient and drape coefficient which is determined in terms of fabric bending length and shear strain. The experiment of 12 different cotton and polyester fabrics and comparisons between experimental and theoretical results were conducted. Fabrics of high frictional coefficients, high bending length, and low shear strain showed high fabric handle forces (low handle values). The handle forces predicted from the equation agreed well with those measured, which indicates that the equation can be used to objectively evaluate fabric handle with respect to fabric's own properties and also provide an information for fabric design to improve the handle performance.

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Vibration Reduction of Walking-type Cultivator's Handle using Modal Analysis and Operational Deflection Shapes Techniques (모드 해석과 운전 중 변형 형상 기법을 이용한 보행형 관리기의 핸들 진동 감소 방안)

  • 박영준;이윤세;김경욱
    • Journal of Biosystems Engineering
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    • v.29 no.2
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    • pp.101-108
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    • 2004
  • The objectives of this study were to determine the natural frequency of a walking-type cultivator's handle using a modal analysis, to determine whether or not the handle resonates with forcing frequency induced by its engine, and to determine a method to reduce the handle vibration using a technique of the operational deflection shapes(ODS). Results of the study are as follows: The natural frequencies of the handle up to third harmonics were found to be 20.4, 22.5 and 92.1 Hz in the vertical direction and 14.9, 93, and 132 Hz in the horizontal direction. It was found that the handle does not resonate with the forcing frequency of the engine, which is 52 Hz. The operational deflection shape analysis revealed the deflected shapes of the handle in the vertical and horizontal directions and suggested that the handle vibration can be reduced by adding some mass to the place where the largest deflection occurs. Attaching of 1.1 kg mass adjacent to the largely deflected area resulted in reductions of vibration from 9.45 to 8.03 m/s$^2$ in x-axis direction from 3.89 to 3.16 m/s$^2$ in y-axis direction and from 7.89 to 3.09 m/s$^2$ in z-axis direction, which are respectively 15, 19 and 61% reductions. The total vibration level was reduced by 29%, indicating that mass-adding method by the ODS is very effective for reducing the handle vibrations of the cultivators.

Optimization of Handle Vibration of Walking-type Cultivator (보행형 관리기 핸들의 진동 최적화)

  • Park S.B.;Park Y.J.;Kim K.U.
    • Journal of Biosystems Engineering
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    • v.31 no.3 s.116
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    • pp.139-145
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    • 2006
  • A previous study showed that the handle vibration of a walking type cultivator can be reduced by adding a mass to the handle. This study was conducted to determine the optimum magnitude and location of the mass to be added for the same cultivator. The possible locations of added mass were determined by investigating nodal points of the handle vibration by an ODS (operational deflection shapes) test at an engine frequency of 52 Hz. The optimum location was then determined as one that moved the nodal points to the hand grip of the handle bar. To determine the optimum magnitude of the mass, the possible locations were added by a mass from 0.2 to 2.0 kg in an increment of 0.2 kg. The optimum magnitude was then determined as a mass which minimized the vibration level at the hand grip. For the case of this study, the z-axis vibration at the hand grip was reduced from $2.67m/s^2\;to\;0.88m/s^2$ resulting in a reduction of 67% and the total vibration from $4.09m/s^2\;to\;3.27m/s^2$ resulting in a 20% reduction by adding an optimum mass to the optimum location.

History of Morse theory (Morse 이론의 역사)

  • Park, Ki-Sung
    • Journal for History of Mathematics
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    • v.19 no.4
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    • pp.107-116
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    • 2006
  • This article reviews the exciting developments in Morse theory by S.Smale, Freedmann and others, including a proof of the generalized Poincare' Conjecture in the handle body theory. We study its relations with handle body theory _and geodesic theory.

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The Analysis of the Effect of the Vibration-proof Handle Used for the Reduction of Hand-transmitted Vibration (수전달 진동 저감을 위한 방진 핸들의 효과 분석)

  • Choi, Seok-Hyun;Jang, Han-Kee;Park, Tae-Won
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.146-149
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    • 2005
  • Thesedays, the reduction of hand-transmitted vibration of hand-held power tools is important issue for operators' welfare, In the study, frequency response function is measured and vibration total value is evaluated for solving the principle and effect of the BOSCH's vibration-proof handle. This handle functions as a dynamic damper and has the effect, 22% vibration total value reduction under idling condition using a system that consists of a PC with data acquisition system and LabVIEW program. The program in the system makes it possible to evaluate vibration total value according to ISO 5349. This handle offers a good example for figuring out the physical contradiction between the work efficiency and operators' health.

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A Study on the Structural Analysis for Plastic Door Handle of Automobile (플라스틱 자동차 손잡이 구조물의 구조해석에 관한 연구)

  • Park, S.R.;Shim, D.C.;Kim, D.;Lyu, M.Y.
    • Transactions of Materials Processing
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    • v.19 no.3
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    • pp.185-190
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    • 2010
  • Application of CAE analyses are wide spread in shaping processes and structural safety verification of plastic products. The importance of CAE analysis and its contributions are getting increase since the processibility and structural safety of product can be predicted. CAE analysis for complex shaped product need a lot of time for modeling and computation compare with simpler one. Therefore careful simulation modeling is required for complex shaped product. Structural analysis for plastic door handle of automobile has been performed and structural safety has been investigated for various load directions and modeling cases. Large stress occurred at the hinge in handle regardless of load direction and modeling case. Consequently hinge is considered structurally very weak among the parts in plastic door handle. It is concluded that simple modeling rather than total modeling with adequate boundary condition equivalent to real situation gives reasonable computational results with saving modeling effort and computation time.

Sensibility Analysis on Jacket Styles with the Handle and Sensibility of Wool Fabrics (양모의 태에 따른 최적 재킷스타일과 감성)

  • 정상무;나영주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.1
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    • pp.67-77
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    • 2003
  • Subjective sensorial experiment was executed with 43 subjects to find the relationships between the sensibility of jacket styles and the handle of wool fabrics. The handle and sensibility of wool fabrics were significantly different according to the wool types, and the handle was defined as two axis of Wild/Exquisite vs. Thin/Thick. The sensibility of jacket styles was different by the types of jacket styles, and the jackets were displayed in the 2D of Masculine/Feminine vs. Country/urban according to the factor analysis using 8 sensibility words. The best-appropriate jacket styles for each wool fabrics were converged into several jacket styles, and it was found that the wool fabrics were divided as for all-purpose or for specific-end usage. For the results of correspondence analysis of the matrix for the best-appropriate jacket style for each wool fabric, the jacket styles and wool fabrics together were grouped as 4: Striking and Yang, Striking and Yin, Plain and Yang, Plain and Yin.

Handle analysis of Cosmetic Textiles and its Correlation with Subjective haracteristics -Focus on puff textile-

  • Jung, Cheul Sun;Koo, Young Seok
    • Fashion & Textile Research Journal
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    • v.16 no.2
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    • pp.312-318
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    • 2014
  • This study examined the correlation between a handle evaluation of cosmetic puff textile and a sensory evaluation. The KES-F system was used to analyze the main mechanical factors for the handle evaluation and a statistical method was used for the sensory evaluation. The results revealed different mechanical properties and handle values of the tested cosmetic puff textiles. A material type and structure of the cosmetic textile affected the handle property of the material which is the most important factor for a cosmetic purpose. Particularly, the physical properties of textile material are likely to be important factors for the sensory property of cosmetic material. In addition, the sensory evaluation also revealed different sensory characteristics of the cosmetic efficiency according to the cosmetic puff textile. No close relationship was observed between the mechanical properties and sensory evaluation on the cosmetic puff textiles. The sensory evaluation of a cosmetic efficiency is not only decided by the physical and mechanical characteristics of the cosmetic textile material. Overall, when using textiles used for the cosmetic purposes, it is important to consider not only the proper mechanical properties of the textiles but also the use and sensory satisfaction. Development and selection of the cosmetic textiles should be focused on both the material function and consumer satisfaction.

A study on coupling effect during lifting (들기 작업시 손잡이의 영향에 관한 연구)

  • 장성록;배동철
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.119-124
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    • 2003
  • Despite rapid technological advance and increased automation facilities, many jobs and activities in our living require manual materials handling(MMH). These include wide variety of activities such as moving things, lifting bags. boxes or cartons, etc. Many studies found that handle could affect on maximum acceptable weight of lifting, but there were few studies f3r the effects of work posture and coupling in lifting tote box. This study performed that ten male college students were required to lift a tote box with and without handle for three postures (bending, straight, right angle posture). From the experiment, following results were obtained. (1) MVC reduced maximum 23% by type of handle. (2) MVC was highest in straight posture, but was lowest in right angle posture. (3) As a result of ANOVA, MVC paid attention to posture and coupling. (p<0.01) (4) To all handle types, biceps brachii activity was increased in right angle posture. but reduced in straight posture. (5) To all posture, biceps brachii activity was most lively in no handle. The results of MVC measurement, subjective rating, EMG analysis, statistic analysis showed that maximum acceptable weight of lifting was influenced by type of handle and straight posture was more comfortable than other postures. Based on these results, it was concluded that acceptable weight of lifting has to differ for work posture and coupling.