• Title/Summary/Keyword: Fitting Characteristics

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Analysis of Hydrogen-tightness on the Metal Sealing of a Fuel Pipe for FCEV according to Material Change of the Fitting Body (체결부 재료에 따른 FCEV 연료파이프 메탈 씰링부의 기밀성 분석)

  • Lee, J.M.;Han, E.S.;Chon, M.S.;Lee, H.W.
    • Transactions of Materials Processing
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    • v.28 no.5
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    • pp.266-274
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    • 2019
  • Metal sealing is used to connecting the parts between valves and fuel pipes for a FCEV which utilizes hydrogen gas of 700 bar. Instead of general carbon steel, stainless steel is the primary material used to manufacture fuel pipes due to hydrogen embrittlement. The shape of deformation between metals is an important factor on the air-tightness of the metal to metal contact. Since the stainless steel pipe is hardened using the plastic forming during the tip shaping stage, this work hardening could have an effect on the deformed shape and characteristics of contact surfaces in fastening of pipes. In this paper, the deformation history of the pipe model was considered in order to analyze the hydrogen-tightness on the metal sealing part. The contact distance and the forward displacement for fastening were compared using experimental results and the simulation results. The simulation of the effect of material change on the fitting body demonstrated that the hardness or the strength of the formed tip of the pipe was designed to a proper valued level since the characteristics of the contact surface was exhibited better when the strength of the pipe was lower than that of the fitting body.

An Accurate Model of Multi-Type Overcurrent Protective Devices Using Eigensystem Realization Algorithm and Practice Applications

  • Cheng, Chao-Yuan;Wu, Feng-Jih
    • Journal of Electrical Engineering and Technology
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    • v.11 no.1
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    • pp.9-19
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    • 2016
  • Accurate models of the characteristics of typical inverse-time overcurrent (OC) protective devices play an important role in the protective coordination schemes. This paper presents a novel approach to determine the OC protective device parameters. The approach is based on the Eigensystem Realization Algorithm which generates a state space model to fit the characteristics of OC protective devices. Instead of the conventional characteristic curves, the dynamic state space model gives a more exact fit of the OC protective device characteristics. This paper demonstrates the feasibility of decomposing the characteristic curve into smooth components and oscillation components. 19 characteristic curves from 13 typical and 6 non-typical OC protective devices are chosen for curve-fitting. The numbers of fitting components required are determined by the maximum absolute values of errors for the fitted equation. All fitted equations are replaced by a versatile equation for the characteristics of OC protective devices which represents the characteristic model of a novel flexible OC relay, which in turn may be applied to improve the OC coordination problems in the sub-transmission and distribution systems.

Analysis of Corneal Topography in Keratoconus (원추각막의 각막지형도 분석)

  • Kim, Douk-Hoon
    • Journal of Korean Clinical Health Science
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    • v.4 no.3
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    • pp.652-661
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    • 2016
  • The analysis of cornea morphology using corneal topographers is a clinical practice for the diagnosis of keratoconus in contact lens fitting. The recently technique has developed with the possibility of achieving a great number of measuring points of both anterior and posterior corneal surfaces in cornea. Also these data are used to extract a series of topographic valuation indices that permit to offer the most exact clinical diagnosis of keratoconus in contact lens fitting. This study describes the technologies in which current corneal topographers are based on the morphological characteristics that the keratoconus status observe on corneal surface. Therefore, this paper can provide that the analysis of corneal topographers applied for the diagnosis of keratoconus in contact lens fitting.

A Study on Aesthetic Characteristics of Drapery Costume (드레이퍼리 의상의 미적 특성)

  • Ahn, Sun-Hee;Lee, Myoung-Hee
    • The Research Journal of the Costume Culture
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    • v.17 no.3
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    • pp.396-406
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    • 2009
  • Drapery costume started with using one fabric to loosely wrap around one's body without using technical skills or needlework. Drapery becomes a beautiful and indeterminate form of pleated costume which determines the costume silhouette and serves as an essential component for the composition of artistic costume. The purpose of this study was to examine the aesthetic characteristics of drapery costume using literature review. The study methods include considerations of the formation process of drapery costume with the analysis of costume in pictures. For modern costume designs, the study analyzed the designer's dress with a focus on drapery forms, which appeared in the collections from 2001 to 2007. First, drapery costume contains the beauty of human body. Drapery costume reveals the smallest movement of the body. The beauty of drapes, which is naturally revealed along the curve of the body, and the pleats which form on the soft cloth create the beauty of body. Second, drapery costume has rhythmical beauty. Drapery pleats feature not only functions, but also unique formativeness that provides rhythmicity and regular or irregular direction effects by line. Third, drapery costume features elegant beauty. Bias cutting by draping can effectively express the elegant characteristics of the fabric. In making a piece of clothing, the composition method can express elegant beauty by covering up the shortcomings of the fitting and by fitting to the body line without cutting the fabric, or fitting it by bias cutting.

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The Research of the Insole Suitability in Accordance with Foot Characteristics of Women (성인 여성의 발 특성에 따른 인솔 적합성 연구)

  • Choi Soon-Bok;Lee Won-Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.6
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    • pp.783-792
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    • 2005
  • The purpose of this research is to develop appropriate Insole according to foot characteristics of female adults. This research concentrates on proving the effectiveness of Insole on resolving foot discomforts by analyzing the differences between the fitting and foot pressure before and after wearing Insole. Among 216 female testers of previous research, six testers wear selected and placed into six different groups classified according to foot discomforts and foot characteristics. After wearing Insole, the results indicates that the entire groups represented the improvement of fitting and the mitigation of foot discomfort. The results of foot pressure experiment shows that the maximum pressure of foot spreads out evenly after wearing Insole, which indicates the effectiveness of Insole. This efficacy works particularly well for foot testers of second and sixth group. The results indicate that group 6, which consist of the flat-footed and the old, have more noticeable effects derived from Insole, whereas group 3 and 5 do not, due to its constitution of people with fairly normal feet. Furthermore, it was evident that maximum pressure played a major role in proving the beneficial effects of Insole, one of which is to scatter the maximum pressure of heel away and lessen the foot pressure of plantar.

Assessment of the effect of fines content on frost susceptibility via simple frost heave testing and SP determination

  • Jin, Hyunwoo;Ryu, Byung Hyun;Lee, Jangguen
    • Geomechanics and Engineering
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    • v.30 no.4
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    • pp.393-399
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    • 2022
  • The Segregation Potential (SP) is one of the most widely used predictors of frost heave in cold regions. Laboratory step-freezing tests determining a representative SP at the onset of the formation of the last ice lens (near the thermal steady state condition) can predict susceptibility to frost heave. Previous work has proposed empirical semi-log fitting for determination of the representative SP and applied it to several fine-grained soils, but considering only frost-susceptible soils. The presence of fines in coarse-grained soil affects frost susceptibility. Therefore, it is required to evaluate the applicability of the empirical semi-log fitting for both frost-susceptible and non-frost-susceptible soils with fines content. This paper reports laboratory frost heave tests for fines contents of 5%-70%. The frost susceptibility of soil mixtures composed of sand and silt was classified by the representative SP, and the suitability of the empirical semi-log fitting method was assessed. Combining semi-log fitting with simple laboratory frost heave testing using a temperature-controllable cell is shown to be suitable for both frost-susceptible and non-frost-susceptible soils. In addition, initially non-frost-susceptible soil became frost susceptible at a 10%-20% weight fraction of fines. This threshold fines content matched well with transitions in the engineering characteristics of both the unfrozen and frozen soil mixtures.

The Influence of Fitting Parameters on the Soil-Water Characteristics Curve in Stability Analysis of an Unsaturated Natural Slope (불포화 자연사면의 안정해석시 흙-함수특성곡선 맞춤계수의 영향)

  • Kim, Jae-Hong;Yoo, Yong-Jae;Song, Young-Suk
    • The Journal of Engineering Geology
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    • v.31 no.2
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    • pp.165-178
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    • 2021
  • The influence of Soil-Water Characteristic Curve (SWCC) fitting parameters for an unsaturated natural slope was evaluated through seepage and slope stability analysis as a function of rainfall. Soil samples were collected from the study area in Jirisan National Park and the physical and mechanical characteristics of unsaturated soil layers were measured in laboratory tests. The saturation depth was calculated via seepage analysis by changing fitting parameters α, the parameter related to the Air Entry Value (AEV) and n, the parameter related to the slope of the SWCC in the range of natural conditions. Slope stability analysis using the limit equilibrium method considered the calculated depth of saturation. Results from seepage analysis for various rainfall conditions indicate the saturation depth in the soil layer suddenly increased as the fitting parameter α decreased; the saturation time for the entire soil layer also decreased. Slope stability analysis considering the calculated depth of saturation shows that the slope safety factor rapidly decreased as the fitting parameter α decreased, whereas the variation in slope safety factor was very small when n increased. Hence, fitting parameter α has a large effect on saturation depth during rainfall and therefore on slope stability, whereas slope stability is relatively unaffected by the fitting parameter n.

A Study on the Rehabilitation Exercise by Bike Pain and Injury and Fitting

  • Gyoung-Hoan Shon
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.5
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    • pp.83-93
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    • 2023
  • The purpose of this study is to improve pain and injury through bicycle fitting and to propose rehabilitation methods. Pain and injuries caused by bicycles can be largely divided into knee and ankle pain, wrist, shoulder, neck, and back pain, and hip pain. The cause of these pains and injuries stems from incorrect bicycle fitting and posture. In order to improve these pain and injuries and prevent recurrence, appropriate bicycle fitting and rehabilitation exercise are needed. Pain and injury are divided into kinetic pain and pain by a fixed posture. In the case of kinetic pain, rehabilitation exercise is required along with inflammatory treatment, and pain by a fixed posture should understand the exact characteristics of the body and learn and practice bicycle posture according to the body's characteristics. Through this method, it can contribute to preventing the recurrence of bicycle pain and injuries and further creating an environment where a safe bicycle culture can be established.

Implementation of Fitting Software for Fully Implantable Middle Ear Hearing Device (완전 이식형 인공중이용 적합 소프트웨어의 구현)

  • Lee, J.W.;Jung, E.S.;Lim, H.K.;Lee, J.H.;Seong, K.W.;Kim, M.N.;Cho, J.H.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.3 no.1
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    • pp.21-25
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    • 2009
  • Generally, fully implantable middle ear hearing device (F-IMEHD) is implanted under the skin nearby human temporal bone with all components including implantable microphone and vibration transducer. The microphone and transducer have different characteristic before and after implant. Fitting process is performed for this characteristic change of them and proper performance of hearing aids for each patient. Conventional hearing aids and partially implantable hearing aids, they have wired connector for fitting process. However in case of F-IMEHD, it is difficult this wired connection, because all components of F-IMEHD is implanted. In this paper, fitting software that can be apply wireless fitting hardware for F-IMEHD has been designed and implemented. It can find out proper fitting parameter reflecting characteristics of the microphone and transducer for patients who has difficulty in hearing.

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A Study on the Adjustment Method of Bicycle Shoe Cleat for Bicycle Fitting System

  • Shon, Gyoung-Hoan
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.5
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    • pp.93-102
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    • 2019
  • The nation's fraternity and elite players who have built up a global bicycle infrastructure often find it to be a problem with the bicycle's speed and speed reduction, pain in knees and hip joints, or even with the bike itself, or with the bike's own physical defects or a riding posture. However, we found that most cases of cleat adjustment errors were likely to be true. Accurate adjustment of the cleats is the most important of the entire fitting process and can be the basis for improving the ability of the bicycle rider and preventing injury. Therefore, the study was intended to give a prior study of bicycle fitting, which can improve bicycle efficiency and prevent injury when riding bicycle, and specific ways of adjusting bicycle shoe cleats, and the following results were obtained. First, the cleat characteristics of Shimano, LOOK and Speedplay, which are currently used in public, and the characteristics during the cleat adjustment process, were derived. In addition, the structure and characteristics of dedicated shoes using cleats and the method of using pedalling by the structure of shoes after adjusting the cleats were derived. Second, the position of the shoe and its relationship with torque in pedalling was discussed, and the method of adjusting front and back of cleats was derived. Third, leg length, ASIS, Q-Angle and Q-factor etc. were analyzed and the method of setting and adjusting cleat left and right values were derived. Fourth, the relationship between walking angle and cleat rotation was analyzed, the method was derived, and the torque size and angle behind the cleat adjustment were compared and analyzed using the spinner to indicate the torque and the effective mean torque angle after the cleat adjustment.