• 제목/요약/키워드: Elastic Factor

검색결과 827건 처리시간 0.032초

40대 여성 골퍼를 위한 슬랙스 패턴 설계에 관한 연구 (A Study on the Golf Slacks Pattern for Women in 40's)

  • 이효정;류신아;박길순
    • 한국의류산업학회지
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    • 제13권1호
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    • pp.116-129
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    • 2011
  • The purpose of this study is to research on changes of body surface according to golf movements in designs of golf slacks pattern and reflect it to designs of golf slacks pattern to enhance adaptability. For the first stage of this study, length of body surface was analyzed by using 3D body shape. In second stage, analysis of wearing test of golf slacks is performed to extract major pattern design factor of golf slacks and then research patterns were designed. In third stage, 4 differently designed 1st, 2nd slacks were used for analysis of 3D Clothing air volume. The results of this research is as follow. The variation rate of body surface length according to golf swing posture resulted the longest on back swing posture and follow through posture. Waist circumference-omphalion, thigh and ankle circumference increased more than 10% of body surface during golf swing. Front waist circumference-omphalion, right waist to hip length, left waist to hip length and right back center length were decreased more than 10%. As a result of analysis on measurements of 1st slacks pattern design, waist front center getting in values, waist front center going down value, front hip width, and front crotch extension had similar industrial pattern design. Back center line angle, back crotch extension, and knee center point~back waist center point had significant differences. The designs and ease proposed for golf slacks pattern in this study are waist circumference 75.5 cm(1.8 cm, 2.38%), hip circumference 95 cm(2 cm, 2.11%), crotch length(front: -0.8 cm, -1.25%; rear: -1.8 cm, -2.83%), slacks length 96c m, gradient of C.B.L $10^{\circ}$, crotch extension (back 9.2~10.4 cm, front 3.2 cm).

MW급 대용량 유도전동기 축계의 모드실험 기반 회전체 동역학 해석모델 수립 및 위험속도 예측 (Rotordynamic Model Development and Critical Speed Estimation Through Modal Testing for the Rotor-Bearing System of a MW Class Large-Capacity Induction Motor)

  • 박지수;최재학;김동준;심규호
    • Tribology and Lubricants
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    • 제36권5호
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    • pp.279-289
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    • 2020
  • In this paper, a method is proposed for establishing an approximate prediction model of rotor-dynamics through modal testing. In particular, the proposed method is applicable to systems that cannot be established according to conventional methods owing to the absence of information regarding the dimensions and material of the rotor-bearing system. The proposed method is demonstrated by employing a motor dynamometer driven by a 1 MW class induction motor without dimension and material information. The proposed method comprises a total of seven steps, wherein an initial model is established by incorporating approximate dimensions and material information, and the model is improved on the basis of the natural frequency characteristics of the system. During model improvement, the modification factor is introduced for adjusting the elastic modulus and shear modulus of the system. Analysis of critical speed and imbalance response indicates that the separation margin is 67% and the maximum vibration amplitude is less than the amplitude limit of 0.032 mm under the API 611 standard, which means that the motor dynamometer can stably operate at a rated speed of 1800 rpm. Hence, the obtained results validate the feasibility of the proposed method. Furthermore, for broad usage, it is necessary to accordingly apply and validate the proposed method for various rotor-bearing systems.

Dynamics of a Globular Protein and Its Hydration Water Studied by Neutron Scattering and MD Simulations

  • Kim, Chan-Soo;Chu, Xiang-Qiang;Lagi, Marco;Chen, Sow-Hsin;Lee, Kwang-Ryeol
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.21-21
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    • 2011
  • A series of Quasi-Elastic Neutron Scattering (QENS) experiments helps us to understand the single-particle (hydrogen atom) dynamics of a globular protein and its hydration water and strong coupling between them. We also performed Molecular Dynamics (MD) simulations on a realistic model of the hydrated hen-egg Lysozyme powder having two proteins in the periodic box. We found the existence of a Fragile-to-Strong dynamic Crossover (FSC) phenomenon in hydration water around a protein occurring at TL=$225{\pm}5K$ by analyzing Intermediate Scattering Function (ISF). On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the High Density Liquid (HDL) form, a more fluid state, to predominantly the Low Density Liquid (LDL) form, a less fluid state, derived from the existence of a liquid?liquid critical point at an elevated pressure. We showed experimentally and confirmed theoretically that this sudden switch in the mobility of the hydration water around a protein triggers the dynamic transition (so-called glass transition) of the protein, at a temperature TD=220 K. Mean Square Displacement (MSD) is the important factor to show that the FSC is the key to the strong coupling between a protein and its hydration water by suggesting TL${\fallingdotseq}$TD. MD simulations with TIP4P force field for water were performed to understand hydration level dependency of the FSC temperature. We added water molecules to increase hydration level of the protein hydration water, from 0.30, 0.45, 0.60 and 1.00 (1.00 is the bulk water). These confirm the existence of the FSC and the hydration level dependence of the FSC temperature: FSC temperature is decreased upon increasing hydration level. We compared the hydration water around Lysozyme, B-DNA and RNA. Similarity among those suggests that the FSC and this coupling be universal for globular proteins, biopolymers.

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탄성파를 적용한 다중 위상 MR Elastography로부터의 점탄성 정수의 측정 (Measurement of Viscoelastic Constants from Multiple Phase MR Elastography Fitting Elastic Wave)

  • 정남채
    • 융합신호처리학회논문지
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    • 제13권3호
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    • pp.119-129
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    • 2012
  • 의료분야에서 조직의 경화는 진단 또는 질환의 진행상황의 파악에 이용되는 중요한 정보의 한 가지이며, 객관적인 진단을 위해서는 경화의 정량적 계측법이 중요하다. 경화의 지표인 점탄성 정수를 비침습적으로 계측하는 방법으로 MRE(Magnetic Resonance Elastography) 법이 제안되고 있다. MRE 법에서는 전파파(propagating wave)의 국소 파장과 국소 감쇠율로부터 점탄성 정수를 구하는데 MRE 화상은 S/N 비가 낮아지므로, 잡음의 영향을 감소시키기 위하여 다중 위상 MRE 화상을 이용한 방법이 검토되고 있다. 본 연구에서는 다중 위상 MRE 화상에 함수를 적용하여 점탄성 정수를 측정하는 방법을 제안한다. 제안 방법은 다중 위상 MRE 화상에 점탄성파를 적용시키지만, 점탄성 정수의 공간방향으로의 변화율이나 화상에 포함된 잡음에 따라 측정값의 공간분해능을 임의적으로 설정할 수 있다는 장점이 있다. 시뮬레이션 화상을 이용한 실험과 silicone-gel phantom을 이용한 실험에 의하여 제안된 방법의 유효성을 확인하였다.

모사 열차하중 재하에 따른 쇄석강화노반의 침하특성 (Settlement Characteristics of the Reinforced Railroad Roadbed with Crushed Stones Under a Simulated Train Loading)

  • Hwang, Seon-Keun
    • 한국지반공학회논문집
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    • 제20권2호
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    • pp.5-13
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    • 2004
  • 기존의 흙을 사용하여 건설된 철도 노반은 반복적인 교통하중의 증가, 열차속도의 향상, 노반상으로의 지하수의 유입, 노반의 배수능력 저하 등의 이유로 인해 시간경과에 따라 쉽게 그 기능을 상실할 수 있다. 본 연구에서는 실대형시험과 수치해석을 수행함으로씨 철도노반으로서의 쇄석강화노반의 성능을 평가하였다. 쇄석강화노반의 탄$.$소성 연직변위는 모사열차하중의 재하횟수에 관계없이 일반 흙노반에 비해 작은 응답특성을 보였으며, 동일한 노반 부설두께에서는 노반반력계수의 증가에 따라 감소하며, 동일한 강성인 경우 노반 부설두께 증가에 따라 감소하는 경향을 보였다. 하지만, 쇄석강화노반의 부설두께에 비해 노반의 강성이 궤도에 발생하는 전체 소성 연직변위에 더욱 큰 영향을 미치는 것으로 평가되었다.

Simplified procedure for seismic demands assessment of structures

  • Chikh, Benazouz;Mehani, Youcef;Leblouba, Moussa
    • Structural Engineering and Mechanics
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    • 제59권3호
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    • pp.455-473
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    • 2016
  • Methods for the seismic demands evaluation of structures require iterative procedures. Many studies dealt with the development of different inelastic spectra with the aim to simplify the evaluation of inelastic deformations and performance of structures. Recently, the concept of inelastic spectra has been adopted in the global scheme of the Performance-Based Seismic Design (PBSD) through Capacity-Spectrum Method (CSM). For instance, the Modal Pushover Analysis (MPA) has been proved to provide accurate results for inelastic buildings to a similar degree of accuracy than the Response Spectrum Analysis (RSA) in estimating peak response for elastic buildings. In this paper, a simplified nonlinear procedure for evaluation of the seismic demand of structures is proposed with its applicability to multi-degree-of-freedom (MDOF) systems. The basic concept is to write the equation of motion of (MDOF) system into series of normal modes based on an inelastic modal decomposition in terms of ductility factor. The accuracy of the proposed procedure is verified against the Nonlinear Time History Analysis (NL-THA) results and Uncoupled Modal Response History Analysis (UMRHA) of a 9-story steel building subjected to El-Centro 1940 (N/S) as a first application. The comparison shows that the new theoretical approach is capable to provide accurate peak response with those obtained when using the NL-THA analysis. After that, a simplified nonlinear spectral analysis is proposed and illustrated by examples in order to describe inelastic response spectra and to relate it to the capacity curve (Pushover curve) by a new parameter of control, called normalized yield strength coefficient (${\eta}$). In the second application, the proposed procedure is verified against the NL-THA analysis results of two buildings for 80 selected real ground motions.

각막굴절수술의 역학적 고찰 및 새로운 기법의 시도 (A MECHANICAL INVESTIGATION OF CORNEAL REFRACTIVE SURGERIES AND PROPOSITION OF NEW TECHNIQUES)

  • 신정욱;한근조;황민철;남상희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 춘계학술대회
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    • pp.95-100
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    • 1995
  • This study investigated the effects of mechanical factors involved in several corneal refractive surgeries on the surgical outcomes. Then we proposed possible new techniques from the mechanical point of a view utilizing finite element method. The models studied are: circumferential keratetomy, combination of excimer laser photorefractive keratectomy and circumferential keratotomy for myopia treatment, arcuate keratotomy for astigmatism treatment. The cornea was assumed to be nonlinear elastic and almost incompressible material as the most soft tissue in the human body. In the circumferential keratotomy the effect of the incision location was investigated. The angle and location of the incision were varied to predict the surgical outcomes in the arcuate keratotomy. The finite element analysis results showed that the location of incision was a critical factor affecting the surgical outcomes in the circumferential keratotomy. In the combination of the excimer laser photorefractive keratectomy and circumferential keratotomy, it was predicted that the circumferential can increase or decrease the refractive power depending on the incision location or it can be used to adjust the overcorrection of undercorrection. In the arcuate keratotomy for astigmatism, the most diopter changes were predicted when the location and the angle of the incision were 3.0mm from the apex and $90^{\circ}$, respectively. In the arcuate keratotomy, the effects of an incision were studied within the incision area as well as outside the incision area. Also, the arcuate keratotomy with two incisions located on the opposite area of the cornea was also studied. As a conclusion, the finite element method is a useful technique in the area of corneal refractive surgeries to develop new techinques.

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장방형 띠철근을 이용한 팔각형 플레어 RC 기둥의 내진성능 (Seismic Performance of Octagonal Flared RC Columns using Oblong Hoops)

  • 고성현
    • 한국구조물진단유지관리공학회 논문집
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    • 제19권6호
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    • pp.1-9
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    • 2015
  • 횡방향철근은 기둥의 소성힌지구간에 충분한 구속효과, 축방향철근의 좌굴방지와 연성거동을 확보하기 위해 적용된다. 기둥에서 사각형 후프 띠철근과 보강 띠철근의 조립 및 배근방법은 시공이 까다롭고 많은 횡방향철근량이 요구된다. 본 논문에서, 이러한 문제점들을 해결하기 위하여 장방형 단면과 플레어 기둥의 횡구속을 위한 장방형 후프 띠철근을 사용한 새로운 횡구속 방법이 제안되었다. 개발된 장방형 후프 띠철근 상세는 장방형 단면과 플레어 기둥의 시공성과 경제성을 향상시켜줄 수 있는 하나의 대안으로서 적용 가능한 것으로 판단된다. 본 연구의 최종목적은 철근콘크리트 교각의 시공성 향상을 위한 장방형 후프 띠철근 상세의 제시와 실험적 기초자료의 제공과 함께 하중단계별 성능 및 손상평가를 위한 정량적 수치와 경향을 제공하기 위한 것이며, 극한변위, 극한드리프트비율, 변위연성도, 응답수정계수, 등가점성감쇠비, 잔류변형지수, 유효강성 등의 주요 내진성능평가 변수들에 대한 분석결과를 나타내었다.

The Most Effective Number of Elastic Taping Applications on the Muscle Activity and Maximum Peak of the Wrist Extensor Muscle in Patients with Stroke

  • Cho, Ju Chul;Lee, Byoung Kwon;Chon, Seung Chul
    • 대한인간공학회지
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    • 제33권6호
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    • pp.533-541
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    • 2014
  • Objective: The aim of this study is to evaluate the differences in electromyographic activities of upper extremity muscle between repeated taping and to compare the effects of each taping method in stroke patients. Background: Taping studies for functional improvement and pain relief of the UE have been conducted using various methods. Despite being an important factor when you treatment to a patient in a clinical attachment numbers situation quantitative research is that there is not at all to the taping at the time of application. Method: Twenty patients volunteered in this study and were tested under four taping conditions as follows, in random order: (1) no taping, (2) taping applied once, (3) taping applied twice, and (4) taping applied thrice. The muscle activity and maximum peak of the extensor carpi radialis muscle in electromyographic activities were measured, respectively. Results: The muscle activity and maximum peak of the extensor carpi radialis muscle showed significant differences among the four conditions (p<.05). In the post hoc test, the extensor muscle showed significant differences in muscle activity and maximum peak in electromyographic activities, except between taping applied twice and thrice. Conclusion: These findings demonstrate that repeated taping up to two times may be useful in improving the muscle activity and maximum peak of the extensor muscle. Application: This study provides useful information to future researchers regarding the effects of repeated taping applications on muscle activity and maximum peak of the muscles of the human body.

현대 서양복식에 나타난 TATTOO에 관한 연구 (A Study on the Tattoo Represented in the Modern Western Costumes)

  • 이효진
    • 복식문화연구
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    • 제7권4호
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    • pp.52-68
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    • 1999
  • The purpose of this study was to be inquired inner contemplation of the tattoo expressed in the modern costumes. For this study, related documentaries and pictures or photos were analyzed in terms of the theretical background for the history of tattoo, the relation between tattoo and the modern western costumes. The primary source of pictures or photos are Vogue, Collections, Collezioni, Harper\`s Bazaar, Modain, Model et Mode etc. The human\`s needs of body decoration had constantly pursued on the body and costumes from the first until lately. Especially in the recents, as the tattoo is implicated a dynamic and charming method of all kinds of body decoration, it\`s used a motive of modern western costumes. The original tattoo means a picture, word etc. that was put permanently onto their skin using a needle and coloring matter. But, these days tattoo is an expression of street style for something new in the subculture. The results were as a follows : The inner meaning of tattoo represented in the modern costumes was classified into two categories. First, the tattooing was a very important factor to complete fashion design through the history of modern costumes, and also the elaborate tattoo of the body was displayed unrestricted formativeness as the skinhead\`s tattoo, raceless\`s ambiguity of street style and artistic decoration, because that can be faded easily. Second, Tattoo Look was expressed as tattoo prints of the see-through, elastic textiles in the modern costumes. That is, the tattoo enhanced the effect of dramatic atmosphere other formative arts as well as the modern costumes by Tattoo Look. Similarity, Tattoo Look could be interpreted as the change of the aesthetic consciousness by the influence of the subculture. Accordingly, in the end of a this century, many experimental designers had applied tattoo to modern costumes. So this study will stand as an important clue to foresee the future costume\`s style and change.

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