• Title/Summary/Keyword: flexibility method

Search Result 1,512, Processing Time 0.026 seconds

Shape Optimization of Multilayer Bellows by Using Sequential Experimental Design (순차적 실험계획법을 적용한 다층관 벨로우즈 형상 최적설계)

  • Oh, Sang-Kyun;Lee, Kwang-Ki;Suh, Chang-Hee;Jung, Yun-Chul;Kim, Young-Suk
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.35 no.9
    • /
    • pp.1007-1013
    • /
    • 2011
  • Because of their high flexibility and durability, multilayer bellows are manufactured for use in commercial vehicles, while single-layer bellows are manufactured for use in passenger vehicles. A study based on the finite element method (FEM) and shape optimization for the single-layer bellows has been actively performed; however, until now, a study based on the FEM has rarely been performed for the multilayer bellows with gaps between the layers. This paper presents a finite-element modeling scheme for the multilayer bellows to improve simulation reliability during the evaluation of stress and flexibility. For performing shape optimization for the multilayer bellows, DOE (design of experiment) and the Kriging metamodel followed by the D-optimal method are used.

A Study on the Design Development Methods and the Characteristics of Zero Waste Fashion Design (최소폐기물 패션디자인의 디자인 개발방식 및 특성 연구)

  • Han, Seung Soo;Suh, Seung Hee
    • Journal of the Korean Society of Costume
    • /
    • v.66 no.4
    • /
    • pp.61-76
    • /
    • 2016
  • The importance of environment has come into focus recently, and this has led to increased attention on zero waste fashion design as a method to minimize waste from the production stage of fashion goods. The purpose of this study was to analyze the development method types and the characteristics of zero waste fashion design in order to study the eco-friendly meanings of zero waste fashion design, as well as its meaning as creative design development methods. Through the case analysis of recent designs, the design types of zero waste fashion design were largely classified into cut and sew, folding, draping, and non-woven types, and they were classified again according to the characteristics of production process. According to the result of analyzing fashion design development methods of zero waste fashion designs based on the process of completing design, they were classified into pattern making, computer programming, draping, assembling of the unit, and non-woven moulding methods, and the aspect of combined use rather than utilization of one method appeared. Formative characteristics of zero waste fashion design included decorative beauty, formative beauty, and transformable beauty and its design characteristics were fortuity and unexpected properties, breaking stereotypes, structural flexibility and futuristic innovation.

Optimum Preliminary Ship Design Technique by Using Sophisticated Sequential Linear Approximation Method -Development and Application of User Oriented Design Optimization Language- (고성능 순차적 선형화 방법을 이용한 선박 최적 초기설계 기법 -최적화 설계 전용 언어의 개발 및 응용-)

  • K.Y.,Lee
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.25 no.3
    • /
    • pp.35-45
    • /
    • 1988
  • This paper presents a sophisticated Sequential Linear Approximation Method(SLAM) to solve nonlinear optimization problem and the performance of this method is compared with those of the Penalty Function Method(SUMT), Tangent Search Method(TSM) and Flexible Tolerance Method(FTM). To improve the convenience and flexibility in using the proposed SLAM, an user oriented design optimization language is developed and the application examples are shown for the optimization of propeller principal dimensions and the optimization of bulk carrier principal particulars.

  • PDF

Effect of Foundation Flexibility of Offshore Wind Turbine on Force and Movement at Monopile Head (해상풍력발전기 기초구조물의 강성이 모노파일 두부의 부재력 및 변위에 미치는 영향)

  • Jung, Sungmoon;Kim, Sung-Ryul;Lee, Juhyung;Le, Chi Hung
    • Journal of the Korean Geosynthetics Society
    • /
    • v.13 no.4
    • /
    • pp.21-31
    • /
    • 2014
  • Recently, the research on renewable energy against depletion of fossil fuel have been actively carried out in the world. Especially, offshore wind turbines are very economical and innovative technology. However, offshore wind turbines experience large base moments due to the wind and wave loading, so the monopile with large diameter needs to be applied. For the economical design of the large diameter pile, it is important to consider the flexibility of the foundation to estimate the maximum moment accurately, based on studies conducted so far. In this paper, the foundation was modeled using the finite element method in order to better describe the large diameter effect of a monopile and the results were compared with those of p-y method. For the examples studied in this paper, the change in maximum moment was insignificant, but the maximum tilt angle from the finite element method was over 14% larger than that of p-y method. Therefore, the finite element approach is recommended to model the flexibility effect of the pile when large tilt angles may cause serviceability issues.

Effects of an Exercise Program Including Promotion of Self-Efficacy on the Physical and Psychological Functions of Middle School Students with Minimal Scoliosis (자기효능증진법을 병용한 척추교정운동이 척추측만증 중학생의 신체적, 심리적 기능에 미치는 효과)

  • Lee, Myung-Sook
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.14 no.2
    • /
    • pp.282-293
    • /
    • 2008
  • Purpose: This study was done to identify the effects of an exercise correction program for scoliosis on the physical and psychological functions of middle-school students with scoliosis. Method: The design of this study was a nonequivalent control group pretest-posttest design. The students who participated in the study were 45 middle school students with scoliosis. Twenty-four students were assigned to the experimental group and 21 to the control group. The treatment given to the experimental group was a scoliosis correction exercise program. The scoliosis correction exercise program was given 3 times a week for a period of 12 weeks. Result: For Cobb's angle, a significant decrease was observed in the experimental group. For flexibility, the sit-and-reach test showed a significant increase in the experimental group. For depression, self-esteem and body satisfaction, the difference between the two groups was not significant. Conclusion: Based on the above results, the effects of a spine correction exercise program produced a decrease in Cobb's angle and an increase in the sit-and-reach test for flexibility. This program is not expensive and is convenient, and thus has been identified as a good nursing intervention for correcting scoliosis.

Effects of Tai Chi Exercise Program on Muscle Strength, Flexibility, Postural balance and Cognition in Patients with Parkinson Disease (태극권 프로그램이 파킨슨병 환자의 하지근력, 관절의 유연성, 균형감 및 인지기능에 미치는 효과)

  • Choi, Dong-Won;Sohng, Kyeong-Yae
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.18 no.2
    • /
    • pp.177-185
    • /
    • 2011
  • Purpose: To examine the effects of Tai Chi exercise (TCE) on muscle strength, flexibility of low extremities, postural balance and cognition in patients with Parkinson disease (PD). Method: A nonequivalent control-group pre and post-test design was used. Of the 30 participants 15 were assigned to the experimental group and 15 to the control group. The experimental group participated in 8 weeks of TCE which included one day of exercise with instructor on site and 3 days of self-exercise at home guided by a videotape. Results: The 8 weeks of TCE were found to be significantly effective in enhancing strength of low extremities, flexibility of ankles and shoulders, time of tandem stand with eye closed and level on the K-MMSE (Korean mini mental state examination). Conclusion: These results suggest that TCE has positive effects on physical fitness and cognition in patients with PD. Research over an extended period with the TCE intervention is recommended to identify further effects.

Study on the Causes of Premature Cracking of Epoxy Coatings for Ship's Ballast Tanks

  • Song, Eun Ha;Lee, Ho Il;Chung, Mong Kyu;Lee, Seong Kyun;Baek, Kwang Ki
    • Corrosion Science and Technology
    • /
    • v.5 no.2
    • /
    • pp.69-76
    • /
    • 2006
  • Premature cracking of the epoxy coatings applied on ship's ballast tanks(BT) can lead to damage of ship's hulls. To avoid this, it's important to have clear understanding of the underlying mechanism and primary factors of the coating crack. In this study, the efforts were made to clarify the integrated effects of main factors, i.e., initial coating shrinkage, thermally induced strain, steel-structural strain and the intrinsic coating flexibility at the initial and after aging, to the early cracking phenomena of epoxy coating in the ship's ballast tank. The coating crack is caused by combination of thermal stress, structural stress, and internal stresses which is closely related to chemical structures of the coatings. On the other hand, thermal stresses and dimensional stabilities would rarely play a major role in coating crack for ballast tank coatings with rather large flexibility. Crack resistance of the coatings at early stages can be estimated roughly by measuring internal stress, FT-IR and $T_g$ value of the coatings. A new screening test method was also proposed in this study, which can be possibly related to the long-term resistance of epoxy-based paints to cracking.

The Effect of a Health Maintenance Program on Physical Function and Mental Health of the Elderly in Nursing Homes (건강유지 프로그램이 시설노인의 신체 건강과 정신 건강에 미치는 효과)

  • Sung, Ki-Wol
    • Journal of Korean Academy of Nursing
    • /
    • v.37 no.4
    • /
    • pp.478-489
    • /
    • 2007
  • Purpose: The purpose of this study was to determine the effects of a Health Maintenance Program on physical functions and mental health of the elderly in nursing homes. Method: Sixty elderly(over 65 years old) in a randomized control study participated in a 16-week group-based intervention including functional exercises and health education. The participants were divided into 3 groups(Health Maintenance Program Group, Supportive Music Exercise Group, and Control Group) of 20 elderly each. Data was collected from Dec. 1st, 2005 to Mar, 30th, 2006. Physical function of lower body strength was assessed using a 30-second chair test, flexibility was assessed using a sit-and-reach test, and static balance was assessed by the ability to balance on one leg with open and closed eyes. Depression was assessed using the Korean Form of the Geriatric Depression Scale and self esteem was assessed using Rosenberg's Self Esteem Questionnaire. Data was analyzed by Chi-square test, One-way ANOVA, and Repeated measure two factor analysis. Results: A Health Maintenance Program significantly increased muscle strength, flexibility and static balance, but depression and self-esteem scores were not significantly changed. Conclusion: Findings demonstrated that a Health Maintenance Program was more effective on physical function than mental health of the elderly in nursing homes.

On Determining the Size and the Timing of the Capacity Expansion in PV Module Manufacturing: Management Flexibility in Real Options Model (태양광모듈 생산 증설투자에 대한 의사결정: 실물옵션모형에 의한 경영유연성 가치 분석)

  • Kim, Kyung-Nam;SonU, Suk-Ho
    • New & Renewable Energy
    • /
    • v.7 no.2
    • /
    • pp.18-27
    • /
    • 2011
  • Management flexibility to adapt its future actions in response to altered future market conditions can expand the value of an investment opportunity by improving its upside potential without the change in the downside losses. Module manufacturers in solar industry continuously have to decide how much and when its production capacity should be expanded with regards to the demand in the global markets. Either over- or under-investment can cause sunk and/or opportunity costs to the module manufacturers. Option of exercising the additional investments only on favorable opportunities can increase total value of the investment. This paper analyzes the case which shows that the expansion of production capacity with more expandibility can have more value than the rigid plan of capacity expansion. The expansion option value is equivalent to KRW 38.286 billion, thus switching the negative NPV of the initial investment opportunity into the positive value. High volatility and the high growth in the cashflows as the major business features of the renewable energy provide condition where real options can play the crucial role in increasing the investment value as well as in determining the size and timing of capacity expansion in the course of capital budgeting process.

The Effect of Self-Management Course on Pain, Flexibility of Lumbar Spine, Uncertainty and Self-efficacy in patients with Ankylosing Spondylitis (자기관리과정이 강직성 척추염환자의 요통, 허리유연성, 불확실성과 자기효능감에 미치는 효과)

  • Paik, Seung-In;Sohng, Kyeong-Yae
    • Journal of muscle and joint health
    • /
    • v.10 no.2
    • /
    • pp.156-166
    • /
    • 2003
  • Purpose: To investigate the effects of self-management course in patients with ankylosing spondylitis. Method: Forty-nine subjects were sampled according to research criteria, and divided into two groups: 24 of the experimental group and 25 of control group. To the experimental group, self-management course which developed by the investigators was applied for 6 weeks, each session adopted for two hours per week and additional 30-minutes exercise was carried out two times a week. Result: After participating the self-management course in experimental group, 1) the degree of pain was significantly decreased 2) significant improvement in the flexibility of lumbar spine, 3) uncertainty was significantly decreased. 4) Self-efficacy was not changed between the two groups after self-management course. Conclusions: These findings indicate that the self-management course could be effective in improving the flexibility of lumbar spine and decreasing pain, and uncertainty in patients with ankylosing spondylitis.

  • PDF