• Ocean Systems Engineering
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• 제4권2호
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• pp.151-167
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• 2014

It is common that analyses of offshore platforms being carried out with the assumption of rigid tubular joints. However, many researches have concluded that it is necessary that local joint flexibility (LJF) of tubular joints should be taken into account. Meanwhile, advanced analysis of old offshore platforms considering local joint flexibility leads to more accurate results. This paper presents an extensive finite-element (FE) based study on the flexibility of uni-planner multi-brace tubular Y-T and K-joints commonly found in offshore platforms. A wide range of geometric parameters of Y-T and K-joints in offshore practice is covered to generate reliable parametric equations for flexibility matrices. The formulas are obtained by non-linear regression analyses on the database. The proposed equations are verified against existing analytical and experimental formulations. The equations can be used reliably in global analyses of offshore structures to account for the LJF effects on overall behavior of the structure.

• 한국자동차공학회논문집
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• 제8권2호
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• pp.110-119
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• 2000

In this study, we considered the method evaluation the flexibility of joint area including member with circular section. We regarded the flexibility of joint area as translational and rotational springs for the purpose of expressing local deformation. We verified this method by the use of normal mode analysis. We also calculated this joint area occurring in penetration so as to apply this method to other cases. Compare with the shell element model. we can the considerably approximate values.

• Steel and Composite Structures
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• 제24권4호
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• pp.425-439
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• 2017

As a thin-walled structure, local joint flexibility (LJF) in a tubular structure is prominent, and it may produce significant effect on the static performance for the overall structure. This study presents a simplified analytical model to analyze the static behavior for a steel tubular structure with LJF. The presented model simplifies a tubular structure into a frame model consisted of beam elements with considering the LJFs at the connections between any two elements. Theoretical equations of the simplified analytical model are deduced. Through comparison with 3-D finite element results of two typical planar tubular structures consisted of T- and Y-joints respectively, the presented method is proved to be accurate. Furthermore, the effect of LJF on the overall performance of the two tubular structures (including the deflection and the internal forces) is also investigated, and it is found from analyses of internal forces and deformation that a rigid connection assumption in a frame model by using beam elements in finite element analysis can provide unsafe and inaccurate estimation.

• Ocean Systems Engineering
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• 제14권1호
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• pp.1-16
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• 2024

This paper investigates the impact of local joint flexibility (LJF) on the fatigue life of jacket-type offshore platforms. Four sample platforms with varying geometric properties are modeled and analyzed using the Opensees software. The analysis considers the LJF of tubular joints through the equivalent element and flexible link approaches, and the results are compared to rigid modeling. Initially, modal analysis is conducted to examine the influence of LJF on the frequency content of the structure. Subsequently, fatigue analysis is performed to evaluate the fatigue life of the joints. The comparison of fatigue life reveals that incorporating LJF leads to reduced fatigue damage and a significant increase in the longevity of the joints in the studied platforms. Moreover, as the platform height increases, the effect of LJF on fatigue damage becomes more pronounced. In conclusion, considering LJF in fatigue analysis provides more accurate results compared to conventional methods. Therefore, it is essential to incorporate the effects of LJF in the analysis and design of offshore jacket platforms to ensure their structural integrity and longevity.

• 근관절건강학회지
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• 제6권2호
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• pp.197-210
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• 1999

Muscle stiffness, pain and discomfort in dally activities are cardinal symtoms on arthritis. To reduce these symtoms, a nonequivalent one-group pre & posttest experiment was carried out at a rural community health post area in Chonbuk province during eight weeks (from 25th of January to 20th of March, 1999). The subjects were sixteen rural old women(65-89yrs) with osteoarthritis. And to reduce the level of pain, discomfort in daily living and to increase that of life satisfaction, 30 minutes of flexibility exercise followed by $15{\sim}20\;minutes$ of local heat therapy were done three times a week. Pain scale from Arthritis Impact Measurement Scales developed by Meenan(1980) for pain, Jette's Daily Activity Discomfort Scales revised by Lee(1988) for discomfort and Life Satisfaction Scales developed by Youn(1982) for life satisfaction were used as research instruments. The data were collected by face-to-face interviews with Investigator and the experiments were done under demonstration and supervision of investigator in community health post. The data were analyzed in percentage and Wilcoxon sign rank sum test by SPSS/PC+ program. The result could be summarized as follows ; 1. The scores of experiment group who were applied hot bag followed by flexibility exercise were tended to be significant lower in the level of pain statistically(Z=4.949, P=0.0001). 2. The scores of experiment group who was applied hot bag followed by flexibility exercise were tended to be significant lower in the level of discomfort in daily living statistically(Z=2.7226, P=0.0279). 3. The scores of experiment group who was applied hot bag followed by flexibility exercise were tended to be higher in the level of life satisfaction, but there was no significant statistical difference(Z=-1.2087, P=0.2171). In conclusion, flexibility exercise with local heat therapy could be identified as an effective therapy to reduce pain and discomfort in daily living of the rural elderly with osteoarthritis. And as a community health practitioner, the investigator concluded that this exercise with local heat therapy could be developed as a health promotion program for the rural aged people.

• 토지주택연구
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• 제5권2호
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• pp.57-68
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• 2014

도시개발에 따른 외부효과 발생을 최소화하고 개발의 편익을 주변지역으로 확산하고자 하는 사회적 요구가 증가하면서 다양한 협력적 계획방식에 대한 논의가 증가하고 있다. 장기적으로는 협력적 계획을 뒷받침할 수 있는 법규 및 제도정비가 필요한 사항이지만 이에 앞서 미국사례의 협력적 계획이 실행될 수 있는 요소, 절차, 방법론 고찰을 통해 단일 행정구역 뿐만 아니라 여러 지자체에 걸쳐 도시개발이 이루어지는 복합경계신도시 등에 적용 가능한 협력적 계획의 대안과 시사점을 도출하고자 한다. 본 논문에서는 미국 위스콘신주의 사례조사 및 분석을 통해 다음과 같은 시사점을 도출하였다. 먼저 다수 지자체 경계 구역 내 공동계획구역을 설정하여 복합경계신도시 등과 같은 특수지역에 협동계획을 위한 구역 설정이 필요하며, 이를 위한 도시 계획적 수단이 마련되어야 한다. 이와 함께 협력계획의 유연성을 높이기 위해서는 생활권 단위의 계획단위 설정과 커뮤니티 활성화를 위한 제도적 운영체계가 마련되어야 한다. 또한 지역의 성장으로 인하여 발생한 수익은 공동세를 통하여 약정된 비율로 각 지자체에 배분하는 등 소규모 지역에서의 서비스 공유 및 공동세를 운영하는 방안도 협력계획의 실천력을 확보하는 방안이 될 수 있을 것이다. 이와 함께 협력적 거버넌스 구축을 위해서 계획단계에서부터의 이해관계자 참여와 중재인을 통한 갈등관리 방안이 마련되어야 하며, 도시기본계획 수준에서 협력계획의 실행 방안이 마련되어야 한다.

• 마이크로전자및패키징학회지
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• 제29권2호
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• pp.113-119
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• 2022

플렉서블, 웨어러블 디바이스 등을 포함한 차세대 전자 기기의 기계적 신뢰성 향상을 위하여 다양한 유연 접합부에서 높은 수준의 기계적 신뢰성이 요구되고 있다. 기존 고분자 기판 접합을 위한 에폭시 등의 유기 접착소재는 접합부 두께 증가가 필연적이며, 반복 변형, 고온 경화에 의한 열기계적 파손 문제를 수반한다. 따라서 유연 접합을 위해서 접합부 두께를 최소화하고 열 손상을 방지하기 위한 저온 접합 공정 개발이 요구된다. 본 연구에서는 플렉서블 기판의 유연, 강건, 저 열 손상 접합이 가능한 플렉서블 레이저 투과 용접(flexible laser transmission welding, f-LTW)를 개발하였다. 유연 기판 위 탄소나노튜브(carbon nanotube, CNT)를 박막 코팅하여 접합부 두께를 줄였으며, CNT 분산 빔 레이저 가열을 통한 고분자 기판 표면의 국부적 용융 접합 공정이 개발되었다. 짧은 접합 공정 시간과 기판의 열 손상을 최소화하는 레이저 공정 조건을 구축하였으며 고분자 기판과 CNT 접합 형성 메커니즘을 분석하였다. 또한 접합부의 강건성 및 유연성 평가를 위해 인장강도 시험, 박리 시험과 반복 굽힘 시험을 진행하였다.

• 근관절건강학회지
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• 제7권2호
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• pp.227-240
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• 2000

The purpose of this article was to identify trend in Arthritis research and to provide ba an approach of Arthritis research. The results of analysis of 69 Arthritis articles public year of between 1970-1999 found that most articles(27.6%, n=19) were published since few(10.1%, n=7) were before 1994. Vast majority of articles(79.8%, n=55) were printed in The Journal of Rheumatology Health, and 79.8%(n=55) of those were quantitative research, 8.7%(n=6) were qualitative research, and 14%(n=1) was methodological research. 29.0%(n=20) of quantitative research were carried in experimental design and over half(50.8%, n=35) in nonexperimental design. Having concerned the types of treatment(or intervention) used in experimental study, the most common treatment was 'exercise' (45.0%, n=9), and other less common were 'self-help education(15.0%, n=3), home care(10.0%, n=2) supportive care(10.0%, n=2), flexibility exercise combined with local heat therapy(5.0%, n=1), relaxation training(5.0%, n=1). Of the types of exercise, aquatic exercise was 30.0%(n=6). The effect of exercise on outcome variable was found to be most strong among the other types of treatment. 18 articles of nonexperimental research were correlational research. From the analysis of correlational research, 29 concepts were identified, and the relationship between depression and other variable were strongly reported. In descriptive studies, most commonly physiological variables were examined in 5 articles(29.5%). Only one study(5.9%) explored patient's perception of the causal factors and those causality. In qualitative researches, two study were carried out by the means of grounded theory. Majority of those subjects were RA patients, and the largest number of sample were 23 and the smallest was 1 In two studies, patient's perceived causality of RA was identified as a research problems, and an experience of ADL, fatigue Phenomenon, an experience of having a total knee replacement with osteoarthritis were each found in one study. Methodological research was carried out to test validity and reliability of the RA Fatigue Scale.