• Title/Summary/Keyword: dynamic relationship

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Inducing stress-strain relationship for element simulation of cyclic triaxial test on unsaturated soil (불포화토에 대한 반복삼축압축시험의 요소시뮬레이션을 위한 응력-변형율 관계의 수립)

  • Lee, Chung-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5654-5663
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    • 2015
  • In the unsaturated soil, suction, the negative pore water pressure leads to increases of the yield stress and the plastic shear stiffness of the soil skeleton due to the growth in interparticle stress. Therefore, in this study, the stress-strain relationship based on cyclic elasto-plastic constitutive model extended for unsaturated soil considering the 1st and the 2nd yield functions was induced in order to account for these effects of suction under the dynamic loading condition such as the earthquake. Through the program code considering this relationship and the routine of the cyclic loading with the reversion of loading direction, the numerical simulation of the cyclic triaxial test under the unsaturated condition would be possible. It is expected that the results of this study possibly contribute to the accuracy improvement on the prediction of unsaturated soil behavior under the dynamic loading condition.

Relationship Between Lower-limb Strength and Y-balance Test in Elderly Women

  • Eun-hye Kim;Sung-hoon Jung;Hwa-ik Yoo;Yun-jeong Baek;Oh-yun Kwon
    • Physical Therapy Korea
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    • v.30 no.3
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    • pp.194-201
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    • 2023
  • Background: Falls are a common and serious problem in the elderly population. Muscle strength and balance are important factors in the prevention of falls. The Y-balance test (YBT) is used to assess dynamic postural control and shows excellent test-retest reliability. However, no studies have examined the relationship between lower-limb strength and YBT scores in elderly women. Objects: This study aimed to examine the relationship between lower-limb strength and YBT scores in elderly women. Methods: Thirty community-dwelling elderly women participated in the study. Lower-limb strength including hip flexor, hip extensor, hip abductor (HAB), hip adductor (HAD), knee flexor, knee extensor, ankle dorsiflexor, and ankle plantar flexor (PF) muscles was examined using a smart KEMA strength sensor (KOREATECH Inc.), and the YBT was used to assess dynamic balance. Relationship between lower-limb strength and YBT was demonstrated using a Pearson's correlation coefficient. Results: HAB strength (r = 0.388, p < 0.05), HAD strength (r = 0.362, p < 0.05), and ankle PF strength (r = 0.391, p < 0.05) positively correlated with the YBT-anterior direction distance. Ankle PF strength was positively correlated with the YBT-posteromedial direction distance (r = 0.396, p < 0.05) and composite score (r = 0.376, p < 0.05). Conclusion: The results of this study suggest that HAB, HAD, and ankle PF strengths should be considered for dynamic postural control in elderly women.

Relationship between Dynamic Elastic Modulus and Lithology using Borehole Prospecting (시추공 물리탐사를 이용한 동탄성계수와 암상과의 상관성 분석)

  • Park, Chung-Hwa;Song, Moo-Young;Park, Jong-Oh
    • Journal of the Korean earth science society
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    • v.23 no.6
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    • pp.507-513
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    • 2002
  • To delineate the relationship between dynamic elastic modulus and lithologies, suspension PS logging was applied to Yuseong granite, Paldang banded gneiss, and Sabuk sedimentary rock. P and S wave velocities were also measured for these lithologies. In addition, uniaxial strength and Poisson’s ratio were measured in a laboratory for Yuseong granite and Paldang banded gneiss. In laboratory measurements, P and S wave velocities in Paldang banded gneiss were higher than those in Yuseong granite whereas Poisson’s ratio in Paldang banded gneiss was lower than that in Yuseong granite. This implies that P and S wave velocities correlate reversely with Poisson’s ratio. The dynamic Young modulus obtained from suspension PS logging was high compared to the dynamic bulk modulus and the dynamic shear modulus.

A "Dynamic Form-Finding" Approach to Environmental-Performance Building Design

  • Yao, Jia-Wei;Lin, Yu-Qiong;Zheng, Jing-Yun;Yuan, Philip F.
    • International Journal of High-Rise Buildings
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    • v.7 no.2
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    • pp.145-151
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    • 2018
  • Newly-designed high-rise buildings, both in China and abroad, have demonstrated new innovations from the creative concept to the creative method. from the creative concept to the creative method. At the same time, digital technology has enabled more design freedom in the vertical dimension. "Twisting" has gradually become the morphological choice of many city landmark buildings in recent years. The form seems more likely to be driven by the interaction of aesthetics and structural engineering. Environmental performance is often a secondary consideration; it is typically not simulated until the evaluation phase. Based on the research results of "DigitalFUTURE Shanghai 2017 Workshop - Wind Tunnel Visualization", an approach that can be employed by architects to design environmental-performance buildings during the early stages has been explored. The integration of a dynamic form-finding approach (DFFA) and programming transforms the complex relationship between architecture and environment into a dialogue of computer language and dynamic models. It allows the design to focus on the relationship between morphology and the surrounding environment, and is not limited to the envelope form itself. This new concept of DFFA in this research consists of three elements: 1) architectural form; 2) integration of wind tunnel and dynamic models; and 3) environmental response. The concept of wind tunnel testing integrated with a dynamic model fundamentally abandons the functional definition of the traditional static environment simulation analysis. Instead it is driven by integral environmental performance as the basic starting point of morphological generation.

Characteristics of Dynamic Properties of Granite Specimen from Chungnam Yeongi Area (충남 연기군 지역 화강암 시험편의 동적물성 특성에 관한 연구)

  • Min, June-Hyun;Lee, Seung-Joong;Choi, Sung-O.
    • Tunnel and Underground Space
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    • v.21 no.6
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    • pp.480-493
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    • 2011
  • Dynamic rock property is one of most important parameters in design of earthquake-resistant structures. In this study, free-free resonant column test has been conducted to obtain dynamic Young's modulus, dynamic shear modulus, and damping ratio among dynamic properties with granite specimen of Chungnam Yeongi area. The dynamic properties obtained from this test were compared with the physical properties from static rock tests, and their relationship has been analyzed. From our study, it has been concluded that the dynamic Young's modulus and the dynamic shear modulus are linearly proportional to the elastic wave velocity. And also the damping ratio has been identified to be in non-linear inverse proportion to the elastic wave velocity.

Prediction of dynamic soil properties coupled with machine learning algorithms

  • Dae-Hong Min;Hyung-Koo Yoon
    • Geomechanics and Engineering
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    • v.37 no.3
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    • pp.253-262
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    • 2024
  • Dynamic properties are pivotal in soil analysis, yet their experimental determination is hampered by complex methodologies and the need for costly equipment. This study aims to predict dynamic soil properties using static properties that are relatively easier to obtain, employing machine learning techniques. The static properties considered include soil cohesion, friction angle, water content, specific gravity, and compressional strength. In contrast, the dynamic properties of interest are the velocities of compressional and shear waves. Data for this study are sourced from 26 boreholes, as detailed in a geotechnical investigation report database, comprising a total of 130 data points. An importance analysis, grounded in the random forest algorithm, is conducted to evaluate the significance of each dynamic property. This analysis informs the prediction of dynamic properties, prioritizing those static properties identified as most influential. The efficacy of these predictions is quantified using the coefficient of determination, which indicated exceptionally high reliability, with values reaching 0.99 in both training and testing phases when all input properties are considered. The conventional method is used for predicting dynamic properties through Standard Penetration Test (SPT) and compared the outcomes with this technique. The error ratio has decreased by approximately 0.95, thereby validating its reliability. This research marks a significant advancement in the indirect estimation of the relationship between static and dynamic soil properties through the application of machine learning techniques.

The Effect of Information Technology on Arms-Length Buyer-Supplier Relationship

  • Kim, Soo-W.
    • International Journal of Quality Innovation
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    • v.9 no.3
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    • pp.57-69
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    • 2008
  • This paper posits that arm's length buyer-supplier relationship as the intermediate type between market exchange relations and strategic partnership might be advisable, and information technology may have a role as a mechanism actualizing the effects of such arm's length relationship by strategic supply-line diversification. Based on the theoretical analysis on interactive feedback relationships among IT level, buyer-supplier relationships, and supply chain structure, we suggest a set of advisable buyer-supplier relationship type for efficient supply chain management. Also, doing so would be helpful in suggesting a dynamic IT investment and adoption model appropriate for the establishment of productive buyer-supplier relationship, and further in providing theoretical foundations and practical guidelines on the role and function of B-to-B E-commerce for efficient SC integration.

Things Recommendation Method using Social Relationship in Social Internet of Things (소셜 사물인터넷에서 소셜 관계를 이용한 사물 추천 기법)

  • Kim, Sung Rim;Kwon, Joon Hee
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.3
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    • pp.49-59
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    • 2014
  • The Internet of Things(IoT) is a new promising technology made from a variety of technology. The IoT links the objects or people, then enabling anytime, anywhere connectivity for anything and not only for anyone. Social networking services have changed the way people communicate. Recently, new research challenges in many areas of Internet of things and social networking services are fired. In this paper, we propose things recommendation method using social relationship in social Internet of Things. We study previous researches about social network service, IoT, and social IoT. We proposed SIoT_FW(Social IoT Friendship Weight) using static and a dynamic social friendship weight. Also, our method considers four social relationships (Ownership Object Relationship, Co-Location Object Relationship, Social Object Relationship, Parental Object Relationship). We presents a music device scenario using our proposed method.