• Title/Summary/Keyword: structural relaxation

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Effects of soil-structure interaction on construction stage analysis of highway bridges

  • Ates, Sevket;Atmaca, Barbaros;Yildirim, Erdal;Demiroz, Nurcan Asci
    • Computers and Concrete
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    • v.12 no.2
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    • pp.169-186
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    • 2013
  • The aim of this paper is to determine the effect of soil-structure interaction and time dependent material properties on behavior of concrete box-girder highway bridges. Two different finite element analyses, one stage and construction stage, have been carried out on Komurhan Bridge between Elazi$\breve{g}$ and Malatya province of Turkey, over Fırat River. The one stage analysis assume that structure was built in a second and material properties of structure not change under different loads and site conditions during time. However, construction stage analysis considers that construction time and time dependent material properties. The main and side spans of bridge are 135 m and 76 m, respectively. The bridge had been constructed in 3 years between 1983 and 1986 by balanced cantilever construction method. The parameters of soil-structure interaction (SSI), time dependent material properties and construction method are taken into consideration in the construction stage analysis while SSI is single parameter taking into consideration in the one stage analysis. The 3D finite element model of bridge is created the commercial program of SAP2000. Time dependent material properties are elasticity modulus, creep and shrinkage for concrete and relaxation for steel. Soft, medium, and firm soils are selected for evaluating SSI in both analyses. The results of two different finite element analyses are compared with each other. It is seen that both construction stage and SSI have a remarkable effect on the structural behavior of the bridge.

A Study on the formation and dissolution of tautological structure in the Frank Stella's work (프랭크 스텔라(Frank Stella)에 있어서 토톨로지 구조(Tautological Structure)의 형성과 해체)

  • Hong Ji-Suk
    • Journal of Science of Art and Design
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    • v.5
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    • pp.35-66
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    • 2003
  • This article dealt with the formation and dissolution of tautological structure in the Frank Stella's work from 1959 to 1980 years by the analysis of signifier. A characteristic of Stella's work change is that it has the gradual progress which condensed into three periods -1) the formation and fixation period of tautological structure 2) the relaxation period of tautological structure and 3) the dissolution period of tautological structure. In other words, the early works of stella in the early 1960s has the structure which minimize differences in one hand, and maximize strictness, clearness, and identity on the other hand However, the stella's work from mid 1960s to mid 1970s extend differences gradually, while keeping a characteristic of prior work. And the stella's work after late 1970s has the decentered disintegration, namely anti-tautological structure which maximize differences. 'The formation and dissolution of tautological structure' in the Stella's work could be understood in relation to the fact that the Greenberg's modernist canon has loss the power gradually after late 1960s. That is to say, the dissolution of tautological structure in the late stella's work could be interpreted as the inevitable product which is produced in the searching for a new canon of painting. However, on the other hand, the structural change of stella's work in the late 20th Century is also understood in relation to the broader context, the social, and cultural context. Here, it is interpreted as the one of typical example which reflect a social and cultural convulsion designated as a 'Coming of Postmodernism'. In short, the late Stella's work which emphasize differences and unclearness, while diverging from early Stella's work which stress identity and rationality could be interpreted that it has the homology with the change of ways of thinking in the late 20th century Society.

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Technical, Individual and Situational Factors Affecting Intention to Use of Mobile Easy Payment Service : Focusing on the Moderating Effects of Subjective Norms (기술, 개인, 상황 특성이 모바일 간편 결제서비스 이용의도에 미치는 영향 : 주관적 규범의 조절효과)

  • Park, Hyunsun;Kim, Sanghyun
    • Journal of Digital Convergence
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    • v.16 no.6
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    • pp.105-115
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    • 2018
  • With the development of information and communication technologies, popularization of smart phones, and relaxation of the government regulation, mobile easy payment service is rapidly growing as a major financial service. Therefore, this study examines factors that influence the intention to use mobile easy payment service through empirical analysis. We collected 386 responses by survey and formed structural equation modeling with AMOS 22.0. The results show that technical factors(relative advantage, security), individual factor(self-efficacy), situational factors(trust in prior services and satisfaction of prior services) had a positive effect on the perceived value. In addition, perceived value had a positive effect on the intention to use mobile easy payment services. Lastly, subjective norms are closely related to the relationship between perceived value and intention to use mobile easy payment services. The results can be expected to provide useful references to the Fintech related industry fields.

Stability Assessment of Building Foundation over Abandoned Mines (채굴 지역에서의 건축물 기초 지반 안정성 평가 연구)

  • 권광수;박연준
    • Tunnel and Underground Space
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    • v.11 no.2
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    • pp.174-181
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    • 2001
  • The cavities created by underground mining, if remained unfilled, can cause ground settlement and surface subsidence as a result of relaxation and breakdown of the carven roof. Construction of structures above the underground mine cavity will have serious problems concerning both structural stability and safely even if the cavity is back-filled. This study was conducted to confirm the location and condition of the cavern as well as the state of the back-fill in A mine area using core logging and borehole camera. The bearing capacity and other mechanical properties of the ground were also measured by the standard penetration test(SPT). Obtained data were used to assess the stability of the ground and the structures to be built by numerical analysis using FLAC. The site investigation results showed that the mine cavities were filled with materials such as boulder and silty sand(SM by unified classification). Result of the numerical analyses indicated that constructing building structures on the over-lying ground above the filled cavities is secure against the potential problems such as surface subsidence and ground settlement.

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Characterization of thermally driven polysilicon micro actuator (폴리실리콘 마이크로 액츄에이터의 열구동 특성분석)

  • Lee, Chang-Seung;Lee, Jae-Youl;Chung, Hoi-Hwan;Lee, Jong-Hyun;Yoo, Hyung-Joun
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.2004-2006
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    • 1996
  • A thermally driven polysilicon micro actuator has been fabricated using surface micromachining techniques. It consists of P-doped polysilicon as a structural layer and TEOS (tetracthylorthosilicate) as a sacrificial layer. The polysilicon was annealed for the relaxation of residual stress which is the main cause to its deformation such as bending and buckling. And the newly developed HF VPE (vapor phase etching) process was also used as an effective release method for the elimination of sacrificial TEOS layer. The thickneas of polysilicon is $2{\mu}m$ and the lengths of active and passive polysilicon cantilevers are $500{\mu}m$ and $260{\mu}m$, respectively. The actuation is incurred by die thermal expansion due to the current flow in the active polysilicon cantilever, which motion is amplified by lever mechanism. The moving distance of polysilicon micro actuator was experimentally conformed as large as $21{\mu}m$ at the input voltage level of 10V and 50Hz square wave. The actuating characteristics are investigated by simulating the phenomena of heat transfer and thermal expansion in the polysilicon layer. The displacement of actuator is analyzed to be proportional to the square of input voltage. These micro actuator technology can be utilized for the fabrication of MEMS (microelectromechanical system) such as micro relay, which requires large displacement or contact force but relatively slow response.

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Screening of Specific Genes Expressed in the Swine Tissues and Development of a Functional cDNA Chip

  • Kim, Chul Wook;Chang, Kyu Tae;Hong, Yeon Hee;Kwon, Eun Jung;Jung, Won Yong;Cho, Kwang Keun;Chung, Ki Hwa;Kim, Byeong Woo;Lee, Jung Gyu;Yeo, Jung-Sou;Kang, Yang Su;Joo, Young Kuk
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.7
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    • pp.933-941
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    • 2005
  • To develop a functional cDNA chip, specific genes expressed in the tissues of swine Kagoshima Berkshire were screened. A total of 4,434 ESTs were obtained by constructing a cDNA library from total RNA isolated from the muscle and fat tissues, affirming their functions by investigating similarity of nucleotide sequences with the database at the NCBI. Among them, 1,230 ESTs were confirmed as novel genes, which, to date, have not been identified. Attaching the genes to a cDNA microarray slide revealed expression patterns of genes in muscle and fat according to the growth stages of swine. As specific genes expressed in the muscle tissues of swine with body weight of 30 kg, 60 genes including actin, myosin, tropomysin, transfer RNA-trp synthetase, Kel-like protein 23, KIAA0182 and COI, Foocen-m, etc were obtained. In addition, 18 novel genes were obtained. As specific genes expressed in fat tissues of swine with body weight of 30 kg, 47 genes including annexin II, Collagen, Fibronectin, Pleckstrin homology domain, serine protease, etc were obtained. 21 novel genes were also obtained. The genes specifically expressed in the muscle and fat tissues of swine affect contraction and relaxation of the muscle and the fat. However, studies on the expression mechanisms of the genes are insufficient. To reveal species of structural genes in swine muscle and fat tissue, interrelation studies in expression and function of genes by using the cDNA chip should be conducted.

A Study on the Precipitation Behavior of Carbide Particle in L12-type Intermetallic Compound Ni3Al (L12형 금속간화합물 Ni3Al중에 탄화물입자의 석출거동에 관한 연구)

  • Han, Chang-Suk;Koo, Kyung-Wan;Oh, Dong-Cheol
    • Korean Journal of Materials Research
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    • v.16 no.4
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    • pp.241-247
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    • 2006
  • Structural studies have been performed on precipitation hardening discovered in $L1_2-ordered\;Ni_3(Al,Cr)$ containing 0.2 to 3.0 mol% of carbon using transmission electron microscopy (TEM). Fine octahedral precipitates of $M_{23}C_6$ appeared in the matrix by aging at temperatures around 973 K after solution treatment at 1423 K. TEM examination revealed that the $M_{23}C_6$ phase and the matrix lattices have a cube-cube orientation relationship and keep partial atomic matching at the {111} interface. After prolonged aging or by aging at higher temperatures, the $M_{23}C_6$ precipitates then adopt a rod-like morphology elongated parallel to the <100> directions. Deformation at temperature below 973 K, typical Orowan loops were observed surrounding the $M_{23}C_6$ particles. At higher deformation temperatures, the Orowan loops disappeared and the morphology of dislocations at the particle-matrix interfaces suggested the existence of attractive interaction between dislocations and particles. The change of the interaction modes between dislocation and particles with increasing deformation temperature can be considered as a result of strain relaxation at the interface between matrix and particles.

Nanoscale imaging of rat atrial myocytes by scanning ion conductance microscopy reveals heterogeneity of T-tubule openings and ultrastructure of the cell membrane

  • Park, Sun Hwa;Kim, Ami;An, Jieun;Cho, Hyun Sung;Kang, Tong Mook
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.6
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    • pp.529-543
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    • 2020
  • In contrast to ventricular myocytes, the structural and functional importance of atrial transverse tubules (T-tubules) is not fully understood. Therefore, we investigated the ultrastructure of T-tubules of living rat atrial myocytes in comparison with ventricular myocytes. Nanoscale cell surface imaging by scanning ion conductance microscopy (SICM) was accompanied by confocal imaging of intracellular T-tubule network, and the effect of removal of T-tubules on atrial excitation-contraction coupling (EC-coupling) was observed. By SICM imaging, we classified atrial cell surface into 4 subtypes. About 38% of atrial myocytes had smooth cell surface with no clear T-tubule openings and intracellular T-tubules (smooth-type). In 33% of cells, we found a novel membrane nanostructure running in the direction of cell length and named it 'longitudinal fissures' (LFs-type). Interestingly, T-tubule openings were often found inside the LFs. About 17% of atrial cells resembled ventricular myocytes, but they had smaller T-tubule openings and a lower Z-groove ratio than the ventricle (ventricular-type). The remaining 12% of cells showed a mixed structure of each subtype (mixed-type). The LFs-, ventricular-, and mixed-type had an appreciable amount of reticular form of intracellular T-tubules. Formamide-induced detubulation effectively removed atrial T-tubules, which was confirmed by both confocal images and decreased cell capacitance. However, the LFs remained intact after detubulation. Detubulation reduced action potential duration and L-type Ca2+ channel (LTCC) density, and prolonged relaxation time of the myocytes. Taken together, we observed heterogeneity of rat atrial T-tubules and membranous ultrastructure, and the alteration of atrial EC-coupling by disruption of T-tubules.

Evaluation of Sleeper Supporting Condition for Railway Ballasted Track using Modal Test Technique (모달시험기법을 이용한 자갈궤도의 침목지지조건평가)

  • Jung-Youl Choi;Tae-Jung Yoon;Jee-Seung Chung
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.4
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    • pp.537-542
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    • 2023
  • Recently, deformation of operating railway structures has occurred due to adjacent excavation works such as new structures and utility tunnel expansion concentrated around downtown areas. However, most of them are focused on structural review, repair and reinforcement of structures. A review of the Track is insufficient. In particular, in the case of the gravel track on the earthwork subgrade, the subgrade and the ballast are not solidified. A slight level of deformation can cause ballast relaxation. Sleeper support conditions may lead to unstable conditions. Sufficient safety must be ensured. In addition, it is a track type with a high risk of train derailment due to unstable support conditions. In this study, the correlation between the deformation characteristics of gravel tracks and track support performance according to subgrade deformation is experimentally and analytically verified. In addition, an evaluation technique that can evaluate the condition of the gravel track and the track support stiffness is presented.

Structural Model Analysis of Changes in Women's Quality of Life and Life Satisfaction by Body Shape Management

  • Kim, Jae-Nam
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.10
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    • pp.211-219
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    • 2020
  • The purpose of this study is to conduct body shape management on women for a certain period of time to determine the structural relationship between the latent variables of life habits, social support, and life satisfaction and the impact on the quality of life. Body shape management was performed with chiropractic adjustments and myofascial relaxation therapy, and a physical therapist with 25 years of experience was used as an expert. The subject of the study was a sample of women in their 20s to 60s residing in Gwangju Metropolitan City, and women who participated in body shape management procedures more than 20 times for the study were asked to fill out a questionnaire using a self-evaluation writing method. The final analysis target was 100 people who made it reasonable to analyze the data. As a result of the study, it was found that the quality of life of women related to health can vary depending on the presence and degree of body shape management. In addition, the degree of life satisfaction varies according to the level of lifestyle and social support, and the direct, indirect, and total effects of the latent variables related to the quality of life were all significant. In this study, the usual body shape management that can improve the quality of life of women gives meaning to the opportunity for women to have desirable lifestyle and to give them a recognition that values quality of life.