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Effect of Velocity-Pulse-Like Ground Motions on Seismic Fragility of Bridges (교량의 지진취약도에 대한 속도 펄스를 가진 지반운동의 영향)

  • Yeeun Kim;Sina Kong;Sinith Kung;Jiho Moon;Jong-Keol Song
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.2
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    • pp.119-131
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    • 2024
  • Pulse-like ground motion can cause greater damage to structures than nonpulse-like ground motion. Currently, much research is being conducted to determine the presence or absence of velocity pulses and to quantify them from seismic-acceleration records. Existing ground motion is divided into far-field (FF) and near-fault ground motion, based on the distance of the measurement point from the fault. Near-fault ground motion is further classified into near-fault pulse-like (NFP) and near-fault nonpulse-like (NFNP) ground motion by quantifying the presence or absence of velocity pulses. For each ground motion group, 40 FF, 40 NFP, and 40 NFNP ground motions are selected; thus, 120 ground motions are used in the seismic analysis to assess the seismic fragility of sample bridges. Probabilistic seismic demand models (PSDMs) are created by evaluating the seismic responses of two types of sample bridges with lead-rubber and elastomeric rubber bearings using three groups of ground motions. Seismic fragility analysis is performed using the PSDM, and from these results, the effect of the presence or absence of seismic velocity pulses on the seismic fragility is evaluated. From the comparison results of the seismic fragility curve, the seismic fragility of NFP ground motion appears to be approximately three to five times greater than that of NFNP ground motion, according to the presence or absence of a velocity pulse of seismic waves. This means that the damage to the bridge is greater in the case of NFP ground motion than that in the case of NFNP ground motion.

ON A STABILITY THEOREM FOR HYPEREXACT OPERATORS

  • Choi, Yong-Bin;Chung, Choon-Kyung
    • Communications of the Korean Mathematical Society
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    • v.11 no.4
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    • pp.959-965
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    • 1996
  • In this paper we study the index stability theorem for a bounded linear operator with closed range and extend the Kato's decomposition theorem for an absence of the index.

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Regulation of Phosphoinositide-specific Phospholipase C-$\gamma$ Isozyme

  • Bae, Yun-Soo
    • Proceedings of the Korean Biophysical Society Conference
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    • 1998.06a
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    • pp.17-17
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    • 1998
  • Although the activation mechanism of PLC-${\gamma}$ isozyme by protein tyrosine kinase (PTK) is well established, several lines of evidence indicate that PLC-${\gamma}$ isozymes can be activated directly by several lipid-derived second messengers In the absence of tyrosine phosphorylation.(omitted)

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Insulin-Like Growth Factor-I Induces Androgen Receptor Activation in Differentiating C2C12 Skeletal Muscle Cells

  • Kim, Hye Jin;Lee, Won Jun
    • Molecules and Cells
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    • v.28 no.3
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    • pp.189-194
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    • 2009
  • The modulating effect of IGF-I on the regulation of AR gene expression and activation in skeletal muscle cells remains poorly understood. In this study, the effects of IGF-I treatment on AR induction and activation in the absence of AR ligands were examined. Differentiating C2C12 cells were treated with different concentrations (0-250 ng/ml) of IGF-I or for various periods of time (0-60 min) of 250 ng/ml IGF-I. Treatment of C2C12 cells with IGF-I resulted in a dose- and time-dependent increase in total AR and phosphorylated AR (Ser 213). IGF-I treatment also led to significantly increased AR mRNA expression when compared with the control. The levels of skeletal ${\alpha}-actin$ and myogenin mRNA, known target genes of AR, were also significantly upregulated after 5 or 10 min of treatment with IGF-I. Confocal images revealed that IGF-I stimulated nuclear localization of AR in the absence of ligands. In addition, an electrophoretic mobility shift assay indicated that IGF-I stimulated the AR DNA binding activity in a time-dependent manner. The present results suggest that IGF-I stimulates the expression and activation of AR by ligand-independent mechanism in differentiating C2C12 mouse skeletal muscle cells.

Two-component Signal Transduction in Synechocystis sp. PCC 6803 under Phosphate Limitation: Role of Acetyl Phosphate

  • Juntarajumnong, Waraporn;Eaton-Rye, Julian J.;Incharoensakdi, Aran
    • BMB Reports
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    • v.40 no.5
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    • pp.708-714
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    • 2007
  • The two-component signal transduction, which typically consists of a histidine kinase and a response regulator, is used by bacterial cells to sense changes in their environment. Previously, the SphS-SphR histidine kinase and response regulator pair of phosphate sensing signal transduction has been identified in Synechocystis sp. PCC 6803. In addition, some response regulators in bacteria have been shown to be cross regulated by low molecular weight phosphorylated compounds in the absence of the cognate histidine kinase. The ability of an endogenous acetyl phosphate to phosphorylate the response regulator, SphR in the absence of the cognate histidine kinase, SphS was therefore tested in Synechocystis sp. PCC 6803. The mutant lacking functional SphS and acetate kinase showed no detectable alkaline phosphatase activity under phosphate-limiting growth conditions. The results suggested that the endogenous acetyl phosphate accumulated inside the mutants could not activate the SphR via phosphorylation. On the other hand, exogenous acetyl phosphate could allow the mutant lacking functional acetate kinase and phosphotransacetylase to grow under phosphate-limiting conditions suggesting the role of acetyl phosphate as an energy source. Reverse transcription PCR demonstrated that the transcripts of acetate kinase and phospho-transacetylase genes in Synechocystis sp. PCC 6803 is up-regulated in response to phosphate limitation suggesting the importance of these two enzymes for energy metabolism in Synechocystis cells

A Study on the Relationship between Anterior Tooth Contact and Temporomandibular Joint Space (전치부 접촉과 측두하악 관절강폭과의 관계에 관한 연구)

  • Sang-Don Kim;Kyung-Soo Han;Min Shin
    • Journal of Oral Medicine and Pain
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    • v.18 no.2
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    • pp.43-53
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    • 1993
  • The aim of this study was to investigate the relationship between the presence or absence of anterior tooth contact and the changes in temporomandibular joint space. The study sample consisted of 32symptom-free dental students and 79 craniomandibular disorders patients with unilateral joint dysfunction. The two groups were categorized into control group or experimental group, respectively. Recordings of the number and distribution of occlusal contacts were made by T-Scan system. Transcranial radiographs were taken with using of accurad-100 head positioner. Measured items in transcranial radiographs were anterior, superior, posterior joint space and relative condylar position to deepest position of glenoid folla. According to the presence or absence of anterior tooth contact, each group was subdivided and compared with each other with respect to TM joint space. Data were processed and tested with SPSS/PC + package. The results of the study showed that the joint space in control group were wider than those of experimental group and the difference of the width of joint space was more remarkable in subjects with anterior contact between control group and experimental group. However, in same group whether the presence of anterior tooth contact could hardly affect the difference of the width of joint space. And anterior tooth contact in grouip are more frequent than in experimental group.

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A Qualitative Study on the Career-interrupted Lives of Career-Interrupted Women in their thirties (직업 경력단절 기혼 여성에 대한 질적 연구: 30대 여성의 경력단절 이후의 삶을 중심으로)

  • Kim, Su Ri;Lee, Sulim;Ryu, Jeong Yi
    • Journal of Family Resource Management and Policy Review
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    • v.19 no.2
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    • pp.75-99
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    • 2015
  • The purpose of this study was to examine the career-interrupted lives of highly educated career-interrupted women. The participants were 11 women in their thirties who had graduated from university graduated and had a child. We collected the qualitative data using a focused group interview. The results of this study can be summarized as follows. First, in personal histories of the career-interrupted women, there were marriages and births, difficulties with child care, priority placed on the family, pressure to retire, and an absence of a layoff system related to births and child care. Second, with regard to their interrupted lives, while there was comfort and an absence of work-stress, there was child care stress, financial stress, anxiety due to career uncertainty, a loss of the social self, depression, emptiness, low self-esteem, dependence on husbands, regret, conflict in career choices, and envy of childcare support. Third, their reasons for seeking reemployment included the financial benefits, increased independence, self-realization in their job, hope for a stable job, self-management, and hope for a social network.