• Title/Summary/Keyword: $P-\Delta$ analysis

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Seismic P-$\Delta$ Effects of Slender RC Columns in Earthquake Analysis (지진하중을 받는 철근콘크리트 장주의 P-$\Delta$ 효과)

  • Kwak, Hyo-Gyoung;Kim, Jin-Kook
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.19 no.4 s.74
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    • pp.375-387
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    • 2006
  • Different from the previous studies which investigated seismic P-$\Delta$ effect in slender columns though comparison of response spectra according to stability coefficients obtained from the analyses based on the assumed moment-curvature relationship, the axial force and P-$\Delta$ effect in RC columns are investigated on the basis of the layered section method which can effectively consider the changes of stiffness and yield strength due to the application of axial force in RC members. Practical ranges of slenderness and stability coefficient are assumed, and sixty sets of horizontal/vertical earthquake inputs are used in the analysis. From the parametric study, it is noted that the maximum deformation of the slender RC column is hardly affected by P-$\Delta$ effect or vortical earthquake but dominantly affected by the applied axial force. Therefore, it can be concluded that no additional consideration for the P-$\Delta$ effect and vortical earthquake is required in the seismic design of a slender RC column if the axial force effect is taken into account in the analysis and design procedures.

Equivalent Column Stiffness Equations for Design of RC Slender Columns under Later Loads (횡하중을 받는 철근콘크리트 장주설계를 위한 기둥의 등가강성식)

  • 이재훈
    • Magazine of the Korea Concrete Institute
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    • v.7 no.1
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    • pp.156-164
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    • 1995
  • P-${\Delta}$ analysis by use of the equivalent colurnn stiffness determined by Momcnt curvature-Thrust curves provides relatively precise analytical results for unbraced reinforced concrete columns, however it needs a complicated arialytical procedure. Equ~valent col~rnn stiffness equations are proposed for a simple analytical procedure which are ckterrnined by the Moment-Curvature Thrust curves of the practically useable sections. Thc proposed stiffness equations are appiled to P-${\Delta}$ analysis and rnornent magnifier method to compare with the selected test result. Use of the proposed stiffness equations may slrnplify the P-${\Delta}$ i.rialvtica1 procedure and improve the accuracy of moment magnifier niethod.

Component Analysis of Laryngeal Cancer Incidence Dynamics in Kazakhstan from 1999 to 2014

  • Zatonskikh, Vera;Igissinov, Nurbek;Igissinov, Saginbek;Igissinova, Gulnur;Bilyalova, Zarina;Kulmirzayeva, Dariyana;Venglovskiy, Anatoliy
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.9
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    • pp.4451-4456
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    • 2016
  • Background: In this study, we examined epidemiological aspects of dynamic changes in incidences of laryngeal cancer in male and female populations in Kazakhstan. Materials and Methods: Primary data were for registered patients with malignant laryngeal tumors in the whole country during the period of 1999-2014. Evaluation of changes in laryngeal cancer incidence in the population of Kazakhstan was performed using component analysis. Results: It was determined that the number of patients with laryngeal cancer in the whole country is decreasing although with conflicting impacts of different factors. Despite population growth (all - ${\Delta}_P=+66.1%$, men - ${\Delta}_P=+70.9%$ and women - ${\Delta}_P=+46.4%$), and aging (all - ${\Delta}_A=+45.1%$, men - ${\Delta}_A=+54.3$ and women - ${\Delta}_A=+22.2$), the reduction in risk of developing the disease (all - ${\Delta}_R=-165.6%$, men - ${\Delta}_R=-170.9%$ and women - ${\Delta}_R=-141.0%$) was overwhelming. Conclusions: This investigation was the first epidemiological study of dynamics of laryngeal cancer by component analysis in population of Kazakhstan. Implementation of the results of the study is recommended in management of anti-cancer activities for laryngeal cancer.

A Study on the Lateral Behavior of Pile-Bent Structures with $P-{\Delta}$ Effect ($P-{\Delta}$ 효과를 고려한 Pile-Bent 구조물의 수평거동 연구)

  • Jeong, Sang-Seom;Kwak, Dong-Ok;Ahn, Sang-Yong;Lee, Joon-Kyu
    • Journal of the Korean Geotechnical Society
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    • v.22 no.8
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    • pp.77-88
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    • 2006
  • In this study, the lateral behavior of Pile-Bent structures subjected to lateral loading was evaluated by a load-transfer approach. An analytical method based on the Beam-Column model and nonlinear load transfer curve method was proposed to consider material non-linearity (elastic and yielding) and $P-{\Delta}$ effect. Special attention was given to the lateral deflection of Pile-Bent structures depending on different soil properties, lateral load, slenderness ratio based on pier length and reinforcing effect of casing. From the results of the parametric study, it is shown that the increase of lateral displacement in a pile is much less favorable for an inelastic analysis than for an elastic analysis. It is found that for inelastic analysis, the maximum bending moment is located within a depth approximately 3.5D(D: pile diameter) below ground surface, but within 1.5D when $P-{\Delta}$ effect is considered. It is also found that the magnitude and distribution of the lateral deflections and bending moments on a pile are highly influenced by the inelastic analysis and $P-{\Delta}$ effect, let alone soil properties around an embedded pile.

Performance Assessment of Precast Segmental PSC Bridge Columns Considering P-delta effects (P-delta 영향을 고려한 프리캐스트 세그먼트 PSC 교각의 성능평가)

  • Kim, Tae-Hoon;Park, Se-Jin;Kim, Young-Jin;Shin, Hyun-Mock
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.4
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    • pp.45-54
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    • 2008
  • The purpose of this study was to investigate the performance of precast segmental PSC bridge columns with regard to P-delta effects. A model of precast segmental PSC bridge columns was tested under a constant axial load and a cyclically reversed horizontal load. A computer program, RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), was used for the analysis of reinforced concrete structures. In addition to the material nonlinear properties, an algorithm for the problem of large displacement that may result in additional deformation has been formulated using total Lagrangian formulation. This study documents the testing of precast segmental PSC bridge columns under cyclic loading, and presents conclusions based on the experimental and analytical findings.

Seismic Performance Evaluation of Inverted V Braced Steel Frames with Considering P-Δ Effects: A Case Study (P-Δ 효과를 고려한 역 V형 철골 가새골조의 내진성능평가: 사례연구)

  • Lee, Cheol-Ho;Kim, Jeong-Jae
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.3
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    • pp.97-103
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    • 2004
  • Most of the columns in centrally braced steel frame buildings are usually designed as the gravity columns to reduce connection cost. For a rational seismic performance evaluation of centrally braced steel frame buildings, it is important to properly incorporate in the analysis  the P-${\Delta}$ effects arising from the gravity columns. An effective scheme for the P-${\Delta}$ effects modeling due to the gravity columns was illustrated based on the concept of fictitious leaning column. Seismic performance evaluation of inverted V braced steel frames with or without P-${\Delta}$ effects modeling was conducted by following the FEMA 273 NSP (Nonlinear Static Procedure). The problem in estimating dynamic P-${\Delta}$ modification factor (C3) in FEMA 273 was discussed. The results of this study indicated that the P-${\Delta}$ effects should be included in the seismic performance evaluation of centrally braced steel frames. This study also showed that the inverted V braced frames, retrofitted by applying the tie bars to redistribute the inelastic demand over the height of the building, exhibit significantly improved seismic performance.

EXISTENCE AND MULTIPLICITY OF SOLUTIONS OF p(x)-TRIHARMONIC PROBLEM

  • Belakhdar, Adnane;Belaouidel, Hassan;Filali, Mohammed;Tsouli, Najib
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.2
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    • pp.349-361
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    • 2022
  • In this paper, we study the following nonlinear problem: $$\{-\Delta_{p}^{3}(x)u\;=\;{\lambda}V_{1}(x){\mid}u{\mid}^{q(x)-2}u\;in\;{\Omega},\\u\;=\;{\Delta}u\;{\Delta}^{2}u\;=\;0\;on\;{\partial}\Omega, $$ under adequate conditions on the exponent functions p, q and the weight function V1. We prove the existence and nonexistence of eigenvalues for p(x)-triharmonic problem with Navier boundary value conditions on a bounded domain in ℝN. Our technique is based on variational approaches and the theory of variable exponent Lebesgue spaces.

Simplified finite element modelling of non uniform tall building structures comprising wall and frame assemblies including P-Δ effects

  • Belhadj, Abdesselem Hichem;Meftah, Sid Ahmed
    • Earthquakes and Structures
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    • v.8 no.1
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    • pp.253-273
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    • 2015
  • The current investigation has been conducted to examine the effect of gravity loads on the seismic responses of the doubly asymmetric, three-dimensional structures comprising walls and frames. The proposed model includes the P-${\Delta}$ effects induced by the building weight. Based on the variational approach, a 3D finite element with two nodes and six DOF per node including P-${\Delta}$ effects is formulated. Dynamic and static governing equations are derived for dynamic and buckling analyzes of buildings braced by wall-frame systems. The influences of P-${\Delta}$ effects and height of the building on tip displacements under Hachinohe earthquake record are investigated through many structural examples.

EXPRESSION OF DOMINANT NEGATIVE p63 ISOFORM IN WELL-DIFFERENCIATED ORAL SQUAMOUS CELL CARCINOMA (분화도 좋은 구강 편평상피세포암종에서 Dominant Negative p63 isoform의 발현)

  • Kim, In-Su;Kim, Chul-Hwan;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.3
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    • pp.191-198
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    • 2007
  • The p53 which is well known as tumor suppressor gene is located at 17p13. p53 is a sequence-specific DNA binding transcription factor that responds to certain cytotoxic stresses, such as DNA damage, by enhancing the transcription of genes that regulate cell-cycle progression as well as programmed cell death. The p63 gene that is located at 3q27-29, is recognized members of the p53 family, and responsible for the transcription of 6 isoforms. Three isoforms ($TAp63{\alpha}$, $TAp63{\beta}$, $TAp63{\gamma}$) contain an N-terminal transactivation (TA) domain and can induce apoptosis. The other 3 isoforms (${\Delta}Np63{\alpha}$, ${\Delta}Np63{\beta}$, ${\Delta}Np63{\gamma}$) lack the TA domain and may function in a dominant-negative fashion by inhibiting the transactivation functions of p53 and TAp63 proteins, and thus act as oncoproteins. A number of studies have investigated the role of p63 in human squamous cell carcinomas from different organs. Only a few studies have examined ${\Delta}Np63$ isoform in oral squamous cell carcinoma including normal epithelium. This study aimed to evaluate expression of ${\Delta}Np63$ isoform in human oral squamous cell carcinoma tissue and normal mucosa. The 3 cases of well differenciated oral squamous cell carcinoma specimen including adjacent normal mucosa were examined, and immunohistochemical study with monoclonal antibody(4A4) and tumor cell apoptosis analysis with Transmission Electon Microscopy were studied. And, RT-PCR analysis was done for expression of ${\Delta}Np63$ isoform. The results were as followed. 1. Normal gingiva showed the restricted p63 expression in basal cell layer. 2. Well differentiated squamous cell carcinoma showed mainly p63 expression in overall area of malignancy, especially in basal cell layer to adjacent stromal tissue. 3. Tumor cells around keratinized area with no p63 expression disclosed less micro-organelle in decreased size cytoplasm and severe chromatin margination with nuclear destruction that means apoptosis. 4. Comparison of mRNA expression of ${\Delta}Np63$ isoform by RT-PCR showed variable expression of ${\Delta}Np63$ isoform, but ${\Delta}Np63{\alpha}$ was most highly expressed in all 3 tumor specimen. From theses results, it should be suggested that ${\Delta}Np63$ isoform expression in well differentiated squamous cell carcinoma was closely related to tumor oncogenesis, expecially overexpression of ${\Delta}Np63{\alpha}$ is a most important factor in tumor genesis of oral squamous cell carcinoma.

Linear Relationships between Thermodynamic Parameters (Part I) Theoretical (熱力學 函數間의 直線關係 (第1報) 理論)

  • Ikchoon Lee
    • Journal of the Korean Chemical Society
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    • v.7 no.3
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    • pp.211-215
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    • 1963
  • Inter-relationship between the Hammett equation and the linear enthalpy-entropy effect has been discussed by deriving a new set of equations; ${\Delta}{\Delata}H^{\neq}=a{\sigma}+b{\Delta}{\Delta}S^{\neq}$ and ${\Delta}{\Delta}F^{\neq}=a{sigma}+(b-T){\Delta}{\Delta}S^{\neq}$ where a = -1.36p. Theoretical analysis show that the Hammett, Leffler and Brown equations are special limited forms of these general equations. A necessary and sufficient test of substituent effect can thus be provided by the plot of $({\Delta}{\Delta}H^{\neq}-a{\sigma)$ versus ${\Delta}{\Delta}S^{\neq}$.

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