• Title/Summary/Keyword: Critical Theory

Search Result 1,506, Processing Time 0.028 seconds

A Critical Reflection on Formation of Regional Identity and Construction of Public Space in Urban Development Strategy (도시발전 전략에 있어 정체성 형성과 공적 공간의 구축에 관한 비판적 성찰)

  • Choi, Byung-Doo
    • Journal of the Korean association of regional geographers
    • /
    • v.14 no.5
    • /
    • pp.604-626
    • /
    • 2008
  • In recent years, the formation of identity has drawn much attention in urban development strategy. This has a dual implication for normative rehabilitation of lost traditional identity for ontological security of human being, and for strategic improvement of newly urban images in order to gain superiority in urban competitions. This duality is reflected on the debate between postmodern theorists, such as Lacan, Foucault and Deleuze, criticizing modem identity, and Arendt and Habermas, suggesting alternative formation of identity through public space. This paper considers some implications of identity for urban development policy, while criticizing urban development strategies which justify themselves with enhancing urban identity but which distort or erode it actually. In particular, this paper argues that the perspective of postmodern theorists is suitable for criticizing pseudo-identity in reality, while critical theoriests' suggestion of formation of authentic identity through and in public space can be understood as an ethical alternative to urban development policy.

  • PDF

Instrumentation on structural health monitoring systems to real world structures

  • Teng, Jun;Lu, Wei;Wen, Runfa;Zhang, Ting
    • Smart Structures and Systems
    • /
    • v.15 no.1
    • /
    • pp.151-167
    • /
    • 2015
  • Instrumentation on structural health monitoring system imposes critical issues for applying the structural monitoring system to real world structures, for which not only on the configuration and geometry, but also aesthetics on the system to be monitored should be considered. To illustrate this point, two real world structural health monitoring systems, the structural health monitoring system of Shenzhen Vanke Center and the structural health monitoring system of Shenzhen Bay Stadium in China, are presented in the paper. The instrumentation on structural health monitoring systems of real world structures is addressed by providing the description of the structure, the purpose of the structural health monitoring system implementation, as well as details of the system integration including the installations on the sensors and acquisition equipment and so on. In addition, an intelligent algorithm on stress identification using measurements from multi-region is presented in the paper. The stress identification method is deployed using the fuzzy pattern recognition and Dempster-Shafer evidence theory, where the measurements of limited strain sensors arranged on structure are the input data of the method. As results, at the critical parts of the structure, the stress distribution evaluated from the measurements has shown close correlation to the numerical simulation results on the steel roof of the Beijing National Aquatics Center in China. The research work in this paper can provide a reference for the design and implementation of both real world structural health monitoring systems and intelligent algorithm to identify stress distribution effectively.

Investigation of continuous and discontinuous contact cases in the contact mechanics of graded materials using analytical method and FEM

  • Yaylaci, Murat;Adiyaman, Gokhan;Oner, Erdal;Birinci, Ahmet
    • Computers and Concrete
    • /
    • v.27 no.3
    • /
    • pp.199-210
    • /
    • 2021
  • The aim of this paper was to examine the continuous and discontinuous contact problems between the functionally graded (FG) layer pressed with a uniformly distributed load and homogeneous half plane using an analytical method and FEM. The FG layer is made of non-homogeneous material with an isotropic stress-strain law with exponentially varying properties. It is assumed that the contact at the FG layer-half plane interface is frictionless, and only the normal tractions can be transmitted along the contacted regions. The body force of the FG layer is considered in the study. The FG layer was positioned on the homogeneous half plane without any bonds. Thus, if the external load was smaller than a certain critical value, the contact between the FG layer and half plane would be continuous. However, when the external load exceeded the critical value, there was a separation between the FG layer and half plane on the finite region, as discontinuous contact. Therefore, there have been some steps taken in this study. Firstly, an analytical solution for continuous and discontinuous contact cases of the problem has been realized using the theory of elasticity and Fourier integral transform techniques. Then, the problem modeled and two-dimensional analysis was carried out by using ANSYS package program based on FEM. Numerical results for initial separation distance and contact stress distributions between the FG layer and homogeneous half plane for continuous contact case; the start and end points of separation and contact stress distributions between the FG layer and homogeneous half plane for discontinuous contact case were provided for various dimensionless quantities including material inhomogeneity, distributed load width, the shear module ratio and load factor for both methods. The results obtained using FEM were compared with the results found using analytical formulation. It was found that the results obtained from analytical formulation were in perfect agreement with the FEM study.

A Structural Equation Model of Clinical Nurses' End-of-life Care Performance (임상간호사의 임종간호수행 구조모형)

  • Park, Hyo jin;Lee, Yun Mi;Kim, Min Hye
    • Journal of Korean Critical Care Nursing
    • /
    • v.14 no.1
    • /
    • pp.1-13
    • /
    • 2021
  • Purpose : Based on Quint's theory and the relevant literature, this study constructed a structural equation model for explaining and predicting end-of-life care performance in clinical nurses. Methods : A self-administered questionnaire was used to collect data from 265 nurses between September 1 and September 30, 2016. The data were analyzed using SPSS ver. 21 and AMOS ver. 21. Results : The goodness of fit of the modified model was found to be relatively satisfactory (χ2=114.82, Nomed χ2(χ2/df)=2.44, SRMR=.06, GFI=.94, AGFI=.89, CFI=.95, TLI=.91, RMSEA=.07). End-of-life care performance was affected by the attitudes toward nursing care of the dying, working unit, and death anxiety. The attitudes toward such care had the highest effect on end-of-life care performance. Conclusion : The results suggest that end-of-life care performance is directly and indirectly affected by attitudes toward nursing care of the dying, participation in end-of-life care education, working unit, death perception, and death anxiety. To improve clinical nurses' end-of-life care performance, effective programs to promote death anxiety and attitudes toward nursing care of the dying need to be developed. In addition, hospital nursing organizations should attempt to produce concrete measures for death anxiety and terminal care attitudes in clinical nurses.

Dynamic Characteristics and Instability of Submerged Plain Journal Bearings in accordance with the Cavitation Model (공동현상 모델에 따른 침수형 평면 저널베어링의 동특성 및 회전 안정성에 대한 연구)

  • Moonho Choi
    • Tribology and Lubricants
    • /
    • v.39 no.4
    • /
    • pp.139-147
    • /
    • 2023
  • Cavitation phenomena observed during the operation of a submerged plain journal bearing (PJB) can affect bearing performance parameters such as dynamic coefficients, whirl frequency ratio, and critical mass. This study presents numerical solutions of the Reynolds equation for steadily and dynamically loaded submerged PJBs with half-Sommerfeld (HS), Reynolds, and Jakobsson-Floberg-Olsson (JFO) cavitation models when the supply pressure is larger or equal to the cavitation pressure. The loads at various eccentricity ratios are identical; however, the attitude angle is approximately 6% smaller when the eccentricity ratio is between 0.2 and 0.7 and the JFO model is used, compared to that when the Reynolds model is used. Dynamic coefficients obtained with the HS and Reynolds model show good agreement with each other, except for kxz, which is sensitive to changes in the force normal to the rotor weight, and is attributed to the difference in the attitude angle obtained with each cavitation model. Stiffness coefficients are determined using the pressure distribution in the film, and therefore, when the JFO model is used, the direct stiffness coefficients are affected and show opposite signs for most eccentricity ratios. The mass-conservative JFO model can predict at least a 30% smaller critical mass compared to that using the HS and Reynolds models. Thus, the instability analysis results can change based on the cavitation model used in a submerged PJB. The results of this research indicate that the JFO model should be used when designing a rotor system supported by submerged PJBs.

Nonlinear shear-flexure-interaction RC frame element on Winkler-Pasternak foundation

  • Suchart Limkatanyu;Worathep Sae-Long;Nattapong Damrongwiriyanupap;Piti Sukontasukkul;Thanongsak Imjai;Thanakorn Chompoorat;Chayanon Hansapinyo
    • Geomechanics and Engineering
    • /
    • v.32 no.1
    • /
    • pp.69-84
    • /
    • 2023
  • This paper proposes a novel frame element on Winkler-Pasternak foundation for analysis of a non-ductile reinforced concrete (RC) member resting on foundation. These structural members represent flexural-shear critical members, which are commonly found in existing buildings designed and constructed with the old seismic design standards (inadequately detailed transverse reinforcement). As a result, these structures always experience shear failure or flexure-shear failure under seismic loading. To predict the characteristics of these non-ductile structures, efficient numerical models are required. Therefore, the novel frame element on Winkler-Pasternak foundation with inclusion of the shear-flexure interaction effect is developed in this study. The proposed model is derived within the framework of a displacement-based formulation and fiber section model under Timoshenko beam theory. Uniaxial nonlinear material constitutive models are employed to represent the characteristics of non-ductile RC frame and the underlying foundation. The shear-flexure interaction effect is expressed within the shear constitutive model based on the UCSD shear-strength model as demonstrated in this paper. From several features of the presented model, the proposed model is simple but able to capture several salient characteristics of the non-ductile RC frame resting on foundation, such as failure behavior, soil-structure interaction, and shear-flexure interaction. This confirms through two numerical simulations.

Critical Success Factors for the Adoption of Health Management Information Systems in Public Hospitals in Zimbabwe

  • Caleb Manjeese;Indira Padayachee
    • Journal of Information Science Theory and Practice
    • /
    • v.11 no.2
    • /
    • pp.82-103
    • /
    • 2023
  • The Zimbabwean healthcare sector faces huge challenges due to increased demands for improved services for a growing number of patients with fewer resources. The use of information and communications technologies, prevalent in many industries, but lacking in Zimbabwean healthcare, could increase productivity and innovation. The adoption of health management information systems (HMISs) can lead to improved patient safety and high-level patient care. These technologies can change delivery methods to be more patient focused by utilising integrated models and allowing for a continuum of care across healthcare providers. However, implementation of these technologies in the health care sector remains low. The purpose of this study is to demonstrate the advantages to be attained by using HMISs in healthcare delivery and to ascertain the factors that influence the uptake of such systems in the public healthcare sector. A conceptual model, extending the technology, organization, and environment framework by means of other adoption models, underpins the study of adoption behavior. A mixed method methodology was used to conduct the study. For the quantitative approach, questionnaires were used to allow for regression analysis. For the qualitative approach, thematic analysis was used to analyse interview data. The results showed that the critical success factors (namely, relative advantage, availability, complexity, compatibility, trialability, observability, management support, information and communication technology expertise, communication processes, government regulation, infrastructure support, organizational readiness, industry and competitive support, external support, perceived ease of use, perceived usefulness, attitude, and intention to use) influenced adoption of HMISs in public hospitals in Zimbabwe.

Engineering Critical Assessement for an Independent Type-B LNG Cargo Tank (독립형 LNG 화물창의 공학적 결함 평가)

  • Jae Hoon Seo;Kyu-Sik Park;Inhwan Cha;Joonmo Choung
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.60 no.4
    • /
    • pp.213-221
    • /
    • 2023
  • The demand for Liquefied Natural Gas (LNG) carriers and LNG-fueled ships has significantly increased in recent years due to the sulfur-oxide emission regulations by the International Maritime Organization (IMO). The main goal of this paper is to introduce the process for the Engineering Critical Assessment (ECA) of IMO independent type-B cargo tanks made from 9% nickel alloy. A methodology proposed by the British Standard was used to conduct ECA for any structure with initial flaws. Based on this standard, a Matlab code was developed to perform ECA. Coarse mesh Finite Element Analysis (FEA) was performed on an independent type-B LNG cargo tank with a capacity of 15,000 m3. The location with the highest development of maximum principal stress was identified at the bottom of the cargo tank. Fine mesh FEA was performed to obtain the stress range required for ECA. The dynamic cargo tank loads used for FEA were determined using some ship rules presented by Det Norske Veritas. As a result of performing a 20-year long-term crack propagation analysis with a semi-elliptical surface crack, the fracture-to-yield ratio exceeded the Fracture Assessment Line (FAL) and some structural reinforcement was necessary. Performing a 15-day short-term crack propagation analysis, the fracture-to-yield ratio remained within the FAL, and no significant LNG leaks were expected. This paper is believed to provide a guide for performing ECA of LNG cargo tanks in the future by providing the basic theory and application sample necessary to perform ECA.

Consideration for the development of room-temperature ambient-pressure superconductor (LK-99) (상온상압 초전도체(LK-99) 개발을 위한 고찰)

  • Sukbae Lee;Jihoon Kim;Sungyeon Im;SooMin An;Young-Wan Kwon;Keun Ho Auh
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.33 no.2
    • /
    • pp.61-70
    • /
    • 2023
  • This paper examines the way of thinking and limitations of physicists regarding the phenomenon of superconductivity and outlines how room-temperature and ambient-pressure superconductors can be developed through the statistical thermodynamic background of the liquid state theory. In hypothesis, the number of electron states should be limited by confining them to a state close to one-Dimension. Simultaneously, the electron-electron interactions should be frequent enough for the electrons to have liquid-like properties. As an example of implementing the hypothesis, our team reports the development of room-temperature and ambient-pressure superconductivity of a material named LK-99 (superconducting compound name developed in the research), whose structure was revealed through numerous experiments with a clue found by chance. Moreover, we summarize the theoretical and experimental basis for the characteristics and discovery of the world's first superconducting material surpassing the critical temperature of 97℃ at atmospheric pressure.

Low Actuation Voltage Capacitive Shunt RF-MEMS Switch Using a Corrugated Bridge with HRS MEMS Package

  • Song Yo-Tak;Lee Hai-Young;Esashi Masayoshi
    • Journal of electromagnetic engineering and science
    • /
    • v.6 no.2
    • /
    • pp.135-145
    • /
    • 2006
  • This paper presents the theory, design, fabrication and characterization of the novel low actuation voltage capacitive shunt RF-MEMS switch using a corrugated membrane with HRS MEMS packaging. Analytical analyses and experimental results have been carried out to derive algebraic expressions for the mechanical actuation mechanics of corrugated membrane for a low residual stress. It is shown that the residual stress of both types of corrugated and flat membranes can be modeled with the help of a mechanics theory. The residual stress in corrugated membranes is calculated using a geometrical model and is confirmed by finite element method(FEM) analysis and experimental results. The corrugated electrostatic actuated bridge is suspended over a concave structure of CPW, with sputtered nickel(Ni) as the structural material for the bridge and gold for CPW line, fabricated on high-resistivity silicon(HRS) substrate. The corrugated switch on concave structure requires lower actuation voltage than the flat switch on planar structure in various thickness bridges. The residual stress is very low by corrugating both ends of the bridge on concave structure. The residual stress of the bridge material and structure is critical to lower the actuation voltage. The Self-alignment HRS MEMS package of the RF-MEMS switch with a $15{\Omega}{\cdot}cm$ lightly-doped Si chip carrier also shows no parasitic leakage resonances and is verified as an effective packaging solution for the low cost and high performance coplanar MMICs.