• Title/Summary/Keyword: New formulation

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Determining elastic lateral stiffness of steel moment frame equipped with elliptic brace

  • Habib Ghasemi, Jouneghani;Nader, Fanaie;Mohammad Talebi, Kalaleh;Mina, Mortazavi
    • Steel and Composite Structures
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    • v.46 no.3
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    • pp.293-318
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    • 2023
  • This study aims to examine the elastic stiffness properties of Elliptic-Braced Moment Resisting Frame (EBMRF) subjected to lateral loads. Installing the elliptic brace in the middle span of the frames in the facade of a building, as a new lateral bracing system not only it can improve the structural behavior, but it provides sufficient space to consider opening it needed. In this regard, for the first time, an accurate theoretical formulation has been developed in order that the elastic stiffness is investigated in a two-dimensional single-story single-span EBMRF. The concept of strain energy and Castigliano's theorem were employed to perform the analysis. All influential factors were considered, including axial and shearing loads in addition to the bending moment in the elliptic brace. At the end of the analysis, the elastic lateral stiffness could be calculated using an improved relation through strain energy method based on geometric properties of the employed sections as well as specifications of the utilized materials. For the ease of finite element (FE) modeling and its use in linear design, an equivalent element was developed for the elliptic brace. The proposed relation was verified by different examples using OpenSees software. It was found that there is a negligible difference between elastic stiffness values derived by the developed equations and those of numerical analysis using FE method.

Static and quasi-static slope stability analyses using the limit equilibrium method for mountainous area

  • Hosung Shin
    • Geomechanics and Engineering
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    • v.34 no.2
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    • pp.187-195
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    • 2023
  • Intensive rainfall during the summer season in Korea has triggered numerous devastating landslides outside of downtown in mountainous areas. The 2D slope stability analysis that is generally used for cut slopes and embankments is inadequate to model slope failure in mountainous areas. This paper presents a new 3D slope stability formulation using the global sliding vector in the limit equilibrium method, and it uses an ellipsoidal slip surface for static and quasi-static analyses. The slip surface's flexibility of the ellipsoid shape gives a lower FS than the spherical failure shape in the Fellenius, Bishop, and Janbu's simplified methods. The increasing sub-columns of each column tend to increase the FS and converge to a steady value. The symmetrical geometric conditions of the convex turning corners do not indicate symmetrical failure of the surface in 3D analysis. Pseudo-static analysis shows that the horizontal seismic force decreases the FS and increases the mass volume at the critical failure state. The stability index takes the FS and corresponding sliding mass into consideration to assess the potential risk of slope failure in complex mountainous terrain. It is a valuable parameter for selecting a vulnerable area and evaluating the overall risk of slope failure.

Effects of size-dependence on static and free vibration of FGP nanobeams using finite element method based on nonlocal strain gradient theory

  • Pham, Quoc-Hoa;Nguyen, Phu-Cuong
    • Steel and Composite Structures
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    • v.45 no.3
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    • pp.331-348
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    • 2022
  • The main goal of this article is to develop the finite element formulation based on the nonlocal strain gradient and the refined higher-order deformation theory employing a new function f(z) to investigate the static bending and free vibration of functionally graded porous (FGP) nanobeams. The proposed model considers the simultaneous effects of two parameters: nonlocal and strain gradient coefficients. The nanobeam is made by FGP material that exists in un-even and logarithmic-uneven distribution. The governing equation of the nanobeam is established based on Hamilton's principle. The authors use a 2-node beam element, each node with 8 degrees of freedom (DOFs) approximated by the C1 and C2 continuous Hermit functions to obtain the elemental stiffness matrix and mass matrix. The accuracy of the proposed model is tested by comparison with the results of reputable published works. From here, the influences of the parameters: nonlocal elasticity, strain gradient, porosity, and boundary conditions are studied.

Paradoxical Rebellion Bound to Conformity: Isaac Watts's "Hurry of the Spirits, in a Fever and Nervous Disorders"

  • Chung, Ewha
    • Journal of English Language & Literature
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    • v.58 no.6
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    • pp.1103-1117
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    • 2012
  • This paper focuses on eighteenth-century English pastor, poet, and hymnist, Isaac Watts (1674-1748), a significant yet neglected nonconformist dissenter, who defines a public religion and transforms poetry as a new literary political genre. During England's post-Revolutionary religio-political turmoil, Watts's poem, "The Hurry of the Spirits, in a Fever and Nervous Disorders" (1734), deliberately engages in a methodical refusal to settle upon a single system of images or terms for describing or referring to the speaker's identity or situation. Watts's, literal and metaphoric, refusal to identify with one religio-political approach to nonconformist dissent has been the very point of criticism that not only undermines the poet's monumental work on hymns but also the lasting impact that the poet had upon England's national consciousness. This study, therefore, questions why the poet refuses to choose one ideal path in his pursuit for religious freedom and, further, analyzes how the hymn writer defends his demotic aesthetics. This paper investigates Watts's comprehensive and detailed formulation of what a secularized "social religion" should entail and, further, explores its beneficial role in the pursuit for society's peace. In contrast to Milton's apocalyptic vengeance, Watts's nonconformist goal seeks to balance and locate authority in the individual with the ancient ideal of a "sacred order" that is represented in "The Hurry of the Spirits" through the means of poetic imagination.

Finite element based free vibration analysis of sandwich FGM plates under hygro-thermal conditions using zigzag theory

  • Aman Garg;Neeraj Kumar Shukla;M.Ramkumar Raja;Hanuman D. Chalak;Mohamed-Ouejdi Belarbi;Abdelouahed Tounsi;Li Li;A.M. Zenkour
    • Steel and Composite Structures
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    • v.49 no.5
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    • pp.547-570
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    • 2023
  • In the present work, a comparative study has been carried out between power, exponential, and sigmoidal sandwich FGM plates for free vibration conditions under hygro-thermal conditions. Rules of mixture is used to determine effective material properties across the thickness for power-law and sigmoid sandwich FGM plates. Exponential law is used to plot effective material properties for exponentially graded sandwich FGM plates. Temperature and moisture dependent material properties were used during the analysis. Free vibration analysis is carried out using recently proposed finite element based HOZT. Present formulation satisfies interlayer transverse stress continuity conditions at interfaces and transverse shear stress-free conditions at the plate's top and bottom surfaces. The present model is free from any penalty or post-processing requirements. Several new results are reported in the present work, especially for unsymmetric sandwich FGM plates and exponential and sigmoidal sandwich FGM plates.

Theoretical rotational stiffness of the flexible base connection based on parametric study via the whale optimization algorithm

  • Mahmoud T. Nawar;Ehab B. Matar;Hassan M. Maaly;Ahmed G. Alaaser;Osman Hamdy
    • Structural Engineering and Mechanics
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    • v.88 no.1
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    • pp.43-52
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    • 2023
  • This paper handles the results of an extensive parametric study on the rotational stiffness of the flexible base connection using ABAQUS program. The results of the parametric study show the relation between the applied moment and the relative rotation for 96 different base connections. The configurations of the studied connections considered different numbers, diameters, and spacing of the anchor bolts along with different thicknesses of the base plate to investigate the effect of these parameters on the rotational stiffness behavior. The results of the previous parametric research used through the whale optimization algorithm (WOA) to detect different equation formulation of the moment-rotation (M-Ɵr) equation to detect optimum equation simulates the general nonlinear rotational behavior of the flexible base connection considering all variables used in the parametric study. WOA is a relatively new promising algorithm, which is used in different types of optimization problems. For more verification, the classical genetic algorithm (GA) is used to make a comparison with WOA results. The results show that WOA is capable of getting an optimum equation of the M-Ɵr relation, which can be used to simulate the actual rotational stiffness of the flexible base connections. The rotational stiffness at H/150 can be calculated using WOA (1) method and be used as a design aid for engineering design.

Considerations on Standardization in Smart Hospitals

  • Sun-Ju Ahn;Sungin Lee;Chi Hye Park;Da Yeon Kwon;Sooyeon Jeon;Han Byeol Lee;Sang Rok Oh
    • Health Policy and Management
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    • v.34 no.1
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    • pp.4-16
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    • 2024
  • Smart hospitals involve the use of recent ICT (information and communications technology) technologies to improve healthcare access, efficiency, and effectiveness. Standardization in smart hospital technologies is crucial for interoperability, scalability, policy formulation, quality control, and maintenance. This study reviewed relevant international standards for smart hospitals and the organizations that develop them. Specific attention was paid to robotics in smart hospitals and the potential for standardization in this area. The study used online resources and existing standards to analyze technologies, standards, and practices in smart hospitals. Key technologies of smart hospitals were identified. Relevant standards from ISO (International Organization for Standardization) and IEC (International Electrotechnical Commission) were mapped to each core technology. Korea's leadership in smart hospital technology were highlighted. Approaches for standardizing smart hospitals were proposed. Finally, potential new international standard items for robotics in smart hospitals were identified and categorized by function: sampling, remote operation, delivery, disinfection, and movement tracking/contact tracing. Standardization in smart hospital technologies is crucial for ensuring interoperability, scalability, ethical use of artificial intelligence, and quality control. Implementing international standards in smart hospitals is expected to benefit individuals, healthcare institutions, nations, and industry by improving healthcare access, quality, and competitiveness.

The Impact of Healthy-pleasure Product Choice Attribute Importance on Buyer Attitudes and Purchase Behavior: a Focus on ow-calorie Foods

  • Kyung Tae JANG;Seung Hyeon LEE;Seong Soo CHA
    • Journal of Wellbeing Management and Applied Psychology
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    • v.7 no.2
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    • pp.23-29
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    • 2024
  • Purpose: This study aims to investigate consumer attitudes towards healthy foods, focusing on low-calorie options, and their impact on purchasing behavior. Methods: The study utilizes structural equation modeling, which incorporates statistical tools such as SPSS and AMOS for thorough analysis. This involves collecting data over a period of time and then inferring patterns and relationships through correlation and trend analysis. Results: The study found that attributes such as quality, price, functional value, and emotional value have a significant impact on customer satisfaction and repurchase intentions, but not on nutrition and brand. The study provides a comprehensive understanding of the factors that influence consumer attitudes and purchase behavior toward healthy indulgences in the context of low-calorie foods, and has important implications for both academic research and practical marketing strategies. Conclusions and Implications: This study provides new insights into consumer behavior theory by validating the impact of the perceived value of low-calorie products on attitudes and purchase behavior, which is of great academic value. It is also expected to provide useful information for the formulation of effective marketing strategies for low-calorie products and the development of products that meet consumer needs.

Residues of a New Fungicide, KNF 1002 in Cucumber and Pepper (신규 살균제 KNF 1002의 오이 및 고추 중 잔류특성)

  • Kim, Tae-Hwa;Lee, Jae-Yeong;Yu, Yong-Man;Kim, Jang-Eok
    • Korean Journal of Environmental Agriculture
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    • v.22 no.3
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    • pp.227-232
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    • 2003
  • This study was conducted to evaluate the terminal residue of a new fungicide, KNF 1002, in cucumber and pepper under greenhouse and field conditions. When a microemulsion formulation (20%) of KNF 1002 was applied once or twice during $1{\sim}7$ days before harvest, its terminal residue in cucumber ranged <$0.02{\sim}0.20\;mg/kg$ under greenhouse condition. In pepper, its figure recorded $0.31{\sim}0.79\;mg/kg$ and $0.11{\sim}0.28\;mg/kg$ under greenhouse and field conditions, respectively. Much higher level of terminal residues was observed in leaves than those in fruits in pepper, showing $7.38{\sim}25.20\;mg/kg$ and $0.11{\sim}1.99\;mg/kg$ under greenhouse and field conditions, respectively. Cultivation condition affected evidently the residue level in pepper harvests. Residual pattern of KNF 1002 seemed to be comparable to strobilurin fungicides currently used.

New Generation of Lead Free Paste Development

  • Albrecht Hans Juergen;Trodler K. G.
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2004.09a
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    • pp.233-241
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    • 2004
  • A new alloy definition will be presented concerning increasing demands for the board level reliability of miniaturized interconnections. The damage mechanism for LFBGA components on different board finishes is not quite understood. Further demands from mobile phones are the drop test, characterizing interface performance of different package constructions in relation to decreased pad constructions and therefore interfaces. The paper discusses the characterization of interfaces based on SnPb, SnPbXYZ, SnAgCu and SnAgCuInNd ball materials and SnAgCuInNd as solder paste, the stability after accelerated tests and the description of modified interfaces strictly related to the assembly conditions, dissolution behavior of finishes on board side and the influence of intermetallic formation. The type of intermetallic as well as the quantity of intermetallics are observed, primaliry the hardness, E modules describing the ability of strain/stress compensation. First results of board level reliability are presented after TCT-40/+150. Improvement steps from the ball formulation will be discussed in conjunction to the implementation of lead free materials In order to optimize ball materials for area array devices accelareted aging conditions like TCTs were used to analyze the board level reliability of different ball materials for BGA, LFBGA, CSP, Flip Chip. The paper outlines lead-free ball analysis in comparison to conventional solder balls for BGA and chip size packages. The important points of interest are the description of processability related to existing ball attach procedures, requirements of interconnection properties and the knowledge gained the board level reliability. Both are the primary acceptance criteria for implementation. Knowledge about melting characteristic, surface tension depend on temperature and organic vehicles, wetting behavior, electrical conductivity, thermal conductivity, specific heat, mechanical strength, creep and relaxation properties, interactions to preferred finishes (minor impurities), intermetallic growth, content of IMC, brittleness depend on solved elements/IMC, fatigue resistance, damage mechanism, affinity against oxygen, reduction potential, decontamination efforts, endo-/exothermic reactions, diffusion properties related to finishes or bare materials, isothermal fatigue, thermo-cyclic fatigue, corrosion properties, lifetime prediction based on board level results, compatibility with rework/repair solders, rework temperatures of modified solders (Impurities, change in the melting point or range), compatibility to components and laminates.

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