• Computers and Concrete
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• v.31 no.1
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• pp.53-69
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• 2023

The rotational stiffness of a semi-rigid beam-to-column connection plays an important role in the reduction of the second-order effects in the precast concrete skeletal frames. The aim of this study is to present a detailed nonlinear finite element study to reproduce the experimental response of a semi-rigid precast beam-to-column connection composed by corbel, dowel bar and continuity tie bars available in the literature. A parametric study was carried using four arrangements of the reinforcing tie bars in the connection, including high ratio of the continuity tie bars passing around the column in the cast-in-place concrete. The results from the parametric study were compared to analytical equations proposed to evaluate the secant rotational stiffness of beam-to-column connections. The good agreement with the experimental results was obtained, demonstrating that the finite element model can accurately predict the structural behaviour of the beam-to-column connection despite its complex geometric configuration. The secant rotational stiffness of the connection was good evaluated by the analytical model available in the literature for ratio of the continuity tie bars of up to 0.69%. Precast beam-to-column connection with a ratio of the continuity tie bars higher than 1.4% had the secant stiffness overestimated. Therefore, an adjustment coefficient for the effective depth of the crack at the end of the beam was proposed for the analytical model, which is a function of the ratio of the continuity tie bars.

• Journal of the Korea Concrete Institute
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• v.11 no.5
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• pp.11-20
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• 1999

This paper deals with behaviors of PSC-Beam bridges according to continuity of spans. To analyze the long-term behavior of bridges, an analytical model which can simulate the effects of creep, the shrinkage of concrete, and the cracking of concrete slabs in the negative moment regions is introduced. To consider the different material properties across the sectional depth, the layer approach in which a section is divided into imaginary concrete and steel layers is adopted. The element stiffness matrix is constructed according to the assumed displacement field formulation, and the creep and shrinkage effects of concrete are considered in accordance with the first-order algorithm based on the expansion of the creep compliance. Correlation studies between analytical and experimental results are conducted with the objective to establish the validity of the proposed model. Besides, many uncertainties related to the continuity of spans are analyzed to minimize deck cracking at interior supports.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.12
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• pp.83-92
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• 2019

The purpose of this study is to analyze the continuous forms of time and space that work as architectural design principles of the Memorial to the Murdered Jews of Europe (Jewish Memorial). Continuity is divided into two, physical and non-physical attributes. The former extends from small installations to furnitures, finishes, spatial composition, and even spatial networks that complete architecture, and the latter is tied to time, from traditional to historical, developmental, commemorative or memorial elements. They are inherent in architecture as continuous forms. The Jewish Memorial is analyzed by the analysing framework of these two items. The analysis of the two layers can be summarized as follows; physical continuity is found in the space networks of the Memorial's inside and outside, the undulating spaces, the finishes, the small furnitures and installations, the entrances of staircases, the expanded underground of the ground order, and non-physical continuity manifests in the topological variation of spatiality, the morphological development of memorial architecture, the connection of semantic sense of space, and the superposition of historicity and modernity. These forms of continuity do not aestheticize the German enormity history, but make the meaning of the Memorial into non-superficial, in-depth architecture as a monument. Thus, the results of this study show that physical and non-physical continuity should be considered as the important design principles of architecture that makes the Memorial architecture possible.

• Structural Engineering and Mechanics
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• v.17 no.6
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• pp.879-898
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• 2004

A method of making simply supported girders continuous is described for bridges with spans of 30-45 m. The splicing method takes advantage of an induced secondary moment to transform the self-weight stresses in the precast simply supported girders into values representative of a continuous girder. The secondary moment results from prestressing of continuity tendons and detensioning of temporary tendons in the girders. Preliminary sections are selected for spliced U-girder bridges with a range of span lengths. Use of the proposed technique results in girder depth reductions of 500-800 mm when compared to standard simply supported I-girder bridges. The flexural behavior of an example bridge with 40-m spans is examined to illustrate the necessary considerations for determining the optimum sequence of splicing operations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.19-29
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• 2015

As the half-depth precast concrete decks are increasingly applied to the construction sites, researches on connection details have been increased. For design of concrete bridge deck with half-depth precast panels, it is required to provide appropriate details of transverse loop joints between panels. In this paper, the structural performance of precast decks was evaluated to investigate continuity of the proposed loop joint details. From the results, the validity of the joints for the continuity of deck was observed in the aspect of flexural strength and crack control. The ultimate strength increased 1.52 times as the reinforcement spacing in the joint was reduced. In terms of crack control, direct crack width calculation for the loop joint showed appropriate results comparing with measured crack width.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1857-1862
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• 2016

Human activity recognition using depth information is an emerging and challenging technology in computer vision due to its considerable attention by many practical applications such as smart home/office system, personal health care and 3D video games. This paper presents a novel framework of 3D human body detection, tracking and recognition from depth video sequences using spatiotemporal features and modified HMM. To detect human silhouette, raw depth data is examined to extract human silhouette by considering spatial continuity and constraints of human motion information. While, frame differentiation is used to track human movements. Features extraction mechanism consists of spatial depth shape features and temporal joints features are used to improve classification performance. Both of these features are fused together to recognize different activities using the modified hidden Markov model (M-HMM). The proposed approach is evaluated on two challenging depth video datasets. Moreover, our system has significant abilities to handle subject's body parts rotation and body parts missing which provide major contributions in human activity recognition.

• International Journal of Aerospace System Engineering
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• v.3 no.1
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• pp.10-16
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• 2016

A trigonometric Layerwise higher order shear deformation theory (TLHSDT) is developed and implemented for free vibration and buckling analysis of laminated composite and sandwich plates by analytical and finite element formulation. The present model assumes parabolic variation of out-plane stresses through the depth of the plate and also accomplish the zero transverse shear stresses over the surface of the plate. Thus a need of shear correction factor is obviated. The present zigzag model able to meet the transverse shear stress continuity and zigzag form of in-plane displacement continuity at the plate interfaces. Hence, botheration of shear correction coefficient is neglected. In the case of analytical method, the governing differential equation and boundary conditions are obtained from the principle of virtual work. For the finite element formulation, an efficient eight noded $C^0$ continuous isoparametric serendipity element is established and employed to examine the dynamic analysis. Like FSDT, the considered mathematical model possesses similar number of variables and which decides the present models computationally more effective. Several numerical predictions are carried out and results are compared with those of other existing numerical approaches.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1296-1305
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• 2008

In this study, the spatial distribution of depth between alluvial soil and weathered soil of Song-do new city is analyzed using geostatistics. From analysis results, the boundary depth of north-east region is deeper than that of south-west region, and average depth of north-east region is 27.14m and average depth of south-west region is 23.25m. The boundary depth is estimated by ordinary kriging and inverse distance method, and estimated results are almost similarity. So, in Song-do new city, these two method can be used to estimate the boundary depth. The ordinary kriging method is a very useful tool because the more exact analysis of spatial continuity and distribution characteristic is possible.

• Journal of Ocean Engineering and Technology
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• v.10 no.3
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• pp.96-104
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• 1996

Hamilton's principle is used to derive Euler-Lagrange equations for free surface flow problems of incompressible ideal fluid. The velocity field is chosen to satisfy the continuity equation a priori. This approach results in a hierarchial set of governing equations consist of two evolution equations with respect to two canonical variables and corresponding boundary value problems. The free surface elevation and the Lagrange's multiplier are the canonical variables in Hamilton's sense. This Lagrange's multiplier is a velocity potential defined on the free surface. Energy is conserved as a consequence of the Hamiltonian structure. These equations can be applied to waves in water of finite depth including generalization of Hamilton's equations given by Miles and Salmon.

• Korean Journal of Health Education and Promotion
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• v.17 no.1
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• pp.185-213
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• 2000

The purpose of this study is to analyze and compare dental hygine curriculum of three countries--Korea, U.S.A., and Japan--, focusing on the ways of organizing content. In this study, 30 curriculum documents of dental hygienist in U.S., Japan, and Korea were analyzed and discussed by a framework of analysis which was constructed referring to Tylerian curriculum model. Using this framework, three kinds of key components of curriculum document were compared according to specific elements of each component. More specifically, comparing those curriculum documents, we must consider the dimension of content organization. In this study, the problem of course organization was viewed on three dimensions: continuity, sequence, and integration of curriculum content. Based on the results of this study, the conclusions are as follows. 1. Courses of dental hygienist education should be organized so that the curriculum foster the cumulative and continuous learning. It will be accomplished by considering the essential procedures or sequence of dental hygiene activities. 2. When organizing curriculum elements, we should consider the continuity dimension of learning content. Continuity deals with the vertical manipulation or repetition of curriculum components. In other words, it accounts for the reappearance in the curriculum of certain major ideas or skills. Therefore, courses should be based on the level of the dental hygienist activities in order to ensure a continuity of learning experiences. 3. Dental hygienist curriculum must be organized in a way to integrate the logic of dental hygiene as a discipline with the process of dental hygiene performance. Integration refers to the linking of all types of knowledge and experiences contained within the curriculum design. It emphasizes horizontal relations among various content topics and themes involving all domains of knowledge recognized. Thus, courses of dental hygiene curriculum should be integrated to allow college students to obtain a unified view of knowledge and an in-depth meaning of the dental hygiene as a profession.