• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.9
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• pp.11-18
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• 2018

As the height of the modular buildings increases, their stability becomes more and more dependent on the core. All traditional construction methods in structural concrete and steel can be utilized for cores in modular buildings but a core system with dry connection is more desirable to complete a greater degree of factory finish and faster erection of modular buildings. In order to do that, the hybrid PC(precast concrete) panel, which has a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, was developed, In this study the cyclic lateral loading test on the hybrid PC panel is carried out and the panel configurations are examined to enhance the structural performance in comparison with the RC wall. Experimental results show that the strength of hybrid PC panel is about 70% of thar ot RC wall and the anchorage of vertical reinforcing bar welded to C-shaped steel beam needs to be improved.

• Steel and Composite Structures
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• v.35 no.4
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• pp.495-508
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• 2020

Double skin composite walls are alternatives to concrete walls to resist gravity load in structures. The composite action between steel faceplates and concrete core largely depends on the internal mechanical connectors. This paper investigates the structural behavior of novel composite wall system with T section and under combined compressive force and bending moment. The truss connectors are used to bond the steel faceplates to concrete core. Four short specimens were designed and tested under eccentric compression. The influences of the thickness of steel faceplates, the truss spacing, and the thickness of web wall were discussed based on the test results. The N-M interaction curves by AISC 360, Eurocode 4, and CECS 159 were compared with the test data. It was found that AISC 360 provided the most reasonable predictions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.890-894
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• 1999

Microencapsulation of anchovy oil as a core material in sodium alginate as a wall material was inves tigated. Microencapsulation was accomplished by injecting an oil/water emulsion, consisting of a mixture of liquefied sodium alginate and emulsifier, under high pressure through an orifice submerged in a calcium lactate solution. Microcapsules suspended in a dispersion fluid were observed under a fluorescence mi croscope to verify the presence of the capsules and to note coalescence or degradation of the capsules. Optimum conditions for microencapsulation of anchovy oil were obtained when 1.0% aqueous solution of sodium alginate contained 3% of a 1:1 ratio of ESPR 25(polyglycerine＋polylinoleate) and TW 20(sorbitan laurate＋ethylene oxide) as an emulsifier in terms of capsule size and size distribution, and emulsion stability. The airless sprayer produced microcapsules with a diameter between 15.9 and 73.9 m with different concentration of a wall material. The optimum mixing ratio of wall material to core material was 90:10(wt/wt). 0.2% calcium lactate was appropriate as a dispersion fluid.

• International Journal of High-Rise Buildings
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• v.11 no.3
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• pp.189-196
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• 2022

The practical difficulties of construction will impose many restrictions on the structural design, and the construction method can also provide unexpected ideas for solving design problems. Through the discussion of three issues closely related to construction in the structural design of Wuhan Center, this paper illustrates the importance of in-depth consideration of the construction situations in the structural design stage. The topics of "Connection between Embedded Steel Plates in Steel Plate Composite Shear Wall" and "Connection Joint between Outrigger Truss and Core Wall" are about how to facilitate on-site construction by simplifying and optimizing detail design. The topic of "Adjusting Internal Force Distribution by Optimizing Construction Sequence" is about how to make the construction process a tool for structural design.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.201-206
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• 1995

This paper presents the experimental study on crack control of core-wall placed with 700kg/$\textrm{cm}^2$ Ultra high strength concrete. The thermal sensors were installed into the core-walls prior to the concrete casting to measure the heat of hydration and atmospheric temperature whose difference might cause the initial crack. Several curing schemes were taken for each basement floor 8 thru 6 to examine the influence of curing method on the crack width, total crack length and the number of crack occurred. This paper demonstrates that the proper curing scheme have a great favorable effect on the initial crack control on the structural elements with noticiable reduction in crack width.

• Journal of KSNVE
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• v.6 no.5
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• pp.671-677
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• 1996

This paper presents the analytical method for predicting turbulence- induced noise in the multilayered cylinder composed of an outer hose, an inner fluid and an internal core. It is assumed that an infinite axisymmetric cylinder is located horizontally in water with free stream velocity and the turbulent boundary layer (TBL) surrounding the outer hose is fully developed and homogeneous. The transfer function at the core surface due to the propagation of the pressure fluctuation within the TBL is formulated using the linearized Navier-Stockes equation for solid and fluid. In the estimation of the energy spectrum of wall pressure fluctuation, the empirical formula proposed by Strawderman based on the Corcos model is used. A general algorithm for the calculation of the pressure level at the surface of a core, that is, turbulence- induced noise, is presented. Through the detailed numerical simulation, it is found that the major noise mechanism is the propagation of the bulge wave along hose.

• Earthquakes and Structures
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• v.15 no.2
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• pp.203-214
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• 2018

Deflection control in tall buildings is a challenging issue. Connecting of the towers is an interesting idea for architects as well as structural engineers. In this paper, two reinforced concrete core-wall towers are connected by a truss bridge with buckling restrained braces. The buildings are 40 and 60-story. The effect of the location of the bridge is investigated. Response spectrum analysis of the linear models is used to obtain the design demands and the systems are designed according to the reliable codes. Then, nonlinear time history analysis at maximum considered earthquake is performed to assess the seismic responses of the systems subjected to far-field and near-field record sets. Fiber elements are used for the reinforced concrete walls. On average, the inter-story drift ratio demand will be minimized when the bridge is approximately located at a height equal to 0.825 times the total height of the building. Besides, because of whipping effects, maximum roof acceleration demand is approximately two times the peak ground acceleration. Plasticity extends near the base and also in major areas of the walls subjected to the seismic loads.

• The Journal of Korean Academy of Prosthodontics
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• v.24 no.1
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• pp.55-65
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• 1986

An in vitro study was performed to evaluate adaptation of custom direct, custom indirect, and prefabricated post system on 15 extracted upper central incisors. 15 specimens were prepared and equally devided into 3 groups under random sampling. Each group of 5 cast posts was made with custom direct, custom indirect, and prefabricated post core method. Gap between inner wall of the dentin and outer wall of the cast post was measured on electron microphotographic prints at x500 magnification. The result were as follows ; 1. No significant difference of adaptation at cervical portion was found between each method. 2. Prefabricated post core method had poor adaptation compared with other methods. 3. Even distribution of adaptation was found in custom direct method between each portion. 4. Prefabricated post core method showed remarkable difference in adaptation between each portion.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.715-722
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• 2014

In this paper, internal blast effect of reinforced concrete core structure were investigated using Ansys Autodyn, which is a specialized hydrocode for the analysis of explosion and impact. It is expected that internal blast case can give additional damage to the structure because it causes rebound of blast loads. Therefore, in this paper, the hazard of internal blast effect is demonstrated using UFC 3-340-02 criteria. In addition, analysis result of Autodyn, experimental result regarding rebound of blast load, and example of UFC 340-02 are compared to verify that Autodyn can analyze internal blast effect properly. Furthermore, progressive collapse mechanism of core structure which is one of the most important parts in high rise buildings is also analyzed using Autodyn. When internal blasts are loaded to core structure, the core structure is mostly damaged on its corner and front part of core wall from explosives. Therefore, if the damaged parts of core wall are demolished, progressive collapse of the core structure can be initiated.

• International Journal of High-Rise Buildings
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• v.10 no.3
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• pp.243-250
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• 2021

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