• Advances in concrete construction
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• v.8 no.1
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• pp.9-19
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• 2019

This paper describes an experimental investigation on hybrid fiber reinforced concrete (HYFRC) beams. And the main aim of this present paper is to examine the dynamic characteristics and damage evaluation of undamaged and damaged HYFRC beams under free-free constraints. In this experimental work, totally four RC beams were cast and analyzed in order to evaluate the dynamic behavior as well as static load behavior of HYFRCs. Hybrid fiber reinforced concrete beams have been cast by incorporating two different fibers such as steel and polypropylene (PP). Damage of HYFRC beams was obtained by cracking of concrete for one of the beams in each set under four-point bending tests with different percentage variation of damage levels as 50%, 70% and 90% of maximum ultimate load. And the main dynamic characteristics such as damping, fundamental natural frequencies, mode shapes and frequency response function at each and every damage level has been assessed by means of non-destructive technique (NDT) with hammer excitation. The fundamental natural frequency and damping values obtained through dynamic tests for HYFRC beams were compared with control (reference) RC beam at each level of damage which has been acquired through static tests. The static experimental test results emphasize that the HYFRC beam has attained higher ultimate load as compared with control reinforced concrete beam.

• Journal of the Korean GEO-environmental Society
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• v.22 no.7
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• pp.5-12
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• 2021

The reliable seismic stability evaluation of the natural slopes and geotechnical structures has become a critical factor of the design. Pseudo-static or permanent displacement methods are typically employed to evaluate the seismic slope performance. In both methods, the effect of input ground motion on the sliding surface is ignored, and failure surface from the limit equilibrium method is used. For the assessment of the seismic sensitivity of failure surface, two-dimensional non-linear finite element analyses are performed. The performance of the finite element model was validated against centrifuge measurements. A parametric study with a range of input ground motion was performed, and numerical results were used to assess the influence of ground motion characteristics on the sliding surface. Based on the results, it is demonstrated that the characteristics of input ground motion have a significant influence on the location of the seismically induce failure surface. In addition to dynamic analysis, pseudo-static analyses were performed to evaluate the discrepancy. It is observed that sliding surfaces developed from pseudo-static and dynamic analyses are different. The location of the failure surface change with the amplitude and T_m of motion. Therefore, it is recommended to determine failure surfaces from dynamic analysis

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.115-117
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• 2022

The electrical characteristics of the monolithic 3-dimensional static random access memory consisting of a feedback field-effect transistor (M3D-SRAM-FBFET) was investigated using technology computer-aided design (TCAD). The N-type FBFET and N-type MOSFET are designed with fully depleted silicon on insulator (FDSOI), and those are located at bottom and top tiers, respectively. For the M3D-SRAM-FBFET, as the supply voltage decreased from 1.9 V to 1.6 V, the reading on-current decreased approximately 10 times.

• Steel and Composite Structures
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• v.51 no.6
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• pp.601-617
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• 2024

This work aims to explore the static behaviour of a tapered functionally graded porous plate (FGPP) with even and uneven porosity distributions resting on two parametric elastic foundations. The plate under investigation is subjected to bi-sinusoidal loading and the edges of the plate are exposed to different combinations of edge restrictions. In order to examin the static behaviour, bending factors (BF) related to bending and normal stresses have been evaluated using classical plate theory. To achieve this, the governing equations have been derived employing the energy concept. And to solve it, the Rayleigh-Ritz method with an algebraic function has been utilised; it is simple, precise, and computationally intensive. After convergence and validation analyses, new findings are made available. The BF of the plate have been exhaustively examined to explain the influence of aspect ratios, material property index, porosity factor, taper factor, and Winkler and Pasternak stiffness. It is observed that the BF of an elastically supported FGPP are influenced by the index of material propery and the aspect ratio. Findings also indicate that the impact of porosity is more when it is spread evenly, as opposed to when it is unevenly distributed. Further, the deformed plate's structure is significantly influenced by the different thickness variations. Examination of bending characteristics of FGPP having different new cases of thickness variations with different types of porosity distribution under fifteen different mixed edge constraints is the prime novality of this work. Results presented are reliable enough to be taken into account for future studies.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.3
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• pp.55-67
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• 1986

The safety and comfort of car seats wee studied by utilization of engineering analysis/ experiment and human engineering data. As important factors of the static seating comfort, static spring constant, body pressure distribution, driving posture were discussed. In connection with the dynamic seating comfort, vibrational characteristics of domestic car seats(natural frequencies, damping, frequency spectrum, transmission ratio)were measured and discussed. Finally, the safety of the seat was analyzed and evaluated through calculation and experiments.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.759-762
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• 1998

In this paper, a SL-DCVSL (static latched differential cascode voltage switch logic) circuit for the asynchronous pipeline is proposed. The proposed SL-DCVSL circuit is a slightly modified version of the DCVSL circuit, and used to improve the storage capability of the precharged functional blocks. The proposed SL-DCVSL has more robust storage characteristics compared to the conventional LDCVSL (latched DCVSL〔2〕). The operation of the proposed circuit is verified by simulating the asynchronous FIFO (First-In First-Out) structure.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.280-284
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• 1997

In this paper theoretical foundation of distribution STATCON, the operating characteristics of D-STATCON, the overview of control technologies for power factor correction of D-STATCON, and the PWM current control of D-STATCON and simulated results are given to shows the practical feasibility of a Flexible AC Transmission System and Distribution Static Condenser.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.05a
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• pp.257-262
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• 1998

In order to understand the characteristics of electrostatic discharge (ESD) by a charged human body, a dynamic analysis method based on RCL circuit and a quasi-static analysis method based on two-body model are introduced. In this paper, these methods calculate waveforms, discharge energy and potential difference to analyze the ESD phenomena from given initial conditions and geometry. Results are compared and discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.225-230
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• 1995

Concrete structures need repair and rehabilitation due to functional deficiencies such as cracks, scaling and spalling. Loss of section such as spalling is caused by corrosion of reinforcing bar, fire, temperature change, poor design and etc. This study aims to examine the characteristics of polymer(epoxy)and polymer-cement(latex) for repair materials and to provide the proper repair scheme through static and fatigue tests. Totally 12 beams were tested. Results from static and fatigue tests of beams repaired with polymer and polymer-cement were compared.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.579-582
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• 2004

This paper presents controller design of a static var compensator using PWM Cuk AC-AC converter. The PWM Cuk AC-AC converter is modelled by using complex circuit DQ transformation and perturbed around the operating point whereby the small signal system characteristics is analytically obtained. Finally, the PSIM simulations show the validity of the modelling and analysis.