• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.8
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• pp.1159-1168
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• 1993

The Switched-Capacitor Integrator(SCI) is a basic building block of Switched-Scpacitor Filter(SCF). But owing to the errors from the finite gain and bandwidth of op-amp on SCI, the most of SCP are limited to their applications. Although many of the compensation methods developed for active RC filters can be directly adapted to SCF, this is not true for the analysis of the effects of the op-amp dynamics on the filter response. The effect of finite op-amp gain is similar to the active RC filters. But SCF is more toter-ant of the finite op-amp bandwidth. In this paper, we have considered the errors of the finite gain and bandwidth of op-amp on SCI , and presented the simple and effective methods of compensating the errors of SCI due to the finite op-amp gain using the buffer circuit.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.2
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• pp.184-191
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• 1993

Continuous-time integrated filters, implemented in MOS VLSI technology, have been receiving considerable attention. In this paper, a continuous-time fifth order elliptic low-pass MOSFET-C filter has been designed with a cutoff frequency 3,400Hz. First an active RC filter is designed using cascade method which each block can be tunable. And then the resistors of an active RC network are replaced by a linear resistor using NMOS depletion transistors operated in the triode region. This continuous-time MOSFET filter have simpler structure than switched-capacitor filter, so reduce the chip area. The designed MOSFET-C filter characteristics are simulated by PSPICE program.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.5
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• pp.69-74
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• 1985

In this paper five-order Butterworth Low pass active RC filter is designed by using FDNR (Frequency Dependent Ncgative Resistor) Method from LC ladder filter having the lowest sensitivity. In process of Transformation to SCF (Switched Capacitor Filter) from active RC filter, Bilinear Z Transfomation method is utilized. By the design of SCF using the bilinear Z transform method the problem of aliasing can be avoided, but the frequency distortion is generated. The transformation from analog filter to digital filter is not equal in the region of the cut off frequency caused by this effect. Avoiding the problem of this effect, we use prewarping method. The result shows that the prewarped SCF makes more remarkable improvement in the frequency distortion than SCF which is transformed by using bilinear Z transform.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.2
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• pp.14-21
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• 1981

This paper describes a method for realizing RC active filters, by the use of the CGIC's In realizing the CGIC circuit, every element in the circuit is selected so as to minimize the effect of the non -ideal characteristic of operational amplifers, and an extra element is added to the, CGIC circuit to compensate the parasitic capacitances of the circuit. The CGIC s are utilized in the design of active filters using ladder embedding technique. The design procedure is presented in detail and the application is illustrated by the design of a band-pass filter of high order.

• Computers and Concrete
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• v.16 no.1
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• pp.141-161
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• 2015

A significant portion of residential areas of Turkey is located in active earthquake zones. In Turkey occurred major earthquakes in last twenty years, such as Erzincan (1992), Kocaeli and $D{\ddot{u}}zce$ (1999), $Bing{\ddot{o}}l$ (2003), Van (2011). These earthquakes have demonstrated that reinforced concrete (RC) buildings having horizontal and vertical irregularities are significantly damaged, which in turn most of them are collapsed. Architectural design and arrangement of load-bearing system have important effect on RC building since architectural design criteria in design process provide opportunity to make this type of buildings safer and economical under earthquake loads. This study aims to investigate comparatively the effects of weak story irregularity on earthquake behavior and rough construction costs of RC buildings by considering different soil-conditions given in the Turkish Earthquake Code. With this aim, Sta4-CAD program based on matrix displacement method is utilized. Considering that different story height and compressive strength of concrete, and infill walls or their locations are the variables, a set of structural models are developed to determine the effect of them on earthquake behavior and rough construction costs of RC buildings. In conclusion, some recommendations and results related to making RC buildings safer and more economical are presented by comparing results obtained from structural analyses.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.276-283
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• 2006

Korea is considered to be immune from the earthquake hazard because it is located far away from the active fault. However, recent earthquake caused a loss of lives and economical loss worldwide. Hence there has been raised an importance of the earthquake resistant design for various infrastructures. In this research, the seismic design and evaluation criterion for RC bridge pier were proposed from the experimental results of 82 circular RC bridge piers tested in domestic and aboard. New seismic criterion was introduced the limited ductile design provision suitable to Korean peninsula, which would be classified as a low or moderate seismic region. In addition, further important topic for the seismic safety of RC bridge piers in Korea is the seismic performance enhancement of RC bridge piers, which were designed and constructed before the 1992 seismic design provision. Therefore, the proposed seismic performance evaluation criterion could be very useful to judge seismic retrofit need or not according to the residual seismic performance of the RC bridge piers. Also, it could reduce an uncertainty for the safety of the infrastructure under earthquakes.

• Smart Structures and Systems
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• v.4 no.4
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• pp.391-406
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• 2008

This study attempts to develop a real-time debonding monitoring system for carbon fiber-reinforced polymer (CFRP) strengthened structures by continuously inspecting the bonding condition between the CFRP layer and the host structure. The uniqueness of this study is in developing a new concept and theoretical framework of nondestructive testing (NDT), in which debonding is detected without relying on previously-obtained baseline data. The proposed reference-free damage diagnosis is achieved based on the concept of time reversal acoustics (TRA). In TRA, an input signal at an excitation point can be reconstructed if the response signal measured at another point is reemitted to the original excitation point after being reversed in the time domain. Examining the deviation of the reconstructed signal from the known initial input signal allows instantaneous identification of damage without requiring a baseline signal representing the undamaged state for comparison. The concept of TRA has been extended to guided wave propagations within the CFRP-strengthened reinforced concrete (RC) beams to improve the detectibility of local debonding. Monotonic and fatigue load tests of large-scale CFRP-strengthened RC beams are conducted to demonstrate the potential of the proposed reference-free debonding monitoring system. Comparisons with an electro-mechanical impedance method and an inferred imaging technique are provided as well.

• ETRI Journal
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• v.27 no.5
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• pp.647-650
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• 2005

A new configuration to realize the most general n-th order voltage transfer function is proposed. It employs only one operational transresistance amplifier (OTRA) as the active element. In the synthesis of the transfer function, the RC:-RC decomposition technique is used. To the best of author's knowledge, this is the first topology to be used in the realization of n-th order transfer function employing single OTRA.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.6
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• pp.8-13
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• 1993

A systematic synthesis process is presented for the simulation of current-controlled grounded inductors. The process is used to obtain three circuits which are believed to be novel. One of the circuits has been implemented using linear operational transconductance amplifiers (OTA's). Computer simulation rusults are used to verify theoretical predictions. The results show close agreement between predicted behaviour and experimental performance.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.12
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• pp.54-62
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• 2003

A systematic synthesis process is described lot the simulation of current-controllable inductors using operational transconductance amplifiers (OTAs). The process is used to obtain three circuits; two are believed It) be novel. The process is also applied to design current-controllable frequency-dependent negative resistances (FDNRs). Operation principles of designed circuits are presented and experimental results are used to verify theoretical predictions. The results show close agreement between predicted behavior and experimental performance. The application of a FDNR to a current-controllable band-pass filter is also presented.