• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.293-297
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• 2009

In this thesis, design of a VCO(Voltage controlled Oscillator) with a novel tuning mechanism is presented for the Radar system. This circuit, the 9.5 GHz oscillator is designed and implemented by restructuring microstrip resonator to raise Q value and to require a wide frequency tuning range. This product is fabricated on 2.6 Teflon substrate and device is NE722S01. In this paper, The new microstrip resonator VCO is proposed to achieve the characteristic of a wide frequency tuning range. This microstrip resonator VCO shows the phase noise characteristic of -108.3 dBc/Hz at 1 MHz offset from the fundamental frequency, the output power of 5.7 dBm and the second harmonic suppression of -38 dBc for the VCO are obtained. The manufacture VCO shows a frequency tuning range of 193.8 MHz. The proposed micro trip resonator VCO can be used for X-band Radar System with required tuning range.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.21-24
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• 2002

This paper presents a fully integrated, wide tuning range differential CMOS voltage-controlled oscillator, tuned by pMOS-varactors. VCO utilizing a novel tuning scheme is reported. Both coarse digital tuning and fine analog tuning are achieved using pMOS-varactors. The VCO were implemented in a 0.18-fm standard CMOS process. The VCO tuned from 1.8㎓ to 2.55㎓ through 2-bit digital and analog input. At 1.8V power supply voltage and a total power dissipation of 8mW, the VCO features a phase noise of -126㏈c/㎐ at 3㎒ frequency offset.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 추계학술대회 논문집
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• pp.182-186
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• 1992

A self tuning technique is derived for PID controllers which are widely used in industries. The tuning algorithm is based upon a fuzzy indirect reasoning method and an iterative technique. The fuzzy technique is considered to obtain ease and simplicity of tuning process. The PID gains for the first tuning action are determined by a method which is modified from the Ziegler-Nichols step response method. The first PID gains are determined to obtain a control performance so close to a design performance that the followed tuning process can be made effectively. The design parameters are given as time-domain variables which human is familiar with. The results of simulation studies show that the proped tuning method can produce an effective tuning for arbitaray design performances.

• 한국공작기계학회논문집
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• 제17권5호
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• pp.44-51
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• 2008

In this paper, the optimal tuning of a cross-coupled controller linked with the feedforward controller is studied to reduce contouring and tracking errors of a bi-axial servomechanisms by using the previously developed integrated tuning method. The CCC system for an arbitrary curve, which is combined with the feedforward controller, is formulated by a state-space based on a series of linear motion trajectories. An optimal tuning problem is formulated as a nonlinear constrained optimization problem including relevant controller parameters of the servo. To verify the effectiveness of the proposed optimal tuning procedure, linear and circular motion experiments are performed on the xy-table. Experimental results confirm that both tracking and contouring errors are significantly reduced by applying the proposed control and tuning system.

• ETRI Journal
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• 제38권3호
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• pp.455-462
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• 2016

Frequency hopping (FH) is a common characteristic of a wide variety of communication systems. On the other hand, software-defined radio (SDR) is an increasingly utilized technology for implementing modern communication systems. The main challenge when trying to realize an SDR FH system is the frequency tuning time, that is, the higher the hopping rate, the lower the required frequency tuning time. In this paper, significant universal hardware driver tuning options (within GNU Radio software) are investigated to discover the tuning option that gives the minimum frequency tuning time. This paper proposes an improved SDR frequency tuning algorithm for the generation of a target signal (with a given target frequency). The proposed algorithm aims to improve the frequency tuning time without any frequency deviation, thus allowing the realization of modern communication systems with higher FH rates. Moreover, it presents the design and implementation of an original GNU Radio Companion block that utilizes the proposed algorithm. The target SDR platform is that of the Universal Software Radio Peripheral USRP-N210 paired with the RFX2400 daughter board. Our results show that the proposed algorithm achieves higher hopping rates of up to 5,000 hops/second.

• 한국산업융합학회 논문집
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• 제25권5호
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• pp.757-764
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• 2022

Recently the car tuning has become a trailblazing and creative culture that expresses the personality of the owner. In this paper, the "Car-Vatar", which is the compound word formed from the words "Car" and "Avatar", has been developed to investigate car tuning on the metaverse engineering platform. The Car-Vatar has been developed as a web-based vehicle dynamic simulation service for providing information about car tuning. That has been focused on investigating diverse vehicular performances, such as acceleration, braking, handling and fuel efficiency, according to the tuning vehicles and tuning parts on the virtual engineering platform. The Car-Vatar platform has provided two major services; one is real-time 3D tuning information system for the dress-up and performance-up tuning parts, the other is diverse vehicle dynamics system for the performance-up tuning parts. To check the validation of the Car-Vatar platform, the comparison between virtual simulation results and driving test results has been discussed on various driving environments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.184-187
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• 1996

In this paper, an algorithm for tuning gains of a PID controller is proposed. The proposed algorithm is composed of two stages. The first is a stage for Lyapunov function-based initial stabilization of an overall system and rough tuning gains of the PID controller. The other is that for fine tuning gains of the PID controller. All tunings are performed by using the well-known fuzzy logic-based tuner. The computer simulations are performed to show the validity of the proposed algorithm and results are presented.

• 대한전기학회논문지
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• 제43권5호
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• pp.819-826
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• 1994

This paper deals with a self-tuning fuzzy controller. The fuzzy controller is constructed with linguistic rules which consist of the fuzzy sets. Each fuzzy set is characterized by a membership function. The tuning fuzzy controller has paramenters that are input/output scaling factors to effect control output. In this paper we propose a tuning method for the scaling factor Computer simulations carried out on first-order and second-order processes will show how the present tuning approach improves the transient and the steady-state characteristics of the overall system.The applicability of the proposed algorithm is certified by computer simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.218-220
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• 1993

This paper deals with a self-tuning fuzzy controller. The fuzzy controller is constructed with linguistic rules which consist of the fuzzy variables and fuzzy sets. Each of fuzzy sets is characterized by a membership function. The tuning fussy controller has paramemters to effect control output. In this paper we propose tuning method for the scaling factor. Computer simulations carried out on a second-order process will show how the present tuning approach improves the transient and steady-state characteristics of the overall system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.102.5-102
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• 2002

In this paper auto-tuning scheme of PID controller based on the reference model has been studied by immune algorithm for a process. Up to this time, many sophisticated tuning algorithms have been tried in order to improve the PID controller performance under such difficult conditions. However, in the actual plant, they are manually tuned through a trial and error procedure, and the derivative action is switched off. Therefore, it is difficult to tune. Simulation results by immune based tuning reveal that tuning approaches suggested in this paper is an effective approach to search for optimal or near optimal process control.