• Journal of Radiation Protection and Research
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• v.26 no.1
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• pp.19-26
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• 2001

In order to assess the atmospheric dispersion for the accidental releases of nuclear power plants, in calculating X/Q values in the XOQAR and PAVAN codes which are based on Reg. Guide 1.145, the X/Q and frequency values are plotted on log-normal paper. Starting with the highest X/Q value of this plot, the codes compare the slope of the line drawn from this point to every other point within an increment containing ten X/Q values. If there are fewer than ten values, only the number available are used. The coefficients that produce the line with the least negative slope are saved. The end point of this line is used as the next starting point, from which slopes to the points within the next increment, containing ten X/Q values, are compared. The X/Q values corresponding to the cumulative frequency values 0.5%, 5% or 50% are calculated to search for the $0{\sim}2$ hour X/Q value that tends to be a very conservative value. In this work, a fuzzy logic inference method is used for nonlinear interpolation of the X/Q values versus the cumulative frequency. The fuzzy logic inference method is known to be a food technique for nonlinear interpolation. The proposed method was applied to a potential accidential radioactive release of the Yonggwang nuclear power plant, which gives more realistic X/Q values.

• East Asian mathematical journal
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• v.23 no.3
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• pp.313-326
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• 2007

The purpose of education of propositional logic is to understand the basic structure of the mathematics and to improve the logical thinking in normal life. But in the seventh curriculum, some basic terms, for examples $\wedge$ and $\vee$, are not introduced, the proposition $p{\\rightarrow}q$ is not defined properly, and use the wrong term $\Rightarrow$ so that it is difficult to understand the propositional logic. In this paper, we present a suitable content for the propositional logic in high-school mathematical class. We also present a proper definition of the proposition $p{x}{\Rightarrow}q{x}$ without using the notation $\rightarrow$. We finally give proper definitions of necessary conditions, sufficient conditions, and necessary and sufficient conditions.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.1
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• pp.79-85
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• 2006

This paper presents a strategy and tactic for robot soccer using furry logic mediator that determines robot action depending on the positions and the roles of adjacent two robots. Conventional Q-learning algorithm, where the number of states increases exponentially with the number of robots, is not suitable for a robot soccer system, because it needs so much calculation that processing cannot be accomplished in real time. A modular Q-teaming algorithm reduces a number of states by partitioning the concerned area, where mediator algorithm for cooperation of robots is used additionally. The proposed scheme implements the mediator algorithm among robots by fuzzy logic system, where simple fuzzy rules make the calculation easy and hence proper for robot soccer system. The simulation of MiroSot shows the feasibility of the proposed scheme.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.268-271
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• 2001

This paper describes the power factor control of doubly fed induction machine using fuzzy logic algorithm in wind power generation system. Under fuzzy logic control, which enables superior dynamic performance, the power factor is independently controllable by decoupled d, q rotor experimental results are presented.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.447-448
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• 2013

This paper investigates a new approach based on the fuzzy-logic controlled methodology that is suitable for analyzing and evaluating large format $LiMn_2O_4$ cell performance via online state-of-health (SOH) estimation for energy storage system (ESS) applications. First of all, the values of the cell resistance R and maximum cell capacity $Q_{max}$ are calculated from three factors such as voltage, current, and time that were measured by discharging/charging sequence. Then, using two values R and $Q_{max}$ previously calculated, present SOH of an arbitrary $LiMn_2O_4$ cell can be estimated using the defined fuzzy-logic inference system. The main advantage of this approach is wide parameters tuning possibility for good correspondence of SOH decay with other accurate estimation method and the possibility to perform suitable online SOH estimation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1283-1291
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• 2002

In this paper, the PLL driven by the DDFS is designed on the schematic using the Q-logic cell based library and is implemented using FPGA QL32 x16B. The measurement results of the frequency synthesizer switching speed were agreement with a register. The simulated results show that the clock delay was generated after eleven clock and if input is random, It has influence on output DA converter has to be very extensive. Therefore, the DDFS used noise shaper to drive PLL by regular interval for input state. Also the bandwidth of DA converter very extensive, the simulation shows that the variation of small input control word is better than the switching speed of PLL.

• Journal of Power Electronics
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• v.11 no.6
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• pp.914-921
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• 2011

Commencing with incandescent light bulbs, every load today creates harmonics. Unfortunately, these loads vary with respect to their amount of harmonic content and their response to problems caused by harmonics. The prevalent difficulties with harmonics are voltage and current waveform distortions. In addition, Electronic equipment like computers, battery chargers, electronic ballasts, variable frequency drives, and switching mode power supplies generate perilous amounts of harmonics. Issues related to harmonics are of a greater concern to engineers and building designers because they do more than just distort voltage waveforms, they can overheat the building wiring, cause nuisance tripping, overheat transformer units, and cause random end-user equipment failures. Thus power quality is becoming more and more serious with each passing day. As a result, active power filters (APFs) have gained a lot of attention due to their excellent harmonic compensation. However, the performance of the active filters seems to have contradictions with different control techniques. The main objective of this paper is to analyze shunt active filters with fuzzy and pi controllers. To carry out this analysis, active and reactive current methods ($i_d-i_q$) are considered. Extensive simulations were carried out. The simulations were performed under balance, unbalanced and non sinusoidal conditions. The results validate the dynamic behavior of fuzzy logic controllers over PI controllers.

• Korean Journal of Logic
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• v.11 no.2
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• pp.93-125
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• 2008

The radical probabilitists deny that propositions represent experience. However, since the impact of experience should be propagated through our belief system and be communicated with other agents, they should find some alternative protocols which can represent the impact of experience. The useful protocol which the radical probabilistists suggest is the Bayes factors. It is because Bayes factors factor out the impact of the prior probabilities and satisfy the requirement of commutativity. My main challenge to the radical probabilitists is that there is another useful protocol, q(E|$N_p$) which also factors out the impact of the prior probabilities and satisfies the requirement of commutativity. Moreover I claim that q(E|$N_p$) has a pragmatic virtue which the Bayes factors have not.

• Journal of Power Electronics
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• v.12 no.5
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• pp.821-829
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• 2012

This research article presents a novel approach based on an instantaneous active and reactive power component (p-q) theory for generating reference currents for shunt active filter (SHAF). Three-phase reference current waveforms generated by proposed scheme are tracked by the three-phase voltage source converter in a hysteresis band control scheme. The performance of the SHAF using the p-q control strategy has been evaluated under various source conditions. The performance of the proposed control strategy has been evaluated in terms of harmonic mitigation and DC link voltage regulation. In order to maintain DC link voltage constant and to generate the compensating reference currents, we have developed Fuzzy logic controller with different (Trapezoidal, Triangular and Gaussian) fuzzy M.F.s. The proposed SHAF with different fuzzy M.F.s is able to eliminate the uncertainty in the system and SHAF gains outstanding compensation abilities. The detailed simulation results using MATLAB/SIMULINK software are presented to support the feasibility of proposed control strategy. To validate the proposed approach, the system is also implemented on a real time digital simulator and adequate results are reported for its verifications.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1358-1361
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• 1993