• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1624-1632
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• 2009

In this study, we introduce the design methodology of an optimized Interval Type-2 fuzzy controller. The fixed MF design of type-1 based FLC leads to the difficulty of rule-based control design for representing the linguistically uncertain expression. In the Type-2 FLC as the expanded type of Type-1 FLC, we can effectively improve the control characteristic by using the footprint of uncertainty(FOU) of membership function. Type-2 FLC has a robust characteristic in the unknown system with unspecific noise when compared with Type-1 FLC. Through computer simulation as well as practical experiment, we compare their performance by applying both the optimized Type-1 and Type-2 fuzzy cascade controllers to ball and beam system. To evaluate each controller performance, we consider controller characteristic parameters such as maximum overshoot, delay time, rise time, settling time and steady-state error.

• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1250-1256
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• 2011

In this study, Bacillus licheniformis cells were immobilized by entrapment in calcium alginate beads and were used for production of alkaline protease by repeated batch process. In order to increase the stability of the beads, the immobilization procedure was optimized by statistical full factorial method, by which three factors including alginate type, calcium chloride concentration, and agitation speed were studied. Optimization of the enzyme production medium, by the Taguchi method, was also studied. The obtained results showed that optimization of the cell immobilization procedure and medium constituents significantly enhanced the production of alkaline protease. In comparison with the free-cell culture in pre-optimized medium, about 7.3-fold higher productivity was resulted after optimization of the overall procedure. Repeated batch mode of operation, using optimized conditions, resulted in continuous production of the alkaline protease for 13 batches in 19 days.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.732-735
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• 2007

Recently the control of induction motor for position control has been extensively studied. The representative method is PIDA controller proposed by Jung&Dorf. By designed PIDA controller' parameter had large value. Moreover, this method is very analyze, so that, not adapted controller parameter in disturbance. Besides using generalize fuzzy controller. Because input and output membership function is linguistic type, therefore system response is very slow. So, in this paper we used optimized fuzzy controller. Optimized fuzzy controller is output membership function is unity value. The controller performance was estimated applied to induction motor' position control.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1929-1930
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• 2006

Human like robot arm posture for grasping by considering the shape of the target object is quite a challenge in the field of robotics. In this paper, an optimized grasp posture with respect to the shape of the object considering the wrist joint angle and elbow elevation angle, in order to verify that the grasp posture is human like has been proposed. Given a target object, the candidates for grasp are computed by the method described in this paper. For each candidate, the closed loop inverse kinematics has been solved for the corresponding hand position and orientation. From the obtained joint angles through inverse kinematics, the elbow elevation angle has been computed and compared with the elbow elevation angle obtained through human movement data by the characteristic equation. After considering all the candidates, the hand position and orientation with minimum wrist joint and difference in elbow elevation angles has been utilized as the optimized grasp posture. Simulation results are presented.

• The Journal of the Acoustical Society of Korea
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• v.25 no.1E
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• pp.8-13
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• 2006

In this paper, an Optimized Ambisonic Panning Algorithm (OAPA) which reduces sound localization error, is proposed. In the conventional Ambisonic Panning Algorithm (APA), sound localization is usually different from the panning angle, especially when listeners are not in an ideal listening position, because of low signal separation among other channels. To overcome this problem, an OAPA using window functions is proposed. A proper window function can be verified, comprising of higher harmonic components than 2M+1 and improved DPC and channel separation. Analysis results demonstrate that the proposed method results in higher signal separation among other channels and lower sound localization errors than the conventional APA.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.1-6
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• 2017

This paper presents an optimized adoption of NVM for the storage system of heterogeneous applications. Our analysis shows that a bulk of I/O does not happen on a single storage partition, but it is varied significantly for different application categories. In particular, journaling I/O accounts for a dominant portion of total I/O in DB applications like OLTP, whereas swap I/O accounts for a large portion of I/O in graph visualization applications, and file I/O accounts for a large portion in web browsers and multimedia players. Based on these observations, we argue that maximizing the performance gain with NVM is not obtained by fixing it as a specific storage partition but varied widely for different applications. Specifically, for graph visualization, DB, and multimedia player applications, using NVM as a swap, a journal, and a file system partitions, respectively, performs well. Our optimized adoption of NVM improves the storage performance by 10-61%.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.156-161
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• 2017

This work presents a novel structure for junction-less tunneling field effect transistor (JL-TFET) with a floating gate over the source region. Introduction of floating gate instead of fixed metal gate removes the limitation of fabrication process suitability. The proposed device is based on a heavily n-type-doped Si-channel junction-less field effect transistor (JLFET). A floating gate over source region and a control-gate with optimized metal work-function over channel region is used to make device work like a tunnel field effect transistor (TFET). The proposed device has exhibited excellent ID-VGS characteristics, ION/IOFF ratio, a point subthreshold slope (SS), and average SS for optimized device parameters. Electron charge stored in floating gate, isolation oxide layer and body doping concentration are optimized. The proposed JL-TFET can be a promising candidate for switching performances.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2219-2225
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• 2007

The reaction mechanisms for the cyclizations of N-methyl-2-(2-chloropyridin-3-yloxy)acetamide to 1-methylpyrido[ 3,2-b][1,4]oxazin-2-one and 1-methyl-pyrido[2,3-b][1,4]oxazin-2-one were investigated using ab initio Hartree-Fock, second-order Moller-Plesset perturbation, single point coupled cluster with both single and double substitution, and density functional theory methods. The 5-membered spiro intermediate (2) is optimized from the cyclization of the acyclic reactants through the proton-transfer reaction, and this intermediate proceeds continuously to the 6-membered intermediate through either a stepwise or a concerted reaction. In the stepwise reaction, an N-bridge-type intermediate as a stable structure is optimized, whereas, in the concerted reaction, the O-bridge-type intermediate is not optimized.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.222-225
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• 2000

In this paper, a synchronous CDMA system accepted for the cdma2000 standard is simulated to propose optimized reverse link power ratio and channel estimation lengths. Differently from IS-95, the pilot channel is used in the proposed system to estimate fading channel, so optimized estimation lengths are needed. Therefore, in this paper we analyze optimized estimation lengths which is needed to decide the power ratio of pilot channel and fundamental channel. From fixed estimation lengths, we calculate FER with various power ratio values.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.291-295
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• 1989

The conventional Optimized Injection Method is a good control technique but can't be applied to 3-phase a.e. line. In this paper, a new technique, Time-sharing Method based on basic principle of conventional Optimized Injection Method is introduced to hold the independence of each phase, and the structure of power circuit is improved to realize the new control method. By this scheme it is possible to simplify the control circuit and power circuit. The characteristic of the new control method are investigated and compared with conventional Optimized Injection Method by computer simulation.