• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.8-15
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• 2000

This study presents an H$_{\infty}$ optimal controller synthesis by the frequency domain analysis of weighting function. The main purpose of our study is to visualize weighting function domains and open loop transfer function domains that satisfy robustness and performance. Also we aim to simplify the iterative algorithm for H$\infty$ optimal controller synthesis. We report that the designed regulator by the proposed method in this paper satisfies the desired specifications and performance in spite of the plant uncertainty variation at any operating point.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.68-75
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• 2012

In this study, the optimal synthesis of planar steering mechanisms for vehicles is studied. The author minimized the steering error between two front wheels subject to the constraints of transmission angles. Nonlinear programming methods such as BFGS method and golden section search method are used for this optimization. As numerical examples, Ackermann's steering mechanism, 6-link and 10-link planar mechanism are adopted to check the usefulness of this method. Consequently, among the three optimized mechanisms, 10-link planar one conducts far more accurate performance subject to tight constraints of transmission angles.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.6
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• pp.656-666
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• 1999

In this paper, we design the optimal PD control system which has the robust performance. This PD control system is designed by applying genetic algorithm (GA) to the determination of proportional gain KP and derivative gain KD that are given by PD servo controller, to make the output of plant follow the output of reference model optimally. These proportional and derivatibe gains are simultaneously optimized in the search domain guaranteeing the robust performance of system. And, this PD control system is compared with $\mu$ -synthesis control system for the robust performance. The PD control system designed by the proposed method has not only the robust performance but also the better command tracking performance than that of the $\mu$ -synthesis control system. The effectiveness of this control system is verified by computer simulation.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.12
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• pp.43-53
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• 1997

In this paper, the optimal synthesis algorithm of multiple-valued logic circuits using universal logic modules (ULM) U$_{f}$ based on 3-variable ternary reed-muller expansions is presented. We check the degree of each varable for the coefficients of reed-muller expansions and determine the order of optimal control input variables that minimize the number of ULM U$_{f}$ modules. The order of optimal control input variables is utilized the realization of multiple-valued logic circuits to be constructed by ULM U$_{f}$ modules based on reed-muller expansions using the circuit cost matrix. This algorithm is performed only unit time in order to search for the optimal control input variables. Also, this algorithm is able to be programmed by computer and the run time on programming is O(p$^{n}$ ).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4A
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• pp.250-259
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• 2012

This paper compared and investigated the choice of optimal algorithm affects on the directivity synthesis of linear array in the satisfaction to the design specification of the desired directivity, convergence characteristic, and adaptability. Optimal algorithms use a quasi-Newton method(DFP and BFGS method) for realizing the desired directivity, used a quasi-ideal beam, steering beam, and a multi-beam, chosen as desired directivity. In the numerical result, this paper verified the effectiveness of the quasi-Newton method to the directivity synthesis, and offered a solving approach of occurred problems in the numerical simulation process.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2726-2728
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• 2001

This paper describes an optimal synthesis method of binary neural network(BNN) for an approximation problem of a circular region using a newly proposed learning algorithm[7] Our object is to minimize the number of connections and neurons in hidden layer by using a Newly Expanded and Truncated Learning Algorithm(NETLA) for the multilayer BNN. The synthesis method in the NETLA is based on the extension principle of Expanded and Truncated Learning(ETL) and is based on Expanded Sum of Product (ESP) as one of the boolean expression techniques. And it has an ability to optimize the given BNN in the binary space without any iterative training as the conventional Error Back Propagation(EBP) algorithm[6] If all the true and false patterns are only given, the connection weights and the threshold values can be immediately determined by an optimal synthesis method of the NETLA without any tedious learning. Futhermore, the number of the required neurons in hidden layer can be reduced and the fast learning of BNN can be realized. The superiority of this NETLA to other algorithms was proved by the approximation problem of one circular region.

• The Korean Journal of Mycology
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• v.15 no.2
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• pp.108-115
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• 1987

Nutritional characteristics and cultural conditions for trehalose synthesis and mycelial yield of Pleurotus sajor-caju and Pleurotus ostreatus 201 in submerged culture were investigated. The results were as follows: Among the carbon sources, glucose was most excellent for trehalose synthesis and mycelial yield. The optimal concentration of glucose was 1%. Among the nitrogen sources, peptone was most excellent for trehalose synthesis and mycelial yield. The optimal concentration of peptone was 0.05%. The optimal concentration of $KH_2PO_4$ and $MgSO_47H_2O$ for trehalose synthesis and mycelial yield was 0.1%,0.04% and 0.2%,0.04-0.08%, respective­ly. The optimal temperature and pH for trehalose synthesis were $25^{\circ}C$ and pH 5.5. but optimal temperature and pH for mycelial yield were $30^{\circ}C$ and pH 5.5. The maximum yield of trehalose was obtanined after 10 day cultivation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.499-500
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• 2008

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1252-1260
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• 2020

(R)-2-(4-hydroxyphenoxy)propionic acid (HPOPA) is a key intermediate for the preparation of aryloxyphenoxypropionic acid herbicides (R-isomer). In order to improve the HPOPA production from the substrate (R)-2-phenoxypropionic acid (POPA) with Beauveria bassiana CCN-A7, static cultivation and H₂O₂ addition were attempted and found to be conducive to the task at hand. This is the first report on HPOPA production under static cultivation and reactive oxygen species (ROS) induction. On this premise, the cultivation conditions and fermentation medium compositions were optimized. As a result, the optimal carbon source, organic nitrogen source, and inorganic nitrogen source were determined to be glucose, peptone, and ammonium sulfate, respectively. The optimal inoculum size and fermentation temperature were 13.3% and 28℃, respectively. The significant factors including glucose, peptone, and H₂O₂, identified based on Plackett-Burman design, were further optimized through Central Composite Design (CCD). The optimal concentrations were as follows: glucose 38.81 g/l, peptone 7.28 g/l, and H₂O₂ 1.08 g/l/100 ml. Under the optimized conditions, HPOPA titer was improved from 9.60 g/l to 19.53 g/l, representing an increase of 2.03-fold. The results obtained in this work will provide novel strategies for improving the biosynthesis of hydroxy aromatics.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.613-618
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• 1986

In this study a s/w system(HENSPIN) for the automatic synthesis of HEN(heat exchanger network) was developed based on Pinch Design Method. The synthesized HEN by HENSPIN are satisfying performance targets such as minimum utility usage with as few as possible capital items. The invented network is near optimal in capital and operating cost. It will be used as initial structure for evolution to the structure which has optimal operability.