• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.309-314
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• 2005

The paper is proposed maximum torque control of SynRM drive using learming mechanism-fuzzy neural network(LM-FNN) controller and artificial neural network(ANN). The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $^i{_d}$ for maximum torque operation is derived. The proposed control algorithm is applied to SynRM drive system controlled LM-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the LM-FNN and ANN controller.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.2045-2048
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• 2003

서비스 거부공격(DoS Attack : Denial-of-Service Attack)이란 공격자가 침입대상 시스템의 시스템 자원과 네트워크 자원을 대량으로 소모시킴으로써 정상 사용자로 하여금 시스템이 제공하는 서비스를 하지 못하도록 하는 공격을 의미한다. TCP SYN Flooding 기법을 이용한 DoS공격은 서비스 자체를 하지 못하도록 하기 보다는 다른 공격을 하기 위한 사전 공격으로써 활용될 소지가 높은 공격법인 것이다. 본 논문에서는 TCP SYN Flooding을 이용한 DoS공격의 근본적인 원인을 분석하고 시스템 보안 관리자의 입장에서 이 공격에 능동적으로 탐지 할 수 있는 해결책을 모색해보고자 한다.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1012-1014
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• 2003

This paper deals with the characteristic Analysis of synchronous reluctance motors (SynRMs) using coupled Preisach modeling & FEM. The focus of this paper is the characteristic Analysis relative to Inductances and losses on the basis of stator slot number, winding in SynRMs. The coupled Finite Elements Analysis (FEA) & Preisach model has been used to evaluate the nonlinear solution. Comparisons arc given with characteristics of normal distributed winding SynRM and those according to stator slot number, winding in concentrated winding SynRM, respectively.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.159-162
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• 2001

This paper is proposed an efficiency optimization operation algorithm for synchronous reluctance motor (SynRM) using current phase angle control technique. The SynRM has to controlled with the optimal current phase angles with load and operation speed variation, to obtain high efficiency over the wide speed ranges. An efficiency optimization condition in SynRM which minimizes the copper and iron losses is derived based on the equivalent circuit model of the machine. The objective of the efficiency optimization control algorithm compensating the optimum current angle, is to seek a combination of d and q-axis current components which provides minimum losses at a certain operating point in steady state. The usefulness of the proposed efficiency optimization control is verified through vector-controlled inverter system with the SynRM.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1011-1012
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• 2007

The paper is proposed maximum torque control of SynRM drive using learning mechanism-fuzzy neural network(LM-FNN) controlle. The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current ${^{i}}_d$ for maximum torque operation is derived. The proposed control algorithm is applied to SynRM drive system controlled LM-FNN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the LM-FNN controller.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1092-1094
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• 2005

This paper deal with the efficiency evaluations in a Synchronous reluctance motor(SynRM) Vs. PMASynRM using a coupled transient finite element method(FEM) and preisach modeling, which is presented to analyze the characteristics under the effect of saturation and hysteresis loss. The focus of this paper is the efficiency evaluation relative to hysteresis loss, copper loss, etc. on the basis of load condition in a SynRM and PMASynRM. Computer simulation and experiment at result for the efficiency using dynamometer shoe the propriety of the proposed method.

• Bulletin of the Korean Chemical Society
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• v.13 no.6
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• pp.684-688
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• 1992

Three photocyclodimers of 5,7-dimethoxycoumarin (DMC) were isolated and characterized from the photolysis of DMC in acetonitrile. The configuration of the dimers was found to be anti head-to-head, syn head-to-head and syn head-to-tail, respectively. The number and the ratio of the products are solvent dependent. The anti head-to-head dimer is favored in nonpolar solvents and the preference decreases as the solvent polarity increases giving almost 100${\%}$ syn dimers and less than 1${\%}$ anti dimer from methanol solution. The overall yields of dimers also increase with the solvent polarity. From sensitization and quenching experiments, anti dimer was found to be formed via excited singlet state while syn dimers were formed via both excited singlet and triplet states.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.97-104
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• 2005

Mass selection (MS) is an efficient selection method to directly improve highly heritable traits. In the present study, two cycles of MS for ear length were conducted on two sweet corn populations, BC2-l0 and $BC1-10{\times}Syn-II$ after introgression of exotic germplasm. The improved populations generated from these selections were evaluated in comparison with the base populations at two locations, to determine the genetic gains and performance of the improved populations. The two base populations showed varied average realized responses to MS. In BC2-l0 derived population, the realized responses were $9.1\%$ in BC2-l0 C1 and $1.2\%$ in BC2-l0 C2, whereas in$BC1-10{\times}Syn-II$ derived population, the realized responses were$ 5.6\%$ in $BC1-10{\times}Syn-II$ C1 and $2.9\%$ in $BC1-10{\times}Syn-II$ C2. All the improved populations showed longer ears than their respective base populations and the check varieties. Ear length, which was used as the selection criterion in this study, showed high broad-sense heritability in the BC2-l0 and $BC1-10{\times}Syn-II$ derived populations, while fresh ear yield revealed low heritability, indicating that selection for ear length in these populations would be more effective than direct selection for yield. Results of this study indicate that MS conducted on BC2­10 and $BC1-10{\times}Syn-II$ had significantly increased ear length and fresh ear yield in both populations. The improved populations obtained would serve as better germplasm sources and further selection in these populations could offer better responses.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.491-498
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• 2005

The Denial of Service(DoS) attacks, which are done by consuming all of the computing or communication resources necessary for the services, are known very difficult to be protected from. TCP has drawbacks in its connection establishment for possible DoS attacks. TCP maintains the state of each partly established connection in the connection queue until it is established completely and accepted by the application. The attackers can make the queue full by sending connection requests repeatedly and not completing the connection establishment steps for those requests. In this paper, we have designed and implemented the extended TCP for preventing from SYN Flood DoS attacks. In the extended TCP, the state of each partly established connection is not maintained in the queue until the connection is established completely. For the extended TCP, we have modified the 3-way handshake procedure of TCP and implemented the extended TCP in the Linux operating system. The test result shows $0.05\%$ delay more than original TCP, but it shows that the extended TCP is strong for SYN Flood attacks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.850-860
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• 2023

The effects of dietary mannan oligosaccharides, Lactobacillus plantarum, Bacillus subtilis, and Bacillus licheniformis supplementation on hybrid grouper Epinephelus akaara ♀×Epinephelus lanceolatus ♂ were evaluated. The fish were fed a basal diet and five other diets consisting of 0.6% mannan oligosaccharides, L. plantarum, B. subtilis, and B. licheniformis and mixture of each 0.15% prebiotic and all the probiotics (designated as MOS, LP, BS, BL, and SYN) for 56 days. Growth performance and feed utilization showed no significant differences among all experimental groups. Lipid level of whole-body was significantly high in MOS and BL groups. Plasma aspartate aminotransferase was significantly low in BL and SYN groups. Nitro-blue tetrazolium, lysozyme and anti-protease, and glutathione peroxidase in BS, SYN, and all probiotic groups, respectively, were significantly high. Intestinal Vibrio bacteria was significantly low in all probiotic and SYN groups. Gene expression of interleukin-1β and interleukin-10 in SYN group; transforming growth factor β2 in MOS and BS groups, toll-like receptor 2-2 in BS and BL groups; and C-type lectin in MOS, LP and SYN groups were significantly upregulated. Our findings indicate that mannan oligosaccharides, L. plantarum, B. subtilis, and B. licheniformis could improve innate immunity, antioxidant capacity, anti-inflammation, and intestinal microbiota of hybrid grouper.