• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.993-996
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• 1993

This paper addresses the structure and its associated learning algorithms of a feedforward multi-layered connectionist network, which has distributed learning abilities, for realizing the basic elements and functions of a traditional fuzzy logic controller. The proposed neural-network-based fuzzy logic control system (NN-FLCS) can be contrasted with the traditional fuzzy logic control system in their network structure and learning ability. An on-line supervised structure/parameter learning algorithm dynamic learning algorithm can find proper fuzzy logic rules, membership functions, and the size of output fuzzy partitions simultaneously. Next, a Reinforcement Neural-Network-Based Fuzzy Logic Control System (RNN-FLCS) is proposed which consists of two closely integrated Neural-Network-Based Fuzzy Logic Controllers (NN-FLCS) for solving various reinforcement learning problems in fuzzy logic systems. One NN-FLC functions as a fuzzy predictor and the other as a fuzzy controller. As ociated with the proposed RNN-FLCS is the reinforcement structure/parameter learning algorithm which dynamically determines the proper network size, connections, and parameters of the RNN-FLCS through an external reinforcement signal. Furthermore, learning can proceed even in the period without any external reinforcement feedback.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.986-989
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• 2007

In this review, several aspects for improving the quality of materials parameters of Nematic Liquid Crystals (NLCs) and Ferroelectric Liquid Crystals (FLCs) will be discussed. In particular the decrease of the response time is a need. It will be demonstrated that the materials parameters of NLCs and FLCs can be improved among other ways due to optimization of chemical structures of the NLCs and /or FLCs mixtures, due to doping them with nanomaterials and by using fast elastic relaxation processes.

• Structural Engineering and Mechanics
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• v.87 no.3
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• pp.231-242
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• 2023

A novel combinatorial type-2 adaptive neuro-fuzzy inference system (T2-ANFIS) and robust proportional integral derivative (PID) control framework for intelligent vibration mitigation of uncertain structural system is introduced. The fuzzy logic controllers (FLCs), are designed independently of the mathematical model of the system. The type-1 FLCs, have a limited ability to reduce the effect of uncertainty, due to their fuzzy sets with a crisp degree of membership. In real applications, the consequent part of the fuzzy rules is uncertain. The type-2 FLCs, are robust to the fuzzy rules and the process parameters due to the fuzzy degree of membership functions and footprint of uncertainty (FOU). The adaptivity of the proposed method is provided with the optimum tuning of the parameters using the neural network training algorithms. In our approach, the PID control force is obtained using the generalized type-2 neuro-fuzzy in such a way that the stability and robustness of the controller are guaranteed. The robust performance and stability of the presented framework are demonstrated in a numerical study for an eleven-story seismically-excited building structure combined with an active tuned mass damper (ATMD). The results indicate that the introduced type-2 neuro-fuzzy PID control scheme is effective to attenuate plant states in the presence of the structured and unstructured uncertainties, compared to the conventional, type-1 FLC, type-2 FLC, and type-1 neuro-fuzzy PID controllers.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.17-27
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• 1996

More fuzzy hardware are expected to be utilized in the future to construct fuzzy logic controllers (FLCs). It is hard to find an existing fuzzy hardware which is adopting advanced functions such as self-tuning algorithm in addition to the conventional inference calculation. That is mainly because conventional self-tuning algorithms designed to implement with some hardware circuits is required for fuzzy hardwares to have self-tuning capability. As a first step toward the feature, a novel self-tuning algorithm is proposed in this paper. Based on the search method, the main idea of the proposed algorithm is to detemine valid ranges of input variables of an FLC in order to maximize performance indices fo the control system. The performance indices are so ismple as to be realized by hardware circuit. in dadditon to the conventional scaling-factor adjustment, the algorithm adjusts offset values as well, which, in effect, modifies fuzzy rules of the FLC. To justify the performance of the proposed algorithm, a simulation study is executed.

• Journal of Information Display
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• v.12 no.3
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• pp.129-134
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• 2011

The universal current reversal method is used for the simultaneous measurement of response time (${\tau}$), azimuthal angle (${\varphi}_o$), spontaneous polarization ($P_S$), and rotational viscosity (${\gamma}_{\varphi}$) of two ferroelectric liquid crystals (FLCs). The application of AC field in FLCs results in reorientational current, which is further analyzed to obtain various parameters. The variation in the parameters with temperature follows the typical trend predicted by the theory. The theoretical curve fits well into the experimental data. Its comparison with traditional current reversal method is confirmed to address certain limitations of that method.

• Transactions of Materials Processing
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• v.9 no.1
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• pp.3-9
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• 2000

The new FLD of the laser welded blank, which includes FLCs of welded zone and base metals, is introduced. For the forming limits of welded zone, the hemispherical dome punch tests were performed with various widths of asymmetric specimen. The FLC0 as well as the dome height at fracture associated with various specimen widths in the same and different thickness combinations were found to see the formability depending on thickness combinations. In order to show the application of the new FLD, the measured strains of squared cup drawing and simulated strains of door inner panel stamping were compared with those of FLCs. The successful prediction of fracture in the applications reveals that the forming limits of welded zone and base metals should be separately found for more accurate evaluation of the formability and workability of the laser welded blank.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1118-1120
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• 1998

In this study, an adaptive evolutionary computation (AEC), which uses adaptively a genetic algorithm having global searching capability and an evolution strategy having local searching capability with different methodologies, is suggested. We applied the AEC to design of fuzzy logic controllers for a PSS (power system stabilizer). FLCs for PSS controllers are designed for damping the low frequency oscillations caused by disturbances such as tile sudden changes of loads, outages in generators, transmission line faults, etc. The membership functions of FLCs is optimally determined by AEC.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06a
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• pp.156-163
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• 1998

During an actual forming operation, a material may undergo considrably large changes in strain path, and these changes can significantly alter the forming limits. So, in this study, modified forming limit curves(FLCs) in complex strain path are determined with specially designed jig to give test specimens with desired prestrains in uniaxial or biaxial deformation mode. In another part of present study, theoretical prediction of FLCs is attempted with MK's theory and Hosford's yield criterion to give forming limit curves in positive minor strain region and with Hill's local necking theory in negative minor strain region. Comparison of these theoretical results with experimental ones will be mentioned for both linear and complex strain path.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.4
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• pp.173-179
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• 2009

The analysis of serum free light chains (sFLCs) can improve the diagnosis and monitoring of multiple myeloma and other plasma cell dyscrasias. As with other immunoassays, sFLCstests are subject to potential antigen excess and heterophilic antibody interference. We describe 9 cases of sFLCs antigen excess in patients with multiple myeloma using the FreeliteTM Human Kappa and Lambda Free Kits (The Binding Site ltd., Birmingham, UK) and the Hitachi7600 P module turbidimetric system. A total of 1,247 consecutive samples from 250 patients with multiple myeloma were assayed for sFLCs from April to September, 2009. The samples were assayed using an initial dilution of 1 :5and subsequent dilutions of 1 :50 and 1: 100. The same samples were analyzed for the presence of monoclonal gammopathies using serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE). There were 9 samples (0.72%) of antigen excess with 3 cases of kappa (0.24%) and 6 cases of lambda (0.48%). These cases represents an example of antigen excess or "hook effect" using the serum free light chain assays and mandates high level of attention to falsely low sFLC levels due to antigen excess, especially when it is disaccordant to other assay results or clinical manifestations.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.3057-3062
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• 2011

We have synthesized and characterized the first cyclic co-oligomeric ferroelectric liquid crystals (FLCs) based on cyclic siloxanes and found that the co-oligomer containing two different mesogenic units exhibits $SmC^*$ mesophase over a wide temperature range from $65^{\circ}C$ to $135^{\circ}C$, much wider than those of the monomer counterparts and the cyclic homo-oligomers. The cyclic co-oligomeric liquid crystal readily filled the display cell and exhibited fast switching times in the range of 4 ms to 6 ms over the entire $SmC^*$ phase. Moreover, the practical absence of layer shrinkage, attributed to de Vries-type transition, shows an additional significant advanage for cyclic co-oligomeric FLCs in LCD applications.