• Korean Journal of Computational Design and Engineering
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• v.9 no.4
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• pp.294-305
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• 2004

Highly detailed geometric models are rapidly becoming commonplace in computer graphics and other applications. These complex models, which is often represented as complex1 triangle meshes, mainly suffer from the vast memory requirement for real-time manipulation of arbitrary geometric shapes without loss of data. Various techniques have been devised to challenge these problems in views of geometric processing, not a representation scheme. This paper proposes the new mesh structure for the compact representation and the efficient handling of the highly complex models. To verify the compactness and the efficiency, the memory requirement of our representation is first investigated and compared with other existing representations. And then we analyze the time complexity of our data structure by the most critical operation, that is, the enumeration of the so-called one-ring neighborhood of a vertex. Finally, we evaluate some elementary modeling functions such as mesh smoothing, simplification, and subdivision, which is to demonstrate the effectiveness and robustness of our mesh structure in the context of the geometric modeling and processing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1232-1235
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• 2005

In recent years, as the robot technology is developed the researches on the artificial muscle actuator that enable robot to move dextrously like biological organ become active. The widely used materials for artificial muscle are the shape memory alloy and the electroactive polymer. These actuators have the higher energy density than the electromechanical actuator such as motor. However, there are some drawbacks for actuator. SMA has the hysterical dynamic characteristics. In this paper the segmented binary control for reducing the hysteresis of SMA is proposed and the simulation of anthropomorphic robotic hand is performed using ADAMS.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.410-413
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• 1988

In this paper, the real-time optical associative memory using multiple hologram which is generated with two angular multiplexed reference beams and Fourier transformed object beam in the $BaTiO_{3}$ crystal based on DFWM mechanism. When one image is recorded in the $BaTiO_{3}$ crystal, complete image can be recalled by 9 % partial input of the stored original image without any additional thresholding and optical feedback process. As an experimental result of multiple Fourier hologram which is recorded with two binary images, OHCHAS and PARKHK, we can obtain complete image recalled by 1/6 partial input of the stored image.

• YAKHAK HOEJI
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• v.55 no.6
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• pp.473-477
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• 2011

Alzheimer's disease (AD), one of the most common forms of dementia, is a progressive neurodegenerative disorder symptomatically characterized by the decline in memory and cognitive abilities. To date, the successful therapeutic strategy to treat AD is to maintain the levels of acetylcholine (ACh) by inhibiting acetylcholinesterase (AChE) to lead five drugs in clinical use. In this study, several coumarin derivatives were designed based on the lead structure of scopoletin and evaluated for their AChE inhibitory activities.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.4
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• pp.277-283
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• 2013

In this study, we propose a novel method for modeling dynamic hysteresis. Hysteresis is a widespread phenomenon that is observed in many physical systems. Many different models have been developed for representing a hysteretic system. Among them, the Duhem model is a classical nonlinear dynamic hysteresis model satisfying the properties of hysteresis. The purpose of this work is to develop a novel method that expresses the local dynamics of the Duhem model by a linear system model. Our approach utilizes a certain type of fuzzy system that is based on Takagi-Sugeno (T-S) fuzzy models. The proposed T-S fuzzy Duhem model is achieved by fuzzy blending of the linear system model. A simulated example applied to shape memory alloy actuators, which have typical hysteretic properties, illustrates the applicability of our proposed scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.310-313
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• 2005

In recent years, as the robot technology is developed, the researches on the artificial muscle actuator that enable robot to move dexterously like biological organ become active. The widely used materials for artificial muscle are the shape memory alloy and the electro-active polymer. These actuators have the higher energy density than the electro-mechanical actuator such as motor. However, there are some drawbacks for actuator. SMA has the hysterical dynamic characteristics. In this paper, the simulation of anthropomophic robotic hand is performed using ADAMS and the segmented binary control for reducing the hysteresis of SMA is proposed. SMA is controlled by thermo-electric module. The relations between the force and the hysteresis are developed to verify the validity of the suggested method.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.124.1-124.1
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• 2003

We investigated whether the mushroom extracts can protect neuronal death and ameliorate memory deficits in Alzheimer"s disease induced by $\beta$-amyloid peptide[A$\beta$(25-35)]. Cellular model of Alzheimer"s disease was produced by using SK-N-SH human neuronal cells treated with $A\beta$. Treatment with 40uM $A\beta$ for 48hours caused a 46% loss of cell viability. First, we examined the effects of 22 mushroom extracts on neuronal death using MTT assay. We found that 3 mushroom extracts increased viability of the cells from 46% to 87%. (omitted)

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.155-163
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• 1996

This paper presents vibration and position tracking control of a smart structure using shape memory alloy(SMA) actuators. A governing equation of motion of the proposed structure is obtained via Hamilton's princeple. The dynamic characteristics of the SMA actuator are experimentally identified and incorporated with the governing equation to furnish a control system model. Subsequently, a sliding mode controller which has inherent robustness to external disturbances is formulated on the basis of the sliding mode conplacement, and also for the position tracking control of desired trajectories with low-frequency sine and square waves.

• Transactions on Electrical and Electronic Materials
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• v.15 no.1
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• pp.24-27
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• 2014

In this study, the effects of Mn-doping and the electrode materials on the memory characteristics of $ZnO_xS_{1-x}$ resistive random access memory (ReRAM) devices on plastic are investigated. Compared with the undoped Al/$ZnO_xS_{1-x}$/Au and Al/$ZnO_xS_{1-x}$/Cu devices, the Mn-doped ones show a relatively higher ratio of the high resistance state (HRS) to low resistance state (LRS), and narrower resistance distributions in both states. For the $ZnO_xS_{1-x}$ devices with bottom electrodes of Cu, more stable conducting filament paths are formed near these electrodes, due to the relatively higher affinity of copper to sulfur, compared with the devices with bottom electrodes of Au, so that the distributions of the set and reset voltages get narrower. For the Al/$ZnO_xS_{1-x}$/Cu device, the ratio of the HRS to LRS is above $10^6$, and the memory characteristics are maintained for $10^4$ sec, which values are comparable to those of ReRAM devices on Si or glass substrates.

• Journal of the Korean Mathematical Society
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• v.32 no.3
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• pp.573-582
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• 1995

J.Milnor[Mi2] has introduced the notion of directional entropy in his study of Cellular Automata. Cellular Automaton map can be considered as a continuous map from a space $K^Z^n$ to itself which commute with the translation of the lattice $Z^n$. Since the space $K^Z^n$ is compact, map S is uniformly continuous. Hence S is a block map(a finite code)[He]. (S is said to have a finite memory.) In the case of n = 1, we have a shift map, T on $K^Z$, and a block map S and they together generate a $Z^2$ action.