• Smart Structures and Systems
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• v.8 no.4
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• pp.367-384
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• 2011

This paper presents the design and experimental evaluation of fast output sampling feedback controller to minimize structural vibration of a cantilever beam using Shape Memory Alloy (SMA) wires as control actuators and piezoceramics as sensor and disturbance actuator. Linear dynamic models of the smart cantilever beam are obtained using online recursive least square parameter estimation. A digital control system that consists of $Simulink^{TM}$ modeling software and dSPACE DS1104 controller board is used for identification and control. The effectiveness of the controller is shown through simulation and experimentation by exciting the structure at resonance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.3
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• pp.3-7
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• 2010

As the distance between signal lines in memories of high density ICs like SoCs decreases rapidly, failure occurs more frequently and effective memory test techniques are needed. In this paper, a new SRAM structure is proposed to decrease test complexity and test time for embedded DRAMs. In the presented technique, because memory test can be handled as a single port testing and read-write operation is possible at dual port without high complexity, test time can be much reduced.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.2
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• pp.96-99
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• 2012

We fabricated fully depleted (FD) SOI-based 1T-DRAM cells with planar channel or recessed channel and the electrical characteristics were investigated. In particular, the dependence of memory operating mode on the channel structure of 1T-DRAM cells was evaluated. As a result, the gate induced drain leakage current (GIDL) mode showed a better memory property for planar type 1T-DRAM. On the other hand, the impact ionization (II) mode is more effective for recessed type.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.72-75
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• 2000

This paper presents a simulation study on the description of the motion and the control of an active catheter actuator with multi-link structure actuated by Shape Memory Alloy(SMA). The model of an active catheter adopted in this paper has 3 links, and the individual links are composed of 3 micro coils of SMA for the omni-directional motion. In order to analyze the motions of multi-link structure, 3-dimensional kinematics description is presented. Also, the motion control of the end point of an active catheter using simple Neural Network is shown based on GUI(Graphic User Interface) system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.358-358
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• 2010

To improve the programming/erasing speed and leakage current of multiple dielectric stack tunnel barrier engineering (TBE) Non-volatile memory, We propose a new concept called staggered structure of TBE memory. In this study, We fabricated staggered structure capacitor on $Si_3N_4$ stacked HfAlO and measured C-V curve that can observe tunneling characteristic of this device as various annealing temperature compared with that of single layer $SiO_2$ capacitor.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.268-273
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• 2014

The forming, reset and set operation of bipolar resistive random access memory (RRAM) have been predicted by using a finite element (FE) model which includes interface effects. To the best of our knowledge, our bipolar RRAM model is applicable to realistic cell structure optimization because our model is based on the FE method (FEM) unlike precedent models.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.4
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• pp.269-274
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• 1999

A bending actuator using zigzag type shape memory alloy springs has been fabricated and characterized. The fabricated millimeter-sized actuator has outer diameter of 3.0mm and inner diameter of 2.0mm. The zigzag type spring is more suitable for thin wall type actuator because the zigzag type spring has a planar structure comparing with the coil type spring which has a three-dimensional structure. The measured characteristics of the fabricated bending actuator show the possibility of practical application to micro active bending catheters.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.218-219
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• 2008

In this paper, we have investigated the phase change memory device with cell structure using three-dimensional finite element analysis tool for reducing reset current. From the simulation, the reset current of PRAM with $SiO_2$ inserting layer is greatly reduced, compared with the conventional device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.85-86
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• 2007

A poly(vinylidene fluoride-trifluoroethyene) (P(VDF-TrFE)) copolymer thin film having ${\beta}$ phase was prepared by sol-gel method. The electrical properties of the film were studied to evaluate the possibility for appling to a ferroelectric random access memory. In order to characterize its electrical properties, we produced a MFS (metal-ferroelectric-semiconductor) structure by evaporation of Au electrodes. The C-V (capacitance-voltage) measurement revealed that the Au/P(VDF-TrFE)/Si structure with a 4 wt% film had a memory window width of about 0.5V for a bias voltage sweep of 1V.

• Knowledge Management Research
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• v.6 no.2
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• pp.67-90
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• 2005

Attention has been focused recently on the concept of shared cognition which encompasses the notion that effective team members hold knowledge that is overlapping and complementary with teammates. This shared cognition is expected to improve team effectiveness. In contrast to the continued efforts in developing theoretical approach of shared cognition, empirical studies are meager. Thus, we conducted an empirical study to investigate the role of shared cognition on team effectiveness. This study classifies shared cognition into two types, team mental model and transactive memory system, by shared meaning. A total of 121 new product development teams in the IT industry were surveyed for the data collection. The results of analysis can be summarized as follows: first, team mental model has a positive influence on team performance, team innovative behavior and team learning effect. And the relation with team mental model and team performance is moderated by the similarity of knowledge structure among the expert. Second, transactive memory system has a positive influence on team performance, team innovative behavior and team learning effect.