• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.728-732
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• 2014

Macro-model of magnetic tunnel junction (MTJ) for spin transfer torque magnetic random access memory (STT-MRAM) has been developed. The macro-model can describe the dynamic behavior such as the state change of MTJ as a function of the pulse width of driving current and voltage. The statistical behavior has been included in the model to represent the variation of the MTJ characteristic due to process variation. The macro-model has been developed in Verilog-A.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.706-709
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• 2004

A numerical method was developed that imposes constraint condition on the order parameters in martensitic phase transformation. In the method, an amplitude function having values of 1 or 0 was multiplied to transformation rates. The merit of the method is that the imposition of the constraint condition is more straightforward than a method with Lagrangian multiplier and easy to implement in the tangent modulus method. The developed method is applied to three-dimensional finite element analyses of single and poly crystalline shape memory alloys.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1687-1696
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• 1996

Most of the main memory database systems use two-phase locking(2PL)for concurrency control. The 2PL method is preferred over other methods for concurrency control because of its simplicity and common usage. However, conventional concurrency control solution will function poorly when the data are memory resident. In this paper, we propose a new optimistic concurrency control protocol for a main memory database system. In our proposed protocol, transaction conflict information is used in validation phase to improve data conflict resolution decisions. Our experiments show that the proposed protocol performs better than 2PL in terms of throughput for main memory database system enshrinements.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.4
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• pp.115-130
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• 2010

In the archival field, the last decade has witnessed much discussion on archives' broad responsibilities for social memory. Considering that the social role of archives has stemmed from postmodern thinking suggests a paradigm shift from viewing archives as static recorded objects to viewing them as dynamic evidence of human memory. The modern archives and archivists are products of nineteenth-century positivism, limiting their function to archiving written documents within stable organizations. The new thoughts on the social role of archives provide a chance to realize that traditional archival practices have preserved only a sliver of organizational memory, thus ignoring fluid records of human activities and memory. Archival description is the primary method for users to access materials in archives. Thus, it can determine how archival materials will be used (or not used). The traditional archival description works as the representation of archival materials and is directly projected from the hierarchy of organizational documents. This paper argues that archivists will need to redefine archival description to be more sensitive to atypical types of archival materials from various cultural contexts. This paper surveys the postmodern approaches to archival concepts in relation to descriptive practices. It also examines some issues related to representing historically marginalized groups in archival description who were previously neglected in traditional archival practices.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.240-240
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• 2010

A multiple alloy metal nano-dots memory using FN tunneling was investigated in order to confirm its structural possibility for future flash memory. In this work, a multiple FePt nano-dots device with a high work function (~5.2 eV) and extremely high dot density (${\sim}\;1.2{\times}10^{13}/cm^2$) was fabricated. Its structural effect for multiple layers was evaluated and compared to one with a single layer in terms of the cell characteristics and reliability. We confirm that MOS capacitor structures with 2-4 multiple FePt nano-dot layers provide a larger threshold voltage window and better retention characteristics. Furthermore, it was also revealed that several process parameters for block oxide and inter-tunnel oxide between the nano-dot layers are very important to improve the efficiency of electron injection into multiple nano-dots. From these results, it is expected that a multiple FePt nano-dots memory using Fowler-Nordheim (FN)-tunneling could be a candidate structure for future flash memory.

• Molecules and Cells
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• v.23 no.3
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• pp.259-271
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• 2007

Investigation of molecular and cellular mechanisms of synaptic plasticity is the major focus of many neuroscientists. There are two major reasons for searching new genes and molecules contributing to central plasticity: first, it provides basic neural mechanism for learning and memory, a key function of the brain; second, it provides new targets for treating brain-related disease. Long-term potentiation (LTP), mostly intensely studies in the hippocampus and amygdala, is proposed to be a cellular model for learning and memory. Although it remains difficult to understand the roles of LTP in hippocampus-related memory, a role of LTP in fear, a simplified form of memory, has been established. Here, I will review recent cellular studies of LTP in the anterior cingulate cortex (ACC) and then compare studies in vivo and in vitro LTP by genetic/pharmacological approaches. I propose that ACC LTP may serve as a cellular model for studying central sensitization that related to chronic pain, as well as pain-related cognitive emotional disorders. Understanding signaling pathways related to ACC LTP may help us to identify novel drug target for various mental disorders.

• Korean Journal of Biological Psychiatry
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• v.10 no.1
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• pp.20-44
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• 2003

Schizophrenics suffer not only psychotic symptoms but also cognitive deficits such as an attentional difficulty, memory impairment, poor abstraction, etc. These cognitive abnormalities have been reported to be significantly related to the social and occupational outcome in schizophrenia. Thus, it is important to explore the cause and pathophysiology for the cognitive abnormalities in patients with schizophrenia. In this regard, hippocampus is one of the most promising brain areas to search for the clue because it is closely involved in memory related function. In fact, during the past several decades, there have been extensive studies supporting hippocampal abnormalities as a cause of schizophrenia in both clinical and preclinical field. In this review, basic anatomical knowledge about hippocampus and major findings of preclinical and clinical studies which investigated the correlation between schizophrenia and hippocampus were highlighted. The contents are 1) anatomical structure of hippocampus, 2) neuronal pathway and receptor distribution in hippocampus, 3) function of hippocampus, 4) hippocampal animal model for schizophrenia, 5) hippocampus-related studies on antipsychotic drugs, and 6) clinical studies in hippocampus in patients with schizophrenia.

• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.29-34
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• 2000

This paper describes transient responses of a very floating structure subjected to dynamic load induced by waves. A time domain method is applied to the hydroelastic problems for this purpose. The method is based on source-dipole and FEM scheme and on Newmark $\beta$ method to pursuit time step process taking advantage of memory effect. The present procedure is carried out to analyze hydroelastic responses in regular waves and impact responses due to dropping aircraft.

• BMB Reports
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• v.42 no.3
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• pp.131-135
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• 2009

MicroRNAs control gene expression by inhibiting translation or promoting degradation of their target mRNAs. Since the discovery of the first microRNAs, lin-4 and let-7, in C. elegans, hundreds of microRNAs have been identified as key regulators of cell fate determination, lifespan, and cancer in species ranging from plants to humans. However, while microRNAs have been shown to be particularly abundant in the brain, their role in the development and activity of the nervous system is still largely unknown. In this review, we describe recent advances in our understanding of microRNA function at synapses, the specialized structures required for communication between neurons and their targets. We also propose how these advances might inform the molecular model of memory.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.282-286
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• 2005

Contents of these treatise propose method to embody station addition and passivity point correction. That store in TCMS's memory being downloaded all train running path data that is consisted of name of station and station code, departure station, destination station, train number, running time through PCMCIA memory card. Search relevant running path data and current station, destination station, the next station start time present to TCMS's display. In case it is no received information of station, device that do function of passenger broadcasting and pilot light does not act. This time, if input information of current station, relevant device does point revision.