• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.241-241
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• 2010

New non-volatile memory with high density and high work-function metal nano-dots, MND (Metal Nano-Dot) memory, was proposed and fundamental characteristics of MND capacitor were evaluated. In this work, nano-dot layer of FePt with high density and high work-function (~5.2eV) was fabricated as a charge storage site in non-volatile memory, and its electrical characteristics were evaluated for the possibility of non-volatile memory in view of cell operation by Fowler-Nordheim (FN)-tunneling. Here, nano-dot FePt layer was controlled as a uniform single layer with dot size of under ~ 2nm and dot density of ${\sim}\;1.2{\times}10^{13}/cm^2$. Electrical measurements of MOS structure with FePt nano-dot layer shows threshold voltage window of ~ 6V using FN programming and erasing, which is satisfied with operation of the non-volatile memory. Furthermore, this structure provides better data retention characteristics compared to other metal dot materials with the similar dot density in our experiments. From these results, it is expected that this non-volatile memory using FePt nano-dot layer with high dot density and high work-function can be one of candidate structures for the future non-volatile memory.

• Korean Journal of Materials Research
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• v.20 no.8
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• pp.401-407
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• 2010

We studied the influence of different types of metal electrodes on the performance of solution-processed zinc tin oxide (ZTO) thin-film transistors. The ZTO thin-film was obtained by spin-coating the sol-gel solution made from zinc acetate and tin acetate dissolved in 2-methoxyethanol. Various metals, Al, Au, Ag and Cu, were used to make contacts with the solution-deposited ZTO layers by selective deposition through a metal shadow mask. Contact resistance between the metal electrode and the semiconductor was obtained by a transmission line method (TLM). The device based on an Al electrode exhibited superior performance as compared to those based on other metals. Kelvin probe force microscopy (KPFM) allowed us to measure the work function of the oxide semiconductor to understand the variation of the device performance as a function of the types metal electrode. The solution-processed ZTO contained nanopores that resulted from the burnout of the organic species during the annealing. This different surface structure associated with the solution-processed ZTO gave a rise to a different work function value as compared to the vacuum-deposited counterpart. More oxygen could be adsorbed on the nanoporous solution-processed ZTO with large accessible surface areas, which increased its work function. This observation explained why the solution-processed ZTO makes an ohmic contact with the Al electrode.

• Proceedings of the CALSEC Conference
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• 1999.07a
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• pp.207-213
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• 1999

When function modeling with IDEF0 which is called as a standard methodology for CALS (FIPS 183), the initial work is to determine the purpose and viewpoint, and the next work is to generate a data list and an activity list. This work requires participant's discussion and agreements. The main problems for these working are a communication between participants and efficient discussion processing. Brainstorming is the most useful method for this work. The paper is for development for the modeling assistant tool to promote the business modeling. In this paper, we will introduce the tool which name is 'MindMapper' and 'Dyna-IDEF'. Mind-mapper is software for mind-map method that is used for creative thinking. Using this tool, we refine the result of the brainstorming about activity list and translate the result into the functional model of IDEF0 using Dyna-IDEF. The translated functional model is prototype model without ICOM arrows.

• Journal of the Korean Home Economics Association
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• v.41 no.7
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• pp.157-168
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• 2003

The purposes of this study were to explore the rural women's labor by measuring labor value economically. To achieve the purpose, this study applied four methods : replacement cost method individual function, replacement cost method generalist, opportunity cost method and shadow wage method. The results of this study were as follows: 1) Time used for agricultural work and household work by with women were 5.3 hours and 3.8 hours each. 2) According to the methods used, the amounts of valuing rural women's labor were varied and ranged from 23,000 won to 43,000 won per day. This study might help recognize the degree of rural women's labor contribution to the household income of farm households and improve the socio-economic status of rural women through showing the productivity of the rural women's labor.

• Communications of the Korean Mathematical Society
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• v.31 no.2
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• pp.329-342
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• 2016

Motivated essentially by Brychkov's work [1], we evaluate some new integrals involving hypergeometric function and the logarithmic function (including those obtained by Brychkov[1], Choi and Rathie [3]), which are expressed explicitly in terms of Gamma, Psi and Hurwitz zeta functions suitable for numerical computations.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.46-49
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• 2001

In this paper. tile validity of work factor approach was investigated to determine compressive fracture toughness of unidirectional graphite/epoxy composites under hydrostatic pressure environment. The elastic work factor was determined under various pressures as a function of delamination length. It was found that elastic work factor was not affected by hydrostatic pressure.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.260-262
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• 2017

During the construction of the project, all surveying and mapping work is collectively referred to as engineering survey. Therefore, the measurement work contains a wide range of content, in the engineering survey, design and construction management stage are involved. To the actual work, the project measurement runs through the project building in a number of stages, and provide basic services. This paper mainly through the analysis of engineering measurement at all stages of the role played by the measurement work in the project management work to do the following description.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.173-177
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• 2006

A noise transfer function(NTF) is the frequency response function between an input force applied to an exterior point of a vehicle body and the resultant interior sound pressure usually measured at the driver's ear position. It represents the measure of noise sensitivity for the output force transmitted to the joints between the body and chassis. The principle of vibro-acoustic reciprocity is often utilized in the measurement of NTF. One difficulty in using the volume source is that most of the previously proposed methods require the knowledge of the volume velocity of the acoustic source in advance. A new method proposed in the present work does not require any calculation related with the volume velocity of the acoustic source, but still yields even more accurate results both in the amplitude and phase of the NTF. In the present work, the new method is applied to obtain NTF data for a midsize sedan.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.489-493
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• 2004

The Modulation Transfer Function (MTF) is commonly used to characterize the spatial quality of imaging systems. This work is the attempt to measure the MTF for KOMPSAT EOC using the non-parametric method as ground inputs. The spatial performance of the KOMPSAT EOC was analyzed by edge method while in flight using multi-temporal image data collected over test site in Seoul. The results from this work demonstrate the potential applicability of this method to estimate MTF for high spatial resolution satellite KOMPSAT-2 that is being developed to be launched in 2005.

• Carbon letters
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• v.14 no.3
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• pp.162-170
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• 2013

The performance of graphene-based electronic devices is critically affected by the quality of the graphene-metal contact. The understanding of graphene-metal is therefore critical for the successful development of graphene-based electronic devices, especially field-effect-transistors. Here, we provide a review of the peculiar properties of graphene-metal contacts, including work function pinning, the charge transport mechanism, the impact of the process on the contract resistance, and other factors.