• Title/Summary/Keyword: Work-function

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Design of 3-bit Arbitrary Logic Circuit based on Single Layer Magnetic-Tunnel-Junction Elements (단층 입력 구조의 Magnetic-Tunnel-Junction 소자를 이용한 임의의 3비트 논리회로 구현을 위한 자기논리 회로 설계)

  • Lee, Hyun-Joo;Kim, So-Jeong;Lee, Seung-Yeon;Lee, Seung-Jun;Shin, Hyung-Soon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.12
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    • pp.1-7
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    • 2008
  • Magnetic Tunneling Junction (MTJ) has been used as a nonvolatile universal storage element mainly in memory technology. However, according to several recent studies, magneto-logic using MTJ elements show much potential in substitution for the transistor-based logic device. Magneto-logic based on MTJ can maintain the data during the power-off mode, since an MTJ element can store the result data in itself. Moreover, just by changing input signals, the full logic functions can be realized. Because of its programmability, it can embody the reconfigurable magneto-logic circuit in the rigid physical architecture. In this paper, we propose a novel 3-bit arbitrary magneto-logic circuit beyond the simple combinational logic or the short sequential one. We design the 3-bit magneto-logic which has the most complexity using MTJ elements and verify its functionality. The simulation results are presented with the HSPICE macro-model of MTJ that we have developed in our previous work. This novel magneto-logic based on MTJ can realize the most complex logic function. What is more, 3-bit arbitrary logic operations can be implemented by changing gate signals of the current drivel circuit.

Performance enhancement of Organic Thin Film Transistor using $C_{60}$ hole injection layer ($C_{60}$(buckminsterfullurene) 홀주입층을 적용한 유기박막트랜지스터의 성능향상)

  • Yi, Moon-Suk
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.5
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    • pp.19-25
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    • 2008
  • In this study, we fabricated Organic Thin Film Transistors(OTFTs) with $C_{60}$ hole injection layer between organic semiconductor(pentacene) and metal electrode, and we compared the electrical characteristics of OTFTs with/without $C_{60}$. When the $C_{60}$ hole injection layer was introduced, the mobility and the threshold voltage were improved from 0.298 $cm^2/V{\cdot}s$ and -13.3V to 0.452 $cm^2/V{\cdot}s$ and -10.8V, and the contact resistance was also reduced. When the $C_{60}$ is inserted, the hole injection was enhanced because the $C_{60}$ prevent the unwanted chemical reaction between pentacene and Au. Furthermore, we fabricated the OTFTs using Al as their electrodes. When the OTFTs were made by only aluminum electrode, the channel were not mostly made because of the high hole injection barrier between pentacene and aluminum, but when the $C_{60}$ layer with an optimal thickness was applied between aluminum and pentacene, the device performances were obviously enhanced because of the vacuum energy level shift of Al and the consequent decrease of the hole injection barrier which was induced by the interface dipole formation between $C_{60}$ and Al. The mobility and $I_{ON}/I_{OFF}$ current ratio of OTFT with $C_{60}/Al$ electrode were 0.165 $cm^2/V{\cdot}s$ and $1.4{\times}10^4$ which were comparable with the normal Au electrode OTFT.

A Study on the Health Screening Solution by Using Electronic Medical Record (전자의무기록을 활용한 건강검진 솔루션에 관한 연구)

  • Lee, Hyo-Seung;Oh, Jae-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.7
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    • pp.825-830
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    • 2015
  • The Electronic Medical Record(: EMR) is to store medical data not in the form of document, but in the data storage. Such EMR can not only solve various problems of document use such as storage/arrangement of and securing space for document, but also make it possible to provide customized-treatment based on large quantity of customer data, so that hospitals can reduce the management cost and also improve the work efficiency. Customers also can receive the great quality of medical service. Owing to such strengths, the EMR has been rapidly introduced and applied to many hospitals and clinics since 1990s. In case of the current health screening system, however, paper forms used for health screening is also stored, on top of EMR. There would be various reasons why it is stored in the form of document. While the EMR used in hospitals is comprised of a unit program performing medical record, the health screening system is comprised of a unit program performing logics related to health screening. For this reason, it might be unavoidable for the health screening system to store document forms. If the EMR function is applied to the health screening system, it is expected to be able to operate more efficient health screening solution.

Harmony Arrangements using B-Spline Tension Curves (B-스플라인 텐션 곡선을 이용한 음악 편곡)

  • Yoo, Min-Joon;Lee, In-Kwon;Kwon, Dae-Hyun
    • Journal of the HCI Society of Korea
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    • v.1 no.1
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    • pp.1-8
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    • 2006
  • We suggest a graphical representation of the tension flow in tonal music using a piecewise parametric curve, which is a function of time illustrating the changing degree of tension in a corresponding chord progression. The tension curve can be edited by using conventional curve editing techniques to reharmonize the original music with reflecting the user's demand to control the tension of music. We introduce three different methods to measure the tension of a chord in terms of a specific key, which can be used to represent the tension of the chord numerically. Then, by interpolating the series of numerical tension values, a tension curve is constructed. In this paper, we show the tension curve editing method can be effectively used in several interesting applications: enhancing or weakening the overall feeling of tension in a whole song, the local control of tension in a specific region of music, the progressive transition of tension flow from source to target chord progressions, and natural connection of two songs with maintaining the smoothness of the tension flow. Our work shows the possibility of controlling the perceptual factor (tension) in music by using numerical methods. Most of the computations used in this paper are not expensive so they can be calculated in real time. We think that an interesting application of our method is an interactive modification of tension in background music according to the user's emotion or current scenario in the interactive environments such as games.

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A Study of the Heating Systems used by Korean Compatriot in Russia - Focusing on Yunhaeju, Kazakhstan and Uzbekistan- (러시아에 거주하는 고려인의 난방 방식에 관한 연구 -연해주, 카자흐스탄, 우즈베키스탄을 중심으로-)

  • Lee YoungShim;Cho JaeSoon;Lee SangHae;Joung JaeKook
    • Journal of the Korean Home Economics Association
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    • v.43 no.1 s.203
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    • pp.145-165
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    • 2005
  • In 1937, most Korean compatriot who lived in Yunhaeju moved to Kazakhstan and Uzbekistan in Central Asia following the deportation policy of Russia. Korean compatriot have kept their traditional life style for 140 years, without a deep relationship with Korea. This study examined the heating systems of Korean compatriot in Yunhaeju, Kazakhstan and Uzbekistan, Russia. A literature review and field research, based on Ethnography as a research method, was employed. The results of the research were as following: 1) Korean compatriot in Yunhaeju use a Pechika, which is a radiator that uses hot water, and a Gudul as the main heating systems, but the use of a Pechika was most common. A Pechika functions for cooking as well as for warming the house. The room with the Gudul was connected to the kitchen, so this space was used as a place for cooking and eating, for family members to meet. Many kinds of fuel, like gas and electricity, were used to power the heating systems. 2) Korean compatriot in Kazakhstan use radiators, with hot water as the main heating system, with ratio using Gudul used in this region being the highest of all the three areas. The most common fuels used for a Gudul were wood and coal, and gas was also used in cooking. The room with the Gudul was planned to be located beside the fireplace, without any walls. The people using a Gudul use that place for eating and meeting, as well as for family members to sleep. 3) The main heating system of Korean compatriot in Uzbekistan was a radiator using hot water, and those with pipes containing hot water buried under the floor were very common. The function is very similar to that of a Gudul, so most people using this type of radiator would sleep on the floor. Those people with a traditional Gudul not using them were mostly in Uzbekistan. The reason for this was that the family members had diminished, so it was hard work for elderly parents to manage an extra building containing a Gudul. Gas was the fuel generally used for heating and cooking in Uzbekistan. 4) Guduls were used in the Korean compatriot's houses in all three areas, even though they have changed in structure to adapt to the Russian life style. However, Guduls have still been functioning to maintain a traditional life style in Korean compatriot's houses for the gathering of family members.

A Study of Collection Development Policies of the University Libraries in Korea (한국의 종합대학도서관 장서개발정책에 관한 연구)

  • 손정표
    • Journal of Korean Library and Information Science Society
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    • v.11
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    • pp.101-142
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    • 1984
  • This study is a survey of collection development policies in the 40 university libraries among 42 in Korea as of 1984. The survey used a questionnaire with 36 questions concerning the basic elements of the collection development policy. The survey results revealed many problems demanding correction. The measures to correct the problems in the university libraries are as follows. 1. It is desirable that the libraries should have a collection development policy statement written and adopted for the systematic collection building. 2. It is advisable that the libraries should include a function of the materials selection among other various functions of the Library Committee for the purpose of informing administrators of the goals of the libraries and the validity of the budgetary allocation. 3. It is desirable that each library should organize the Collection Development Committee for minimizing the possibility of personal bias on the part of the individual selectors. 4. It is advisable that the primary responsibility for materials selection should be delegated as follows: for the materials for faculty research, to the faculty members; for the other collections, to the professional staff of each department; for the final review of whether or not to purchase, to the Collection Development Committee. 5. It is desirable for the purchase priority of materials to be set up in accordance with the order of 6 levels of collection development. 6. It is advisable that the libraries should, as top priority, purchase materials in direct su n.0, pport of the undergraduate and graduate academic programs, and in subject matter areas other than languages and literature, Korean materials should have not only the higher priority than the foreign language materials, but also maintain the comprehensive collection level. 7. It is desirable that the special collections should be purchased by special funds from the authority, and the special collections librarian should have the responsibility of the materials selection under the advice of the faculty members relating to the subject area. 8. It is advisable that duplicate copies should be bought only for high use items, but for reserve books, by the program enrollment, and textbooks should not be bought in general, except as su n.0, pplemental materials for course work in which they are necessary and heavily used. 9. It is reasonable that the material budget should be distributed as follows: by the ratio for distributing funds, about 60-70% for the library and 30-40% for departments; by the type of materials, about 50% for books, 40% for periodicals and 10% for other materials, or when not bought other materials, about 50-60% for books and 40-50% for periodicals. In addition, it is desirable that undergraduate class enrollment, graduate class enrollment, undergraduate majors, graduate majors, average book cost in the discipline, number of faculty, and use rate by subject should be considered as the factors for the allocation of funds by department, and special consideration should be given to newly-founded departments so the library holdings can be adequate to su n.0, pport them.

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Estimating Cumulative Distribution Functions with Maximum Likelihood to Sample Data Sets of a Sea Floater Model (해상 부유체 모델의 표본 데이터에 대해서 최대우도를 갖는 누적분포함수 추정)

  • Yim, Jeong-Bin;Yang, Won-Jae
    • Journal of Navigation and Port Research
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    • v.37 no.5
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    • pp.453-461
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    • 2013
  • This paper describes evaluation procedures and experimental results for the estimation of Cumulative Distribution Functions (CDF) giving best-fit to the sample data in the Probability based risk Evaluation Techniques (PET) which is to assess the risks of a small-sized sea floater. The CDF in the PET is to provide the reference values of risk acceptance criteria which are to evaluate the risk level of the floater and, it can be estimated from sample data sets of motion response functions such as Roll, Pitch and Heave in the floater model. Using Maximum Likelihood Estimates and with the eight kinds of regulated distribution functions, the evaluation tests for the CDF having maximum likelihood to the sample data are carried out in this work. Throughout goodness-of-fit tests to the distribution functions, it is shown that the Beta distribution is best-fit to the Roll and Pitch sample data with smallest averaged probability errors $\bar{\delta}(0{\leq}\bar{\delta}{\leq}1.0)$ of 0.024 and 0.022, respectively and, Gamma distribution is best-fit to the Heave sample data with smallest $\bar{\delta}$ of 0.027. The proposed method in this paper can be expected to adopt in various application areas estimating best-fit distributions to the sample data.

New Ruthenium Complexes for Semiconductor Device Using Atomic Layer Deposition

  • Jung, Eun Ae;Han, Jeong Hwan;Park, Bo Keun;Jeon, Dong Ju;Kim, Chang Gyoun;Chung, Taek-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.363-363
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    • 2014
  • Ruthenium (Ru) has attractive material properties due to its promising characteristics such as a low resistivity ($7.1{\mu}{\Omega}{\cdot}cm$ in the bulk), a high work function of 4.7 eV, and feasibility for the dry etch process. These properties make Ru films appropriate for various applications in the state-of-art semiconductor device technologies. Thus, it has been widely investigated as an electrode for capacitor in the dynamic random access memory (DRAM), a metal gate for metal-oxide semiconductor field effect transistor (MOSFET), and a seed layer for Cu metallization. Due to the continuous shrinkage of microelectronic devices, better deposition processes for Ru thin films are critically required with excellent step coverages in high aspect ratio (AR) structures. In these respects, atomic layer deposition (ALD) is a viable solution for preparing Ru thin films because it enables atomic-scale control of the film thickness with excellent conformality. A recent investigation reported that the nucleation of ALD-Ru film was enhanced considerably by using a zero-valent metallorganic precursor, compared to the utilization of precursors with higher metal valences. In this study, we will present our research results on the synthesis and characterization of novel ruthenium complexes. The ruthenium compounds were easy synthesized by the reaction of ruthenium halide with appropriate organic ligands in protic solvent, and characterized by NMR, elemental analysis and thermogravimetric analysis. The molecular structures of the complexes were studied by single crystal diffraction. ALD of Ru film was demonstrated using the new Ru metallorganic precursor and O2 as the Ru source and reactant, respectively, at the deposition temperatures of $300-350^{\circ}C$. Self-limited reaction behavior was observed as increasing Ru precursor and O2 pulse time, suggesting that newly developed Ru precursor is applicable for ALD process. Detailed discussions on the chemical and structural properties of Ru thin films as well as its growth behavior using new Ru precursor will be also presented.

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Preparation and Electrochemical Characteristics of Polymer Electrolyte Based on MCM-41/Poly(ethylene oxide) Composites (MCM-41/Po1y(ethylene oxide) 복합체로 구성된 고분자 전해질의 제조와 전기화학적 특성)

  • Kim Seok;Kang Jin-Young;Lee Sung-Goo;Lee Jae-Rook;Park Soo-Jin
    • Polymer(Korea)
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    • v.29 no.4
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    • pp.403-407
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    • 2005
  • In this work, the solid polymer electrolyte (SPE) composites, which are composed of poly(ethylene oxide) (PEO), mesoporous mobil crystalline material-41 (MCM-41), and lithium salt, are prepared in order to investigate the influence of MCM-41 contents on the ionic conductivity of the composites. The crystallinity of the SPE composites was evaluated using differential scanning calorimeter (DSC) and X-ray diffraction (XRD). The ionic conductivity of the SPE composites was measured by the frequency response analyzer (FRA). As a result, the addition of MCM-41 into the polymeric mixture prohibited the growth of PEO crystalline domain due to the mesoporous structures of the MCM-41. The $P(EO)_{16}LiClO_4$/MCM-41 electrolytes show an increased ion conductivity as a function of MCM-41 content up to 8 $wt\%$ and a slightly decreased conductivity over 8 $wt\%$. These ion conductivity characteristics are dependent on a change of polymer crystallinity in the presence of MCM-41 system.

Value Management of Private Finance Initiative Projects (민간투자사업을 위한 VE 적용방안)

  • Lim, Jong-Kwon;Kim, Seoung-Il
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2006.11a
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    • pp.123-130
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    • 2006
  • Recently, Korean government promotes BTL(Build-Transfer-Lease) for their public construction project to apply private sector's experience and finance initiatives. Many of public buildings and civil infrastructure projects were planned to be delivered by BTL and it helps to continue public projects under tight budget conditions. Since the characteristics of BTL projects, creative ideas for the project function, performance and its LCC (Life Cycle Cost) become more important than usual public work project. This paper introduces the systematic "VE job Plan" application techniques for BTL project and shows the process. This study shows the application of "VE job Plan" for BTL project to help decision making and value improvement. Also, Project cost was estimated by LCC (Life Cycle Cost) analysis. Technical "FAST diagram"was developed and used to find major functions of the project. So, it helps to improve performance of functions and make creative ideas. FAST diagram also help to find relationships between functions and cost. A case study (Daegu Art Gallery BTL Project) was conducted using proposed "VE job Plan. Study demonstrates how value management helps save money and increase functional performance. Researcher found that project can save cost and improve performance of functions significantly by using appropriate VE analysis process at appropriate time.

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