• Title/Summary/Keyword: five-states

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Theoretical Study on the Nonadiabatic Transitions in the Photodissociation of Cl2, Br2, and I2

  • Asano, Yukako;Yabushita, Satoshi
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.703-711
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    • 2003
  • We have theoretically studied the nonadiabatic transitions among the five lower states with the Ω=$1_u$ symmetry ($1_u^{(1)} to 1_u^{(5)}$) in the photodissociation of Cl₂, Br₂, and I₂by using the spin-orbit configuration interaction (SOCI) method and the semiclassical time-dependent coupled Schrodinger equations. From the configuration analyses of the SOCI wavefunctions, we found that the nonadiabatic transition between $1_u^{(2)}$ and $1_u^{(1)}$ is a noncrossing type, while that between $1_u^{(3)}$ and $1_u^{(4)}$ is a crossing type for all the molecules. The behavior of the radial derivative coupling element between $1_u^{(1)}$ and $1_u^{(2)}$ and that between $1_u^{(3)}$ and $1_u^{(4)}$ is analyzed in detail. In Cl₂, nonadiabatic transitions can take place even between the states correlating to different dissociation limits, while in Br₂ and I₂, with the usual photon energies e.g. less than 20 eV, nonadiabatic transitions occur only between the states correlating to the same dissociation limits, reflecting the different magnitudes of the spin-orbit interactions.

A study on characteristics of ZnSe epilayer by using surface photovoltage (표면 광전압을 이용한 ZnSe 에피층의 특성 연구)

  • 최상수;정명랑;김주현;배인호;박성배
    • Journal of the Korean Vacuum Society
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    • v.10 no.3
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    • pp.350-355
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    • 2001
  • We have investigated characteristics of ZnSe epilayer grown by molecular beam epitaxy(MBE) on semi-insulating(SI) GaAs by using surface photovoltage(SPV). The measurements of SPV were performed with illumination intensity and modulation frequency. The bandgap energy of ZnSe epilayer was determined from derivative surface photovoltage (DSPV). The five states were observed at room temperature(RT), and those states relate to the impurity and defect formed hetero-interface of ZnSe and GaAs during the sample growth. The observed states represented as a tendency of typical extrinsic transition on the increasing illumination intensity. The 1s and 2s signals related to the excitonic absorption were not observed at RT, but those were presented with the splitted of two peaks in the SPV at 80 K. From the modulation frequency dependence, we obtained the junction conductance and capacitance of the sample.

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Development of Water Quality Modeling in the United States

  • Ambrose, Robert B;Wool, Tim A;Barnwell, Thomas O.
    • Environmental Engineering Research
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    • v.14 no.4
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    • pp.200-210
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    • 2009
  • The modern era of water quality modeling in the United States began in the 1960s. Pushed by advances in computer technology as well as environmental sciences, water quality modeling evolved through five broad periods: (1) initial model development with mainframe computers (1960s - mid 1970s), (2) model refinement and generalization with minicomputers (mid 1970s - mid 1980s), (3) model standardization and support with microcomputers (mid 1980s - mid 1990s), (4) better model access and performance with faster desktop computers running Windows and local area networks linked to the Internet (mid 1990s - early 2000s), and (5) model integration and widespread use of the Internet (early 2000s - present). Improved computer technology continues to drive improvements in water quality models, including more detailed environmental analysis (spatially and temporally), better user interfaces and GIS software, more accessibility to environmental data from on-line repositories, and more robust modeling frameworks linking hydrodynamics, water quality, watershed and atmospheric models. Driven by regulatory needs and advancing technology, water quality modeling will continue to improve to better address more complicated water bodies and pollutant types, and more complicated management questions. This manuscript describes historical trends in water quality model development in the United States, reviews current efforts, and projects promising future directions.

A Chronological Study on the Transformation and the Spatial Characteristics of Emergency department in the United States (미국의료시설 응급부의 시대적 변천과 공간적 특성에 관한 연구)

  • Lee, Sukyung;Choi, Yoonkyung
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.24 no.3
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    • pp.17-27
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    • 2018
  • Purpose: This study aims to examine spatial characteristics of emergency department Chronologically through case studies; and to consider the social implication of these spatial changes. Methods: In this study, a total of eight emergency departments, one for each period, were selected in order to analyze the spatial characteristics. The spatial maps of Space Syntax were employed for analyzing case studies. Results: The spatial configuration of emergency department has been changed from five or more emergency department specialties to four or less specialties such as psychiatric, pediatrics, emergency, and trauma. In the case of care initiation area, the concentrated arrangement mode was switched from the distributed arrangement mode. The spatial maps indicate that it can be seen that the tree structure changes to an annular structure emphasizing the connection between the spaces in the emergency department. This shows that the space efficiency, safe, visual control and flexibility in the planning of the emergency department are important factors affecting the spatial structure of the emergency department. Implications: In the future, it is expected that Korean emergency department will be more focused on efficiency, safe, visual control, and flexibility in the planning as in the case studies of the United States.

Simplified Model Predictive Control Method for Three-Phase Four-Leg Voltage Source Inverters

  • Kim, Soo-eon;Park, So-Young;Kwak, Sangshin
    • Journal of Power Electronics
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    • v.16 no.6
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    • pp.2231-2242
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    • 2016
  • A simplified model predictive control method is presented in this paper. This method is based on a future reference voltage vector for a three-phase four-leg voltage source inverter (VSI). Compared with the three-leg VSIs, the four-leg VSI increases the possible switching states from 8 to 16 owing to a fourth leg. Among the possible states, this should be considered in the model predictive control method for selecting an optimal state. The increased number of candidate switching states and the corresponding voltage vectors increase the calculation burden. The proposed technique can preselect 5 among the 16 possible voltage vectors produced by the three-phase four-leg voltage source inverters, based on the position of the future reference voltage vector. The discrete-time model of the future reference voltage vector is built to predict the future movement of the load currents, and its position is used to choose five preselected vectors at every sampling period. As a result, the proposed method can reduce calculation load by decreasing the candidate voltage vectors used in the cost function for the four-leg VSIs, while exhibiting the same performance as the conventional method. The effectiveness of the proposed method is demonstrated with simulation and experiment results.

Developing an Art-based Integration Program for the Korean Schools in the United States

  • Jung, Hyunil
    • International Journal of Advanced Culture Technology
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    • v.6 no.1
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    • pp.1-7
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    • 2018
  • The purpose of this study is to develop an art-based integration program for the Korean schools in the United States to improve students' academic performance and nurture the spirit of the young and can enable students taking art classes to better understand social and cultural phenomena influencing their lives. This study integrates with six other subjects that are language art, math, religion, social studies, and Korean history. Art classes are considered the main vehicle for integrating the entire program using a thematic approach. The methodology of this study is based on the literature research and the information of the place, the Korean School of Columbus, is that the school is one of 124 Korean Schools in the Mid-western states and is located in the northern part of Columbus, Ohio. In this study, I developed an art-based integration program to be connected well with other subjects to help students to make sense of them in the complex societies and to help them to obtain the five goals that are included: First, students will understand about a Korean history and culture through making a kite; Second, they will know that a kite can be used as ways of communication with people and God; Third, they will also know how different types of kites respond to the airflow of the wind; Fourth, they will understand an enjoyable and different way of learning about aspects of Fine art, Bible, Language art, Mathematics, Science, History, and Social studies; Lastly, they will learn how important to cooperate with each other.

Analysis, Recognition and Enforcement Procedures of Foreign Arbitral Awards in the United States

  • Chang, Byung Youn;Welch, David L.;Kim, Yong Kil
    • Journal of Arbitration Studies
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    • v.27 no.3
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    • pp.53-76
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    • 2017
  • Korean businesses, and their legal representatives, have observed the improvements of enforcement of commercial judgments through arbitration over traditional collections litigation in U.S. Courts-due to quicker proceedings, exceptional cost savings and more predictable outcomes-in attaching assets within U.S. jurisdictions. But how are the 2016 interim measures implemented by the Arbitration Act of Korea utilized to avoid jurisdictional and procedure pitfalls of enforcement proceedings in the Federal Courts of the United States? Authors examine the necessary prerequisites of the U.S. Federal Arbitration Act as adopted through the New York Convention, to which Korea and the U.S. are signatories, as distinguished from the Panama Convention. Five common U.S. arbitration institutions address U.S. "domestic" disputes, preempting U.S. state law arbitrations, while this article focuses on U.S. enforcement of "international" arbitration awards. Seeking U.S. recognition and enforcement of Korean arbitral awards necessitates avoiding common defenses involving due process, public policy or documentary formality challenges. Provisional and conservatory injunctive relief measures are explored. A variety of U.S. cases involving Korean litigants are examined to illustrate the legal challenges involving non?domestic arbitral awards, foreign arbitral awards and injunctive relief. Suggestions aimed toward further research are focused on typical Korean business needs such as motions to confirm foreign arbitration awards, enforce such awards or motions to compel arbitration.

Setting a Direction for United States Water Policy

  • Reid, Kenneth D.;Engberg, Richard A.
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.121-121
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    • 2010
  • The water resources of the United States are increasingly at risk and the nation's water policy is in serious difficulty. Water resources protection laws primarily passed since 1950 often contradict water resources development laws passed before 1950. These contradictions complicate efficient and effective responses to the nation's water resources challenges including climate change, our aging infrastructures, changing population dynamics, drought, floods, wetlands and aquatic species loss, ecosystem restoration and many others. In addition, water law and policy determination, management and enforcement are so broadly distributed between, local, state and federal responsibilities that effective responses again are difficult. For example, at the national level alone, more than a dozen federal agencies have water resources responsibilities including resource development, resource assessment, and resource protection. They are presided over by six cabinet (Ministerial) departments, at least 13 congressional (parliamentarian) committees and 23 subcommittees, and are funded by five appropriations subcommittees. Lastly, good science and the public accountability associated with it are often overshadowed by political considerations at local, state and federal levels. The United States approach to solving water resources challenges is ad hoc - we address problems as they appear or as they merit political support rather than using good science to address our long term water resources needs.

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Study on Memristive Characteristics in Electronic Devices Based on Vanadium Dioxide Thin Films Using 966nm Laser Pulses (966nm 레이저 펄스를 이용한 바나듐 이산화물 박막 기반 전자 소자에서의 멤리스터 특성에 관한 연구)

  • Kim, Jihoon;Lee, Yong Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.11
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    • pp.59-65
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    • 2015
  • By harnessing the thermal hysteresis behavior of vanadium dioxide($VO_2$), we demonstrated multi-resistance states in a two-terminal electronic device based on a $VO_2$ thin film by using a 966nm infrared laser diode as an excitation light source for resistance modulation. Before stimulating the device using 966nm laser pulses, the thermal hysteresis behavior of the device resistance was measured by using a temperature chamber. After that, the $VO_2$ device was thermally biased at ${\sim}71.6^{\circ}C$ so that its temperature fell into the thermal hysteresis region of the device resistance. Six multi-states of the device resistance could be obtained in the fabricated $VO_2$ device by five successive laser pulses with equal 10ms duration and increasing power. Each resistance states were maintained while the temperature bias was applied. And, the resistance fluctuation level was within 2.2% of the stabilized resistance and decreased down to less than 0.9% of the stabilized resistance 5s after the illumination.

Interpretation of Strain States during Clad-Rolling of STS/Al 5 Ply Composites by Means of Texture Analysis (집합조직 분석에 의한 5겹 STS/Al 복합재 클래드 압연 시 변형상태 해석)

  • Kang H. G.;Park J. S.;Park S. H.;Huh M. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.05a
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    • pp.303-306
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    • 2005
  • Two composites of five plies of STS/Al/Al/Al/STS and STS/Al/STS/Al/STS were produced by roll-cladding at $350^{\circ}C$ from ferritic stainless steel (STS) and aluminum (Al) sheets. In order to analyze the strain states during roll-cladding, the evolution of textures at different through-thickness positions in the roll-clad composites was investigated. Simulations with the finite element method (FEM) disclosed that a strain state which was similar to that of normal rolling with a high friction between roll surface and Al sample led to the formation of texture gradients in the Al sheets in the STS/Al/Al/Al/STS composite. Differences in the material velocity of STS and Al in the rolling direction gave rise to the formation of the shear texture in the Al sheets in the STS/Al/STS/Al/STS composite.

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