• Title/Summary/Keyword: school transitions

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Photoelectron Imaging Spectroscopy for (2+1) Resonance-Enhanced Multiphoton Ionization of Atomic Bromine

  • Kim, Yong-Shin;Jung, Young-Jae;Kang, Wee-Kyung;Jung, Kyung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.23 no.2
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    • pp.189-194
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    • 2002
  • Two-photon resonant third photon ionization of atomic bromine $(4p^5\;^2P_{3/2}\;and\;^2P_{1/2})$ has been studied using a photoelectron imaging spectroscopy in the wavelength region 250 - 278 nm. The technique has yielded simultaneously both relative branching ratios to the three levels of $Br^+(^3P_2,\;^3P_{0.1}\;and^1D_2)$ with $4p^4$ configuration and the angular distributions of outgoing photoelectrons. The product branching ratios reveal a strong propensity to populate particular levels in many cases. Several pathways have been documented for selective formation of $Br^+(^3P_2)$ and $Br^+(^3P_{0.1})$ ions. In general, the final ion level distributions are dominated by the preservation of the ion core configuration of a resonant excited state. Some deviations from this simple picture are discussed in terms of the configuration interaction of resonant states and the autoionization in the continuum. The photoelectron angular distributions are qualitatively similar for all transitions, with a positive $A_2$ anisotropy coefficient of 1.0-2.0 and negligible $A_4$ in most cases, which suggests that the angular distribution is mainly determined by the single-photon ionization process of a resonant excited state induced from the third photon absorption.

Electrical Properties of Conductive Copper Filler/Epoxy Resin Composites (전도성 구리충전제/에폭시수지 복합체의 전기적 특성)

  • Lee, Jung-Eun;Park, Young-Hee;Oh, Seung-Min;Lim, Duk-Jum;Oh, Dae-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.3
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    • pp.472-479
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    • 2013
  • The conductive polymer composites recently became increasingly to many fields of industry due to their electrical properties. To understand these properties of composites, electrical properties were measured and were studied relatively. Electrical conductivity measurements showed percolation phenomena. Percolation theories are frequently applied to describe the insulator-to-conductor transitions in composites made of a conductive filler and an insulating matrix. It has been showed both experimentally and theoretically that the percolation threshold strongly depends on the aspect ratio of filler particles. The critical concentration of percolation formed is defined as the percolation threshold. This paper was to study epoxy resin filled with copper. The experiment was made with vehicle such as epoxy resin replenished with copper powder and the study about their practical use was performed in order to apply to electric and electronic industry as well as general field. The volume specific resistance of epoxy resin composites was 3.065~13.325 in using copper powder. The weight loss of conductive composites happened from $350^{\circ}C{\sim}470^{\circ}C$.

Development of the Activity Posture Classifier for Ubiquitous Health Care (유비쿼터스 헬스케어를 위한 활동상태 분류기 개발)

  • Kim, Se-Jin;Chung, Wan-Young;Jeong, Do-Un
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.703-706
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    • 2007
  • The real-time monitoring about the activity of the human provides useful information about the activity quantity and an ability. This study developed a system for human physical activity assessment in ambulatory monitoring using portable sensing device combining a tri-axial accelerometer and wireless sensor node. This real-time system is able to identify several postures, posture transitions and movements with classification algorithm. In addition, this system also features fall detection capability. The results of the assessment for evaluating the performance of the system show high identification accuracy.

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Transition of Corporate Designers' Perception for Social Impact Management

  • Park, Junsang;Nam, Wonsuk
    • International Journal of Advanced Culture Technology
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    • v.8 no.3
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    • pp.28-37
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    • 2020
  • This is an era in which companies should realize sustainable management through business models that propose social values beyond financial benefits and solve social problems. Accordingly, the role of corporate designers should be extended to social value propositions and materializations, including corporate profit-seeking. Among the members and organizations of the company, design organization and designers have strengths in terms of humanities and creativity compared to other organizations and members. We should actively seek opportunities for corporate designers to find the context of connecting businesses and society on their own, actively seek opportunities to integrate them with corporate design, expand the role of corporate designers through creative ideas, and actively pursue sustainable and wide social career development that encompasses both inside and outside of the company. To this end, we suggested three transitions of thougths to change the perception of fixed and straight-line forms of enterprise organization, enterprise design approach and product development process so far to present useful insights through case studies, how enterprise designers can accommodate social impact through new communication and access.

Doping-Concentration and Annealing Effects on Photoluminescence Profile of Eu(III)-doped CeO2 nanorods

  • Lee, Juheon;Park, Yohan;Joo, Sang Woo;Sohn, Youngku
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3319-3325
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    • 2014
  • Eu(III)-doped $CeO_2$ nanorods were prepared by a co-precipitation method at room temperature, and their photoluminescence profiles were examined with different Eu(III)-doping concentrations and thermal annealing temperatures. Scanning electron microscopy, X-ray diffraction crystallography and UV-Vis absorption spectroscopy were employed to examine the morphology, crystal structure and photon absorption profiles of the nanorods, respectively. Additionally, their 2D and 3D-photoluminescence profile maps were obtained to fully understand the photoluminescence mechanism. We found that the magnetic dipole $^5D_0{\rightarrow}^7F_1$ and the electric dipole $^5D_0{\rightarrow}^7F_2$ transitions of Eu(III) were highly dependent on the doping concentration, annealing temperature and excitation wavelength, which was explained by the presence of different Eu(III)-doping sites (with and without an inversion center) in the $CeO_2$ host with a cubic crystal structure.

Studies for Physicochemical and In Vitro Digestibility Characteristics of Flour and Starch from Chickpea (Cicer arietinum L.)

  • Chung, Hyun-Jung
    • Preventive Nutrition and Food Science
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    • v.16 no.4
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    • pp.339-347
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    • 2011
  • Flour and isolated starch from chickpea (desi type, 328S-8) were evaluated for their in vitro digestibility and physicochemical properties. The protein content, total starch content and apparent amylose content of chickpea flour and isolated starch were 22.2% and 0.6%, 45.8% and 91.5%, and 11.7% and 35.4%, respectively. Chickpea starch granules had an oval to round shape with a smooth surface. The X-ray diffraction pattern of chickpea starch was of the C-type and relative crystallinity was 24.6%. Chickpea starch had only a single endothermic transition (13.3 J/g) in the DSC thermogram, whereas chickpea flour showed two separate endothermic transitions corresponding to starch gelatinization (5.1 J/g) and disruption of the amylose-lipid complex (0.7 J/g). The chickpea flour had a significantly lower pasting viscosity without breakdown due to low starch content and interference of other components. The chickpea starch exhibited significant high setback in the viscogram. The average branch chain length, proportion of short branch chain (DP 6~12), and long branch chains (DP${\geq}$37) of isolated chickpea starch were 20.1, 20.9% and 9.2%, respectively. The rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) contents of chickpea flour and starch were 9.9% and 21.5%, 28.7% and 57.7%, and 7.1% and 9.3%, respectively. The expected glycemic index (eGI) of chickpea flour (39.5), based on the hydrolysis index, was substantially lower than that of isolated chickpea starch (69.2).

Electrical Properties of Conductive Nickel Powder-Epoxy Resin Composites (전도성 니켈분말-에폭시수지 복합체의 전기적 특성)

  • Oh, Dae-Hee;Lim, Duk-Jum;Lee, Jung-Eun;Park, Young-Hee;Oh, Seung-Min
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.2
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    • pp.329-336
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    • 2014
  • The conductive polymer composites have attracted considerable attention in the field of industry due to their electrical properties. To understand electrical properties of the composites, their volume specific resistance was measured. Electrical conductivity results showed percolation phenomena. Percolation theories are frequently applied to describe the insulator-to-conductor transitions in the composites composed of conductive filler and insulating matrix. It was found that the percolation threshold strongly depends on the aspect ratio of filler particles. The critical concentration of percolation formed is defined as the percolation threshold. The purpose of this study was to examine electrical properties of the epoxy resins filled with nickel. The sample was prepared using vehicle such as epoxy resin replenished with nickel powder, and the evaluation on their practical use was performed in order to apply them to electric and electronic industry as well as general field. The volume specific resistance of epoxy resin composites was 4.666~13.074 when using nickel powder. Weight loss of the conductive composites took place at $350^{\circ}C{\sim}470^{\circ}C$.

Task-Level Dynamic Voltage Scaling for Embedded System Design: Recent Theoretical Results

  • Kim, Tae-Whan
    • Journal of Computing Science and Engineering
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    • v.4 no.3
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    • pp.189-206
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    • 2010
  • It is generally accepted that dynamic voltage scaling (DVS) is one of the most effective techniques of energy minimization for real-time applications in embedded system design. The effectiveness comes from the fact that the amount of energy consumption is quadractically proportional to the voltage applied to the processor. The penalty is the execution delay, which is linearly and inversely proportional to the voltage. According to the granularity of tasks to which voltage scaling is applied, the DVS problem is divided into two subproblems: inter-task DVS problem, in which the determination of the voltage is carried out on a task-by-task basis and the voltage assigned to the task is unchanged during the whole execution of the task, and intra-task DVS problem, in which the operating voltage of a task is dynamically adjusted according to the execution behavior to reflect the changes of the required number of cycles to finish the task before the deadline. Frequent voltage transitions may cause an adverse effect on energy minimization due to the increase of the overhead of transition time and energy. In addition, DVS needs to be carefully applied so that the dynamically varying chip temperature should not exceed a certain threshold because a drastic increase of chip temperature is highly likely to cause system function failure. This paper reviews representative works on the theoretical solutions to DVS problems regarding inter-task DVS, intra-task DVS, voltage transition, and thermal-aware DVS.

Fault-Tolerant Corrective Control for Non-fundamental Mode Faults in Asynchronous Sequential Machines (비동기 순차 머신의 비-기본모드에서 발생하는 고장 극복을 위한 교정 제어)

  • Yang, Jung-Min;Kwak, Seong Woo
    • Journal of IKEEE
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    • v.24 no.3
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    • pp.727-734
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    • 2020
  • Fault tolerant corrective control for asynchronous sequential machines (ASMs) with transient faults is discussed in this paper. The considered ASM is vulnerable to a kind of faults whose manifestation may arise during transient transitions of the ASM, leading to transient faults occurring in non-fundamental mode. To overcome adverse effects caused by these faults, we present a novel corrective control scheme that can detect and tolerate transient faults in non-fundamental mode. The existence condition and design algorithm for an appropriate fault tolerant controller is addressed in the framework of corrective control theory. The applicability of the proposed control methodology is demonstrated in the FPGA experiment.

Selective Coordination of Silver Ions to Poly(styrene-b-(ethylene-co-butylene)-b-styrene) and its Influence on Morphology and Facilitated Olefin Transport

  • Lee, Dong-Hoon;Kang, Yong-Soo;Kim, Jong-Hak;Kang, Sang-Wook
    • Macromolecular Research
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    • v.16 no.8
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    • pp.676-681
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    • 2008
  • The $\pi$-complex membranes of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) of two silver salts of $AgBF_4$ and $AgCF_3SO_3$ were prepared and tested for the separation of the propylene/propane mixtures. The Fourier-transform infrared (FT-IR) spectra of these complexes showed that the silver salts were dissolved in SEBS up to a silver mole fraction of 0.14, due to $\pi$-complexation between the aromatic C=C bonds of styrene blocks and silver ions. Above this solubility limit, ion pairs and high-order ionic aggregates began to form, so that silver salts were distributed unselectively in both the EB and PS blocks. The domain size of the PS blocks was enlarged up to this critical concentration with increasing silver concentration without structural transitions, as confirmed by small angle x-ray scattering (SAXS). These structural properties of the SEBS/silver salt complexes may explain the lower separation properties for propylene/propane mixtures compared to poly(styrene-b-butadiene-b-styrene)(SBS)/silver salt complex membranes.