• Title/Summary/Keyword: EMIC

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Pc1/EMIC waves observed at subauroral latitude during sudden magnetospheric compressions

  • Kim, Khan-Hyuk;Shiokawa, Kazuo;Lee, Dong-Hun;Kwon, Hyuck-Jin;Lee, Ensang
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.117.2-117.2
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    • 2012
  • It is generally accepted that sudden compressions of the magnetosphere cause electromagnetic ion cyclotron (EMIC) wave growth by increasing the proton temperature anisotropy. These compression-associated EMIC waves are expected to be on higher latitudes (i.e., higher-L regions close to the magnetopause). In this study we examine Pc1 pulsations, which are believed to be generated by the EMIC instability, observed at subauroral latitude near the nominal plasmapause when the magnetosphere is suddenly compressed by solar wind dynamic pressure variations, using induction magnetometer data obtained from Athabasca, Canada (geomagnetic latitude = 61.7 N, L ~ 4.5). We identified 9 compression-associated Pc1 waves with frequencies of ~0.5-2.0 Hz. The wave activity appears in the horizontal H (positive north) and D (positive eastward) components. All of events show low coherence between H and D components. This indicates that the Pc1 pulsations in H and D oscillate with a different frequency. Thus, we cannot determine the polarization state of the waves. We will discuss the occurrence location of compression-associated Pc1 pulsations, their spectral structure, and wave properties.

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Structural Analysis of Species in NbCI5-EMIC Room-Temperature Molten Salt with Raman Spectroscopic Measurement and Ab Initio Molecular Orbital Calculation

  • Koura, Nobuyuki;Matsuzawa, Hidenori;Kato, Tomoki;Idemoto, Yasushi;Matsumoto, Futoshi
    • Journal of the Korean Electrochemical Society
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    • v.5 no.4
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    • pp.183-188
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    • 2002
  • The structure of species formed in $NbCI_5-I-ethyl-3-methylimidazolium$ chloride (EMIC) room-temperature molten salt (RTMS) was examined with the Raman spectroscopic measurement and ab initio molecular orbital calculation. The equilibrium structures of $NbCl_5,\;NbCl_6^-,\;Nb_2CI_{10},\;Nb_2CI_{11}^-,\;Nb_3CI_6^-,\;NbCI_6^--EMI^+\;(in\;which\;NbCI_6^-$ anion approaches $EMI^+$ cation with strong interaction) and $Nb_2CI_{11}^--EMI^+$ were obtained with the HF/LANL2DZ level of calculation. The harmonic frequencies at each equilibrium structure were compared with Raman spectra. The harmonic frequencies of $NbCI_6^--EMI^+,\; Nb_2CI_{11}^--EMI^+,\;and\;Nb_2CI_{10}$ were in good agreement with the Raman spectra of RTMS melts. In the $NbCI_5-EMIC RTMS$, the main species were $NbCI_6^-\;and\;EMI^+$. In the $NbCl_5-EMIC$ RTMS added $NbCl_5\;over\;50mol\%$, small amount of $Nb_2CI_{11}^-\;and\; Nb_2CI_{10}$ were also formed. The structures of anions and cation in the RTMS distorted from free ions with Coulomb force.

Harmony through Holistic Engagement: An Emic Model of Greater East Asian Regionalism

  • von Feigenblatt, Otto F.
    • Journal of Contemporary Eastern Asia
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    • v.12 no.2
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    • pp.61-87
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    • 2013
  • This study applies grounded theory to develop an emic substantive theory of regional integration in Greater East Asia. The role of norms and policies is explored through discursive content analysis of a wide theoretical sample of official elite policy statements dealing with regionalism and related policy areas. A resulting model of regional integration titled "Harmony through Holistic Engagement" is then discussed in relation to the etic consensus on the phenomenon. The study concludes that the etic consensus on the nature of regional integration in Greater East Asia greatly differs from the results of an emic approach and thus reflects a normative consensus rather than a descriptive reality.

Radiation belt electron losses induced by wave-particle interactions

  • Summers, Danny
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.32.2-32.2
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    • 2009
  • We examine cyclotron resonant interactions of radiation belt electrons with VLF chorus, plasmaspheric ELF hiss and electromagnetic ion cyclotron (EMIC) waves. Bounce-averaged diffusion rates depend on wave mode, equatorial pitch-angle, electron energy and L-shell. As well, diffusion rates can be sensitive to the latitudinal distributions of particle density and wave power. For different configurations of the plasmasphere, we calculate electron precipitation loss timescales due to combined scattering by VLF chorus, ELF hiss and EMIC waves.

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Limitations of Electromagnetic Ion Cyclotron Wave Observations in Low Earth Orbit

  • Hwang, Junga;Kim, Hyangpyo;Park, Jaeheung;Lee, Jaejin
    • Journal of Astronomy and Space Sciences
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    • v.35 no.1
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    • pp.31-37
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    • 2018
  • Pc1 pulsations are geomagnetic fluctuations in the frequency range of 0.2 to 5 Hz. There have been several observations of Pc1 pulsations in low earth orbit by MAGSAT, DE-2, Viking, Freja, CHAMP, and SWARM satellites. However, there has been a clear limitation in resolving the spatial and temporal variations of the pulsation by using a single-point observation by a single satellite. To overcome such limitations of previous observations, a new space mission was recently initiated, using the concept of multi-satellites, named the Small scale magNetospheric and Ionospheric Plasma Experiments (SNIPE). The SNIPE mission consists of four nanosatellites (~10 kg), which will be launched into a polar orbit at an altitude of 600 km (TBD) in 2020. Four satellites will be deployed in orbit, and the distances between each satellite will be controlled from 10 to 1,000 km by a high-end formation-flying algorithm. One of the possible science targets of the SNIPE mission is observing electromagnetic ion cyclotron (EMIC) waves. In this paper, we report on examples of observations, showing the limitations of previous EMIC observations in low earth orbit, and suggest possibilities to overcome those limitations through a new mission.

Incorporation of Electromagnetic Ion cyclotron waveinto Radiation Belt environment model

  • Kang, Suk-Bin;Choi, Eunjin;Hwang, Junga;Kim, Kyung-Chan;Lee, Jaejin;Fok, Mei-ching;Min, Kyoungwook;Choi, Cheongrim;Park, Young-Deuk
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.132.1-132.1
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    • 2012
  • Radiation Belt Environment (RBE) model has developed to understand radiation belt dynamics as it considers whistler mode hiss and chorus waves which is responsible for relativistic electron acceleration and precipitation. Recently, many studies on electron loss by pitch-angle scattering have reported that elctromagnetic ion cyclotron (EMIC) wave is also responsible for main loss mechanism in dusk and equatorial regeion. Here, we attempt to incorporate EMIC into RBE model simulation code to understand more detailed physical dynamics in Radiation belt environemnt. We compare this developed model to data during storm events where both of electron loss and EMIC waves were detected.

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A Study on Design of Medical Advice Support System in Emergency using Agent System (에이전트를 활용한 응급의료지도 지원시스템 설계에 관한 연구)

  • Kim, Kyoung-Hwan
    • The Journal of Information Systems
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    • v.19 no.3
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    • pp.263-278
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    • 2010
  • Emergency Medical Service(EMS) requires a system that supports the communication between emergency medical technicians (EMT)s and the doctor in the emergency department. Because the rapid triage and on-site treatment of patients need doctor's medical advice. However, a system to assist the doctor assign for medical advice does not exist in Korea. This paper suggests a medical advice support system that focuses on appropriate doctor assign and real-time communication among the ambulance, the Emergency Medical Information Center (EMIC), and the doctor using an agent system. We expect that the system can help to solve the problems affecting prehospital EMS and improve its general quality.

PIC simulation study of the turbulence of the Alfven ion-cyclotron waves induced by electromagnetic ion-cyclotron instability

  • Kaang, Helen H.;Ryu, Chang-Mo;Mok, Chinook;Rha, Ki-Cheol
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.29.3-29.3
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    • 2011
  • The turbulence in the nonlinear regime of the electromagnetic ion-cyclotron (EMIC) instability are investigated via a particle-in-cell (PIC) simulation. EMIC instability arises from anisotropic ion temperature and excites the Alfven ion-cyclotron (AIC) waves. The excited AIC waves undergo inverse-cascade via the nonlinear wave interaction of two AIC and one ion density modes. Induced ion density modes are the normal and second harmonic ion-acoustic (IA) waves. They have the same group velocity, but the second harmonic IA mode only generates the longitudinal electric field.

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Simulation study on the nonlinear evolution of EMIC instability

  • Rha, Kicheol;Ryu, Chang-Mo;Yoon, Peter H.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.119.2-119.2
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    • 2012
  • Charged particle energization is an outstanding problem in space physics. This paper investigates the nonlinear dynamics of Alfve'n-cyclotron waves accompanying particle heating processes and the drift Alfv'en-cyclotron (or EMIC) instability associated with a current disruption event on 29 January 2008 observed with THEMIS satellite by means of a particle-in-cell simulation. The simulation shows that the drift Alfv'en-cyclotron instabilities are excited in two regimes, a relatively low frequency mode propagating in a quasi-perpendicular direction while the second high-frequency branch propagating in a predominantly parallel propagation direction, which is consistent with observation as well as earlier theories. It is shown that parametric decay processes lead to an inverse cascade of Alfv'en-cyclotron waves and the generation of ion-acoustic waves by decay instability. It is also shown that the nonlinear decay processes are accompanied by small perpendicular heating and parallel cooling of the protons, and a pronounced parallel heating of the electrons.

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The Effect of Cultural Predictors on Perceived Ethicality of Negotiation Behavior A Comparison of 'Chemyon' and Hofstede's Cultural Dimensions (문화 변수가 협상 윤리에 미치는 영향 '체면'과 홉스테드 변수의 비교)

  • Kim, Yung-Wook;Yang, Jung-Eun
    • Korean journal of communication and information
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    • v.46
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    • pp.212-244
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    • 2009
  • This study examined the effects of cultural factors and demographic factors on the perceived appropriateness and likelihood of using five categories of inappropriate negotiation strategies. Five categories of inappropriate negotiation strategies consist of traditional competitive bargaining, attacking opponent's network, false promises, misrepresentation of information and inappropriate information gathering. Two kinds of cultural variables, Hofstede's cultural dimensions and 'Chemyon' dimensions were used as universal, etic variables versus indigenous, emic variables. Survey result shows age and gender had significant effects only for traditional competitive bargaining, but gender and personal negotiation style did not have any effects for the inappropriate strategies. Hofstede's dimensions as well as Chemyon dimensions had significant effect for perceived inappropriateness and likelihood of using inappropriate strategies. While both Chemyon and Hofstede's dimensions were significant, Chemyon accounted for more variance than Hofstede dimensions in most cases. This suggests Chemyon's vital role in explaining Korean negotiators' perception and attitude towards inappropriate negotiation strategies. Implications of the results and future research are discussed.

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