• 제목/요약/키워드: Transition state theory

검색결과 132건 처리시간 0.026초

Augmentation of Hidden Markov Chain for Complex Sequential Data in Context

  • Sin, Bong-Kee
    • Journal of Multimedia Information System
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    • 제8권1호
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    • pp.31-34
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    • 2021
  • The classical HMM is defined by a parameter triple �� = (��, A, B), where each parameter represents a collection of probability distributions: initial state, state transition and output distributions in order. This paper proposes a new stationary parameter e = (e1, e2, …, eN) where N is the number of states and et = P(|xt = i, y) for describing how an input pattern y ends in state xt = i at time t followed by nothing. It is often said that all is well that ends well. We argue here that all should end well. The paper sets the framework for the theory and presents an efficient inference and training algorithms based on dynamic programming and expectation-maximization. The proposed model is applicable to analyzing any sequential data with two or more finite segmental patterns are concatenated, each forming a context to its neighbors. Experiments on online Hangul handwriting characters have proven the effect of the proposed augmentation in terms of highly intuitive segmentation as well as recognition performance and 13.2% error rate reduction.

Multichannel Quantum-Defect Study of q reversals in Overlapping Resonances in Systems involving 1 Open and 2 Closed Channels

  • Cho, Byung-Hoon;Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • 제31권2호
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    • pp.315-326
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    • 2010
  • This study examined the overlapping resonances in the systems involving 1 open and 2 closed channels using the phase-shifted version of multichannel quantum-defect theory (MQDT). The results showed that 21 patterns for the q reversals in the autoionization spectra are possible depending on the relative arrangements of the two simple poles and roots of the quadratic equations. Complete cases could be generated easily using the q zero planes determined using only 3 asymmetric spectral line profile indices. The transition of the spectra of the coarse interloper Rydberg series from the lines into a structured continuum by being dispersed onto the entire Rydberg series was found. The overall behavior of the time delays was found to be governed by the dense Rydberg series, which is quite different from the one of the autoionization cross sections that is governed by an interloper, indicating that different dynamics prevail for them. This is in contrast to the two channel system where both quantities behave similarly. The dynamics obtained in the presence of overlapping resonances is as follows. The absorption process is instant and dominated by a transition to the interloper line. This process is followed by rapid leakage into the dense Rydberg series, which has a longer residence time before ionization than that of the interloper state. This is because the orbiting period is proportional to $\upsilon^3$ so that an excited electron has a shorter lifetime in the interloper state belonging to a lower member of the Rydberg series.

시간 제한 조건을 가진 결정성 신호 전이 그래프로부터 비동기 회로의 합성 (Synthesis of Asynchronous Circuits from Deterministic Signal Transition Graph with Timing Constraints)

  • 김희숙;정성태
    • 한국정보과학회논문지:시스템및이론
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    • 제27권2호
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    • pp.216-226
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    • 2000
  • 본 논문에서는 시간 제한 조건을 가진 신호 전이 그래프로부터 바동기 회로를 합성하는 방법을 기술한다. 이 방법에서는 기존의 방법과는 달랴 상태 그래프를 생성하지 않고 신호 전이 그래프로부터 직접 신호 전이들간의 관계를 구하여 비동기 회로를 합성한다. 본 논문의 합성 과정에서는 먼저 타이밍 분석을 통하여 임의의 두 신호 전이 사이에 시간 제한 조건 내에서 병렬 관계와 인과 관계가 있는지를 구 한다. 그 다음에는 이들 관계들로부터 우선 순위 그래프를 생성하고 이 그래프 상에서 경로들을 구함으로써 해저드가 없는 회로를 생성한다. 실험 결과에 의하면 본 논문에서 제안한 합성 방법은 상태 수가 많은 회로에 대해서 현저하게 합성 시간을 단축시킬 수 있을 뿐만 아니라 기존의 합성 방법과 비교하여 거의 같은 면적의 회로를 합성한다.

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임베디드 시스템에서의 상황인식 제어를 위한 상태전이 기반 상황 모델링과 이를 응용한 상황-동작 변환기 (SAC)의 설계 (A state transition based situation modeling and its application to design of SAC(Situation-Action Converter) for situation-aware control for embedded systems)

  • 허길;박희정;조위덕;최재영
    • 한국정보과학회논문지:시스템및이론
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    • 제33권9호
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    • pp.642-649
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    • 2006
  • 지능형 서비스를 제공하는 환경에서 상황을 인식하기 위하여 임베디드 시스템이 갖는 제한적인 리소스와 컴퓨팅 파워 환경에 적합한 상태 전이 기반 상황 표현 모델을 제안하고, 이를 인식하는 상황 인식기와 제어 신호를 발생시키는 동작 발생기를 결합한 임베디드 시스템에 탑재하기에 적합한 상황-동작 변환기(SAC)를 설계하였다. 또한 ARM 프로세서 기반의 임베디드 보드에 설계된 상황-동작 변환기를 응용한 상황 관리기를 구현하여 이를 스마트 스케줄러 서비스에 활용하였다.

Sodium ethylene glycolate 용액에 의한 PET 극세사 직물의 분해 특성 (The Characteristics of PET Micro Fiber Fabrics Decomposed dy Sodium Ethylene glycol Solution)

  • 배정숙;조용석
    • 대한가정학회지
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    • 제36권8호
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    • pp.95-104
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    • 1998
  • PET microfiber fabric dissociation reactions by ethylene glycol (EG) catalayzed by the corresponding EG anions were examined to provide an empirical basis for the improvement of a PET microfiber fabrics. The alkoxide ions, monosodium ethylene glycolate in ethylene glycol solution(MSEG-EG) are prepared by the reaction between NaH and the EG respectively. The dissociation reactions were carried out until the sample PET microfiber fabrics dissociate up to 80%. Temperature used ranged 100~$160^{\circ}C$. The kinetic behaviors of the dissociated PET microfiber fabrics were examined. The results are as follows : 1. In all cases, it was found that the PET-alkoxide dissociation rate constants increased exponentially with increasing temperature. The activation energies (Ea) of the reactions were 23.31kcal/mol in PET-EG system respectively. The calculated enthalpies of the activated [PET-EG] complexes from the corresponding Ea values were 22.53 ~ 22.61 kcal/mol, and the entropies were -19.03 ~ -19.24 kcal/mol/k respectively. 2. The kinetic behavior of the PET-alkoxide dissociation reactions examined was explained by the transition state theory. PET-alkoxide transition state is believed to be formed during the ester interchange mechanism between PET and MSEG-EG in the course of the PET dissociation reactions.

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Photodissocaition Dynamics of Propiolic Acid at 212 nm: The OH Production Channel

  • Shin, Myeong Suk;Lee, Ji Hye;Hwang, Hyonseok;Kwon, Chan Ho;Kim, Hong Lae
    • Bulletin of the Korean Chemical Society
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    • 제33권11호
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    • pp.3618-3624
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    • 2012
  • Photodissociation dynamics of propiolic acid ($HC{\equiv}C-COOH$) at 212 nm in the gas phase was investigated by measuring rotationally resolved laser-induced fluorescence spectra of OH ($^2{\Pi}$) radicals exclusively produced in the ground electronic state. From the spectra, internal energies of OH and total translational energy of products were determined. The electronic transition at 212 nm responsible for OH dissociation was assigned as the ${\pi}_{C{\equiv}C}{\rightarrow}{\pi}^*{_{C=O}}$ transition by time-dependent density functional theory calculations. Potential energy surfaces of both the ground and electronically excited states were obtained employing quantum chemical calculations. It was suggested that the dissociation of OH from propiolic acid excited at 212 nm should take place along the $S_1/T_1$ potential energy surfaces after internal conversion and/or intersystem crossing from the initially populated $S_2$ state based upon the potential energy calculations and model calculations for energy partitioning of the available energy among products.

플래시 메모리를 위한 효율적인 사상 알고리즘 (An Efficient FTL Algorithm for Flash Memory)

  • 정태선;박형석
    • 한국정보과학회논문지:시스템및이론
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    • 제32권9호
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    • pp.483-490
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    • 2005
  • 플래시 메모리는 비 휘발성(non-volatility), 빠른 접근 속도, 저전력 소비, 그리고 간편한 휴대성 등의 장점을 가지므로 최근에 많은 임베디드 시스템에서 많이 사용되고 있다 그런데 플래시 메모리는 그 하드웨어 특성상 플래시 변환 계층(FTL. flash translation layer)이라는 시스템 소프트웨어를 필요로 한다. 이 FTL의 주요 기능은 파일 시스템으로부터 내려오는 논리 주소를 플래시 메모리의 물리 주소로 변환하는 일이다. 본 논문에서는 STAFF(State Transition Applied Fast Flash Translation Layer)라 불리는 FTL 알고리즘을 제안한다. 기존의 FTL 알고리즘에 비하여 STAFF는 적은 메모리를 필요로 하면서 기존 일반 방법인 블록 사상 방법에 비하여 5배 정도 좋은 성능을 보인다. 본 논문에서는 기존 FTL 알고리즘과 STAFF의 성능 비교를 보였다.

The Adsorption of the 3-methyl 5-pyrazolone on the Ge(100) Surface

  • 이명진;이한길
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.189.2-189.2
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    • 2014
  • The most stable adsorption structures and energies of four tautomerized forms (keto-1, enol-1, keto-2, and enol-2) of 3-methyl 5-pyrazolone (MP) adsorbed on Ge(100) surfaces have been investigated by Density Functional Theory (DFT) calculation method. Among its four tautomerized forms, we confirmed three tautomerized forms except keto-1 form show the stable adsorption structures when they adsorbed on the Ge(100)-$2{\times}1$ surface as we calculate the respective stable adsorption structures, activation barrier, transition state energy, and reaction pathways. Moreover, among three possible adsorption structures, we acquired that enol-2 form has most stable adsorption structure with O-H dissociated N-H dissociation bonding structure.

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화학반응성의 분자궤도론적 연구 (제7보). 시클로펜타디엔과 아크릴로니트릴 치환체간의 Diels-Alder 반응에 대한 SCF-IMO 연구 (Determination of Reactivities by Molecular Orbital Theory (VII). SCF-IMO Studies on the Diels-Alder Reactions between Cyclopentadiene and 2-Substituted Acrylonitriles)

  • 이익춘;최은화
    • 대한화학회지
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    • 제19권4호
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    • pp.218-224
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    • 1975
  • 바닥상태에 대한 자기무당착장 상호작용 에너지 이론을 2-치환-아크릴로니트릴과 시클로펜타디엔의 Diels-Alder 반응에 적용하여 반응성과 입체 선택성을 조사하였다. 출발점으로는 $\sigma$전자와 $\pi$전자를 다 고려하는 CNDO/2 MO가 사용되었다. 1차 상호작용 에너지 계산으로 정성적인 반응성이 얻어 졌으며 활성화 에너지 값은 실측치 범위의 것이 계산되었다. 2차 상호작용 에너지 계산으로 얻은 입체 선택성은 치환기에 대하여 모두 endo 선택성을 보여주었다. 비대칭 폐환의 원인을 반응원자의 원잣가 비활성 전자밀도로서 설명하였다.

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Capital Structure and Its Determinants: Evidence from Vietnam

  • NGUYEN, Tan Gia;NGUYEN, Lan;NGUYEN, Tuan Duc
    • The Journal of Asian Finance, Economics and Business
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    • 제8권10호
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    • pp.1-10
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    • 2021
  • This paper attempts to investigate the determinants of capital structure of Vietnamese firms and also shed light on some of the factors of the modern theory of capital structure which is relevant for explaining the capital structure in advanced countries which are also relevant in the context of Vietnam. Using panel data from more than 1000 Vietnamese listed enterprises census 2017-2020, the paper finds that leverage ratio of Vietnamese firms is significantly related to probability. The firms have high level of fixed assets which they use as collateral, resulting in higher debt ratio, which is in line with the pecking order theory. The result also confirm that highly targeted debt ratio is positively correlated with the industry characteristics (using real estate firms as a benchmark), in which firm operates. Furthermore, consistent with the trade-off hypothesis, the leverage ratio is positively affected by non - debt tax shield. The result confirms that a large number of companies are state - owned, will have an insignificant impact of firm's size (as reverse proxy for bankruptcy cost) on leverage ratio. We also find that there is no distinction between state-owned enterprises and private enterprises due to strict adherence to the rules set by the Vietnamese government. Distinct from other countries, corporate income tax has slight impact on capital structure in Vietnamese firms.