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  • 제목/요약/키워드: two-level

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Two-Level SCPC 시스템에 대한 주파수배치 알고리듬 (A New Frequency Assignment Algorithm for Increasing C/IM in Two-Level SCPC Systems)

  • 이상문;고성찬;최형진
    • 한국통신학회논문지
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    • 제18권4호
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    • pp.572-584
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    • 1993
  • 본 논문에서는 Hub와 Remote 지구국들이 위성중계기를 통해 교신하는 방식의 Two-Level SCPC 시스템에서 혼변조적을 최소화하는 효과적인 주파수배치 방법론을 제시하였으며, 아울러 Two-Level SCPC 시스템에서의 혼변조적을 산출하는 데에 소요되는 계산시간을 줄일 수 있는 방법론을 새로이 소개하였다. Okinaka가 One-Level SCPC 시스템에 적용하였던 Deletion과 Insertion 동작을 Two-Level SCPC 시스템에 확장 적용할때 고려할 수 있는 여러 방법론들을 연구분석한 후 이들 중 최적이라 사료되는 방법론을 체계화하여 Two-Level SCPC 시스템에서의 주파수배치 알고리듬으로 제안하였다. 제안하는 알고리듬은 기존의 주파수배치 방법들에 비해, 우수한 성능을 보일 뿐만 아니라 특히 융통성의 측면에서는 매우 뛰어난 특성을 보이고 있다. 현재까지 발표된 Two-Level SCPC 시스템의 주파수배치 방법론들은 일반성이 매우 결여되어 있기 때문에 실제의 위성시스템에 효과적으로 적용할 수 없는 점을 감안하면, 본 논문에서 제안한 알고리듬은 매우 큰 의미를 지닌다고 할 수 있다.

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Two-level 한국어 형태소 해석에서의 복합명사 처리 (A Compound Noun Processing in the Two-level Morphological Analysis of Korean)

  • 이근용;박기선;이용석
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2002년도 봄 학술발표논문집 Vol.29 No.1 (B)
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    • pp.505-507
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    • 2002
  • Two-level 형태소 해석 모델은 단어들이 결합할 때 발생하는 철자변화를 처리하는 언어 독립적인 형태소 해석 모델이다. 그러나 한국어의 경우 활용과 첨용이 자유로운 교착어에 속하며 음절단위 표현법 때문에 two-level 모델을 이용한 형태소 해석 방법보다는 언어 종속적인 형태소 해석 방법을 사용하여 왔다. 한국어 용언과 다양한 변형을 처리하기 위한 two-level 규칙이 표현되었지만, 형태소 해석에서 사용하기 위해서 필요한 복합명사 치리와 미지어 처리에 대한 적절한 방법이 아직 계시되지 않았다. 본 논문은 어절 생성 규칙을 이용한 사전 구성을 이용하여 two-level 모델에서의 한국어 복합명사의 처리에 대해서 다루고, two-level 모델에서 한국어 복합명사 처리가 가능함을 보이고자 한다.

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4-수준 계량인자가 포함된 2-수준 일부실시 실험계획 (Design of Fractional Factorial Experiments with Four-Level Quantitative and Two-Level Factors)

  • 최규필;변재현
    • 대한산업공학회지
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    • 제27권4호
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    • pp.352-365
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    • 2001
  • Two-level factorial designs are popular in industry due to their simplicity, efficiency, graphical interpretation, and flexibility in sequential experimentation. However, experimenters are often frustrated when they have factors with more than two levels. There have been some works on design of experiments with two- and four-level factors, which mostly deal with qualitative four-level factors. This paper discusses differences between qualitative and quantitative four-level factors. Optimal designs are provided for some designs with four-level quantitative and two-level factors.

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A Prospective Study with Cage-Only or Cage-with-Plate Fixation in Anterior Cervical Discectomy and Interbody Fusion of One and Two Levels

  • Kim, Sam Yeol;Yoon, Seung Hwan;Kim, Dokeun;Oh, Chang Hyun;Oh, Seyang
    • Journal of Korean Neurosurgical Society
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    • 제60권6호
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    • pp.691-700
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    • 2017
  • Objective : The authors prospectively analyzed the effect of one-level or two-level anterior cervical discectomy and fusion (ACDF), comparing stand-alone cages and cage-with-plate fixation constructs with respect to clinical outcomes and radiologic changes. Methods : A total of 84 patients who underwent one-level (n=52) or two-level ACDF (n=32) for cervical disc disease and who completed 2 years of follow-up were included in this study. The patients were divided by cervical level and grouped into ACDF-Cage-only and ACDF-Cage-with-plate groups. The following parameters were assessed using radiographs : subsidence, C2-C7 lordosis angle, fusion segment angle, adjacent disc space narrowing, and fusion status. Clinical outcomes were assessed using the neck disability index (NDI) and visual analog scale scores for arm pain. Results : In the comparison of one-level ACDF-cage-only and ACDF-cage-with-plate groups, the NDI score was better in the cage-only group at the 3-, 12-, and 24-month follow-ups : however, no significant difference in clinical outcomes was observed. In the comparison of two-level ACDF-cage-only and ACDF-cage-with-plate groups, no difference in any clinical outcome was observed between the two groups. At the 24-month follow-up, subsidence was observed in 45.8% of patients in the one-level cage-only group and 32.1% of patients in the one-level cage-with-plate fixation group. There was no statistically significant difference in the incidence rate between the two groups (p=0.312). Subsidence in the two-level cage-only group (66.6%) was significantly more frequent than in the two-level cage-with-plate fixation group (30%; p=0.049). The fusion rate for patients in the one-level cage-only group was not significantly different from that in the one-level cage-with-plate fixation group (cage-only, 87.5%; cage-with-plate fixation, 92.9%; p=0.425) ; fusion rate in the two-level patients were also similar between groups (cage-only, 83.3%; cage-with-plate fixation, 95%; p=0.31). Conclusion : Our clinical results showed that for single-level cases, plate fixation had no additional benefit versus cage-only; for two-level ACDF cases, the fusion rate and clinical outcomes were similar, although the cage-with-plate fixation group had a lower incidence of cage subsidence than did the cage-only group. We conclude that physicians should be aware of this possible disadvantage associated with using cervical plates in one-level ACDF. However, in two-level ACDF, subsidence is more likely to occur without plate fixation, and thus the addition of plate fixation should be considered.

어휘 및 형태 정보를 이용한 한국어 Two-level 어휘사전 자동 구축 (Automatic Construction of Korean Two-level Lexicon using Lexical and Morphological Information)

  • 김보겸;이재성
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제2권12호
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    • pp.865-872
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    • 2013
  • Two-level 형태소 분석 방법은 규칙 기반 방법 중 하나로 형태소의 변화 현상을 규칙으로 처리하고, 기본 어휘 사전을 기반으로 형태소 결합관계를 분석한다. 이는 언어에 독립적인 방법으로 한국어에 대해서도 일부 구축되어 적용됨이 증명되었다. 그러나 기존 한국어에 대한 Two-level 형태소 분석기는 사전을 수동으로 구축하여 규모가 매우 작고 실제 사용에 제한적이었으며, 과분석이 많아 효율성이 매우 떨어졌다. 본 논문은 세종 품사부착 말뭉치에서 대규모의 Two-level 어휘 사전을 자동으로 구축하여 형태소 분석기의 적용 범위를 넓히고, 형태소간의 결합관계를 어휘 정보와 어휘 형태에 따른 하위품사 정보를 이용하여 분석함으로써 형태소 분석기의 성능을 향상시킬 수 있는 방법을 제시한다. 실험 결과, 기존의 방법보다 형태소 분석기의 과분석을 68% 이상 줄여 f-measure를 25.5% point 이상 향상시킬 수 있었다.

Efficient Eye Location for Biomedical Imaging using Two-level Classifier Scheme

  • Nam, Mi-Young;Wang, Xi;Rhee, Phill-Kyu
    • International Journal of Control, Automation, and Systems
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    • 제6권6호
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    • pp.828-835
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    • 2008
  • We present a novel method for eye location by means of a two-level classifier scheme. Locating the eye by machine-inspection of an image or video is an important problem for Computer Vision and is of particular value to applications in biomedical imaging. Our method aims to overcome the significant challenge of an eye-location that is able to maintain high accuracy by disregarding highly variable changes in the environment. A first level of computational analysis processes this image context. This is followed by object detection by means of a two-class discrimination classifier(second algorithmic level).We have tested our eye location system using FERET and BioID database. We compare the performance of two-level classifier with that of non-level classifier, and found it's better performance.

A TWO-LEVEL FINITE ELEMENT METHOD FOR THE STEADY-STATE NAVIER-STOKES/DARCY MODEL

  • Fang, Jilin;Huang, Pengzhan;Qin, Yi
    • 대한수학회지
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    • 제57권4호
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    • pp.915-933
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    • 2020
  • A two-level finite element method based on the Newton iterative method is proposed for solving the Navier-Stokes/Darcy model. The algorithm solves a nonlinear system on a coarse mesh H and two linearized problems of different loads on a fine mesh h = O(H4-𝜖). Compared with the common two-grid finite element methods for the considered problem, the presented two-level method allows for larger scaling between the coarse and fine meshes. Moreover, we prove the stability and convergence of the considered two-level method. Finally, we provide numerical experiment to exhibit the effectiveness of the presented method.

하구에서 Two-level 모델에 의한 해수유동 및 확산에 관한 수치실험 (Numerical Experiments on the Hydrodynamic and Diffusion in Estuary by using Two-level Model)

  • 김차겸;이종섭
    • 한국수산과학회지
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    • 제24권1호
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    • pp.59-69
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    • 1991
  • Two-level numerical models are formulated to predict the flow pattern, SS(suspended solids) distribution and the behavior of discharged fresh water in estuary, and are applied to the Suyoung River estuary in Pusan, Korea. To verify the application of the models, field observations of tidal current, salinity and 55 were performed during the period of spring tide. Computed upper level velocities by two-level model are in better agreement with observed values than single model. Apart from the magnitude of the velocities, the predicted flow fields at upper level are similar to those obtained at lower level. Upper level velocities in river channel during ebb spring tide are about 2 times stronger than those during flood spring tide due to the discharging flow rate from the Suyoung River. Two-level model results on the salinity and 55 distribution at upper level are compared with the observed ones at the surface. Computed salinity distributions are in good agreement with the observed values, but computed 55 distributions show 6\~10 ppm higher values than the observed ones.

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개선된 two-level costate prediction method를 이용한 원자로 출력 제어 (A study on power control of nuclear reactor using revised two-level costate prediction method)

  • 천희영;박귀태;이희정
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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    • pp.244-247
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    • 1986
  • A revised two-level costate prediction algorithm is developed for the optimization of nonlinear nuclear power plant. The algorithm is proved to converge very well, and appears to require substantially small computation time and storage than previous nonlinear optimization algorithm. To cope with unknown external disturbances, we construct a closed loop control system. In order to get a smaller sampling time, this paper proposes the two-level Kalman filter.

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수준별 소집단 협력학습 유형이 학습자의 학업적 자기효능감과 영어학업성취도에 미치는 영향 (Effects on learners' learning self-efficacy and English accomplishments by two types of level-based collaborative groupworks)

  • 이남숙;임병빈
    • 영어어문교육
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    • 제12권4호
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    • pp.211-234
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    • 2006
  • The purpose of the present study was to investigate how two types of cooperative groupworks will affect learners' academic self-efficacy and English achievement in the first graders of Middle school. Experimental class A was done by similar-level groupwork, experimental class B by differential-level groupwork, and controlled class C by whole classwork. In order to accomplish the goals of the study, questionnaires on learners' academic self-efficacy were examined before and after the experiment. Also English achievement tests were done during the experiment. The analytic results of the questionnaires and English achievement tests were like the following conclusions: First, two types of cooperative groupworks were more effective on improving learners' academic self-efficacy than the whole classwork. Second, two types of cooperative groupworks were more effective on improving two levels' (higher and medium) academic self-efficacy. Third, among three types of classworks, differential-level groupwork was the most effective on improving learners' English achievement. Fourth, in case of medium-level learners, differential-level groupwork was more effective on improving their English achievement than similar-level groupwork.

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