• 제목/요약/키워드: S−stable

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Stability Analysis of a Biped Walking Robot with Foot Rotation Indicator

  • Noh, Kyung-Kon;Lee, Bo-Hee;Kim, Jin-Geol
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.105.2-105
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    • 2002
  • $\textbullet$ Statically stable walk with COG(center of gravity) $\textbullet$ Dynamically stable walk with ZMP(zero moment point) $\textbullet$ Dynamically adaptational stable walk with FRI(foot ratation indicator) $\textbullet$ Simplified inverted pendulum model approach $\textbullet$ Analysis posture of biped's foot as passive joint $\textbullet$ Stability compensation method of FRI against falling down $\textbullet$ Simulation of ZMP and FRI to real biped robot IWR-III

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TOTAL SCALAR CURVATURE AND EXISTENCE OF STABLE MINIMAL SURFACES

  • Hwang, Seung-Su
    • 호남수학학술지
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    • 제30권4호
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    • pp.677-683
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    • 2008
  • On a compact n-dimensional manifold M, it has been conjectured that a critical point metric of the total scalar curvature, restricted to the space of metrics with constant scalar curvature of volume 1, should be Einstein. The purpose of the present paper is to prove that a 3-dimensional manifold (M,g) is isometric to a standard sphere if ker $s^*_g{{\neq}}0$ and there is a lower Ricci curvature bound. We also study the structure of a compact oriented stable minimal surface in M.

Effects of Tillage and Cultivation Methods on Carbon Accumulation and Formation of Water-stable Aggregates at Different Soil Layer in Rice Paddy

  • Kim, Sukjin;Choi, Jong-Seo;Kang, Shingu;Park, Jeong-Hwa;Hong, Sunha;Kim, Tae-su;Yang, Woonho
    • 한국토양비료학회지
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    • 제50권6호
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    • pp.634-643
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    • 2017
  • No-tillage is an effective practice to save labor input and reduce methane emission from the paddy. Effects of tillage and cultivation methods on carbon accumulation and soil properties were investigated in the treatments of tillage-transplanting (T-T), tillage-wet hill seeding (T-WS), minimum tillage-dry seeding (MT-S) and no-tillage dry seeding (NT-S) of rice. Soil carbon was higher in NT-S and MT-S, compared to T-T and T-WS. In NT-S and MT-S, soil carbon contents were the highest in the top soil (5 cm depth) and decreased with soil depth. In T-T and T-WS, however soil carbon contents showed no significant difference up to soil depth of 15 cm from the top. Carbon content was the highest in the soil particle size under $106{\mu}m$ and decreased as the soil particle size increased. Contents of water-stable aggregates in NT-S and MT-S were higher than those of T-T and T-WS. In NT-S and MT-S, contents of water-stable aggregates were the highest in the top soil and significantly decreased with soil depth while no significant difference up to the soil depth of 15 cm in T-T and T-WS. Available $SiO_2$ contents in the top soil were the highest in NT-S and MT-S while the lowest in T-T and T-WS. It is concluded that minimum or no disturbance of soil in rice cultivation can increase carbon accumulation in the soil, especially in the top layer, and subsequently contribute to the formation of the water-stable soil aggregates.

빛에 의한 Cz 실리콘 기판의 carrier lifetime 감소에 대한 연구 (Investigation of the Carrier Lifetime of Cz-Si after Light Induced Degradation)

  • 이지연;이수홍
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.985-988
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    • 2004
  • The carrier lifetime of boron doped Cz silicon samples after light induced degradation could be improved by optimized rapid thermal processing (RTP). The important five different parameters varied in order to investigate which parameter is important for the stable lifetime after light induced degradation, $\tau_d$. The Plateau temperature and the Plateau time influenced on the lifetime after light induced degradation. Especially, the Plateau temperature showed a strong influence on the stable lifetime. The optimal plateau temperature is approximately $900^{\circ}C$ t for a plateau time of 120 s. The stable lifetime increased from $15\mu}s$ to $25.5{\mu}s$. The normalized defect concentration, $N_t^*$, decreased from $0.06{\mu}s^{-1}$ to $0.037{\mu}s^{-1}$ by RTP-process.

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Survey of the Arithmetic and Geometric Approach to the Schottky Problem

  • Jae-Hyun Yang
    • Kyungpook Mathematical Journal
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    • 제63권4호
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    • pp.647-707
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    • 2023
  • In this article, we discuss and survey the recent progress towards the Schottky problem, and make some comments on the relations between the André-Oort conjecture, Okounkov convex bodies, Coleman's conjecture, stable modular forms, Siegel-Jacobi spaces, stable Jacobi forms and the Schottky problem.

지지면에 따른 호흡운동 기법이 배근육 두께에 미치는 영향 (Effect of the Breathing Methods in Accordance with Surfaces during Bridging Exercises)

  • 배원식;이건철
    • 대한물리의학회지
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    • 제11권2호
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    • pp.33-40
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    • 2016
  • PURPOSE: The purpose of this study was to determine the impact of stable and unstable surfaces on abdominal muscle thickness and changes in trunk muscle thickness in accordance with breathing methods during bridging exercises. METHODS: Bridging exercise on a stable surface, bridging exercise on an unstable surface, bridging exercise using a drawing-in maneuver on a stable surface, bridging exercise using a drawing-in maneuver on an unstable surface, bridging exercise using bracing on a stable surface, bridging exercise using bracing on an unstable surface. In sequence, the muscles' thickness was measured three times before and after each exercise, and the measured value was averaged. RESULTS: There were significant differences in internal oblique and transversus abdominis muscles' thickness in the drawing-in maneuver in both stable and unstable surface (p<0.05). There were no significant differences in external oblique muscle's thickness in the bridging exercise in both stable and unstable surface. The type of surface did not have a significant influence on the abdominal muscles' thickness. CONCLUSION: As a result of the study, the drawing-in maneuver had a greater effect than bridging or bracing maneuver on muscle thickness. We suggest that drawing-in maneuver will be more effective in a person with a weak abdominal muscle.

노화 (I): 생활환경이 다른 노인군간 인지기능의 차이 (Aging (I): Difference of Cognitive Function Related to Living Condition of the Aged)

  • 강혜경
    • 한국식생활문화학회지
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    • 제17권3호
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    • pp.275-288
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    • 2002
  • The purpose of this study was to investigate the cognitive differences among the aged who have different living conditions. 91 free-meal receivers and 86 people with stable lives were asked about their living conditions and cognitive function by using K-MMSE. All data were analyzed by SPSS 10.0 package. Free meal receivers had poorer socioeconomic status than the subjects who had stable lives. Cognitive function of free meal receivers was lower than the people with stable lives in the most cognitive factors. Especially age of 50 to 64, pre-aged group, who had been receiving free meals, showed lowest cognitive level than the other age groups. Among 7 cognitive factors, there was the greatest difference in attention and calculation between 2 groups. Percentage of 'conclusive dementia' among the free meal receivers was statistically higher than the people with stable lives and that of 'conclusively normal' was statistically lower in free meal receivers comparing with the people with stable lives. Moreover, socioeconomic factors like income, former job, marital status, housing and education, blood pressure and physical activity were significantly related to the subject's cognitive function.

${\alpha}$-stable 랜덤잡음에 노출된 이미지에 적용하기 위한 비선형 잡음제거 알고리즘에 관한 연구 (A Study on Nonlinear Noise Removal for Images Corrupted with ${\alpha}$-Stable Random Noise)

  • 한희일
    • 대한전자공학회논문지SP
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    • 제44권6호
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    • pp.93-99
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    • 2007
  • 본 논문에서는 ${\alpha}$-stable 확률분포를 갖는 잡음에 열화된 이미지의 화질을 개선하는 알고리즘을 제안한다. 제안한 진폭제한 평균필터(amplitude-limited sample average filter)는 heavy-tailed 가우시안 잡음환경 하에서 maximum likelihood estimator (MLE)임을 증명한다. 그리고, 이 알고리즘에 해당하는 error norm은 Huber의 minimax norm과 일치하고, 위에서 언급한 잡음 환경 하에서 efficacy를 최대화한다는 점에서 최적의 필터임을 보인다. 이 개념을 미리어드(myriad) 필터와 결합하여 진폭제한 미리어드 필터(amplitude-limited myriad filter)를 제안하고 실험을 통하여 이의 성능을 확인한다.

플랭크 운동 시 지지면의 형태가 복부 근육의 두께 변화에 미치는 영향 (Effect of Support Surface Form on Abdominal Muscle Thickness During Flank Exercise)

  • 김현수;이건철
    • 대한통합의학회지
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    • 제7권3호
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    • pp.197-204
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    • 2019
  • Purpose: The purpose of this study was to investigate the effects of the plank exercise to strengthen the core muscles on the muscle thickness of external and internal obliques and transverse abdominis muscle depending on the form of the support surface. Methods: This study was randomized to 12 males and 12 females in their 20s and conducted three times a week for 4 weeks. The subjects were divided into the two groups and performed flank exercise on a stable surface (stable surface group) and an unstable surface (unstable surface group). A mat was used as a stable surface, and an TOGU used as a unstable surface. Results : In both stable and unstable surface, the thickness changes of the transverse abdominis and external and internal oblique muscle increased (p<.05). In the unstable surface, there was a greater increase in the thickness change of the transverse abdominis and external oblique muscles in the flank exercise than in the stable surface (p.<05). Among them, the greatest increase was found in the external abdominal muscle (p<.05). Conclusion : This study found that the flank exercise was more effective in strengthening the abdominal muscles on an unstable surface, when compared with the outcomes on a stable one. It is also thought to have the most effect on the muscle activity of the external oblique muscle on unstable surface.