• Title/Summary/Keyword: biased distribution

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Discharge Estimation Using Non-dimensional Velocity Distribution and Index-Velocity Method in Natural Rivers (자연하천에서 무차원 유속분포-지표유속법을 이용한 유량산정)

  • Kim, Chang-Wan;Lee, Min-Ho;Jung, Sung-Won;Yoo, Dong-Hoon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.855-859
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    • 2007
  • It is essential to obtain accurate and highly reliable streamflow data for water resources planning, evaluation and management as well as design of hydraulic structures. A new discharge estimation method, which is named 'non-dimensional velocity distribution and index-velocity method,' was proposed in this research. This method showed very close channel discharges which were calculated with the exiting velocity-area method. When velocity-area method is used to estimate channel discharge, it is required to observe point velocities at every desired point and vertical using a current meter like Price-AA. However 'non-dimensional velocity distribution and index-velocity method' is used, it become optional to observe point velocities at every desired point and vertical. But this method can not be applied for the cases of very complex and strongly asymmetric channel cross-sections because non-dimensional velocity distribution by entropy concept may be quite biased from that of natural rivers.

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Plan Research to Overcome Regionality of 5·18 Democratization Movement: Focusing on biased distribution of academic paper writers and journals (5·18 민주화운동의 지역성 극복을 위한 방안연구 -학술논문 저자와 학술지 편중분포를 중심으로 -)

  • Jung, Geun-Ha
    • Korea and Global Affairs
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    • v.1 no.2
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    • pp.5-32
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    • 2017
  • 5.18 Gwangju Democratization Movement was approved as a legal democratization movement by president Kim Young Sam in May 1993 and was approved as a global recording inheritance by UNESCO in May 2011 for the honor of Gwangju citizens to be restored. However, assessment on this until today after 35 years of occurrence is not nationally unified and the mind of Gwangju maybe only remembered as pride by Gwangju. There are several factors of this continuing situation but this researcher thinks the biggest factor is that professionals reanalyzing the truth ascertainment fitting spirit of the times who are in charge of citizen education are intensively distributed in Jeolla-do and Seoul. Moreover, the journal unlikely assessing 5.18 have enemies in the assailant area during activity that unity is not taking place with divided assessments and trapped in Honam. This study judges that the reason the meaning of 5.18 is trapped in Honam and not nationally unified is because of the limit of "adversary system." Especially researchers who should analyze and explain this incident in a objective views are bias distributed (Gwangju Jeolla-do> Seoul>Gyeongnam) in hometown areas that the possibility of 5.18 meaning not being unified was focused. Academic research studies, journal writers, and publication locations are divided in this study to reveal they are bias distributed and reveal that there is possibility that this biased distribution of researches are becoming obstacles in overcoming regionality.

Bootstrap Confidence Intervals of the Process Capability Index Based on the EDF Expected Loss (EDF 기대손실에 기초한 공정능력지수의 붓스트랩 신뢰구간)

  • 임태진;송현석
    • Journal of Korean Society for Quality Management
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    • v.31 no.4
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    • pp.164-175
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    • 2003
  • This paper investigates bootstrap confidence intervals of the process capability index(PCI) based on the expected loss derived from the empirical distribution function(EDF). The PCI based on the expected loss is too complex to derive its confidence interval analytically, so the bootstrap method is a good alternative. We propose three types of the bootstrap confidence interval; the standard bootstrap(SB), the percentile bootstrap(PB), and the acceleration biased­corrected percentile bootstrap(ABC). We also perform a comprehensive simulation study under various process distributions, in order to compare the accuracy of the coverage probability of the bootstrap confidence intervals. In most cases, the coverage probabilities of the bootstrap confidence intervals from the EDF PCI turned out to be more accurate than those from the PCI based on the normal distribution. It is expected that the bootstrap confidence intervals from the EDF PCI can be utilized in real processes where the true distribution family may not be known.

Fault Tolerant Homopolar Magnetic Bearings with Flux Coupling (자기연성을 이용한 동극형 자기베어링의 고장강건 제어)

  • Na, Uhn-Joo
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.3
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    • pp.83-92
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    • 2008
  • This paper develops the theory for a fault-tolerant, permanent magnet biased, homopolar magnetic bearing. If some of the coils or power amplifiers suddenly fail, the remaining coil currents change via a novel distribution matrix such that the same magnetic forces are maintained before and after failure. Lagrange multiplier optimization with equality constraints is utilized to calculate the optimal distribution matrix that maximizes the load capacity of the failed bearing. Some numerical examples of distribution matrices are provided to illustrate the theory. Simulations show that very much the same dynamic responses (orbits or displacements) are maintained throughout failure events (up to any combination of 3 coils failed for the 6 pole magnetic bearing) while currents and fluxes change significantly. The overall load capacity of the bearing actuator is reduced as coils fail. The same magnetic forces are then preserved up to the load capacity of the failed.

Analysis of Time-Dependent Behavior of Plasma Sheath using Ion Fluid Model (이온유체방정식을 이용한 Plasma Sheath 시변 해석)

  • Lee, Ho-Jun;Lee, Hae-June
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.12
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    • pp.2173-2178
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    • 2007
  • Dynamics of plasma sheath was analyzed using simple ion fluid model with poison equation. Incident ion current, energy, potential distribution and space charge density profile were calculated as a function of time. The effects of initial floating sheath on the evolution of biased sheath were compared with ideal matrix sheath. The effects of finite rising time of pulse bias voltage on the ion current and energy was studied. The influence of surface charging on the evolution of sheath was also investigated

Estimation of Interval Censored Regression Spline Model with Variance Function

  • Joo, Yong-Sung;Lee, Keun-Baik;Jung, Hyeng-Joo
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.4
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    • pp.1247-1253
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    • 2008
  • In this paper, we propose a interval censored regression spline model with a variance function (non-constant variance that depends on a predictor). Simulation studies show our estimates from MCECM algorithm are consistent, but biased when the sample size is small because of boundary effects. Also, we examined how the distribution of $x_i$ affects the converging speed of these consistent estimates.

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Study on the Growth Characteristics, Seasonal Anthesis Distribution and Botanical Composition of Spring Sown Wildflower Pastures (춘파 야생화초지의 생육특성, 계절개화분포 및 식생변화에 관한 연구)

  • Lee, Byong-Chul;Lee, In-Duk;Lee, Hyung-Suk
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.30 no.1
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    • pp.67-76
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    • 2010
  • The purpose of this study was to suggest the growth characteristics, seasonal anthesis distribution and botanical composition of wildflower pasture. The experimental wildflower were 34 species (1 turfgrass species, 4 native wildflower species and 29 introduced wildflower species). The experiment were administered in the Chungnam National University experimental field from March, 2008 to December, 2009 and the result is as follows: the wildflower length were within the range of 8-60 cm and their up-and-down space arrangement quite good. They bloomed into several colors of nine but one or three of nine colors were biased during August, September, and October. Their anthesis was biased toward May and June, and their seasonal distribution and permanence maintenance were too difficult from August and moreover two years later (2009) because of the decrease of the botanical distribution of annual wildflower after winter, the color, seasonal distribution, and permanence of wildflower became a problem. The botanical composition of wildflower, turf grass, and weeds came to 24%, 62%, and 14% each one year later (2008) and two years later (2009) 16%, 69%, and 15% each. Being grounded upon this result, in case of wildflower pasture of spring seeding, it is more important to maintain the color, seasonal distribution, and permanence of wildflower two years later than in the establishment year.

Biased Zero-Error Probability for Adaptive Systems under Non-Gaussian Noise (비-가우시안 잡음하의 적응 시스템을 위한 바이어스된 영-오차확률)

  • Kim, Namyong
    • Journal of Internet Computing and Services
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    • v.14 no.1
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    • pp.9-14
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    • 2013
  • The criterion of zero-error probability provides a limitation on error probability functions being used for adaptive systems when the error samples are shifted by the influence of DC-bias noise. In this paper, we employ a bias term in the error distribution and propose a new criterion of the biased zero-error probability with error being zero. Also, by maximizing the proposed criterion on expanded filter structures, a supervised adaptive algorithm has been derived. From the simulation results of supervised equalization, the algorithm based on the proposed criterion yielded zero-centered and highly concentrated error samples without disturbance in the environments of strong impulsive and DC-bias noise.

Cross Diamond Search Using Motion Direction Biased Characteristics (움직임 방향 치우침 특성을 이용한 십자형 다이아몬드 탐색)

  • Ryu, Kwon-Yeol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.8
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    • pp.1527-1533
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    • 2009
  • In this paper, we design directional search pattern using motion direction biased characteristics of MVP distribution, and proposes a direction applied cross diamond search method that adaptively change search pattern according to moving direction of search point. Proposed method predict motion vectors from neighbor macro blocks, and define initial motion direction by using predicted motion vectors. It improve search efficiency by using alternately proposed search pattern according to motion direction of BMP in search process. The simulation results show that proposed method is able to fast motion estimation compared with conventional cross diamond search, according as it reduce computational complexity that is required of motion estimation with $0.43%{\sim}1.76%$.

De-colonialism and the Collection Study - Research on Bias of Library Collection with Reference to History of Social Thoughts (탈식민주의 글쓰기와 장서 연구 -도서관 장서의 편향성에 관한 사회사상사적 접근)

  • Kim Young-Gi
    • Journal of Korean Library and Information Science Society
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    • v.36 no.1
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    • pp.173-193
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    • 2005
  • The modern society is one of knowledge and information, and the library is one of the important routes through which they are obtained. But the collection in the library, from the onset of its creation and the process of accumulation, could only be bent and biased due to the prejudice and distortion, inevitably acting as an agent that mires the essence of the library as a distribution channel for knowledge and information of modern society. This study is the discussion about the necessity, main assignment and the methodology of library collection study. The collection study needs to focus on the process of accumulating the collection in the library to track down the Process of becoming biased.

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