• Title/Summary/Keyword: Unit Process

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Nonstationary Time Series and Missing Data

  • Shin, Dong-Wan;Lee, Oe-Sook
    • The Korean Journal of Applied Statistics
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    • v.23 no.1
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    • pp.73-79
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    • 2010
  • Missing values for unit root processes are imputed by the most recent observations. Treating the imputed observations as if they are complete ones, semiparametric unit root tests are extended to missing value situations. Also, an invariance principle for the partial sum process of the imputed observations is established under some mild conditions, which shows that the extended tests have the same limiting null distributions as those based on complete observations. The proposed tests are illustrated by analyzing an unequally spaced real data set.

Robust Unit Root Tests for a Panel TAR Model

  • Shin, Dong-Wan
    • The Korean Journal of Applied Statistics
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    • v.24 no.1
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    • pp.11-23
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    • 2011
  • Robust unit root tests are developed for dynamic panels consisting of TAR processes. The test statistics are all based on diverse combinations of individual t-type tests for significance of TAR coefficients. Limiting null distributions are established. A Monte-Carlo experiment compares the proposed tests. The tests are applied to a panel data set of Canadian unemployment rates which show asymmetric features as well as having outliers.

Advanced Effects of Pulp Bleaching Treated Hemicellulase (Hemicellulase 처리에 의한 목재 펄프의 고해 효과 변화)

  • Kim, Byong-Hyun
    • Journal of the Korean Graphic Arts Communication Society
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    • v.26 no.1
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    • pp.65-72
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    • 2008
  • Kappa number and brightness were more increased with treatment of endo-xylanase than hydrogen-peroxide. In pulp bleaching process, endo-xylanse was most effective in the other enzyme treatment. Exo-xylanase was effective more than 4 unit treatment. Kappa number was tiny increased with enzyme ratio, but less than 4 unit treatment, increased with hydrogen peroxide treatment ratio. In more than 4 unit acetyl-estease treatment, Kappa number and brightness were not influenced with enzyme treatment ratio, but concentration of hydrogen-peroxide.

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A New Resource Allocation Algorithm for Low Power Architecture (저 전력 아키텍처 설계를 위한 새로운 자원할당 알고리즘)

  • 신무경;인치호
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.329-332
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    • 2000
  • This paper proposed resource allocation algorithm for the minimum power consumption of functional unit in high level synthesis process as like DSP which is circuit to give many functional unit. In this paper, the proposed method though high level simulation find switching activity in circuit each functional unit exchange for binary sequence length and value bit are logic one value. To used the switching activity find the allocation with minimal power consumption, the proposed method visits all control steps one by one and determines the allocation with minimal power consumption at each control step.

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NEW LM TESTS FOR UNIT ROOTS IN SEASONAL AR PROCESSES

  • Oh, Yu-Jin;So, Beong-Soo
    • Journal of the Korean Statistical Society
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    • v.36 no.4
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    • pp.447-456
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    • 2007
  • On the basis of marginal likelihood of the residual vector which is free of nuisance mean parameters, we propose new Lagrange Multiplier seasonal unit root tests in seasonal autoregressive process. The limiting null distribution of the tests is the standardized ${\chi}^2-distribution$. A Monte-Carlo simulation shows the new tests are more powerful than the tests based on the ordinary least squares (OLS) estimator, especially for large number of seasons and short time spans.

A Study on Algorithm of Bogie Unit Braking System (차세대전동차 대차단위 제동시스템 알고리즘에 관한 연구)

  • Kim, Gil-Dong;Lee, Han-Min;Park, Sung-Hwan
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1916-1921
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    • 2008
  • In the braking process of rolling stocks, the equivalent braking force is applied to the all bogies. However, the load applied to the front and rear bogie are different in the actual commercial traveling. In the case, since the different slip situation is occurred in each bogie, it is essential to use the independent anti-slip control per bogie unit in order to reduce the loss of braking force. In this paper, the algorithm about bogie unit braking is proposed and verified.

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Unit Root Tests for Autoregressive Moving Average Processes Based on M-estimators

  • Shin, Dong-Wan;Lee, Oesook
    • Journal of the Korean Statistical Society
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    • v.31 no.3
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    • pp.301-314
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    • 2002
  • For autoregressive moving average (ARMA) models, robust unit root tests are developed using M-estimators. The tests are parametric in the sense ARMA parameters are estimated jointly with unit roots. A Monte-Carlo experiment reveals superiority of the parametric tests over the semipararmetric tests of Lucas (1995a) in terms of both empirical sizes and powers.

A study on the fabrication method of middle size LGP using continuous micro-lenses made by LIGA reflow

  • Kim, Jong-Sun;Ko, Young-Bae;Hwang, Chul-Jin;Kim, Jong-Deok;Yoon, Kyung-Hwan
    • Korea-Australia Rheology Journal
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    • v.19 no.3
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    • pp.171-176
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    • 2007
  • LCD-BLU (Liquid Crystal Display-Back Light Unit) of medium size is usually manufactured by forming numerous dots with $50{\sim}300\;{\mu}m$ in diameter by etching process and V-grove shape with $50\;{\mu}m$ in height by mechanical cutting process. However, the surface of the etched dots is very rough due to the characteristics of the etching process and V-cutting needs rather high cost. Instead of existing optical pattern made by etching and mechanical cutting, 3-dimensional continuous micro-lens of $200\;{\mu}m$ in diameter was applied in the present study. The continuous micro-lens pattern fabricated by modified LIGA with thermal reflow process was tested to this new optical design of LGP. The manufacturing process using LIGA-reflow is made up of three stages as follows: (i) the stage of lithography, (ii) the stage of thermal reflow process and (iii) the stage of electroplating. The continuous micro-lens patterned LGP was fabricated with injection molding and its test results showed the possibility of commercial use in the future.

A Study on Environment, Care Process, and Patient-related Factors Associated with Patient Falls - A Retrospective Study of Inpatient Falls in the Unit of General Medicine in the United States (환자낙상에 영향을 주는 환경, 의료과정, 그리고 환자 관련 요소에 관한 연구 - 미국의 일반내과병동 환자낙상 데이터 분석을 통한 후향성 연구)

  • Choi, Young-Seon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.24 no.1
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    • pp.33-40
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    • 2018
  • Purpose: The main objective of this paper is, to assess environment, care process, and patient-related factors associated with patient falls. The study also aims at identifying various factors that would affect inpatient falls and, therefore, helping both caregivers and designers contribute to better prevent inpatient falls in their own areas of expertise. Methods: A retrospective analysis of inpatient falls that occurred in the unit of General Medicine in the United States has been conducted and environment, care process, patient-related factors associated with those falls have been analyzed at the same time. Results: The study identified several factors associated with inpatient falls. They range from environmental factors to care process- and patient-related factors. Patient visibility and patient accessibility can matter to patient falls and where those falls occur, along with patient days per room, the percentage of patient days with high fall risk patients per room, the percentage of high fall risk patients per room. Implications: The findings of the study can provide design implications that can be incorporated into design process and design decisions to promote fall prevention in inpatient care units. Inpatient falls can be effectively reduced when caregivers and designers work together to understand the complex nature of inpatient falls and the importance of multidisplinary efforts among various experts in the areas of healthcare.

Analysis of the Control Variables for Natural Gas Liquefied Process Using Mixed Refrigerant (혼합냉매를 이용한 천연가스 액화공정의 제어변수 분석)

  • Lee, Jae Yong;Kim, Mun-Hyun;Park, Chan-Cook
    • Journal of the Korean Institute of Gas
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    • v.17 no.4
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    • pp.51-57
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    • 2013
  • The process of liquefied natural gas is less then $-160^{\circ}C$ to natural gas by cooling at atmospheric pressure. When control strategy was made, one of the most significant is analysis of process. It is important to understand the control variable change according to manipulated variable change. In this study, we experiment natural gas liquefied process using C3MR(Propane Pre-cooled Mixed Refrigerant) process by BSU(Bench Scale Unit). We analyzed the change of refrigerant temperature and natural gas temperature according to the change of refrigerant flow rate so as to search an influence flow rate according to adjust each manipulated variables. One of the manipulated variable affected a number of control variables, but were able to confirm a control variable with a large response.