• Title/Summary/Keyword: case - control study

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Control Limits of Time Series Data using Hilbert-Huang Transform : Dealing with Nested Periods (힐버트-황 변환을 이용한 시계열 데이터 관리한계 : 중첩주기의 사례)

  • Suh, Jung-Yul;Lee, Sae Jae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.4
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    • pp.35-41
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    • 2014
  • Real-life time series characteristic data has significant amount of non-stationary components, especially periodic components in nature. Extracting such components has required many ad-hoc techniques with external parameters set by users in a case-by-case manner. In this study, we used Empirical Mode Decomposition Method from Hilbert-Huang Transform to extract them in a systematic manner with least number of ad-hoc parameters set by users. After the periodic components are removed, the remaining time-series data can be analyzed with traditional methods such as ARIMA model. Then we suggest a different way of setting control chart limits for characteristic data with periodic components in addition to ARIMA components.

Tracking performance evaluation of adaptive controller using neural networks (신경망을 이용한 적응제어기의 추적 성능 평가)

  • 최수열;박재형;박선국
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1561-1564
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    • 1997
  • In the study, simulation result was studied by connecting PID controller in series to the established Neural Networks Controller. Neural Network model is composed of two layers to evaluate tracking performance improvement. The reqular dynamic characteristics was also studied for the expected error to be minimized by using Widrow-Hoff delta rule. As a result of the study, We identified that tracking performance inprovement was developed more in case of connecting PID than Neural Network Contoller and that tracking plant parameter in 251 sample was approached rapidly case of time variable.

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An Application Case Study of Inventive Mathematical Club for Mathematics Talented students (수학영재교육을 위한 자발적 수학 동아리 운영 사례 분석)

  • Suh, Bo-Euk
    • Proceedings of the Korea Society of Mathematical Education Conference
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    • 2010.04a
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    • pp.77-82
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    • 2010
  • This study assumes alternative character of the operation of gifted class in middle school. The case that operated the voluntary mathematics club for one year was analyzed and the educational effect was considered. First, the examination instrument for choosing the members of mathematics club was developed and used. Second, diverse teaching and learning materials for improving creativity and mathematical ability of the members were used. Third, the difference of learning result between the experiment group and control one who joined the activities of mathematics club was analyzed.

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Association between the Alleles of the Dopamine $D_1$ Receptor and Schizophrenia (정신분열증환자와 도파민 $D_1$ 수용체 대립유전자 연합)

  • Kim, Jeong Il;Lee, Min Soo;Kwak, Dong Il
    • Korean Journal of Biological Psychiatry
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    • v.4 no.2
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    • pp.218-224
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    • 1997
  • The results regarding an association between the polymorphism sites in the dopamine $D_1$ receptor gene and schizophrenia compelled us to study the distribution of the polymorphism in Korean schizophrenia and controls. Eighty-eight schizophrenic patients and normal controls were examined by case-control study for distribution of the polymorphism of the dopamine $D_1$ receptor gene in Korean popualtion to minimize the effect of racial differencies in gene frequencies. The frequencies of the $B_1$ and $B_2$ in schizophrenic patients were 0.11 and 9.89, respectively. And 0.10 and 0.90 in normal control. Ther was no significant differences in the frequencies in the allele $B_1$ and $B_2$between schizophrenic patients and normal controls. The author present here the evidence of a lack of alleic association between the polymorphism of the dopamine $D_1$ receptor gene and Korean schizophrenic patients. The assumption that the dopamine $D_1$ receptor gene has a genetic role in the development of schizophrenia was not suppoorted by this case-control study.

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Effects of Combination of Danggwibohyeol-tang Herbal-acupuncture on Anemic Rats (배합비율(配合比率)에 따른 당귀보혈탕(當歸補血湯) 약침(藥鍼)이 빈혈백서(貧血白鼠)에 미치는 영향(影響))

  • Jin Jae-Do;Kim Yun-Hong;Jung Tae-Young;Seo Jeong-Chul;Leem Seong-Cheol;Han Sang-Won
    • Korean Journal of Acupuncture
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    • v.20 no.2
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    • pp.77-92
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    • 2003
  • Objective; This study was investigated to test the anti-anemic effects of Danggwibohyeol-tang for herbal acupuncture on rat with anemia induced by phenylhydrazine according to composition ratio. Methods; Danggwibohyeol-tang herbal-acupuncture was administered into Kyoksu(膈兪穴, BL17) and RBC, Hemoglobin, Hematocrit, MCV, MCH, MCHC, RDW, platelet, MPV, PDW, indirect bilirubin and lactate dehydrogenase were tested. Results; The obtained results are summarized as follows: (1) In control group RBC was significantly reduced in comparison with normal group. And in Danggwibohyeol-tang group A, B, C there was significant inhibitory effect on reduction in comparison with control group. The effect of Danggwibohyeol-tang group C was similiar to that of Danggwibohyeol-tang group B and was higher than that of Danggwibohyeol-tang group A. (2) In control group hemoglobin was significantly reduced in comparison with normal group. And in Danggwibohyeol-tang group A, B, C there was significant inhibitory effect on reduction in comparison with control group but there was no significant difference between Danggwibohyeol-tang group A, B, C. (3) In control group hematocrit was significantly reduced in comparison with normal group. And in Danggwibohyeol-tang group A, B, C there was significant inhibitory effect on reduction in comparison with control group. The effect of Danggwibohyeol-tang group C was higher than that of Danggwibohyeol-tang group A or B. (4) In case of MCV, MCH, MCHC and RDW there was no significant anti-anemic effect. (5) Danggwibohyeol-tang group significantly inhibited the growth of platelet. In case of Danggwibohyeol-tang A and B group there was more inhibitory effect than Danggwibohyeol-tang C group but there was no significant difference between Danggwibohyeol-tang A and B group. (6) In case of MPV, PDW and indirect bilirubin there was no significant difference between Danggwibohyeol-tang group and control group. (7) Danggwibohyeol-tang group significantly inhibited the growth of lactate dehydrogenase. In case of Danggwibohyeol-tang C group there was more inhibitory effect than Danggwibohyeol-tang B group and Danggwibohyeol-tang B group showed more inhibitory effect than Danggwibohyeol-tang A group. Conclusion; From above results Danggwibohyeol-tang for herbal acupuncture showed significant anti-anemic effect in some parameters. Further study is needed for the effect of Danggwibohyeol-tang according to different composition ratio.

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A Bayesian Poisson model for analyzing adverse drug reaction in self-controlled case series studies (베이지안 포아송 모형을 적용한 자기-대조 환자군 연구에서의 약물상호작용 위험도 분석)

  • Lee, Eunchae;Hwang, Beom Seuk
    • The Korean Journal of Applied Statistics
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    • v.33 no.2
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    • pp.203-213
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    • 2020
  • The self-controlled case series (SCCS) study measures the relative risk of exposure to exposure period by setting the non-exposure period of the patient as the control period without a separate control group. This method minimizes the bias that occurs when selecting a control group and is often used to measure the risk of adverse events after taking a drug. This study used SCCS to examine the increased risk of side effects when two or more drugs are used in combination. A conditional Poisson model is assumed and analyzed for drug interaction between the narcotic analgesic, tramadol and multi-frequency combination drugs. Bayesian inference is used to solve the overfitting problem of MLE and the normal or Laplace prior distributions are used to measure the sensitivity of the prior distribution.

A Study on Decisions of Building Design Control Committee in Jeju-Si (제주시 건축위원회의 심의성향에 관한 연구)

  • Park Chul-Min;Kim Jae-Chel
    • Journal of the Korean housing association
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    • v.15 no.6
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    • pp.77-88
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    • 2004
  • The Building Design Control Commission has various important roles as the final check point for the overall urban management. Although nobody can argue that the committee is useless, participants' assessments on the results of the introduction and operation of the Building Design Control Commission are diversified. The primary purpose of this thesis lies in the institutional examination of the contents related with Building Design Control Commission by using the literature inquiry. The second purpose is to provide a help for the improvement of discussion of the administrative structure and improvement of the urban aesthetic through the systematic analysis of Building Design Control System. The extent of space is selected according to the case of building planning deliberation of Jeju-Si as the axis of Free International City, the center of administration, education, and culture. The period of time of examination is from January, 2002 to December, 2002. The subject of study is apartment which is deeply related with our lives by analyzing 2,231 discussion cases.

A Study on the Wake Flow behind a Circular Cylinder with a Spinning Control Cylinder (회전하는 제어원주가 설치된 원주후류의 유동장에 관한 연구)

  • 부정숙;류병남;심정훈
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.3
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    • pp.58-69
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    • 2000
  • An experimental study was conducted to investigate the influence of the spinning control cylinders which was set on the surface of a fixed circular cylinder in uniform flow, $Re=1.24\times10^4$. The measurements of velocity vectors and pressure distributions are carried out in various spin parameters and angles of spinning control cylinder. The results show that velocity profiles and pressure distributions are different with angles of control cylinder and spin parameters. When the control cylinder angle is $100^{\circ}$, there is more effect in increasing the velocity and the pressure distribution than other cases. In this case, the vortex shedding frequency was increased as increasing spin parameter.

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A Study on Qualification Procedures of Flight Control Software on Military Aircraft (군용항공기 비행제어 소프트웨어 품질인증 절차에 관한 연구)

  • Heo, Jin-Goo
    • Journal of Korean Society for Quality Management
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    • v.41 no.3
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    • pp.433-441
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    • 2013
  • Purpose: This study investigates software qualification procedures based on the FA-50 flight control software to satisfy high reliability and flight safety. Methods: We studied software qualification categories, standard/specification and developed country case. We proposed procedure to satisfy not only flight safety but also international standard. Results: The proposed software qualification procedure satisfied flight safety and airworthiness based on the testing result of the FA-50 flight control software. Conclusion: This paper showed an appropriate qualification procedures of the flight control software in domestic circumstance through the FA-50 flight control software qualification.

A Study on the Relation between Multivariate Process Control Techniques and Trend Algorithm (다변량 공정관리 기술과 추세알고리즘의 연계에 관한 조사연구)

  • Jung, Hae-Woon
    • Journal of the Korea Safety Management & Science
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    • v.13 no.4
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    • pp.225-235
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    • 2011
  • Autoregressed Controller, which have trend algorithm, seeks to minimize variability by transferring the output variable to the related process input variable, while multivariate process control techniques seek to reduce variability by detecting and eliminating assignable causes of variation. In the case of process control, a very reasonable objective is to try to minimize the variance of the output deviations from the target or set point. We also investigate algorithm with relevant Shewhart chart, Theoretical control charts, precontrol and process capability. To help the people who want to make the theoretical system, we compare the main techniques in "a study on the relation between multivariate process control techniques and trend algorithms".