• Title/Summary/Keyword: baseline model

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Kinematic GPS Positioning with Baseline Length Constraint Using the Maximum Possibility Estimation Method

  • Wang, Xinzhou;Xu, Chengquan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.247-250
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    • 2006
  • Based on the possibility theory and the fuzzy set, the Maximum Possibility Estimation method and its applications in kinematic GPS positioning are presented in this paper. Firstly, the principle and the optimal criterion of the Maximum Possibility Estimation method are explained. Secondly, the kinematic GPS positioning model of single epoch single frequency with baseline length constraint is developed. Then, the authors introduce the artificial immune algorithm and use this algorithm to search the global optimum of the Maximum Possibility Estimation model. The results of some examples show that the method is efficient for kinematic GPS positioning.

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Estimating the Mixture of Proportional Hazards Model with the Constant Baseline Hazards Function

  • Kim Jong-woon;Eo Seong-phil
    • Proceedings of the Korean Reliability Society Conference
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    • 2005.06a
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    • pp.265-269
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    • 2005
  • Cox's proportional hazards model (PHM) has been widely applied in the analysis of lifetime data, and it can be characterized by the baseline hazard function and covariates influencing systems' lifetime, where the covariates describe operating environments (e.g. temperature, pressure, humidity). In this article, we consider the constant baseline hazard function and a discrete random variable of a covariate. The estimation procedure is developed in a parametric framework when there are not only complete data but also incomplete one. The Expectation-Maximization (EM) algorithm is employed to handle the incomplete data problem. Simulation results are presented to illustrate the accuracy and some properties of the estimation results.

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Prospective Study on the Relating Factors to the Stages of Change in Smoking Cessation and Barriers in Coronary Artery Disease Patients* (관상동맥질환자의 금연변화단계와 관련된 요인 및 장애요인에 대한 전향적 연구)

  • Kim, Hwa-Soon
    • Journal of Korean Academy of Nursing
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    • v.35 no.1
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    • pp.27-36
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    • 2005
  • Purpose: The main purpose of this study was to investigate that the stages of change in smoking cessation behavior among coronary artery disease patients for six months progressed following the stages of change suggested by the transtheoretical model. Method: Subjects for this descriptive survey were 59 coronary disease patients who were smoking or who had stopped smoking for less than six months. Result: In the baseline, the distribution of the subjects’ stages of change was as follows: pre-contemplation stage 25.4%, contemplation stage 25.4%, preparation stage 22%, and action stage 27.1%. After six months, more subjects in the contemplation(33.3%) and preparation stages(30.8%) progressed to the action stage than those of the pre-contemplation stage(0%). Eighty-one percent of the subjects in the action stage at baseline progressed to the maintenance stage. The relationship between the numbers of smoking cessation attempts for six months and stages of change at baseline was significant(p=.001). However, the relationships between self-efficacy and nicotine dependence at baseline and progression in stages of change after six months were not significant. Conclusion: Progression in the stages of change for six months among subjects corresponded to the stages of change suggested by the transtheoretical model. Hence, future development and evaluation of intervention programs should be tailored individually considering each patient's stage of change.

Graphemes Segmentation for Arabic Online Handwriting Modeling

  • Boubaker, Houcine;Tagougui, Najiba;El Abed, Haikal;Kherallah, Monji;Alimi, Adel M.
    • Journal of Information Processing Systems
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    • v.10 no.4
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    • pp.503-522
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    • 2014
  • In the cursive handwriting recognition process, script trajectory segmentation and modeling represent an important task for large or open lexicon context that becomes more complicated in multi-writer applications. In this paper, we will present a developed system of Arabic online handwriting modeling based on graphemes segmentation and the extraction of its geometric features. The main contribution consists of adapting the Fourier descriptors to model the open trajectory of the segmented graphemes. To segment the trajectory of the handwriting, the system proceeds by first detecting its baseline by checking combined geometric and logic conditions. Then, the detected baseline is used as a topologic reference for the extraction of particular points that delimit the graphemes' trajectories. Each segmented grapheme is then represented by a set of relevant geometric features that include the vector of the Fourier descriptors for trajectory shape modeling, normalized metric parameters that model the grapheme dimensions, its position in respect to the baseline, and codes for the description of its associated diacritics.

Damage Detection in Cracked Model Plate-Girder using Damage Index Method and System Identification Technique (손상지수법과 구조식별(SID) 기법을 통한 균열된 강판형 모형의 손상검색)

  • 백종훈;류연선;김정태;조현만
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.109-116
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    • 2001
  • An integrated damage identification system (IDIS) and system identification (SID) technique using modal information to detect damage in structures is presented. The objective is to detect damages in cracked model plate-girder without baseline modal parameters. The theory of damage localization and system identification is outlined. Experiments on a model plate-girder was described and a baseline model representing the experimental modal characteristics of the model plate-girder is updated using the system identification technique. Finally, damage inflicted in the model plate-girder is predicted using the IDIS software.

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A generalized logit model with mixed effects for categorical data (다가자료에 대한 혼합효과모형)

  • 최재성
    • The Korean Journal of Applied Statistics
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    • v.15 no.1
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    • pp.129-137
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    • 2002
  • This paper suggests a generalized logit model with mixed effects for analysing frequency data in multi-contingency table. In this model nominal response variable is assumed to be polychotomous. When some factors are fixed but considered as ordinal and others are random, this paper shows how to use baseline-category logits to incoporate the mixed-effects of those factors into the model. A numerical algorithm was used to estimate model parameters by using marginal log-likelihood.

The Benefit of Ambiguity Resolution Using Triple Frequency

  • Tominaga, Reiji;Gomi, Yasuto;Zhang, Yun;Kubo, Nobuaki;Yasuda, Akio
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.23-26
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    • 2006
  • Modernized GPS will have three frequencies modulated with three signals, which will be accessible to all users in the near future. This new frequency provides an opportunity to resolve the double differenced (DD) integer ambiguity very fast and with almost no baseline constraints. In order to study the performance of triple frequency system for Ambiguity Resolution (AR) over the medium baseline under different ionospheric levels, the Klobuchar Model was implemented and used in our triple simulation to generate the ionospheric delay. Furthermore, the White-Gaussian noise applying to distance-dependent parameters was added to the DD ionospheric delay. For medium baseline (defined as here 20 to 40kms), success rates of AR has been pretty improved. In this paper, the medium baseline AR strategies that take advantage of carrier phase measurement on the third frequency will be discussed.

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A Baseline Correction for Effective Analysis of Alzheimer’s Disease based on Raman Spectra from Platelet (혈소판 라만 스펙트럼의 효율적인 분석을 위한 기준선 보정 방법)

  • Park, Aa-Ron;Baek, Sung-June
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.1
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    • pp.16-22
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    • 2012
  • In this paper, we proposed a method of baseline correction for analysis of Raman spectra of platelets from Alzheimer's disease (AD) transgenic mice. Measured Raman spectra include the meaningful information and unnecessary noise which is composed of baseline and additive noise. The Raman spectrum is divided into the local region including several peaks and the spectrum of the region is modeled by curve fitting using Gaussian model. The additive noise is clearly removed from the process of replacing the original spectrum with the fitted model. The baseline correction after interpolating the local minima of the fitted model with linear, piecewise cubic Hermite and cubic spline algorithm. The baseline corrected models extract the feature with principal component analysis (PCA). The classification result of support vector machine (SVM) and maximum $a$ posteriori probability (MAP) using linear interpolation method showed the good performance about overall number of principal components, especially SVM gave the best performance which is about 97.3% true classification average rate in case of piecewise cubic Hermite algorithm and 5 principal components. In addition, it confirmed that the proposed baseline correction method compared with the previous research result could be effectively applied in the analysis of the Raman spectra of platelet.

A Study for Improving the Positioning Accuracy of DGPS Based on Multi-Reference Stations by Applying Exponential Modeling on Pseudorange Corrections

  • Kim, Koon-Tack;Park, Kwan-Dong;Lee, Eunsung;Heo, Moon Beom
    • Journal of Positioning, Navigation, and Timing
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    • v.2 no.1
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    • pp.9-17
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    • 2013
  • In this paper, a pseudorange correction regeneration algorithm was developed to improve the positioning accuracy of DGPS using multi-reference stations, and the optimal minimum number of reference sites was determined by trying out different numbers of reference. This research was conducted using from two to five sites, and positioning errors of less than 1 m were obtained when pseudorange corrections are collected from at least four reference stations and interpolated as the pseudorange correction at the rover. After determining the optimal minimum number of reference stations, the pseudorange correction regeneration algorithm developed was tested by comparison with the performance of other algorithms. Our approach was developed based on an exponential model. If pseudorange corrections are regenerated using an exponential model, the effect of a small difference in the baseline distance can be enlarged. Therefore, weights can be applied sensitively even when the baseline distance differs by a small amount. Also weights on the baseline distance were applied differently by assigning weights depending on the difference of the longest and shortest baselines. Through this method, the positioning accuracy improved by 19% compared to the result of previous studies.

Instrumentation and Structural Health Monitoring of Bridges (교량구조물의 헬스모니터 링을 위한 진동계측)

  • 김두기;김종인;김두훈
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.5
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    • pp.108-122
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    • 2001
  • As bridge design is advancing toward the performance-based design. it becomes increasingly important to monitor and re-evaluate the long-term structural performance of bridges. Such information is essential in developing performance criteria for design. In this research. sensor systems for long-term structural performance monitoring have been installed on two highway bridges. Pre1iminary vibration measurement and data analysis have been performed on these instrumented bridges. On one bridge, ambient vibration data have been collected. based on which natural frequencies and mode shapes have been extracted using various methods and compared with those obtained by the preliminary finite element analysis. On the other bridge, braking and bumping vibration tests have been carried out using a water truck In addition to ambient vibration tests. Natural frequencies and mode shapes have been derived and the results by the breaking and bumping vibration tests have been compared. For the development of a three dimensional baseline finite element model, the new methodology using a neural network is proposed. The proposed one have been verified and applied to develop the baseline model of the bridge.

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