• 제목/요약/키워드: Functional measurement

검색결과 918건 처리시간 0.031초

Semiparametric Bayesian estimation under functional measurement error model

  • Hwang, Jin-Seub;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • 제21권2호
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    • pp.379-385
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    • 2010
  • This paper considers Bayesian approach to modeling a flexible regression function under functional measurement error model. The regression function is modeled based on semiparametric regression with penalized splines. Model fitting and parameter estimation are carried out in a hierarchical Bayesian framework using Markov chain Monte Carlo methodology. Their performances are compared with those of the estimators under functional measurement error model without semiparametric component.

Evaluation of the Functional and Non-functional Seat Sponge Effect in Sitting Chairs

  • Min, Seung Nam;Park, Se Jin;Subramaniyam, Murali;Lee, Heeran
    • 대한인간공학회지
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    • 제33권4호
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    • pp.255-265
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    • 2014
  • Objective: The purpose of this study was to evaluate comfort levels of functional and non-functional chairs using subjective comfort rating, interface pressure measurement, muscle activity measurement, and skin temperature measurement. Background: Chairs are used for a prolonged period of time for sitting in many places such as the office, at university, at school, in industry, and so on. Almost all people use chairs in their everyday life. The functional properties of the chair are associated with comfort. Method: The subjective evaluation contains questions regarding chair comfort which can be rated with five point scale. The body-seat interface pressure was measured using a pressure mat system. The symmetry of sitting was measured using electromyography. The change in body part (thigh and buttock) temperature before and after sitting on a chair was measured with an infrared camera. Results: Participants rated significantly (p < 0.05) higher comfort scores for the functional chair in relation to the buttock and thigh region. Also, the participants felt a better cushion effect in the functional chair. When using the functional chair, lower interface pressure, better thermal comfort, and better symmetry of erector spinae muscle activity were observed. Conclusion: Overall, interface pressure measurement, muscle activity measurement, thermal imaging and subjective comfort score results showed that the functional chair was more comfortable than the non-functional chair. Application: The adopted methodologies could be used to measure the seating comfort of train seats.

Feasibility study on the contact angle measurement by laser beam projection

  • Ahn, Seon-Hoon;Kim, Seong-Hun;Shin, Kyung-In;IM, Seung-Soon
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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    • pp.103-103
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    • 2003
  • A newly developed contact angle measurement instrument by laser beam projection allows for rapid and direct determination of contact angles. From the result of comparative experiment and questionnaire, the laser contact angle.

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Multivariable Bayesian curve-fitting under functional measurement error model

  • Hwang, Jinseub;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제27권6호
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    • pp.1645-1651
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    • 2016
  • A lot of data, particularly in the medical field, contain variables that have a measurement error such as blood pressure and body mass index. On the other hand, recently smoothing methods are often used to solve a complex scientific problem. In this paper, we study a Bayesian curve-fitting under functional measurement error model. Especially, we extend our previous model by incorporating covariates free of measurement error. In this paper, we consider penalized splines for non-linear pattern. We employ a hierarchical Bayesian framework based on Markov Chain Monte Carlo methodology for fitting the model and estimating parameters. For application we use the data from the fifth wave (2012) of the Korea National Health and Nutrition Examination Survey data, a national population-based data. To examine the convergence of MCMC sampling, potential scale reduction factors are used and we also confirm a model selection criteria to check the performance.

Relation between Weight Bearing Ratio in the Standing Posture Immediately after Performing Standing Task and Balance and Functional Ambulation in Stroke Patients

  • Hwang, Da-Gyeom;Kim, Joong-Hwi
    • The Journal of Korean Physical Therapy
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    • 제27권5호
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    • pp.320-324
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    • 2015
  • Purpose: The purpose of this study was to provide methods for assessment of functional balance through study of correlation with the weight bearing ratio, functional balance, and functional gait on patients with stroke. Methods: Thirty-nine patients with stroke participated in this study. The timed up and go test was used to measure balance and the functional ambulation category test to measure functional gait. Weight bearing was measured in the quiet standing posture and weight bearing in the quiet standing posture immediately after performing the standing-task. Results: Both timed up and go test and functional ambulation category test showed significant correlation with balance in the quiet standing posture immediately after performing the standing task. Conclusion: Measurement of balance in the quiet standing posture immediately after performing the standing-task was considered a meaningful scale for measurement of both balance function and gait function of patients with stroke.

A numerical method for improving the reliability of knee translation measurement in skin marker-based motion analysis

  • Wang, Hongsheng;Zheng, Nigel
    • Advances in biomechanics and applications
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    • 제1권4호
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    • pp.269-277
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    • 2014
  • In skin-marker based motion analysis, knee translation measurement is highly dependent on a pre-selected reference point (functional center) on each segment determined by the location of anatomical landmarks. However, the placement of skin markers on palpable anatomical landmarks (i.e., femoral epicondyles) has limited reproducibility. Thus, it produces large variances in knee translation measurement among different subjects, as well as across studies. In order improve the repeatability of knee translation measurement, in this study an optimization method was introduced, by which the femoral functional center was numerically determined. At that point the knee anteroposterior translation during the stance phase of walking was minimized. This new method was tested on 30 healthy subjects during walking in gait lab with motion capture system. Using this new method, the impact of skin marker position (at anatomical landmarks) on the knee translation measurement has been minimized. In addition, the ranges of anteroposterior knee translations during stance phase were significantly (p<0.001) smaller than those measured by conventional method which relies on a pre-selected functional center ($11.1{\pm}3.5mm$ vs. $19.9{\pm}5.5mm$). The results of anteroposterior translation using this new method were very close to a previously reported knee translation (12.4 mm) from dual fluoroscopic imaging technique. Moreover, this new method increased the reproducibility of knee translation measurement by 50%.

뒤시엔느 근 이영양증 환자에서 기능 수준과 측정 자세에 따른 최대호기유량, 1초간노력성호기량 및 최대기침유량의 변화 (Changes in Peak Expiratory Flow, Forced Expiratory Volume in 1 Second and Peak Cough Flow Related to Functional Level and Measurement Position in Patients With Duchenne Muscular Dystrophy)

  • 김기송;신헌석
    • 한국전문물리치료학회지
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    • 제16권3호
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    • pp.1-8
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    • 2009
  • It is important to find the effective position for cough and sputum clearance in respiratory physical therapy. The purpose of this study was to compare the changes in peak expiratory flow (PEF), forced expiratory volume in 1 second ($FEV_1$), and peak cough flow (PCF) related to functional level and measurement position in patients with Duchenne muscular dystrophy. Twenty one subjects were classified into three functional levels, and measurements was undertaken in three different measurement positions (upright sitting, $45^{\circ}$ reclining and supine). Vitalograph PEF/FEV DIARY was used to measure PEF and $FEV_1$, and Ferraris Pocket Peak was used to measure PCF. Mixed two-way analysis of variance and Bonferroni post-hoc test were used for statistical analysis. The results of the study were as follows: 1) Significant main effects for measurement position were found. 2) PEF was the highest in upright sitting, followed by $45^{\circ}$ reclining, and supine in order. 3) $FEV_1$ in upright sitting and $45^{\circ}$ reclining were significantly greater compared with that in supine. 4) PCF in upright sitting and $45^{\circ}$ reclining were significantly greater compared with that in supine. 5) No significant main effects for functional level were found in PEF, $FEV_1$, and PCF. 6) No significant functional level by measurement position interactions were found in PEF, $FEV_1$, and PCF. Therefore, it is concluded that upright sitting and $45^{\circ}$ degree reclining positions are recommended for effective cough and sputum clearance.

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ZOOMING FUNCTIONAL METHOD FOR POSITION MEASUREMENT IN ENCLOSING SIGNAL FIELD BASED N CONCEPT OF PROGRESSIVE LEARNING MEASUREMENT SYSTEM

  • Ohyama, Shinji;Cao, Li;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.1318-1321
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    • 1997
  • A method for two-dimensional position measurement using an enclosing field has been studied and reported. The feature of this mehtod is zooming functional measurement by operating both the initial phase shift and the brightness ratio of the lighting function. An experimental system was developed and the experimental results on zooming effects are shown in this paper. This system is also an example of a "progressive learning measurement system".tem".uot;.

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Functional Genomics in the Context of Biocatalysis and Biodegradation

  • Koh Sung-Cheol;Kim Byung-Hyuk
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2002년도 추계학술대회
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    • pp.3-14
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    • 2002
  • Functional genomics aims at uncovering useful information carried on genome sequences and at using it to understand the mechanisms of biological function. Elucidating the unknown biological functions of new genes based upon the genomics rationales will greatly speed up the extensive understanding of biocatalysis and biodegradation in biological world including microorganisms. DNA microarrays generate a system for the simultaneous measurement of the expression level of thousands of genes in a single hybridization assay. Their data mining (transcriptome) strategy has two categories: differential gene expression and coordinated gene expression. Furthermore, measurement of proteins (proteome) generates information on how the transcribed sequences end up as functional characteristics within the cell, and quantitation of metabolites yields information on how the functional proteins act to produce energy and process substrates (metabolome). Various composite functional genomics databases containing genetic, enzymatic and metabolic information have been developed and will contribute to the understanding of the life blue print and the new discoveries and practices in biocatalysis and biodegradation that could enrich their industrial and environmental applications.

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Bayesian curve-fitting with radial basis functions under functional measurement error model

  • Hwang, Jinseub;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제26권3호
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    • pp.749-754
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    • 2015
  • This article presents Bayesian approach to regression splines with knots on a grid of equally spaced sample quantiles of the independent variables under functional measurement error model.We consider small area model by using penalized splines of non-linear pattern. Specifically, in a basis functions of the regression spline, we use radial basis functions. To fit the model and estimate parameters we suggest a hierarchical Bayesian framework using Markov Chain Monte Carlo methodology. Furthermore, we illustrate the method in an application data. We check the convergence by a potential scale reduction factor and we use the posterior predictive p-value and the mean logarithmic conditional predictive ordinate to compar models.