• Title/Summary/Keyword: Reference interval

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Application of Bootstrap and Bayesian Methods for Estimating Confidence Intervals on Biological Reference Points in Fisheries Management (부트스트랩과 베이지안 방법으로 추정한 수산자원관리에서의 생물학적 기준점의 신뢰구간)

  • Jung, Suk-Geun;Choi, Il-Su;Chang, Dae-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.2
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    • pp.107-112
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    • 2008
  • To evaluate uncertainty and risk in biological reference points, we applied a bootstrapping method and a Bayesian procedure to estimate the related confidence intervals. Here we provide an example of the maximum sustainable yield (MSY) of turban shell, Batillus cornutus, estimated by the Schaefer and Fox models. Fitting the time series of catch and effort from 1968 to 2006 showed that the Fox model performs better than the Schaefer model. The estimated MSY and its bootstrap percentile confidence interval (CI) at ${\alpha}=0.05$ were 1,680 (1,420-1,950) tons for the Fox model and 2,170 (1,860-2,500) tons for the Schaefer model. The CIs estimated by the Bayesian approach gave similar ranges: 1,710 (1,450-2,000) tons for the Fox model and 2,230 (1,760-2,930) tons for the Schaefer model. Because uncertainty in effort and catch data is believed to be greater for earlier years, we evaluated the influence of sequentially excluding old data points by varying the first year of the time series from 1968 to 1992 to run 'backward' bootstrap resampling. The results showed that the means and upper 2.5% confidence limit (CL) of MSY varied greatly depending on the first year chosen whereas the lower 2.5% CL was robust against the arbitrary selection of data, especially for the Schaefer model. We demonstrated that the bootstrap and Bayesian approach could be useful in precautionary fisheries management, and we advise that the lower 2.5% CL derived by the Fox model is robust and a better biological reference point for the turban shells of Jeju Island.

Comparison Study about Surface Mapping of Motor Points in Biceps Brachii Muscle Using Surface EMG and Electric Probe (표면 근전도와 전기 탐침기를 이용한 상완이두근의 운동점 표지 비교 연구)

  • Park, Jaewon;Keum, Dongho
    • Journal of Korean Medicine Rehabilitation
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    • v.28 no.1
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    • pp.85-96
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    • 2018
  • Objectives This study was performed to compare the electrical methods of motor points mapping using surface EMG and electric probe (Pointer Excel II). Methods 32 healthy adults (male 16, female 16) were selected. and classified into two groups; surface EMG group, electric probe (Pointer Excel II) group. In surface EMG group, motor points were searched by recoding the compound muscle potentials. In electric probe (Pointer Excel II) group, motor points were searched by scanning the skin with Pointer Excel II at low level stimulation. The locations of the motor points were expressed as X and Y values in relation to the reference line. The horizontal reference line was set as elbow crease and the vertical reference line was set as the line connecting coracoid process to the center of the horizontal reference line. The data was analyzed by 'Independent T-test' and 'equivalence test'. Results 1. The motor points of short head and long head of biceps brachii muscle were located at about 2/3 length of the vertical reference line from coracoid process and about 1/5~1/4 length of the half of the horizontal reference line from the vertical reference line in both group. 2. The motor points of the short head were located more distally and close to the vertical reference line (p<0.001). 3. In surface EMG group, the motor points of the long head were located more laterally in the female than male. And the motor points of the long head were located more distally in the left side than right side (p<0.05). In electric probe (Pointer Excel II) group, similar tendency was observed but there was no statistically significant difference (p>0.05). 4. As a result of the equivalence test between surface EMG group and electric probe (Pointer Excel II) group, the confidence intervals of the difference were within the equivalence limit. Therefore, the locations of the motor points searched by two ways are equa l (p>0.05, equivalence interval=3%). Conclusions The results indicate that electric probe (Pointer Excel II) can be used to search the motor points instead of surface EMG. This might improve the clinical efficiency when using the motor points to treat muscle dysfunction.

Proposed Assessment for Quality of Experience of Live IPTV in Home Environments

  • Jeong, Jongpil;Choi, Jae-Young
    • International journal of advanced smart convergence
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    • v.4 no.1
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    • pp.18-30
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    • 2015
  • As the speed of networks that subscribers can use has greatly increased, demand for high-quality broadcast content, such as from Internet Protocol Television (IPTV) and Video on Demand (VoD), is likewise increasing. Therefore, while broadcasters are increasing content and channels, they are striving to improve consumer quality of experience (QoE) to differentiate themselves from competitors, including by producing higher physical-quality content. Recently, subjective measurement methods have been internationally standardized as the most reliable approach for measuring and evaluating IPTV QoE. However, a majority of these methods are performed in experimental environments and are based on the extremely brief viewing period of approximately ten seconds using original reference videos. It is actually difficult to apply standard evaluation methods based on a ten-second viewing interval to assess real broadcast watching of IPTV or other services that involve a longer time (i.e., more than thirty minutes). In this paper, we therefore propose a method that accommodates actual viewing environments. Using the mean opinion score, we experimentally analyze the effects of evaluation interval changes under actual conditions in which IPTV service is provided. In addition, we propose improvements by applying the results into actual live broadcast IPTV service and by analyzing consumer service QoE.

Effectiveness of Nutrition Intervention : Systematic Review & Meta-Analysis (임상영양서비스의 효과성 평가 : 체계적 검토와 메타분석을 통하여)

  • 이해영;김현아;양일선;남정모;박은철
    • Korean Journal of Community Nutrition
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    • v.9 no.1
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    • pp.81-89
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    • 2004
  • A systematic review and meta-analysis of the literatures was conducted to evaluate the effectiveness of nutrition intervention by dietitian. The 31 studies that were all randomized controlled trials, were identified from computerized search of published researches on MEDLINE, Embase database until January, 2003 and review of reference lists. The main search terms were the combination “dietitian”, “dietary intervention”, “nutrition intervention” or “nutritional intervention” and “effectiveness”. The subgroup analysis was performed by the publication year, quality score, type of disease, content of intervention, intervention provider, type of intervention (nutritional counseling and education/nutrilion counseling and education + diet modification), method of intervention (individual/group/individual + group) and follow-up period. Two reviewers independently selected trials for inclusion, assessed the quality and extracted the data. The meta-analysis of 31 studies based on the random effect model showed that the medical nutrition therapy was significantly effective in treating the diseases (effect size 0.1715 : 95% confidence interval 0.0938-0.2491). This study showed the clear evidence of the effectiveness of nutrition intervention through the meta-analysis. So the nutrition intervention by dietitian should be recommended and recognized as the effective therapy of treating the diseases. Also the nutrition intervention should be conducted regularly to maintain the effectiveness of the nutrition intervention. The nutrition intervention was significantly effective in treating the diseases on the random effect model (effect size 0.1715 : 95% confidence interval 0.0938-0.2491).

Design and Sensitivity Analysis of Input Shaping Filter in the Z-domain (Z-영역에서 입력성형기의 설계와 민감도 해석)

  • Park, Un-Hwan;Lee, Jae-Won;Im, Byeong-Deok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.7 s.178
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    • pp.1854-1862
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    • 2000
  • Input shaping method is to convolute input shaper, which is sequence of impulses, with reference input command not to excite the natural frequency of system. To reduce residual vibration for the ch ange of frequency, the number of impulses should be increased. Until now, amplitudes and time interval of those has been searched from the derivative of residual vibration. However, if time interval of impulses is fixed as the half of vibration period of system, input shaper H(z) in z-domain becomes (I-pz-1)n/K in which increasing n is the mean that robustness for change of parameter is improved. Also, design of many types of input shapers in z-domain is very easy because sensitivity curve is displayed with $\mid$H(z)zn$\mid$$\times$100. In the z-domain, EI(Extra-Insensitive) input shaper could be designed without solving nonlinear simultaneous equations as design in continuous time domain. In addition to, the design possibility of input shaper for a damped system was shown.

Development of the Standard Size Dimensions and Reference Sizes for Improving Size Suitability of Gloves (장갑치수적합성 향상을 위한 기본치수 및 참고치수 설정)

  • Kim, Eun-Kyong
    • Fashion & Textile Research Journal
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    • v.10 no.6
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    • pp.966-978
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    • 2008
  • The aim of this study was to provide size intervals in hand requisite in design of gloves. In this study, a survey was administered to gather information about glove manufacturers' sizing systems. In addition, KS glove standards' size dimensions were analyzed. As well, the ISO hand sizing system was also studied. Based on all the analyses' results, a new glove size intervals were composed. The size comprised the control dimensions of hand length and hand circumference. The size interval was 8mm in hand length and 13mm in hand circumference. The size range was established by making the coverage above 80%. The coverage of the new size interval system for an adult's hand was 86.4% and 13 sizes were suggested. The coverage of the male size system was 86.0% and 10 sizes were suggested. The coverage of the female size system was 87.6% and 8 sizes were suggested. For the unfitted gloves, size ranges based on hand length and hand circumference were developed. For the adults group, S, M, L, and XL were suggested and the coverage of the new size range was 78.8%. For the male group, S, M, and L were suggested and the coverage was 82.3%. For the female group, S, M, and L were also suggested and the coverage was 81.3%.

Application of Reliability based Inspection for an Effective RCM Approach of Railway System (철도시스템의 효과적 RCM접근을 위한 신뢰성 기반 검사(RBI)적용)

  • Song, Kee-Tae;Kim, Min-Ho;Baek, Young-Gu;Ahn, Eun-Jin;Lee, Key-Seo
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1294-1300
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    • 2008
  • In the current railway industry in Korea, a lot of researches and studies have been progressed to establish RAMS process and construction of RCM system in accordance with international standards. On the point of view of applying the RCM to the railway system, many problems (i.e., reliability of the existing field data, the lack and incorrectness of failure information, etc) are described. To solve these problems, it is need to study and effort the RCM, practically. In this paper, lots of problems and solutions for methods determining the preventive maintenance interval of application of the RCM will be described. To do this, the method using the theory of RBI (Reliability Based Inspection) which is applied to the existing chemical plants and power plants is described. From this study, it is expected that in this situation that the quantitative data is not enough, the results that an analyst quantifies the qualitative factors and/or items will be a good reference that can effectively approach, on the side of determination about each maintenance task and inspection interval.

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Evaluation of Inbreeding and Genetic Variability of Five Pig Breeds in Czech Republic

  • Krupa, Emil;Zakova, E.;Krupova, Z.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.1
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    • pp.25-36
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    • 2015
  • The complex analysis of the pedigree records of Czech Landrace (CLA), Czech Large White-dam line (CLWd), Czech Large White-sire line (CLWs), Duroc (DC), and Pietrain (PN) was performed to determine trends of genetic diversity (GD), and to find the main sources of the GD loss. The total size of the pedigree was 132,365, 391,151, 32,913, 13,299, and 7,160 animals in CLA, CLWd, CLWs, DC, and PN, respectively. Animals born in the years 2011 through 2013 were assumed as the reference population. The average pedigree completeness index for one generation back was 95.9%, 97.4%, 91.2%, 89.8%, and 94.2% for appropriate breeds. Number of ancestors explaining 100% of gene pool was 186, 373, 125, 157, and 37 in CLA, CLWd, CLWs, DC, and PN, respectively. The relative proportion of inbred animals (58%, 58%, 54%, 47%, and 25%), the average inbreeding (2.7%, 1.4%, 2.5%, 3.6%, and 1.3%) and the average co-ancestry (3.1%, 1.6%, 3.3%, 4.2%, and 3.3%) were found over the past decade in analysed breeds. The expected inbreeding under random mating increased during the last 10 years in CLWs and PN and varied from 1.27% to 3.2%. The effective population size computed on the basis of inbreeding was 76, 74, 50, 35, and 83 in 2012 in CLA, CLWd, CLWs, DC, and PN, respectively. The shortest generation interval (1.45) was observed for CLWd in sire to son selection pathway. The longest generation interval obtained PN (1.95) in sire to daughter pathway. The average relative GD loss within last generation interval was 7.05%, 4.70%, 9.81%, 7.47%, and 10.46%, respectively. The relative proportion of GD loss due to genetic drift on total GD loss was 85.04%, 84.51%, 89.46%, 86.19%, and 83.68% in CLA, CLWd, CLWs, DC, and PN, respectively. All breeds were characterized by a high proportion of inbred animals, but the average inbreeding was low. The most vulnerable breeds to loss of GD are DC and PN. Therefore, a breeding program should be more oriented to prevent the increase of GD loss in these breeds.

Time to Recover Consciousness in Patients with Diffuse Axonal Injury : Assessment with Reference to Magnetic Resonance Grading

  • Park, Sung-Jun;Hur, Jin-Woo;Kwon, Ki-Young;Rhee, Jong-Joo;Lee, Jong-Won;Lee, Hyun-Koo
    • Journal of Korean Neurosurgical Society
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    • v.46 no.3
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    • pp.205-209
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    • 2009
  • Objective : This study was conducted to investigate the correlation between the degrees of injury on brain magnetic resonance imaging (MRI) and the time interval to recovery of consciousness in patients with diffuse axonal injury. Methods : From January 2004 to December 2008, 25 patients with diffuse axonal injury were treated at our hospital. We retrospectively investigated the patients' medical records and radiological findings. We divided the patients into three groups according to the grade of MRI finding : grade I, small scattered lesions on the white matter of the cerebral hemisphere; grade II, focal lesions on the corpus callosum; and grade III, additional focal lesions on the brain stem. Result : Seven patients belonged to the grade I group; 10 to the grade II group; and 8 to the grade III group. The mean Glasgow Coma Scale (GCS) score of all patients at the time of admission was 7.28. Recovery of consciousness was observed in 23 of the 25 patients; the remaining two patients never regained consciousness. The time interval to recovery of consciousness (awake status) ranged from 1 day to 125 days (mean 22.1 days) : grade I group patients, within approximately 1 week (mean 3.7 days); grade II group patients, within approximately 2 weeks (mean 12.5 days); and grade III group patients, within approximately 2 months (mean 59.5 days). Conclusion : Our study results suggest a correlation between the mean time interval to recovery of consciousness in patients with diffuse axonal injuries and the degrees of brain injuries seen on MRI. Patients with grade I and II diffuse axonal injuries recovered consciousness within 2 weeks, while patients with grade III injuries required approximately 2 months.

Feasibility study of the beating cancellation during the satellite vibration test

  • Bettacchioli, Alain
    • Advances in aircraft and spacecraft science
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    • v.5 no.2
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    • pp.225-237
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    • 2018
  • The difficulties of satellite vibration testing are due to the commonly expressed qualification requirements being incompatible with the limited performance of the entire controlled system (satellite + interface + shaker + controller). Two features cause the problem: firstly, the main satellite modes (i.e., the first structural mode and the high and low tank modes) are very weakly damped; secondly, the controller is just too basic to achieve the expected performance in such cases. The combination of these two issues results in oscillations around the notching levels and high amplitude beating immediately after the mode. The beating overshoots are a major risk source because they can result in the test being aborted if the qualification upper limit is exceeded. Although the abort is, in itself, a safety measure protecting the tested satellite, it increases the risk of structural fatigue, firstly because the abort threshold has been already reached, and secondly, because the test must restart at the same close-resonance frequency and remain there until the qualification level is reached and the sweep frequency can continue. The beat minimum relates only to small successive frequency ranges in which the qualification level is not reached. Although they are less problematic because they do not cause an inadvertent test shutdown, such situations inevitably result in waiver requests from the client. A controlled-system analysis indicates an operating principle that cannot provide sufficient stability: the drive calculation (which controls the process) simply multiplies the frequency reference (usually called cola) and a function of the following setpoint, the ratio between the amplitude already reached and the previous setpoint, and the compression factor. This function value changes at each cola interval, but it never takes into account the sensor signal phase. Because of these limitations, we firstly examined whether it was possible to empirically determine, using a series of tests with a very simple dummy, a controller setting process that significantly improves the results. As the attempt failed, we have performed simulations seeking an optimum adjustment by finding the Least Mean Square of the difference between the reference and response signal. The simulations showed a significant improvement during the notch beat and a small reduction in the beat amplitude. However, the small improvement in this process was not useful because it highlighted the need to change the reference at each cola interval, sometimes with instructions almost twice the qualification level. Another uncertainty regarding the consequences of such an approach involves the impact of differences between the estimated model (used in the simulation) and the actual system. As limitations in the current controller were identified in different approaches, we considered the feasibility of a new controller that takes into account an estimated single-input multi-output (SIMO) model. Its parameters were estimated from a very low-level throughput. Against this backdrop, we analyzed the feasibility of an LQG control in cancelling beating, and this article highlights the relevance of such an approach.