• Title/Summary/Keyword: Observational error

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Reliability and validity of rehabilitative ultrasound images obtained using a hands-free fixed probe in measuring the muscle structures of the tibialis anterior and the gastrocnemius

  • Choi, Mun-Sang;Shin, Jang-Hoon;Park, Hye-Kang;Lee, Wan-Hee
    • Physical Therapy Rehabilitation Science
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    • v.8 no.4
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    • pp.194-201
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    • 2019
  • Objective: This study aimed to investigate the reliability and validity of muscle thickness (MT) and pennation angle (PA) measurements of the ankle muscle, including the tibialis anterior (TA) and the medial gastrocnemius (MGCM), using a hands-free fixed probe and to compare it with the conventional linear probe. Design: Observational inter-rater reliability study. Methods: Thirty-three healthy subjects (20 male, 13 female) were included. In all subjects, ultrasound images were acquired from the TA and MGCM using a hands-free fixed probe and a conventional linear probe in random sequence by two examiners at two time-points within a 7-day interval. MT and PA were calculated on the taken images. Intra-class correlation coefficients (ICC), 95% confidence intervals, standard error of measurement and the Pearson's correlation coefficient were used to estimate reliability and validity. And also, Bland-Altman plots were generated for a visual representation of MT and PA at the TA and MGCM. Results: The ICC for all intra-rater reliability was 0.943 to 0.995 and that for all inter-rater reliability was 0.928 to 0.993, indicating excellent reliability. A significantly high correlation was observed between MT and PA at the TA and MGCM with use of the hands-free fixed probe and the conventional linear probe (r>0.938; p<0.001). Conclusions: The hands-free fixed probe provided excellent images for measurement of the MT and PA of the TA and MGCM and is a useful device for making clinical measurements of muscle structure without grasping of the probe.

Development of a Data Reduction Algorithm for Optical Wide Field Patrol (OWL) II: Improving Measurement of Lengths of Detected Streaks

  • Park, Sun-Youp;Choi, Jin;Roh, Dong-Goo;Park, Maru;Jo, Jung Hyun;Yim, Hong-Suh;Park, Young-Sik;Bae, Young-Ho;Park, Jang-Hyun;Moon, Hong-Kyu;Choi, Young-Jun;Cho, Sungki;Choi, Eun-Jung
    • Journal of Astronomy and Space Sciences
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    • v.33 no.3
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    • pp.221-227
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    • 2016
  • As described in the previous paper (Park et al. 2013), the detector subsystem of optical wide-field patrol (OWL) provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time) data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.

Citrus Fruits Intake and Prostate Cancer Risk: A Quantitative Systematic Review

  • Bae, Jong-Myon;Lee, Eun-Ja;Guyatt, Gordon
    • Journal of Preventive Medicine and Public Health
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    • v.41 no.3
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    • pp.159-164
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    • 2008
  • Objectives : The purpose of this systematic review was to investigate the association between dietary intake of citrus fruits and prostate cancer risk. Methods : Authors searched electronic databases and the reference lists of publications of diet and prostate cancer studies until August 2007. All of the epidemiological studies that obtained individual data on dietary intake of citrus fruits and presented risk estimates of the association between intake of citrus fruits and risk of prostate cancer were identified and included. Using general variance-based methods, study-specific odds ratios (OR)/ relative risk (RR) and associated confidence interval (CI)/ standard error (SE) for highest versus lowest intake of citrus fruits level were extracted from each paper. Results : Eleven articles including six case-control studies, one nested case-control study and four cohort studies, proved eligible. Overall summary OR using random effect model did not show an association in risk of prostate caner with intake of citrus fruits (summary OR=1.03, 95% CI=0.89-1.19) with large heterogeneity across studies that we were unable to explain ($I^2$=67.88%). The summary ORs in case-control studies and cohort studies were 1.10 (95% CI=0.97-1.22) and 1.05 (95% CI=0.96-1.14), respectively. Conclusions : Pooled results from observational studies did not show an association between intake of citrus fruits and the risk of prostate cancer, although results vary substantially across studies.

Estimation of Surface Layer Heat Flux Using the UHF Sensor Installed on UAV (UHF 센서 탑재 UAV를 이용한 지표층 열 플럭스 산출)

  • Kim, Min-Seong;Kwon, Byung Hyuk;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.1
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    • pp.265-276
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    • 2018
  • Observation and data analysis techniques have been developed for observational blind areas in the lower atmosphere that are difficult to be monitored with fixed equipment on the ground. The vertical data of temperature and relative humidity are remotely collected by the UHF radiosonde installed on UAV and compared with the data measured in the 10 m weather tower. From the validated vertical profile, extrapolated surface temperature and the bulk transfer method were used to estimate the sensible heat flux depending on the atmospheric stability. Compared with the sensible heat flux measured by the 3-dimensional ultrasonic anemometer on the ground, the error of the sensible heat flux estimated was 23% that is less than the range of 30% allowed in the remote sensing. Estimated atmospheric boundary layer height from UAV sensible heat fluxes can provide useful data for air pollution diffusion models in real time and economically.

Application of Carbon Tracking System based on Ensemble Kalman Filter on the Diagnosis of Carbon Cycle in Asia (앙상블 칼만 필터 기반 탄소추적시스템의 아시아 지역 탄소 순환 진단에의 적용)

  • Kim, JinWoong;Kim, Hyun Mee;Cho, Chun-Ho
    • Atmosphere
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    • v.22 no.4
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    • pp.415-427
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    • 2012
  • $CO_2$ is the most important trace gas related to climate change. Therefore, understanding surface carbon sources and sinks is important when seeking to estimate the impact of $CO_2$ on the environment and climate. CarbonTracker, developed by NOAA, is an inverse modeling system that estimates surface carbon fluxes using an ensemble Kalman filter with atmospheric $CO_2$ measurements as a constraint. In this study, to investigate the capability of CarbonTracker as an analysis tool for estimating surface carbon fluxes in Asia, an experiment with a nesting domain centered in Asia is performed. In general, the results show that setting a nesting domain centered in Asia region enables detailed estimations of surface carbon fluxes in Asia. From a rank histogram, the prior ensemble spread verified at observational sites located in Asia is well represented with a relatively flat rank histogram. The posterior flux in the Eurasian Boreal and Eurasian Temperate regions is well analyzed with proper seasonal cycles and amplitudes. On the other hand, in tropical regions of Asia, the posterior flux does not differ greatly from the prior flux due to fewer $CO_2$ observations. The root mean square error of the model $CO_2$ calculated by the posterior flux is less than the model $CO_2$ calculated by the prior flux, implying that CarbonTracker based on the ensemble Kalman filter works appropriately for the Asia region.

Design of a Hopeful Career Forecasting Program for the Career Education (진로교육을 위한 희망진로 예측프로그램 설계)

  • Kim, Geun-Ho;Kim, Eui-Jeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.8
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    • pp.1055-1060
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    • 2018
  • In the wake of the 4th Industrial Revolution, the problem of career education in schools has become a big issue. While various studies are being conducted on services or technologies to effectively handle artificial intelligence and big data, in the field of education, data on students is simply processed. Therefore, in this paper, we are going to design and present career prediction programs for students using artificial intelligence and big data. Using observational data from students at the institute, the decision tree is constructed with the C4.5 algorithm known to be most intelligent and effective in the decision tree and is used to predict students' path of hope. As a result, the coefficient of kappa exceeded 0.7 and showed a fairly low average error of 0.1 degrees. As shown in this study, a number of studies and data will be deployed to help guide students in their consultation and to provide them with classroom attitudes and directions.

Minimum Temperature Mapping in Complex Terrain Considering Cold Air Drainage (냉기침강효과를 고려한 복잡지형의 최저기온 분포 추정)

  • 정유란;서형호;황규홍;황범석;윤진일
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.4 no.3
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    • pp.133-140
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    • 2002
  • Site-specific minimum temperature forecasts are critical in a short-term decision making procedure for preventive measures as well as a long-term strategy such as site selection in fruits industry. Nocturnal cold air pools frequently termed in mountainous areas under anticyclonic systems are very dangerous to the flowering buds in spring over Korea, but the spatial resolution to detect them exceeds the current weather forecast scale. To supplement the insufficient spatial resolution of official forecasts, we developed a GIS - assisted frost risk assesment scheme for using in mountainous areas. Daily minimum temperature data were obtained from 6 sites located in a 2.1 by 2.1 km area with complex topography near the southern edge of Sobaek mountains during radiative cooling nights in spring 2001. A digital elevation model with a 10 m spatial resolution was prepared for the entire study area and the cold air inflow was simulated for each grid cell by counting the number of surrounding cells coming into the processing cell. Primitive temperature surfaces were prepared for the corresponding dates by interpolating the Korea Meteorological Administration's automated observational data with the lapse rate correction. The cell temperature values corresponding to the 6 observation sites were extracted from the primitive temperature surface, and subtracted from the observed values to obtain the estimation error. The errors were regressed to the flow accumulation at the corresponding cells, delineating a statistically significant relationship. When we applied this relationship to the primitive temperature surfaces of frost nights during April 2002, there was a good agreement with the observations, showing a feasibility of site-specific frost warning system development in mountainous areas.

Combined Adjustment of Photogrammetric and Geodetic Observations for Accuracy Improvement (사진측량의 정확도향상을 위한 사진 및 측지관측값의 결합조정)

  • Jung, Young-Dong;Kang, Tae-Suck;Kwon, Hyon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.7 no.2
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    • pp.35-43
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    • 1989
  • The improvements of highly accurate and dense control networks are major requirements to carry out numerical surveying and a large scale mapping for cadastral renovation. In the most conventional photogrammetric solutions, adjusted control coordinates have been applied to block triangulations. However, this study, imploying real data and those of simulated as well, contributes to a simultaneously combined adjustment. It also contains such photogrammetric as photocoordinates and geodetic observations like distances, angles and hight differences. Its purpose is to introduce the improved results, despite it is not sufficient for the ground network. In addition, through the detection of gross error, more precise observational data can be selected for the better adjustment. All in all, the result of this study can be summarized as follows : First, even if the ground control points are not sufficient nor existed at all, the combination of pbotogrammetric and geodetic observations are improved its accuracy. Secondly, the case #2 is more accurate than that of #3, and the case #7 comes into close to that of #6.

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Novel nomogram-based integrated gonadotropin therapy individualization in in vitro fertilization/intracytoplasmic sperm injection: A modeling approach

  • Ebid, Abdel Hameed IM;Motaleb, Sara M Abdel;Mostafa, Mahmoud I;Soliman, Mahmoud MA
    • Clinical and Experimental Reproductive Medicine
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    • v.48 no.2
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    • pp.163-173
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    • 2021
  • Objective: This study aimed to characterize a validated model for predicting oocyte retrieval in controlled ovarian stimulation (COS) and to construct model-based nomograms for assistance in clinical decision-making regarding the gonadotropin protocol and dose. Methods: This observational, retrospective, cohort study included 636 women with primary unexplained infertility and a normal menstrual cycle who were attempting assisted reproductive therapy for the first time. The enrolled women were split into an index group (n=497) for model building and a validation group (n=139). The primary outcome was absolute oocyte count. The dose-response relationship was tested using modified Poisson, negative binomial, hybrid Poisson-Emax, and linear models. The validation group was similarly analyzed, and its results were compared to that of the index group. Results: The Poisson model with the log-link function demonstrated superior predictive performance and precision (Akaike information criterion, 2,704; λ=8.27; relative standard error (λ)=2.02%). The covariate analysis included women's age (p<0.001), antral follicle count (p<0.001), basal follicle-stimulating hormone level (p<0.001), gonadotropin dose (p=0.042), and protocol type (p=0.002 and p<0.001 for short and antagonist protocols, respectively). The estimates from 500 bootstrap samples were close to those of the original model. The validation group showed model assessment metrics comparable to the index model. Based on the fitted model, a static nomogram was built to improve visualization. In addition, a dynamic electronic tool was created for convenience of use. Conclusion: Based on our validated model, nomograms were constructed to help clinicians individualize the stimulation protocol and gonadotropin doses in COS cycles.

A Study on Speechreading about the Korean 8 Vowels (한국어 8모음 자동 독화에 관한 연구)

  • Lee, Kyong-Ho;Yang, Ryong;Kim, Sun-Ok
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.3
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    • pp.173-182
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    • 2009
  • In this paper, we studied about the extraction of the parameter and implementation of speechreading system to recognize the Korean 8 vowel. Face features are detected by amplifying, reducing the image value and making a comparison between the image value which is represented for various value in various color space. The eyes position, the nose position, the inner boundary of lip, the outer boundary of upper lip and the outer line of the tooth is found to the feature and using the analysis the area of inner lip, the hight and width of inner lip, the outer line length of the tooth rate about a inner mouth area and the distance between the nose and outer boundary of upper lip are used for the parameter. 2400 data are gathered and analyzed. Based on this analysis, the neural net is constructed and the recognition experiments are performed. In the experiment, 5 normal persons were sampled. The observational error between samples was corrected using normalization method. The experiment show very encouraging result about the usefulness of the parameter.