• Title/Summary/Keyword: reference range

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Reference Trajectory Generation of Flight Tests Using an Aircraft through Post-Processing of GPS Receiver Data (GPS 수신기 데이터의 후처리를 통한 항공기 비행시험 기준궤적 생성)

  • Moon, Ji-Hyeon;Kwon, Byung-Moon;Shin, Yong-Sul;Choi, Hyung-Don
    • Aerospace Engineering and Technology
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    • v.9 no.1
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    • pp.60-66
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    • 2010
  • This paper deals with a post-processing of GPS receiver data in order to acquire a reference flight trajectory of an aircraft test. The flight test using an aircraft that is carried out several times since 2007 is the integrated test to verify the performance of the tracking and communications facilities in Naro Space Center and Jeju Tracking Center. In order to analyze performance of the tracking and navigation equipments, true reference data should be used for performance comparisons. Therefore off-the-shelf commercial GPS receiver, DL-V3 made by NovAtel Inc., is operated on the test to collect the GPS navigation data and the collected data is post-processed by GrafNav which is the off-the-shelf post-processing program made by NovAtel Inc. Through the post-processing of the collected data, a reference trajectory is generated with small error range about several decade centimeter level.

Design and Performance Evaluation of DGPS Based on Optimal and Sub-optimal Reference Point (Optimal 및 Sub-optimal 기준점을 사용한 DGPS 설계 및 성능평가)

  • 고광섭;홍성래;정세모
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.3
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    • pp.343-352
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    • 1998
  • The use of DGPS enhances standalone GPS accuracy and removes common errors from two or more receivers viewing the same satellites. The design of DGPS system contains a precise reference point which is able to compute the common errors to update the pseudo range of users receivers. It should take a great time and cost to provide precise and sufficient accuracy of the reference point. That is, it is natural to measure the parameters from satellites with specific survey instrument system, and then obtain that by post processing. The purpose of the study is to examine the bounds of accuracy which resulted from RTCM correction data transmitted from a simply designed DGPS system. In the paper, We design and evaluate the DGPS system based m the surveyed reference point, and Sub-optimal no by a Standalone GPS as well. As a result of the study, it is shown that the designed system may be applied to the specific marine activity in civilian and military.

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Evidence-based approaches for establishing the 2015 Dietary Reference Intakes for Koreans

  • Shin, Sangah;Kim, Subeen;Joung, Hyojee
    • Nutrition Research and Practice
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    • v.12 no.6
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    • pp.459-468
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    • 2018
  • BACKGROUND/OBJECTIVES: The Dietary Reference Intakes for Koreans (KDRIs), a set of reference intake values, have served as a basis for guiding a balanced diet that promotes health and prevents disease in the general Korean population. In the process of developing DRIs, a systematic review has played an important role in helping the DRI committees make evidence-based and transparent decisions for updating the next DRIs. Thus, the 2015 KDRI steering committee applied the systematic review framework to the revision process of the KDRIs. The purpose of this article is to summarize the revision process for the 2015 KDRIs by focusing on the systematic review framework. MATERIALS/METHODS: The methods used to develop the systematic review framework for 2015 KDRIs followed the Agency for Healthcare Research and Quality and the Tufts Evidence-based Practice Center. The framework for systematic review of the 2015 KDRIs comprised of the 3 following steps: (1) development of an analytic framework and refinement of key questions and search terms; (2) literature search and data extraction; and, (3) appraisal of the literature and summarizing the results. RESULTS: A total of 203,237 studies were retrieved through the above procedure, with 2,324 of these studies included in the analysis. General information, main results, comments of reviewers, and results of quality assessment were extracted and organized by study design. The average points of quality appraisals were 3.0 (range, 0-5) points for intervention, 6.1 (0-9) points for cohort, 6.0 (3-9) points for nested case-control, 5.4 (1-8) points for case-control, 14.6 (0-22) points for cross-sectional studies, and 7.0 (0-11) points for reviews. CONCLUSIONS: Systematic review helped to establish the 2015 KDRIs as a useful tool for evidence-based approach. Collaborative efforts to improve the framework for systematic review should be continued for future KDRIs.

Prerequisite Research for the Development of an End-to-End System for Automatic Tooth Segmentation: A Deep Learning-Based Reference Point Setting Algorithm (자동 치아 분할용 종단 간 시스템 개발을 위한 선결 연구: 딥러닝 기반 기준점 설정 알고리즘)

  • Kyungdeok Seo;Sena Lee;Yongkyu Jin;Sejung Yang
    • Journal of Biomedical Engineering Research
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    • v.44 no.5
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    • pp.346-353
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    • 2023
  • In this paper, we propose an innovative approach that leverages deep learning to find optimal reference points for achieving precise tooth segmentation in three-dimensional tooth point cloud data. A dataset consisting of 350 aligned maxillary and mandibular cloud data was used as input, and both end coordinates of individual teeth were used as correct answers. A two-dimensional image was created by projecting the rendered point cloud data along the Z-axis, where an image of individual teeth was created using an object detection algorithm. The proposed algorithm is designed by adding various modules to the Unet model that allow effective learning of a narrow range, and detects both end points of the tooth using the generated tooth image. In the evaluation using DSC, Euclid distance, and MAE as indicators, we achieved superior performance compared to other Unet-based models. In future research, we will develop an algorithm to find the reference point of the point cloud by back-projecting the reference point detected in the image in three dimensions, and based on this, we will develop an algorithm to divide the teeth individually in the point cloud through image processing techniques.

Diagnosis of Pulmonary Arterial Hypertension in Children by Using Cardiac Computed Tomography

  • Shyh-Jye Chen;Jou-Hsuan Huang;Wen-Jeng Lee;Ming-Tai Lin;Yih-Sharng Chen;Jou-Kou Wang
    • Korean Journal of Radiology
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    • v.20 no.6
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    • pp.976-984
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    • 2019
  • Objective: To establish diagnostic criteria for pulmonary arterial hypertension (PAH) in children by using parameters obtained through noninvasive cardiac computed tomography (CCT). Materials and Methods: We retrospectively measured parameters from CCT images of children from a single institution in a multiple stepwise process. A total of 208 children with mean age of 10.5 years (range: 4 days-18.9 years) were assessed. The variables were classified into three groups: the great arteries; the ventricular walls; and the bilateral ventricular cavities. The relationship between the parameters obtained from the CCT images and mean pulmonary arterial pressure (mPAP) was tested and adjusted by the children's body size. Reference curves for the pulmonary trunk diameter (PTD) and ratio of diameter of pulmonary trunk to ascending aorta (rPTAo) of children with CCT images of normal hearts, adjusted for height, were plotted. Threshold lines were established on the reference curves. Results: PTD and rPTAo on the CCT images were significantly positively correlated with mPAP (r > 0.85, p < 0.01). Height was the body size parameter most correlated with PTD (r = 0.91, p < 0.01) and rPTAo (r = -0.69, p < 0.01). On the basis of the threshold lines on the reference curves, PTD and rPTAo both showed 88.9% sensitivity for PAH diagnosis, with negative predictive values of 93.3% and 92.9%, respectively. Conclusion: PTD and rPTAo measured from CCT images were significantly correlated with mPAP in children. Reference curves and the formula of PTD and rPTAo adjusted for height could be practical for diagnosing PAH in children.

A Design of a 5 GHz Low Phase Noise Voltage Tuned Dielectric Resonator Oscillator Using Loop Group Delay (루프 군지연을 이용한 저위상 잡음 5 GHz 전압제어 유전체 공진기 발진기 설계)

  • Son, Beom-Ik;Jeong, Hae-Chang;Yeom, Kyung-Whan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.3
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    • pp.269-281
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    • 2014
  • In this paper, a systematic design of a low phase noise voltage-tuned dielectric resonator oscillator(VTDRO) using loop group delay is proposed. Designed VTDRO is closed-loop type and consists of a cascade connection of a resonator, phase shifter, and amplifier. Firstly, a reference VTDRO is fabricated and its phase noise and electrical frequency tuning range are measured. Both the phase noise and electrical frequency tuning range depend on the loop group delay. Then, a required value of loop group delay for a new VTDRO with a low phase noise can be systematically computed. In addition, its phase noise and electrical frequency tuning range can be theoretically estimated using those obtained from the measurement of the reference VTDRO. When the loop group delay increases, the phase noise decreases and the electrical frequency tuning range also decreases. The former predominantly depends on the resonator structure. Therefore we propose a systematic design procedure of a resonator with high group delay characteristics. The measured loop group delay of the new VTDRO is about 700 nsec. The measured phase noise of the new VTDRO show a state-of-the-art performance of 154.5 dBc/Hz at 100 kHz frequency offset and electrical frequency tuning range of 448 kHz for a voltage change of 0~10V. The oscillation power is about 4.39 dBm.

Simple Method of Evaluating the Range of Shoulder Motion Using Body Parts

  • Yun, Yeo-Hon;Jeong, Byeong-Jin;Seo, Myeong-Jae;Shin, Sang-Jin
    • Clinics in Shoulder and Elbow
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    • v.18 no.1
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    • pp.13-20
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    • 2015
  • Background: The purpose of this study is to assess the range of shoulder motion using an indirect evaluation method without physical examinations of patients based on questionnaires regarding several specific arm postures referenced by patient's own body parts. Methods: Nine criteria of specific shoulder motion including 4 forward flexion, 2 external rotation, and 3 internal rotation were decided as reference position which can represent a certain shoulder motion. Flexion contains postures such as lifting arm to waist-height, shoulder-height, eye-height, and raising arm above head with arm touching ears. External rotation comprises grasping ears and placing hands on back of the head. Vertebral height in internal rotation is determined by calculating the samples' motions, which are holding on to trouser belts, opposite-elbow, and scapula. These postures are included in questionnaires for patients to evaluate the validity and effectiveness of this indirect method. Results: The range of flexion was $77^{\circ}$ ($60^{\circ}$ to $100^{\circ}$), $96^{\circ}$ ($87^{\circ}$ to $115^{\circ}$), $135^{\circ}$ ($115^{\circ}$ to $150^{\circ}$), and $167^{\circ}$ ($150^{\circ}$ to $175^{\circ}$) when arms go up to waist, shoulder, eye, and high vertically. Range of external rotation was $39.6^{\circ}$ ($30^{\circ}$ to $50^{\circ}$) when grasping ears and $69.2^{\circ}$ ($60^{\circ}$ to $80^{\circ}$) with the hands on the back of the head. Range of internal rotation was L4 when placing trouser belts, T12 for holding opposite elbow, and T9 for reaching scapula. The mismatch rates of flexion, external rotation, and internal rotation were 11.6%, 9.6%, and 7.8%. Conclusions: The range of shoulder motion using this method is expected to be applied to an established shoulder scoring system which included shoulder motion evaluation item.

An Improved Input Image Selection Algorithm for Super Resolution Still Image Reconstruction from Video Sequence (비디오 시퀀스로부터 고해상도 정지영상 복원을 위한 입력영상 선택 알고리즘)

  • Lee, Si-Kyoung;Cho, Hyo-Moon;Cho, Sang-Bok
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.1
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    • pp.18-23
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    • 2008
  • In this paper, we propose the input image selection-method to improve the reconstructed high-resolution (HR) image quality. To obtain ideal super-resolution (SR) reconstruction image, all input images are well-registered. However, the registration is not ideal in practice. Due to this reason, the selection of input images with low registration error (RE) is more important than the number of input images in order to obtain good quality of a HR image. The suitability of a candidate input image can be determined by using statistical and restricted registration properties. Therefore, we propose the proper candidate input Low Resolution(LR) image selection-method as a pre-processing for the SR reconstruction in automatic manner. In video sequences, all input images in specified region are allowed to use SR reconstruction as low-resolution input image and/or the reference image. The candidacy of an input LR image is decided by the threshold value and this threshold is calculated by using the maximum motion compensation error (MMCE) of the reference image. If the motion compensation error (MCE) of LR input image is in the range of 0 < MCE < MMCE then this LR input image is selected for SR reconstruction, else then LR input image are neglected. The optimal reference LR (ORLR) image is decided by comparing the number of the selected LR input (SLRI) images with each reference LR input (RLRI) image. Finally, we generate a HR image by using optimal reference LR image and selected LR images and by using the Hardie's interpolation method. This proposed algorithm is expected to improve the quality of SR without any user intervention.

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Development of Surface Velocity Measurement Technique without Reference Points Using UAV Image (드론 정사영상을 이용한 무참조점 표면유속 산정 기법 개발)

  • Lee, Jun Hyeong;Yoon, Byung Man;Kim, Seo Jun
    • Ecology and Resilient Infrastructure
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    • v.8 no.1
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    • pp.22-31
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    • 2021
  • Surface image velocimetry (SIV) is a noncontact velocimetry technique based on images. Recently, studies have been conducted on surface velocity measurements using drones to measure a wide range of velocities and discharges. However, when measuring the surface velocity using a drone, reference points must be included in the image for image correction and the calculation of the ground sample distance, which limits the flight altitude and shooting area of the drone. A technique for calculating the surface velocity that does not require reference points must be developed to maximize spatial freedom, which is the advantage of velocity measurements using drone images. In this study, a technique for calculating the surface velocity that uses only the drone position and the specifications of the drone-mounted camera, without reference points, was developed. To verify the developed surface velocity calculation technique, surface velocities were calculated at the Andong River Experiment Center and then measured with a FlowTracker. The surface velocities measured by conventional SIV using reference points and those calculated by the developed SIV method without reference points were compared. The results confirmed an average difference of approximately 4.70% from the velocity obtained by the conventional SIV and approximately 4.60% from the velocity measured by FlowTracker. The proposed technique can accurately measure the surface velocity using a drone regardless of the flight altitude, shooting area, and analysis area.

Dietary Intakes, Serum Concentrations, and Urinary Excretions of Fe, Zn, Cu, Mn, Se, Mo, and Cr of Korean Young Adult Women (일부 젊은 성인여자의 Fe, Zn, Cu, Mn, Se, Mo 및 Cr의 식사섭취, 혈청농도 및 소변배설)

  • Kim, Kyune-Hee;Lim, Hyeon-Sook
    • Journal of Nutrition and Health
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    • v.39 no.8
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    • pp.762-772
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    • 2006
  • This study was conducted to investigate dietary intakes, serum concentrations, and urinary excretions of iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), selenium (Se), molybdenum (Mo), and chromium (Cr) of Korean young adult women. A total of 19 apparently healthy young adult women aged in their twenties or thirties participated voluntarily. One-tenth of all foods they consumed for 3 consecutive days were collected, all urine excreted for the same 3 days was gathered, and fasting venous blood was withdrawn for the trace mineral analyses. Of the food, blood, and urine samples, the contents of Zn, Cu, Mn, Se, Mo, and Cr were analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS) and that of Fe by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) after wet digestion. The intake of Fe, $6.94{\pm}2.18mg$, did not meet the estimated average requirement (EAR) for Korean women aged 20-29 years old. On the contrary, the intakes of Zn ($9.35{\pm}4.95mg$), Cu ($1.18{\pm}0.26mg$), and Mn ($3.69{\pm}0.69mg$) were sufficient for each respective EAR. However, some of the subjects did not take the EAR for Zn. The Se intake, $41.93{\pm}9.28{\mu}g$, however, was almost similar to the EAR for Se. Although there are no references for Mo and Cr, the intakes of these minerals ($134.0{\pm}49.1\;and\;136.5{\pm}147.9{\mu}g$, respectively) seemed to be excessively sufficient. Serum Fe concentration, $88.7{\pm}36.8{\mu}g/dL$, seemed to be a little bit lower than its reference median but within its normal range. Approximately one-fourth of the subjects were in anemic determined by Hb and Hct and below the deficiency serum level of Fe, $60{\mu}g/dL$. In addition, serum Se concentration, $3.73{\pm}0.60{\mu}g/dL$, was also below its reference median and normal range. However, serum concentrations of Zn ($99.6{\pm}30.6{\mu}g/dL$) and Mo ($0.25{\pm}0.10{\mu}g/dL$) were fairly good compared to each reference median. The status of Cu could be determined as good although its serum concentration ($91.6{\pm}14.6{\mu}g/dL$) was slightly below its reference median. Since there are no decisive reference values, it was not easy to evaluate serum concentrations of Mn ($0.93{\pm}0.85{\mu}g/dL$) and Cr ($8.60{\pm}7.25{\mu}g/dL$). But Mn and Cr status seemed to be adequate. Urinary Fe excretion, $4.48{\pm}1.98{\mu}g/dL$, was pretty much lower than its reference and that of Se, $2.45{\pm}1.17{\mu}g/dL$, was also lower than its average. On the other hand, those of Zn ($42.95{\pm}20.47{\mu}g/dL$) and Cu ($5.68{\pm}1.50{\mu}g/dL$) were flirty good. In case of Mn, urinary excretion, $0.31{\pm}0.09{\mu}g/dL$, was much greater than its reference. Urinary excretions of Mo ($7.48{\pm}2.95{\mu}g/dL$) and Cr ($1.37{\pm}0.41{\mu}g/dL$) were very higher compared to each reference. The results of this study revealed that Korean young adult women were considerably poor in Fe status, a bit inadequate in Se status, partly inadequate in Zn status, and flirty good in Cu, Mn, Mo and Cr status. However, there was a problem of excessive intakes of Mo and Cr. It, therefore, should be concerned to increase the intakes of Fe, Se and Zn but to decrease Mo and Cr consumption for young adult women.