• Title/Summary/Keyword: correction

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Effect of Posture Correction Band on Pulmonary Function in Individuals With Neck Pain and Forward Head Posture

  • Kim, Jae-hyeon;Jeong, Yeon-woo;Kim, Su-jin
    • Physical Therapy Korea
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    • v.27 no.4
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    • pp.278-285
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    • 2020
  • Background: Individuals with forward head posture (FHP) have neck pain. To correct the FHP, a posture correction band is commonly used. However, we do not know the posture correction band influenced the pulmonary function in individuals with FHP. Objects: This study aimed to elucidate the effects of the posture correction band on the pulmonary function in young adults with neck pain and FHP and to monitor how the pulmonary function changed over time. Methods: Twenty subjects with chronic neck pain and forward head posture were recruited. Subjects performed pulmonary function test four times: before, immediately, and 2 hours after wearing the postural band, and immediately after undressing the postural band. Vital capacity (VC), forced vital capacity (FVC), peak expiratory flow (PEF), and forced expiratory volume at one second (FEV1) were measured. The modified Borg dyspnea scale was used to measure each subject's responses to the posture correction band. The mixed-effect linear regression was used to the effect of the posture correction band over time. Results: There were no significant differences in VC, FVC, PEF, FEV1 values over time (p > 0.05), although all values slightly decreased after applying posture correction band. However, the score of the modified Borg scale significantly changed after wearing the postural bands (p < 0.05), indicating the subject felt discomfort with posture correction band during breathing. Conclusion: Because the posture correction band did not change the pulmonary function over time, but it induces psychological discomforts during breathing in people with FHP. Therefore, this posture correction band can be used for FHP realignment after discussion with the subjects.

Study on Structure and Principle of Linear Block Error Correction Code (선형 블록 오류정정코드의 구조와 원리에 대한 연구)

  • Moon, Hyun-Chan;Kal, Hong-Ju;Lee, Won-Young
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.4
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    • pp.721-728
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    • 2018
  • This paper introduces various linear block error correction code and compares performances of the correction circuits. As the risk of errors due to power noise has increased, ECC(: Error Correction Code) has been introduced to prevent the bit error. There are two representatives of ECC structures which are SEC-DED(: Single Error Correction Double Error Detection) and SEC-DED-DAEC(: Double Adjacent Error Correction). According to simulation results, the SEC-DED circuit has advantages of small area and short delay time compared to SEC-DED-DAEC circuits. In case of SED-DED-DAEC, there is no big difference between Dutta's and Pedro's from performance point of view. Therefore, Pedro's code is more efficient than Dutta' code since the correction rate of Pedro's code is higher than that of Dutta's code.

Atmospheric Correction of Sentinel-2 Images Using Enhanced AOD Information

  • Kim, Seoyeon;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.38 no.1
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    • pp.83-101
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    • 2022
  • Accurate atmospheric correction is essential for the analysis of land surface and environmental monitoring. Aerosol optical depth (AOD) information is particularly important in atmospheric correction because the radiation attenuation by Mie scattering makes the differences between the radiation calculated at the satellite sensor and the radiation measured at the land surface. Thus, it is necessary to use high-quality AOD data for an appropriate atmospheric correction of high-resolution satellite images. In this study, we examined the Second Simulation of a Satellite Signal in the Solar Spectrum (6S)-based atmospheric correction results for the Sentinel-2 images in South Korea using raster AOD (MODIS) and single-point AOD (AERONET). The 6S result was overall agreed with the Sentinel-2 level 2 data. Moreover, using raster AOD showed better performance than using single-point AOD. The atmospheric correction using the single-point AOD yielded some inappropriate values for forest and water pixels, where as the atmospheric correction using raster AOD produced stable and natural patterns in accordance with the land cover map. Also, the Sentinel-2 normalized difference vegetation index (NDVI) after the 6S correction had similar patterns to the up scaled drone NDVI, although Sentinel-2 NDVI had relatively low values. Also, the spatial distribution of both images seemed very similar for growing and harvest seasons. Future work will be necessary to make efforts for the gap-filling of AOD data and an accurate bi-directional reflectance distribution function (BRDF) model for high-resolution atmospheric correction. These methods can help improve the land surface monitoring using the future Compact Advanced Satellite 500 in South Korea.

Performance Improvement of Context-Sensitive Spelling Error Correction Techniques using Knowledge Graph Embedding of Korean WordNet (alias. KorLex) (한국어 어휘 의미망(alias. KorLex)의 지식 그래프 임베딩을 이용한 문맥의존 철자오류 교정 기법의 성능 향상)

  • Lee, Jung-Hun;Cho, Sanghyun;Kwon, Hyuk-Chul
    • Journal of Korea Multimedia Society
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    • v.25 no.3
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    • pp.493-501
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    • 2022
  • This paper is a study on context-sensitive spelling error correction and uses the Korean WordNet (KorLex)[1] that defines the relationship between words as a graph to improve the performance of the correction[2] based on the vector information of the word embedded in the correction technique. The Korean WordNet replaced WordNet[3] developed at Princeton University in the United States and was additionally constructed for Korean. In order to learn a semantic network in graph form or to use it for learned vector information, it is necessary to transform it into a vector form by embedding learning. For transformation, we list the nodes (limited number) in a line format like a sentence in a graph in the form of a network before the training input. One of the learning techniques that use this strategy is Deepwalk[4]. DeepWalk is used to learn graphs between words in the Korean WordNet. The graph embedding information is used in concatenation with the word vector information of the learned language model for correction, and the final correction word is determined by the cosine distance value between the vectors. In this paper, In order to test whether the information of graph embedding affects the improvement of the performance of context- sensitive spelling error correction, a confused word pair was constructed and tested from the perspective of Word Sense Disambiguation(WSD). In the experimental results, the average correction performance of all confused word pairs was improved by 2.24% compared to the baseline correction performance.

The Application of Dynamic Acquisition with Motion Correction for Static Image (동적 영상 획득 방식을 이용한 정적 영상의 움직임 보정)

  • Yoon, Seok-Hwan;Seung, Jong-Min;Kim, Kye-Hwan;Kim, Jae-Il;Lee, Hyung-Jin;Kim, Jin-Eui;Kim, Hyun-Joo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.46-53
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    • 2010
  • Purpose: The static image of nuclear medicine study should be acquired without a motion, however, it is difficult to acquire static image without movement for the serious patients, advanced aged patients. These movements cause decreases in reliability for quantitative and qualitative analysis, therefore re-examination was inevitable in the some cases. Consequently, in order to improve the problem of motion artifacts, the authors substituted the dynamic acquisition technique for the static acquisition, using motion correction. Materials and Methods: A capillary tube and IEC body phantom were used. First, the static image was acquired for 60 seconds while the dynamic images were acquired with a protocol, 2 sec/frame${\times}$30 frames, under the same parameter and the frames were summed up into one image afterwards. Also, minimal motion and excessive motion were applied during the another dynamic acquisition and the coordinate correction was applied towards X and Y axis on the frames where the motion artifact occurred. But the severe blurred images were deleted. Finally, the resolution and counts were compared between the static image and the summed dynamic images which before and after applying motion correction, and the signal of frequency was analysed after frequency spatial domain was transformed into 2D FFT. Supplementary examination, the blind test was performed by the nuclear medicine department staff. Results: First, the resolution in the static image and summed dynamic image without motion were 8.32 mm, 8.37 mm on X-axis and 8.30 mm, 8.42 mm on Y-axis, respectively. The counts were 484 kcounts, 485 kcounts each, so there was nearly no difference. Secondly, the resolution in the image with minimal motion applying motion correction was 8.66 mm on X-axis, 8.85 mm on Y-axis and had 469 kcounts while the image without motion correction was 21.81 mm, 24.02 mm and 469 kcounts in order. So, this shows the image with minimal motion applying motion correction has similar resolution with the static image. Lastly, the resolution in the images with excessive motion applying motion correction were 9.09 mm on X-axis, 8.83 mm on Y-axis and had 469 kcounts while the image without motion correction was 47.35 mm, 40.46 mm and 255 kcounts in order. Although there was difference in counts because of deletion of blurred frames, we could get similar resolution. And when the image was transformed into frequency, the high frequency was decreased by the movement. However, the frequency was improved again after motion correction. In the blind test, there was no difference between the image applying motion correction and the static image without motion. Conclusion: There was no significant difference between the static image and the summed dynamic image. This technique can be applied to patients who may have difficulty remaining still during the imaging process, so that the quality of image can be improved as well as the reliance for analysis of quantity. Moreover, the re-examination rate will be considerably decreased. However, there is a limit of motion correction, more time will be required to successfully image the patients applying motion correction. Also, the decrease of total counts due to deletion of the severe blurred images should be calculated and the proper number of frames should be acquired.

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Two-Dimensional Image-Based Respiratory Navigator for Free-Breathing Coronary Magnetic Resonance Angiography

  • Shin, Taehoon
    • Investigative Magnetic Resonance Imaging
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    • v.22 no.1
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    • pp.71-77
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    • 2018
  • Purpose: To develop a two-dimensional (2D) image-based respiratory motion correction technique for free-breathing coronary magnetic resonance angiography (MRA). Materials and Methods: The proposed respiratory navigator obtained aliased a 2D sagittal image from under-sampled k-space data and utilized motion correlation between the aliased images. The proposed navigator was incorporated into the conventional coronary MRA sequence including the diaphragm navigator and tested in three healthy subjects. Results: The delineation of major coronary arteries was significantly improved using the proposed 2D motion correction (S/I and A/P) compared to one-dimensional (S/I) correction using the conventional diaphragm navigator. Conclusion: The 2D image-based respiratory navigator was proposed for free-breathing coronary angiography and showed the potential for improving respiratory motion correction compared to the conventional 1D correction.

Numerical algorithm with the concept of defect correction for incompressible fluid flow analysis (오차수정법을 도입한 비압축성 유체유동 해석을 위한 수치적 방법)

  • Gwon, O-Bung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.3
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    • pp.341-349
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    • 1997
  • The characteristics of defect correction method are discussed in a sample heat conduction problem showing the numerical solution of the error correction equation can predict the error of the numerical solution of the original governing equation. A way of using defect correction method combined with the existing algorithm for the incompressible fluid flow, is proposed and subsequently tested for the driven square cavity problem. The error correction equations for the continuity equation and the momentum equations are considered to estimate the errors of the numerical solutions of the original governing equations. With this new approach, better velocity and pressure fields can be obtained by correcting the original numerical solutions using the estimated errors. These calculated errors also can be used to estimate the orders of magnitude of the errors of the original numerical solutions.

Performance Evaluation of English Word Pronunciation Correction System (한국인을 위한 외국어 발음 교정 시스템의 개발 및 성능 평가)

  • Kim Mu Jung;Kim Hyo Sook;Kim Sun Ju;Kim Byoung Gi;Ha Jin-Young;Kwon Chul Hong
    • MALSORI
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    • no.46
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    • pp.87-102
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    • 2003
  • In this paper, we present an English pronunciation correction system for Korean speakers and show some of experimental results on it. The aim of the system is to detect mispronounced phonemes in spoken words and to give appropriate correction comments to users. There are several English pronunciation correction systems adopting speech recognition technology, however, most of them use conventional speech recognition engines. From this reason, they could not give phoneme based correction comments to users. In our system, we build two kinds of phoneme models: standard native speaker models and Korean's error models. We also design recognition network based on phonemes to detect Koreans' common mispronunciations. We get 90% detection rate in insertion/deletion/replacement of phonemes, but we cannot get high detection rate in diphthong split and accents.

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Residual error selecting method for precise geometric correction

  • Kim, Myoung-Sun;Ohno, Yasuo;Takagi, Mikio
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.3-7
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    • 1999
  • The images of the meteorological satellite NOAA contain geometrical distortions caused by its ambiguous position, its vibration, its sensor's movement, and so on. Geometric correction of satellite images is one of the most important parts in many remote sensing as the primary processing. Ground control points (GCP's) are necessary to check the accuracy of geometric correction and used for precise geometric correction. In this paper, a method for automatically selecting the residual error is presented. Calculating the effective angle and residual errors vector using the succeeded matching GCP's, precise geometric correction using an affine transformation is applied to systematically a corrected image. And the error is decreased by an affine transformation. The above enable the geometric correction of high quality.

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Correction of Fisheye Distortion and Perspective Distortion (어안렌즈왜곡 및 원근왜곡의 보정)

  • Song, Gwang-Yul;Yoon, Pal-Joo;Lee, Joon-Woong
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.10
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    • pp.22-29
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    • 2006
  • This paper considers the lens distortions such as a fisheye distortion and a perspective distortion. While a fisheye lens has a wide field-of-view, it causes a large distortion to the images. Regardless of a fisheye lens or a rectilinear lens, a lens generates perspective distortion in a vertical direction when the lens views in an upward direction or downward direction. These distortions deform images differently from human visual functions. Therefore, this paper presents a method to correct the distortions, and whereby, the research in this paper enlarges choices of images to image processing algorithm that may select the distorted images and the corrected images depending on applications. An infinite polynomial model is employed in the fisheye radial distortion correction, and the vertical perspective distortion correction is done by using a vanishing point. The methods introduced in this paper are implemented on the images captured by a rear-view camera installed on a vehicle and showed their robustness of the correction.