• Title/Summary/Keyword: Image size

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Drop Size Measurement using Image Processing Method under High Ambient Pressure Condition (고압환경에서 이미지 프로세싱 기법을 이용한 액적크기 측정)

  • Lim Byoungjik;Khil Taeock;Jung Kihoon;Yoon Youngbin
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.111-114
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    • 2003
  • Drop size is one of the most important parameters which are control the performance of the engine using liquid fuel/oxidizer and drop formation is mainly controlled by aerodynamic force caused by ambient gas. Because of this, empirical data and correlation acquired under standard ambient condition are not valid. So experiments under high ambient pressure condition to measure the drop size using image processing method And find the empirical correlation between SMD and chamber pressure(density), injection velocity.

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The Optimal GSD and Image Size for Deep Learning Semantic Segmentation Training of Drone Images of Winter Vegetables (드론 영상으로부터 월동 작물 분류를 위한 의미론적 분할 딥러닝 모델 학습 최적 공간 해상도와 영상 크기 선정)

  • Chung, Dongki;Lee, Impyeong
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1573-1587
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    • 2021
  • A Drone image is an ultra-high-resolution image that is several or tens of times higher in spatial resolution than a satellite or aerial image. Therefore, drone image-based remote sensing is different from traditional remote sensing in terms of the level of object to be extracted from the image and the amount of data to be processed. In addition, the optimal scale and size of data used for model training is different depending on the characteristics of the applied deep learning model. However, moststudies do not consider the size of the object to be found in the image, the spatial resolution of the image that reflects the scale, and in many cases, the data specification used in the model is applied as it is before. In this study, the effect ofspatial resolution and image size of drone image on the accuracy and training time of the semantic segmentation deep learning model of six wintering vegetables was quantitatively analyzed through experiments. As a result of the experiment, it was found that the average accuracy of dividing six wintering vegetablesincreases asthe spatial resolution increases, but the increase rate and convergence section are different for each crop, and there is a big difference in accuracy and time depending on the size of the image at the same resolution. In particular, it wasfound that the optimal resolution and image size were different from each crop. The research results can be utilized as data for getting the efficiency of drone images acquisition and production of training data when developing a winter vegetable segmentation model using drone images.

Image Coding by Block Based Fractal Approximation (블록단위의 프래탈 근사화를 이용한 영상코딩)

  • 정현민;김영규;윤택현;강현철;이병래;박규태
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.2
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    • pp.45-55
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    • 1994
  • In this paper, a block based image approximation technique using the Self Affine System(SAS) from the fractal theory is suggested. Each block of an image is divided into 4 tiles and 4 affine mapping coefficients are found for each tile. To find the affine mapping cefficients that minimize the error between the affine transformed image block and the reconstructed image block, the matrix euation is solved by setting each partial differential coefficients to aero. And to ensure the convergence of coding block. 4 uniformly partitioned affine transformation is applied. Variable block size technique is employed in order to applynatural image reconstruction property of fractal image coding. Large blocks are used for encoding smooth backgrounds to yield high compression efficiency and texture and edge blocks are divided into smaller blocks to preserve the block detail. Affine mapping coefficinets are found for each block having 16$\times$16, 8$\times$8 or 4$\times$4 size. Each block is classified as shade, texture or edge. Average gray level is transmitted for shade bolcks, and coefficients are found for texture and edge blocks. Coefficients are quantized and only 16 bytes per block are transmitted. Using the proposed algorithm, the computational load increases linearly in proportion to image size. PSNR of 31.58dB is obtained as the result using 512$\times$512, 8 bits per pixel Lena image.

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The Effects of Programs on Body-Image Improvement in Adolescents: A Systematic Review and Meta-Analysis (청소년 대상 신체상 증진 프로그램의 효과에 대한 체계적 문헌 고찰 및 메타분석)

  • Yun, Hyun Jung;Seo, Kyoungsan;Han, Dallong
    • Journal of Korean Academy of Nursing
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    • v.51 no.5
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    • pp.597-616
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    • 2021
  • Purpose: This study's objective was to investigate the effects of programs that improve adolescents' body image, using a systematic review and meta-analysis. Methods: A literature search was performed in eleven electronic databases, using preferred reporting items for systematic reviews and meta-analysis guidelines. Population characteristics, contents of the programs, and measured outcomes were systematically reviewed from 21 selected studies. To estimate the size of the effects, meta-analysis was conducted using Comprehensive Meta-Analysis software. Results: The contents of the programs that aimed to improve body image included physical, psychological, interpersonal, and sociocultural interventions. Sixteen studies were meta-analyzed to estimate the effect size of body-image improvement programs. Results showed that the program for body-image improvement had significant effects on body satisfaction (effect size [ES] = 0.56, 95% confidence interval [CI] = 0.23 to 0.89), and body dissatisfaction (ES = - 0.15, 95% CI = - 0.23 to - 0.08). Conclusion: The program for body image improvement in adolescents includes a combination of physical, psychological, interpersonal relationship, and socio-cultural dimensions. The program that seeks to improve body image appears to be effective at increasing body satisfaction, and at reducing body dissatisfaction in adolescents. Thus, it is necessary to develop and apply multidimensional programs for adolescents to have a positive body image.

4th-grade elementary-school children's body image and dietary habits according to body mass index (초등학교 4학년 어린이에서 비만도에 따른 신체상과 식습관)

  • Shim, Eugene;Yang, Yoon Kyoung
    • Journal of Nutrition and Health
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    • v.47 no.4
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    • pp.287-299
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    • 2014
  • Purpose: The goal of this study was to examine body image satisfaction and perception according to weight status, and to investigate those associations with dietary habits and nutritional status among preadolescent children. Methods: Body image and dietary habits and intake were assessed in 134 elementary school students in grade 4. Children were categorized according to normal and overweight or obese groups. Figure rating scales were used to assess body image perception (identification of perceived current body size) and dissatisfaction (difference between perceived current body size and ideal body image). Results: There were sex differences in body image perceptions. Normal-weight girls, overweight or obese girls and boys were more likely to desire a leaner body size than their perceived body size compared with normal-weight boys. Body image satisfaction and perception showed an association with weight status. More overweight or obese children indicated dissatisfaction or underestimation of body image than normal-weight children. Children with body image dissatisfaction due to heavier perceived body size than ideal body image showed lower frequencies of consumption of meals and vegetables, compared to those who were satisfied with their body image. Children who underestimated their body image were more likely to have a lower frequency of breakfast and meal regularity and a higher frequency of eating out of home or food deliveries than those with accurate body image perception. In addition, body image underestimation showed an association with lower intakes of protein, dietary fiber and calcium, and the higher percentage of calories derived from fat. Conclusion: Body image dissatisfaction as well as underestimation in children before puberty showed an association with overweight or obesity, and was also related to unhealthy dietary habits. These findings highlight the importance of accurate perception and satisfaction with body image in preadolescent children in order to prevent development of obesity in adolescents and adults.

Body Image Distortion among Inpatients with Schizophrenia (입원한 조현병 환자의 신체이미지 왜곡)

  • Kim, Sung-Jin;Moon, Seok-Woo;Kim, Daeho
    • Korean Journal of Biological Psychiatry
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    • v.19 no.4
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    • pp.211-218
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    • 2012
  • Objectives Body image distortion is found in eating disorder and obesity and there are some evidence that schizophrenia is associated with body image distortion. This study sought to find whether schizophrenic patients report more body image distortion than healthy individuals and whether it is related with symptomatology. Methods A total of 88 inpatients with schizophrenia and 88 healthy controls were recruited. Weight, height, and body image accuracy were assessed in all participants, and assessment of mood, psychotic symptom severity and self-esteem, and personal and social performance scale were conducted. Results The patients with schizophrenia had higher Body Mass Index (p < 0. 001) and underestimated their body size more than controls (26.14% vs. 5.13%, p < 0.001). Multiple regression analysis showed that lower depressive symptoms and higher scores of general psychopathology predicted underestimation of body size. Conclusion Weight gain and metabolic syndrome are common adverse events of pharmacological treatment of schizophrenia. Thus, underestimation of body size among patients with schizophrenia may interfere with effort to lose weight or seek weight reduction programs. Clinicians need to consider possible unterestimation of underestimation of body size in patients whose general symptomatology is severe.

Development of the Korean Handwriting Assessment for Children Using Digital Image Processing

  • Lee, Cho Hee;Kim, Eun Bin;Lee, Onseok;Kim, Eun Young
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.8
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    • pp.4241-4254
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    • 2019
  • The efficiency and accuracy of handwriting measurement could be improved by adopting digital image processing. This study developed a computer-based Korean Handwriting Assessment tool. Second graders participated in this study by performing writing tasks of consonants, vowels, words, and sentences. We extracted boundary parameters for each letter using digital image processing and calculated the variables of size, size coefficient of variation (CV), misalignment, inter-letter space, inter-word space, and ratio of inter-letter space to inter-word space. Children were also administered traditional handwriting and visuomotor tests. Digital variables from image processing were correlated with these previous tests. Using these correlations, we established a three-point scoring system that computed test scores for each variable. We analyzed inter-rater reliability between the computer rater and human rater and test-retest reliability between the first and second performances. The validity was examined by analyzing the relationship between the Korean Handwriting Assessment and previous handwriting and visuomotor tests. We suggested the Korean Handwriting Assessment to measure size, size consistency, misalignment, inter-letter space, inter-word space, and space ratio using digital image processing. This Korean Handwriting Assessment tool proved to have reliability and validity. It is expected to be useful for assessing children's handwriting.

Development of Image Processing Algorithm Using Boundary Curvature Information in Particle Size Measurement (영상 처리 기법에서 곡률을 이용한 입경 측정 알고리듬의 개발)

  • 김유동;이상용;김상수
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.10
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    • pp.1445-1450
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    • 2002
  • In the present study, a new pattern recognition algorithm was proposed to size spray particles using the boundary curvature information. Conceptually, this algorithm has an advantage over the others because it can identify the particle size and shape simultaneously, and also can separate the overlapped particles more effectively. Curvature of a boundary was obtained from the change of the slopes of two neighboring segments at the corresponding part. The algorithm developed in this study was tested by using an artificially prepared image of a group of spherical particles which were either isolated or overlapped. Particle sizes obtained from the measured curvatures agreed well with the true values. By detecting abrupt changes of the curvature along the image boundary, the element particles could be separated out from their overlapped images successfully.

DETERMINATION OF USER DISTRIBUTION IMAGE SIZE AND POSITION OF EACH OBSERVATION AREA OF METEOROLOGICAL IMAGER IN COMS

  • Seo, Jeong-Soo;Seo, Seok-Bae;Kim, Eun-Kyou;Jung, Sung-Chul
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.228-231
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    • 2006
  • In this paper, requirements of Meteorological Administration about Meteorological Imager (MI) of Communications, Ocean and Meteorological Satellite (COMS) is analyzed for the design of COMS ground station and according to the analysis results, the distribution image size of each observation area suitable for satellite Field Of View (FOV) stated at the requirements of meteorological administration is determined and the precise satellite FOV and the size of distribution image is calculated on the basis of the image size of the determined observation area. The results in this paper were applied to the detailed design for COMS ground station and also are expected to be used for the future observation scheduling and the scheduling of distribution of user data.

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A Study on the Automatic Inspection System using Invariant Moments Algorithm with the Change of Size and Rotation

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    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.164-169
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    • 2003
  • The purpose of this study is to develop a practical image inspect ion system that could recognize it correctly, endowing flexibility to the productive field, although the same object for work will be changed in the size and rotated. In this experiment, it selected a fighter, rotating the direction from 30$^{\circ}$ to 45 simultaneously while changing the size from 1/4 to 1/16, as an object inspection without using another hardware for exclusive image processing. The invariant moments, Hu has suggested, was used as feature vector moment descriptor. As a result of the experiment, the image inspect ion system developed from this research was operated in real-time regardless of the chance of size and rotation for the object inspection, and it maintained the correspondent rates steadily above from 94% to 96%. Accordingly, it is considered as the flexibility can be considerably endowed to the factory automat ion when the image inspect ion system developed from this research is applied to the product ive field.

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