• Title/Summary/Keyword: Image classification.

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Estimation of Paddy Field Area in North Korea Using RapidEye Images (RapidEye 영상을 이용한 북한의 논 면적 산정)

  • Hong, Suk Young;Min, Byoung-Keol;Lee, Jee-Min;Kim, Yihyun;Lee, Kyungdo
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.6
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    • pp.1194-1202
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    • 2012
  • Remotely sensed satellite images can be applied to monitor and obtain land surface information on inaccessible areas. We classified paddy field area in North Korea based on on-screen digitization with visual interpretation using 291 RapidEye satellite images covering the whole country. Criteria for paddy field classification based on RapidEye imagery acquired at different time of rice growth period was defined. Darker colored fields with regular shape in the images with false color composite from early May to late June were detected as rice fields. From early July to late September, it was hard to discriminate rice canopy from other type of vegetation including upland crops, grass, and forest in the image. Regular form of readjusted rice field in the plains and uniform texture when compared with surrounding vegetation. Paddy fields classified from RapidEye imagery were mapped and the areas were calculated by administrative district, province or city. Sixty six percent of paddy fields ($3,521km^2$) were distributed in the west coastal regions including Pyeongannam-do, Pyeonganbuk-do, and Hwanghaenam-do. The paddy field areas classified from RapidEye images showed less than 1% of difference from the paddy field areas of North Korea reported by FAO/WFP (Food and Agriculture Organization/World Food Programme).

Recent updated diagnostic methods for esophageal motility disorders (식도의 운동장애에 관한 최신지견)

  • Yoon, Seok-Hwan
    • Journal of radiological science and technology
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    • v.27 no.4
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    • pp.11-16
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    • 2004
  • Classification of esophageal motility disorders not yet finalized and is still ongoing as the new disorders are reported, and the existing classification is changed or removed. In terms of radiology, the primary peristalsis does not exist, and the lower end of the esophagus show the smooth, tapered, beak-like appearance. The esophageal motility disorder, which mostly occurs in the smooth muscle area, show the symptoms of reduction or loss (hypomotility) or abnormal increase (hypermotility) of peristalsis of the esophagus. It is important to understand the anatomy and physiology of the esophagus for the appropriate radiological method and diagnosis. Furthermore, the symptom of the patient and the manometry finding must be closely referred for the radiological diagnosis. The lower esophageal sphincter can be normally functioning and open completely as the food moves lower. Sperandio M et al. argues that the name diffuse esophageal spasm must be changed to distal esophageal spasm (DES) as most of the spasm occurs in the distal esophagus, composed of the smooth muscle. According to Ott et al., usefulness of barium method for diagnosing the esophageal motility disorder is Achalasia 95%, DES 71% and NEMD 46%, with the overall sensitivity of 56%. However, excluding the nutcracker esophagus or nonspecific disorder which cannot be diagnosed with the radiological methods, the sensitivity increases to 89%. Using videofluoroscopy and 5 time swallows, the average sensitivity was over 90%. In conclusion, the barium method is a simple primary testing method for esophageal motility test. Using not only the image but also the videofluoroscopy with good knowledge of the anatomy and physiology, it is believed that the method will yield the accurate diagnosis.

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Anomaly Detection for User Action with Generative Adversarial Networks (적대적 생성 모델을 활용한 사용자 행위 이상 탐지 방법)

  • Choi, Nam woong;Kim, Wooju
    • Journal of Intelligence and Information Systems
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    • v.25 no.3
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    • pp.43-62
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    • 2019
  • At one time, the anomaly detection sector dominated the method of determining whether there was an abnormality based on the statistics derived from specific data. This methodology was possible because the dimension of the data was simple in the past, so the classical statistical method could work effectively. However, as the characteristics of data have changed complexly in the era of big data, it has become more difficult to accurately analyze and predict the data that occurs throughout the industry in the conventional way. Therefore, SVM and Decision Tree based supervised learning algorithms were used. However, there is peculiarity that supervised learning based model can only accurately predict the test data, when the number of classes is equal to the number of normal classes and most of the data generated in the industry has unbalanced data class. Therefore, the predicted results are not always valid when supervised learning model is applied. In order to overcome these drawbacks, many studies now use the unsupervised learning-based model that is not influenced by class distribution, such as autoencoder or generative adversarial networks. In this paper, we propose a method to detect anomalies using generative adversarial networks. AnoGAN, introduced in the study of Thomas et al (2017), is a classification model that performs abnormal detection of medical images. It was composed of a Convolution Neural Net and was used in the field of detection. On the other hand, sequencing data abnormality detection using generative adversarial network is a lack of research papers compared to image data. Of course, in Li et al (2018), a study by Li et al (LSTM), a type of recurrent neural network, has proposed a model to classify the abnormities of numerical sequence data, but it has not been used for categorical sequence data, as well as feature matching method applied by salans et al.(2016). So it suggests that there are a number of studies to be tried on in the ideal classification of sequence data through a generative adversarial Network. In order to learn the sequence data, the structure of the generative adversarial networks is composed of LSTM, and the 2 stacked-LSTM of the generator is composed of 32-dim hidden unit layers and 64-dim hidden unit layers. The LSTM of the discriminator consists of 64-dim hidden unit layer were used. In the process of deriving abnormal scores from existing paper of Anomaly Detection for Sequence data, entropy values of probability of actual data are used in the process of deriving abnormal scores. but in this paper, as mentioned earlier, abnormal scores have been derived by using feature matching techniques. In addition, the process of optimizing latent variables was designed with LSTM to improve model performance. The modified form of generative adversarial model was more accurate in all experiments than the autoencoder in terms of precision and was approximately 7% higher in accuracy. In terms of Robustness, Generative adversarial networks also performed better than autoencoder. Because generative adversarial networks can learn data distribution from real categorical sequence data, Unaffected by a single normal data. But autoencoder is not. Result of Robustness test showed that he accuracy of the autocoder was 92%, the accuracy of the hostile neural network was 96%, and in terms of sensitivity, the autocoder was 40% and the hostile neural network was 51%. In this paper, experiments have also been conducted to show how much performance changes due to differences in the optimization structure of potential variables. As a result, the level of 1% was improved in terms of sensitivity. These results suggest that it presented a new perspective on optimizing latent variable that were relatively insignificant.

An Implementation of OTB Extension to Produce TOA and TOC Reflectance of LANDSAT-8 OLI Images and Its Product Verification Using RadCalNet RVUS Data (Landsat-8 OLI 영상정보의 대기 및 지표반사도 산출을 위한 OTB Extension 구현과 RadCalNet RVUS 자료를 이용한 성과검증)

  • Kim, Kwangseob;Lee, Kiwon
    • Korean Journal of Remote Sensing
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    • v.37 no.3
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    • pp.449-461
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    • 2021
  • Analysis Ready Data (ARD) for optical satellite images represents a pre-processed product by applying spectral characteristics and viewing parameters for each sensor. The atmospheric correction is one of the fundamental and complicated topics, which helps to produce Top-of-Atmosphere (TOA) and Top-of-Canopy (TOC) reflectance from multi-spectral image sets. Most remote sensing software provides algorithms or processing schemes dedicated to those corrections of the Landsat-8 OLI sensors. Furthermore, Google Earth Engine (GEE), provides direct access to Landsat reflectance products, USGS-based ARD (USGS-ARD), on the cloud environment. We implemented the Orfeo ToolBox (OTB) atmospheric correction extension, an open-source remote sensing software for manipulating and analyzing high-resolution satellite images. This is the first tool because OTB has not provided calibration modules for any Landsat sensors. Using this extension software, we conducted the absolute atmospheric correction on the Landsat-8 OLI images of Railroad Valley, United States (RVUS) to validate their reflectance products using reflectance data sets of RVUS in the RadCalNet portal. The results showed that the reflectance products using the OTB extension for Landsat revealed a difference by less than 5% compared to RadCalNet RVUS data. In addition, we performed a comparative analysis with reflectance products obtained from other open-source tools such as a QGIS semi-automatic classification plugin and SAGA, besides USGS-ARD products. The reflectance products by the OTB extension showed a high consistency to those of USGS-ARD within the acceptable level in the measurement data range of the RadCalNet RVUS, compared to those of the other two open-source tools. In this study, the verification of the atmospheric calibration processor in OTB extension was carried out, and it proved the application possibility for other satellite sensors in the Compact Advanced Satellite (CAS)-500 or new optical satellites.

Correlation Analysis Between 3D Kidneys Measurements and Abdominal Obesity Level in Computed Tomography (전산화단층영상에서 콩팥 3차원 영상 계측치와 복부 비만도 간의 상관관계 분석)

  • Ji-Yeong Kim;Youl-Hun Seoung
    • Journal of the Korean Society of Radiology
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    • v.17 no.3
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    • pp.315-325
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    • 2023
  • The purpose of this study was to predict abdominal obesity with 3-Dimensional computed tomography (3D CT) measurements of kidneys by analyzing the correlation between kidney sizes and abdominal obesity level. The subjects were 178 healthy adults without underlying diseases who had a comprehensive health examination at the Health Medical Center of Jesus Hospital in Jeonju. Abdominal obesity was measured by CT cross-sectional image at the level of the umbilicus and divided into visceral fat area, subcutaneous fat area, visceral fat/total fat ratio. The average comparison of kidney sizes classified according to abdominal obesity were performed through one-way analysis of variance (ANOVA) and Scheffe test. Pearson correlation analysis was performed to correlate all measurement values. The results of kidney size ANOVA analysis according to abdominal obesity were as follows. The means of kidney measurements according to visceral fat classification were significantly different in all kidney measurements (p<0.05). And in case of subcutaneous fat classification, the means of kidney measurements by 3D CT of the severe obesity group were significantly different in the right kidney width (p<0.05). In case of visceral fat area/total fat area ratio, the means of kidney measurements by 3D CT of the severe obesity group were significantly different in both kidneys width (p<0.05). Pearson correlation between kidneys measurements and CT abdominal obesity showed that visceral fat area had the highest correlation with the left kidney width measured by 3D CT (r=0.467) and subcutaneous fat area had correlation with the right kidney width measured by 3D CT (r=0.249). The visceral fat area/total fat area ratio had correlation with the left kidney width measured by 3D CT (r=0.291).

Sorghum Field Segmentation with U-Net from UAV RGB (무인기 기반 RGB 영상 활용 U-Net을 이용한 수수 재배지 분할)

  • Kisu Park;Chanseok Ryu ;Yeseong Kang;Eunri Kim;Jongchan Jeong;Jinki Park
    • Korean Journal of Remote Sensing
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    • v.39 no.5_1
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    • pp.521-535
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    • 2023
  • When converting rice fields into fields,sorghum (sorghum bicolor L. Moench) has excellent moisture resistance, enabling stable production along with soybeans. Therefore, it is a crop that is expected to improve the self-sufficiency rate of domestic food crops and solve the rice supply-demand imbalance problem. However, there is a lack of fundamental statistics,such as cultivation fields required for estimating yields, due to the traditional survey method, which takes a long time even with a large manpower. In this study, U-Net was applied to RGB images based on unmanned aerial vehicle to confirm the possibility of non-destructive segmentation of sorghum cultivation fields. RGB images were acquired on July 28, August 13, and August 25, 2022. On each image acquisition date, datasets were divided into 6,000 training datasets and 1,000 validation datasets with a size of 512 × 512 images. Classification models were developed based on three classes consisting of Sorghum fields(sorghum), rice and soybean fields(others), and non-agricultural fields(background), and two classes consisting of sorghum and non-sorghum (others+background). The classification accuracy of sorghum cultivation fields was higher than 0.91 in the three class-based models at all acquisition dates, but learning confusion occurred in the other classes in the August dataset. In contrast, the two-class-based model showed an accuracy of 0.95 or better in all classes, with stable learning on the August dataset. As a result, two class-based models in August will be advantageous for calculating the cultivation fields of sorghum.

A Study on the Establishment of Database for the Efficient Management of Unexecuted Urban Planning Facilities (미집행 도시계획시설의 효율적 관리를 위한 DB구축 방안에 관한 연구)

  • KIM, Kwang-Yeol;KIM, Shin-Hey;BAEK, Tae-Kyung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.3
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    • pp.1-11
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    • 2020
  • The purpose of this study is to conduct an analysis for classification of unexecuted urban planning facilities using the Geographic Information System(GIS) to prepare measures for systematic and efficient management of unexecuted urban planning facilities and to find ways to establish national territory information for continuous management and operation by database of spatial data of classified unexecuted urban planning facilities. For this purpose, the present state of urban management plan, thematic map, cadastral map, satellite image of Korea Land Information System(KLIS) were collected from Miryang City, and qualitative analysis of the execution and non-execution of urban planning facilities was conducted by combining the layer of urban planning facilities, satellite images, and continuous cadastral layers of cadastral maps with classified and processed owner attribute information. According to the analysis, the unexecuted facilities were derived as unexecuted facilities, as most of the private land, without any current status roads or facilities created in satellite imagery. In addition, although the current status road was opened, the facilities that included some private land were derived as facilities that were recognized and executed by the local government as the de facto controlling entity through public transportation. The derived unexecuted urban planning facilities were divided into layers of shape data and the unexecuted property data were organized to quickly and accurately identify the status of non-executed and statistical information. In this study, we proposed an analysis plan that introduced GIS technology for scientific and rational analysis of unexecuted urban planning facilities and the establishment of reliable spatial data, and proposed a plan to establish a database for connection with existing systems and use of information.

Radiological Findings and Treatment Period of Acute Low Back Pain Patients Diagnosed as Having Lumbar Sprain and Strain - with Focus on X-ray and CT Findings - (요천추부 염좌로 진단된 급성 요통 환자의 방사선학적 소견과 치료기간에 대한 임상적 고찰 - X-ray와 CT 소견 분석 -)

  • Koh, Pil-Seong;Yi, Won-Il;Joh, Byung-Jin;Kwon, Sin-Ae;Lee, Jung-Woo;Kim, Min-Jung;Seo, Byung-Kwan;Woo, Hyun-Soo;Baek, Yong-Hyun;Kim, Jae-Kyu;Park, Dong-Suk
    • Journal of Acupuncture Research
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    • v.27 no.4
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    • pp.19-28
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    • 2010
  • Objectives : To demonstrate the need for differential diagnosis between discogenic pain and lumbar sprain and strain in acute low-back pain patients. Methods : Outpatients who made their first visits during May 1, 2009 to Oct. 30, 2009(n=53) were examined by history taking, physical examination, X-rays, and CT imaging. Disorders found on lumbosacral spine X-ray cuts and those on lumbosacral spine CT images were separately recorded. The relationship between treatment period, disc space narrowing and disc degeneration on X-rays, and HIVD on CT images was examined. Results : 1. Correlation between disc space narrowing on X-rays and HIVD found on CT images was analyzed. 21(72.41%) out of 29 patients having disc space narrowing on X-rays and HIVD on CT at the same level required treatment for over 8 weeks. 2. 2(50%) out of 4 Lawrence classification grade I patients, 8(66.67%) out of 12 grade II patients, and 14(70%) out of 20 grade III patients needed treatment for over 8 weeks. Conclusions : Disc space narrowing on X-ray and HIVD on CT at the same level, or disc space narrowing and disc degeneration on X-ray image alone indicate a tendency for treatment periods over 8 weeks, which is longer than the conventional treatment period for lumbar strain and sprain.

Monitoring of Lake area Change and Drought using Landsat Images and the Artificial Neural Network Method in Lake Soyang, Chuncheon, Korea (Landsat 영상 및 인공 신경망 기법을 활용한 춘천 소양호 면적 및 가뭄 모니터링)

  • Eom, Jinah;Park, Sungjae;Ko, Bokyun;Lee, Chang-Wook
    • Journal of the Korean earth science society
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    • v.41 no.2
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    • pp.129-136
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    • 2020
  • Drought is an environmental disaster typically defined as an unusual deficiency of water supply over an extended period. Satellite remote sensing provides an alternative approach to monitoring drought over large areas. In this study, we monitored drought patterns over about 30 years (1985-2015), using satellite imagery of Lake Soyang, Gangwondo, South Korea. Landsat images were classified using ISODATA, maximum likelihood analysis, and an artificial neural network to derive the lake area. In addition, the relationship between areas of Lake Soyang and the Standardized Precipitation Index (SPI) was analyzed. The results showed that the artificial neural network was a better method for determining the area of the lake. Based on the relationship between the SPI value and changes in area, the R2 value was 0.52. This means that the area of the lake varied depending on SPI value. This study was able to detect and monitor drought conditions in the Lake Soyang area. The results of this study are used in the development of a regional drought monitoring program.

Analysis for Concentration Range of Fluorescein Sodium (플루오레신나트륨의 농도 범위 분석)

  • Lee, Da-Ae;Kim, Yong-Jae;Yoon, Ki-Cheol;Kim, Kwang-Gi
    • Journal of Biomedical Engineering Research
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    • v.41 no.2
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    • pp.67-74
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    • 2020
  • Brain tumors or gliomas are fatal cancer species with high recurrence rates due to their strong invasiveness. Therefore, the goal of surgery is complete tumor resection. However, the surgery is difficult to distinguish the border because tumors and blood vessels have the same color tone and shape. The fluorescein sodium is used as a fluorescence contrast agent for boundary separation. When the external light source is irradiated, yellow fluorescence is expressed in the tumor, which helps distinguish between blood vessels and tumor boundaries. But, the fluorescence expression of fluorescence sodium depends on the concentration of fluorescein sodium and such analytical data is insufficient. The unclear fluorescence can obscure the boundaries between blood vessels and tumors. In addition, reduce the efficiency of fluorescence sodium use. This paper proposes a protocol of concentration range for fluorescence expression conditions. Fluorescent expression was observed using a near-infrared (NIR) color camera with corresponding dilution using normal saline in 1 ml microtube. The flunoresence emission density range is 1.00 mM to 0.15 mM. The fluorescence emission begin to 1.00 mM and the 0.15 mM discolor. The discolor is difficult to fluorescence emission condition obserbation. Thus, the maximum density range of the bright fluoresecein is 0.15 mM to 0.30 mM. When the concentration range of fluorescein sodium is analyzed based on the gradient of fluorescence expression and the power measurement, the brightest fluorescence is expected to facilitate the complete resection of the tumor. For the concentration range protocol, setting concentration ranges and analyzing fluorescence expression image according to saturation and brightness to find optimal fluorescence concentration are important. Concentration range protocols for fluorescence expression conditions can be used to find optimal concentrations of substances whose expression pattern varies with concentration ranges. This study is expected to be helpful in the boundary classification and resection of brain tumors and glioma.