• Title/Summary/Keyword: Image-based reconstruction

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A Study on Stroke Extraction for Handwritten Korean Character Recognition (필기체 한글 문자 인식을 위한 획 추출에 관한 연구)

  • Choi, Young-Kyoo;Rhee, Sang-Burm
    • The KIPS Transactions:PartB
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    • v.9B no.3
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    • pp.375-382
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    • 2002
  • Handwritten character recognition is classified into on-line handwritten character recognition and off-line handwritten character recognition. On-line handwritten character recognition has made a remarkable outcome compared to off-line hacdwritten character recognition. This method can acquire the dynamic written information such as the writing order and the position of a stroke by means of pen-based electronic input device such as a tablet board. On the contrary, Any dynamic information can not be acquired in off-line handwritten character recognition since there are extreme overlapping between consonants and vowels, and heavily noisy images between strokes, which change the recognition performance with the result of the preprocessing. This paper proposes a method that effectively extracts the stroke including dynamic information of characters for off-line Korean handwritten character recognition. First of all, this method makes improvement and binarization of input handwritten character image as preprocessing procedure using watershed algorithm. The next procedure is extraction of skeleton by using the transformed Lu and Wang's thinning: algorithm, and segment pixel array is extracted by abstracting the feature point of the characters. Then, the vectorization is executed with a maximum permission error method. In the case that a few strokes are bound in a segment, a segment pixel array is divided with two or more segment vectors. In order to reconstruct the extracted segment vector with a complete stroke, the directional component of the vector is mortified by using right-hand writing coordinate system. With combination of segment vectors which are adjacent and can be combined, the reconstruction of complete stroke is made out which is suitable for character recognition. As experimentation, it is verified that the proposed method is suitable for handwritten Korean character recognition.

Occurrence of Nuclear Inclusions in Plant Cells (식물세포 내 핵 함유구조 발달 양상)

  • Kim, In-Sun
    • Applied Microscopy
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    • v.41 no.4
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    • pp.229-234
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    • 2011
  • The occurrence of nuclear inclusions has been reported in various plant groups from primitive ferns to higher flowering plants. Their presence within a group seems to be randomly distributed without any phylogenetic relationships among species. According to the current survey, nuclear inclusions have been widely documented in more than several hundreds of species from various families of plants. The morphology and internal structures of nuclear inclusions are diverse and at least five types of inclusions develop within plant nuclei; amorphous, crystalline, fibrous, lamellar, and tubular form. Among these types, crystalline inclusions are the ones that are the most frequently reported. The inclusions are not bound by membranes and appear to be related to the nucleoli, either spatially by a close association or by an inverse relationship in size during development. The idea that nuclear inclusions are of a proteinaceous nature has been widely accepted. Further link to nucleolar activity as a protein storing site has also been suggested based on the association between the nucleolus and nuclear inclusions. Various investigations of nuclear inclusions have revealed more information about their structural features, but characterizing their precise function and subunit complexity employing molecular analysis and 3-D reconstruction remains to be elucidated. Tilting and tomography of serial sections with appropriate image processing can provide valuable information on their subunit(s). The present review summarizes discussion about different nuclear inclusions in plants from previous works, giving special attention to their fine, ultrastructural morphology, function, and origin.

The Strategic Adoption of Creative Industry and Its Impact on the Reconstruction of Cultural Identity in Andong Province (문화콘텐츠산업의 전략적 수용과 안동 문화정체성의 재구성)

  • Cho, Gwan-Yeon
    • Journal of the Korean association of regional geographers
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    • v.17 no.5
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    • pp.568-581
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    • 2011
  • Having gone through the international financial crisis in 1997, the Korean government has sought a new future economic breakthrough. In this line, the government chose the cultural contents business and has supported this area intensively. With the cultural contents promotion policy initiated to foster the world-class culture business based on the traditional Korean culture, Andong, which has diverse cultural traditions, was rediscovered. The Andong local government and the local power elites decided that this promotion policy can not only be an opportunity to invigorate the sluggish local economy, but also help eliminate the old-fashioned image of Andong, and thus actively promoted the cultural contents business. However, there's a conflict among the local elites over which cultural tradition should be chosen as a genuine local cultural tradition. The different views and efforts regarding the cultural identity of the region by each entity not only contributed significantly to the recovery of the local economy by revitalizing tourism, but also helped the region gain an advantageous position in competition with other regions over limited resources. This progress became the groundwork for attracting major institutions and facilities, which are essential for the revitalization of the local economy.

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Road Extraction from Images Using Semantic Segmentation Algorithm (영상 기반 Semantic Segmentation 알고리즘을 이용한 도로 추출)

  • Oh, Haeng Yeol;Jeon, Seung Bae;Kim, Geon;Jeong, Myeong-Hun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.3
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    • pp.239-247
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    • 2022
  • Cities are becoming more complex due to rapid industrialization and population growth in modern times. In particular, urban areas are rapidly changing due to housing site development, reconstruction, and demolition. Thus accurate road information is necessary for various purposes, such as High Definition Map for autonomous car driving. In the case of the Republic of Korea, accurate spatial information can be generated by making a map through the existing map production process. However, targeting a large area is limited due to time and money. Road, one of the map elements, is a hub and essential means of transportation that provides many different resources for human civilization. Therefore, it is essential to update road information accurately and quickly. This study uses Semantic Segmentation algorithms Such as LinkNet, D-LinkNet, and NL-LinkNet to extract roads from drone images and then apply hyperparameter optimization to models with the highest performance. As a result, the LinkNet model using pre-trained ResNet-34 as the encoder achieved 85.125 mIoU. Subsequent studies should focus on comparing the results of this study with those of studies using state-of-the-art object detection algorithms or semi-supervised learning-based Semantic Segmentation techniques. The results of this study can be applied to improve the speed of the existing map update process.

Evaluation of MR Based Respiratory Motion Correction Technique in Liver PET/MRI Study (Liver PET/MRI 검사 시 MR 기반 호흡 움직임 보정 방법의 유용성 평가)

  • Do, Yong Ho;Lee, Hong Jae;Kim, Jin Eui;Noh, Gyeong Woon
    • The Korean Journal of Nuclear Medicine Technology
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    • v.22 no.1
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    • pp.15-22
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    • 2018
  • Purpose Respiratory motion during PET/MRI acquisition may result in image blurring and error in measurement for volume and quantification of lesion. The aim of this study was to evaluate changes of quantitative accuracy, tumor size and image quality by applying MR based respiratory motion correction technique (MBRMCT) using integrated PET/MR scanner. Materials and Methods Data of 30 patients (aged $62.5{\pm}10.2y$) underwent $^{18}F-FDG$ liver PET/MR (Biograph mMR 3.0T, Siemens) study were collected. PET listmode data for 7 minutes was simultaneously acquired with maximum average gate (MAG), minimum time gate (MTG) and non gate (NG) T1 weighted MR images. Gated PET reconstruction was performed using mu-maps generated from MAG and MTG by setting 35% of efficiency window. Maximum SUV ($SUV_{max}$), peak SUV ($SUV_{peak}$), tumor size and full width at half maximum (FWHM) in the z-axis direction of MAG, MTG and NG PET images were evaluated. Results Compared to NG, mean $SUV_{max}$ and $SUV_{peak}$ were increased in MAG 13.15%(p<0.0001), 8.66%(p<0.0001), MTG 13.27%(p<0.0001), 8.80%(p<0.0001) and mean tumor size and FWHM were decreased in MAG 14.47%(p<0.0001), 15.49%(p=0.0004), MTG 14.89%(p<0.0001), 15.79%(p=0.0003) respectively. Mean $SUV_{max}$ and $SUV_{peak}$ of MTG were increased by 0.07%(p=0.8802), 0.13%(p=0.7766). Mean tumor size and FWHM of MTG were decreased by 0.49%(p=0.2786), 0.36%(p=0.2488) compared to MAG. There was no statistically significant difference between MAG and MTG which increase total scan time for about 7 and 2 minutes. Conclusion SUV, accuracy of tumor size and spatial resolution were improved in both of MAG and MTG by applying MBRMCT without installing additional hardware in liver PET/MR study. More accurate information can be provided with the increase of 2 minutes scan time if applying MTG of MBRMCT to various abdominal PET/MR studies affected by respiratory motion.

A Study on the Wooden Seated Vairocana Tri-kaya Buddha Images in the Daeungjeon Hall of Hwaeomsa Temple (화엄사 대웅전 목조비로자나삼신 불좌상에 대한 고찰)

  • Choe, Songeun
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.100
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    • pp.140-170
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    • 2021
  • This paper investigates the Wooden Seated Tri-kaya Buddha Images(三身佛像) of Vairocana, Rushana, and Sakyamuni enshrined in Daeungjeon Hall of Hwaeomsa temple(華嚴寺) in Gurae, South Cheolla Province. They were produced in 1634 CE and placed in 1635 CE, about forty years after original images made in the Goryeo period were destroyed by the Japanese army during the war. The reconstruction of Hwaeomsa was conducted by Gakseong, one of the leading monks of Joseon Dynasty in the 17th century, who also conducted the reconstructions of many Buddhist temples after the war. In 2015, a prayer text (dated 1635) concerning the production of Hwaeomsa Tri-kaya Buddha images was found in the repository within Sakyamuni Buddha. It lists the names of participants, including royal family members (i.e., prince Yi Guang, the eighth son of King Seon-jo), and their relatives (i.e., Sin Ik-seong, son-in-law of King Seonjo), court ladies, monk-sculptors, and large numbers of monks and laymen Buddhists. A prayer text (dated 1634) listing the names of monk-sculptors written on the wooden panel inside the pedestal of Rushana Buddha was also found. A recent investigation into the repository within Rushana Buddha in 2020 CE has revealed a prayer text listing participants producing these images, similar to the former one from Sakyamuni Buddha, together with sacred relics of hoo-ryeong-tong copper bottle and a large quantity of Sutra books. These new materials opened a way to understand Hwaeomsa Trikaya images, including who made them and when they were made. The two above-mentioned prayer texts from the repository of Sakyamuni and Rushana Buddha statues, and the wooden panel inside the pedestal of Rushan Buddha tell us that eighteen monk-sculptors, including Eungwon, Cheongheon and Ingyun, who were well-known monk artisans of the 17th century, took part in the construction of these images. As a matter of fact, Cheongheon belonged to a different workshop from Eungwon and Ingyun, who were most likely teacher and disciple or senior and junior colleagues, which means that the production of Hwaeomsa Tri-kaya Buddha images was a collaboration between sculptors from two workshops. Eungwon and Ingyun seem to have belonged to the same community studying under the great Buddhist priest Seonsu, the teacher of Monk Gakseong who was in charge of the reconstruction of Haweonsa temple. Hwaeomsa Tri-kaya Buddha images show a big head, a squarish face with plump cheeks, narrow and drooping shoulders, and a short waist, which depict significant differences in body proportion to those of other Buddha statues of the first half of 17th century, which typically have wide shoulders and long waists. The body proportion shown in the Hwaeomsa images could be linked with images of late Goryeo and early Joseon period. Rushana Buddha, raising his two arms in a preaching hand gesture and wearing a crown and bracelets, shows unique iconography of the Bodhisattva form. This iconography of Rushana Buddha had appeared in a few Sutra paintings of Northern Song and Late Goryeo period of 13th and 14th century. BodhaSri-mudra of Vairocana Buddha, unlike the general type of BodhaSri-mudra that shows the right hand holding the left index finger, places his right hand upon the left hand in a fist. It is similar to that of Vairocana images of Northern and Southern Song, whose left hand is placed on the top of right hand in a fist. This type of mudra was most likely introduced during the Goryeo period. The dried lacquer Seated Vairocana image of Bulheosa Temple in Naju is datable to late Goryeo period, and exhibits similar forms of the mudra. Hwaeomsa Tri-kaya Buddha images also show new iconographic aspects, as well as traditional stylistic and iconographic features. The earth-touching (bhumisparsa) mudra of Sakymuni Buddha, putting his left thumb close to the middle finger, as if to make a preaching mudra, can be regarded as a new aspect that was influenced by the Sutra illustrations of the Ming dynasty, which were imported by the royal court of Joseon dynasty and most likely had an impact on Joseon Buddhist art from the 15th and 16th centuries. Stylistic and iconographical features of Hwaeomsa Tri-kaya Buddha images indicate that the traditional aspects of Goryeo period and new iconography of Joseon period are rendered together, side by side, in these sculptures. The coexistence of old and new aspects in one set of images could indicate that monk sculptors tried to find a new way to produce Hwaeomsa images based on the old traditional style of Goryeo period when the original Tri-kaya Buddha images were made, although some new iconography popular in Joseon period was also employed in the images. It is also probable that monk sculptors of Hwaeomsa Tri-kaya Buddha images intended to reconstruct these images following the original images of Goryeo period, which was recollected by surviving monks at Hwaeomsa, who had witnessed the original Tri-kaya Buddha images.

Development of cardiopulmonary resuscitation nursing education program of web-based instruction (웹 기반의 심폐소생술 간호교육 프로그램 개발)

  • Sin, Hae-Won;Hong, Hae-Sook
    • Journal of Korean Biological Nursing Science
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    • v.4 no.1
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    • pp.25-39
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    • 2002
  • The purpose of this study is to develop and evaluate a web-based instruction Program(WBI) to help nurses improving their knowledge and skill of cardiopulmonary resuscitation. Using the model of web-based instruction(WBI) program designed by Rhu(1999), this study was carried out during February-April 2002 in five different steps; analysis, design, data collection and reconstruction, programming and publishing, and evaluation. The results of the study were as follows; 1) The goal of this program was focused on improving accuracy of knowledge and skills of cardiopulmonary resuscitation. The program texts consists of the concepts and importances of cardiopulmonary resuscitation(CPR), basic life support(BLS), advanced cardiac life support(ACLS), treatment of CPR, nursing care after CPR treatment. And in the file making step, photographs, drawings and image files were collected and edited by web-editor(Namo), scanner and Adobe photoshop program. Then, the files were modified and posted on the web by file transfer protocol(FTP). Finally, the program was demonstrated and once again revised by the result, and then completed. 2) For the evaluation of the program, 36 nurses who in K university hospital located in D city, and related questionnaire were distributed to them as well. Higher scores were given by the nurses in its learning contents with $4.2{\pm}.67$, and in its structuring and interaction of the program with $4.0{\pm}.79$, and also in its satisfactory of the program with $4.2{\pm}.58$ respectively. In conclusion, if the contents of this WBI educational program upgrade further based upon analysis and applying of the results the program evaluation, it is considered as an effective tool to implement for continuing education as life-long educational system for nurse.

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Error Analysis of Delivered Dose Reconstruction Using Cone-beam CT and MLC Log Data (콘빔 CT 및 MLC 로그데이터를 이용한 전달 선량 재구성 시 오차 분석)

  • Cheong, Kwang-Ho;Park, So-Ah;Kang, Sei-Kwon;Hwang, Tae-Jin;Lee, Me-Yeon;Kim, Kyoung-Joo;Bae, Hoon-Sik;Oh, Do-Hoon
    • Progress in Medical Physics
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    • v.21 no.4
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    • pp.332-339
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    • 2010
  • We aimed to setup an adaptive radiation therapy platform using cone-beam CT (CBCT) and multileaf collimator (MLC) log data and also intended to analyze a trend of dose calculation errors during the procedure based on a phantom study. We took CT and CBCT images of Catphan-600 (The Phantom Laboratory, USA) phantom, and made a simple step-and-shoot intensity-modulated radiation therapy (IMRT) plan based on the CT. Original plan doses were recalculated based on the CT ($CT_{plan}$) and the CBCT ($CBCT_{plan}$). Delivered monitor unit weights and leaves-positions during beam delivery for each MLC segment were extracted from the MLC log data then we reconstructed delivered doses based on the CT ($CT_{recon}$) and CBCT ($CBCT_{recon}$) respectively using the extracted information. Dose calculation errors were evaluated by two-dimensional dose discrepancies ($CT_{plan}$ was the benchmark), gamma index and dose-volume histograms (DVHs). From the dose differences and DVHs, it was estimated that the delivered dose was slightly greater than the planned dose; however, it was insignificant. Gamma index result showed that dose calculation error on CBCT using planned or reconstructed data were relatively greater than CT based calculation. In addition, there were significant discrepancies on the edge of each beam while those were less than errors due to inconsistency of CT and CBCT. $CBCT_{recon}$ showed coupled effects of above two kinds of errors; however, total error was decreased even though overall uncertainty for the evaluation of delivered dose on the CBCT was increased. Therefore, it is necessary to evaluate dose calculation errors separately as a setup error, dose calculation error due to CBCT image quality and reconstructed dose error which is actually what we want to know.

A Theoretical Model for the Analysis of Residual Motion Artifacts in 4D CT Scans (이론적 모델을 이용한 4DCT에서의 Motion Artifact 분석)

  • Kim, Tae-Ho;Yoon, Jai-Woong;Kang, Seong-Hee;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.23 no.3
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    • pp.145-153
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    • 2012
  • In this study, we quantify the residual motion artifact in 4D-CT scan using the dynamic lung phantom which could simulate respiratory target motion and suggest a simple one-dimension theoretical model to explain and characterize the source of motion artifacts in 4DCT scanning. We set-up regular 1D sine motion and adjusted three level of amplitude (10, 20, 30 mm) with fixed period (4s). The 4DCT scans are acquired in helical mode and phase information provided by the belt type respiratory monitoring system. The images were sorted into ten phase bins ranging from 0% to 90%. The reconstructed images were subsequently imported into the Treatment Planning System (CorePLAN, SC&J) for target delineation using a fixed contour window and dimensions of the three targets are measured along the direction of motion. Target dimension of each phase image have same changing trend. The error is minimum at 50% phase in all case (10, 20, 30 mm) and we found that ${\Delta}S$ (target dimension change) of 10, 20 and 30 mm amplitude were 0 (0%), 0.1 (5%), 0.1 (5%) cm respectively compare to the static image of target diameter (2 cm). while the error is maximum at 30% and 80% phase ${\Delta}S$ of 10, 20 and 30 mm amplitude were 0.2 (10%), 0.7 (35%), 0.9 (45%) cm respectively. Based on these result, we try to analysis the residual motion artifact in 4D-CT scan using a simple one-dimension theoretical model and also we developed a simulation program. Our results explain the effect of residual motion on each phase target displacement and also shown that residual motion artifact was affected that the target velocity at each phase. In this study, we focus on provides a more intuitive understanding about the residual motion artifact and try to explain the relationship motion parameters of the scanner, treatment couch and tumor. In conclusion, our results could help to decide the appropriate reconstruction phase and CT parameters which reduce the residual motion artifact in 4DCT.

Comparison of using CBCT with CT Simulator for Radiation dose of Treatment Planning (CBCT와 Simulation CT를 이용한 치료계획의 선량비교)

  • Kim, Dae-Young;Choi, Ji-Won;Cho, Jung-Keun
    • The Journal of the Korea Contents Association
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    • v.9 no.12
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    • pp.742-749
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    • 2009
  • The use of cone-beam computed tomography(CBCT) has been proposed for guiding the delivery of radiation therapy. A kilovoltage imaging system capable of radiography, fluoroscopy, and cone-beam computed tomography(CT) has been integrated with a medical linear accelerator. A standard clinical linear accelerator, operating in arc therapy mode, and an amorphous-silicon (a-Si) with an on-board electronic portal imager can be used to treat palliative patient and verify the patient's position prior to treatment. On-board CBCT images are used to generate patient geometric models to assist patient setup. The image data can also, potentially, be used for dose reconstruction in combination with the fluence maps from treatment plan. In this study, the accuracy of Hounsfield Units of CBCT images as well as the accuracy of dose calculations based on CBCT images of a phantom and compared the results with those of using CT simulator images. Phantom and patient studies were carried out to evaluate the achievable accuracy in using CBCT and CT stimulator for dose calculation. Relative electron density as a function of HU was obtained for both planning CT stimulator and CBCT using a Catphan-600 (The Phantom Laboratory, USA) calibration phantom. A clinical treatment planning system was employed for CT stimulator and CBCT based dose calculations and subsequent comparisons. The dosimetric consequence as the result of HU variation in CBCT was evaluated by comparing MU/cCy. The differences were about 2.7% (3-4MU/100cGy) in phantom and 2.5% (1-3MU/100cGy) in patients. The difference in HU values in Catphan was small. However, the magnitude of scatter and artifacts in CBCT images are affected by limitation of detector's FOV and patient's involuntary motions. CBCT images included scatters and artifacts due to In addition to guide the patient setup process, CBCT data acquired prior to the treatment be used to recalculate or verify the treatment plan based on the patient anatomy of the treatment area. And the CBCT has potential to become a very useful tool for on-line ART.)