• Title/Summary/Keyword: Cylindrical projection

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Building Dataset of Sensor-only Facilities for Autonomous Cooperative Driving

  • Hyung Lee;Chulwoo Park;Handong Lee;Junhyuk Lee
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.1
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    • pp.21-30
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    • 2024
  • In this paper, we propose a method to build a sample dataset of the features of eight sensor-only facilities built as infrastructure for autonomous cooperative driving. The feature extracted from point cloud data acquired by LiDAR and build them into the sample dataset for recognizing the facilities. In order to build the dataset, eight sensor-only facilities with high-brightness reflector sheets and a sensor acquisition system were developed. To extract the features of facilities located within a certain measurement distance from the acquired point cloud data, a cylindrical projection method was applied to the extracted points after applying DBSCAN method for points and then a modified OTSU method for reflected intensity. Coordinates of 3D points, projected coordinates of 2D, and reflection intensity were set as the features of the facility, and the dataset was built along with labels. In order to check the effectiveness of the facility dataset built based on LiDAR data, a common CNN model was selected and tested after training, showing an accuracy of about 90% or more, confirming the possibility of facility recognition. Through continuous experiments, we will improve the feature extraction algorithm for building the proposed dataset and improve its performance, and develop a dedicated model for recognizing sensor-only facilities for autonomous cooperative driving.

Development of Quality Assurance Software for $PRESAGE^{REU}$ Gel Dosimetry ($PRESAGE^{REU}$ 겔 선량계의 분석 및 정도 관리 도구 개발)

  • Cho, Woong;Lee, Jaegi;Kim, Hyun Suk;Wu, Hong-Gyun
    • Progress in Medical Physics
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    • v.25 no.4
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    • pp.233-241
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    • 2014
  • The aim of this study is to develop a new software tool for 3D dose verification using $PRESAGE^{REU}$ Gel dosimeter. The tool included following functions: importing 3D doses from treatment planning systems (TPS), importing 3D optical density (OD), converting ODs to doses, 3D registration between two volumetric data by translational and rotational transformations, and evaluation with 3D gamma index. To acquire correlation between ODs and doses, CT images of a $PRESAGE^{REU}$ Gel with cylindrical shape was acquired, and a volumetric modulated arc therapy (VMAT) plan was designed to give radiation doses from 1 Gy to 6 Gy to six disk-shaped virtual targets along z-axis. After the VMAT plan was delivered to the targets, 3D OD data were reconstructed from 512 projection data from $Vista^{TM}$ optical CT scanner (Modus Medical Devices Inc, Canada) per every 2 hours after irradiation. A curve for converting ODs to doses was derived by comparing TPS dose profile to OD profile along z-axis, and the 3D OD data were converted to the absorbed doses using the curve. Supra-linearity was observed between doses and ODs, and the ODs were decayed about 60% per 24 hours depending on their magnitudes. Measured doses from the $PRESAGE^{REU}$ Gel were well agreed with the TPS doses at central region, but large under-doses were observed at peripheral region at the cylindrical geometry. Gamma passing rate for 3D doses was 70.36% under the gamma criteria of 3% of dose difference and 3 mm of distance to agreement. The low passing rate was resulted from the mismatching of the refractive index between the PRESAGE gel and oil bath in the optical CT scanner. In conclusion, the developed software was useful for 3D dose verification from PRESAGE gel dosimetry, but further improvement of the Gel dosimetry system were required.

Performance Characteristics of MicroPET R4 Scanner for Small Animal Imaging (소동물 영상을 위한 MicroPET R4스캐너의 특성평가)

  • Lee, Byeong-Il;Lee, Jae-Sung;Kim, Jin-Su;Lee, Dong-Soo;Choi, Chang-Un;Lim, Sang-Moo
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.1
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    • pp.49-56
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    • 2005
  • Purpose: Dedicated animal PET is useful equipment for the study of new PET tracer. recently, microPET R4 was installed in the Korea institute of radiology and medical science. In this study, we measured the characteristics of scanner. Materials and methods: Resolution was measured using a line source (F-18:65 ${\mu}Ci$, inner diameter: 0.5 mm). The line source was put in the axial direction and was moved from the center of field of view to outside with 1 mm interval. PET images were reconstructed using a filtered back-protection and ordered subset expectation maximization. line source (16.5 ${\mu}Ci$, 78 mm) was put on the tenter of axial direction to measure the sensitivity when the deadtime was under 1%. Images were acquired during 4 minutes respectively from center to 39 mm outward. Delayed count was subtracted from total count and then decay was corrected for the calculation of sensitivity. Noise equivalent count ratio and scatter fraction were calculated using cylindrical phantom. Results: Spatial resolution of reconstructed image using filtered back-projection was 1.86 mm(radial), 1.95 mm(tangential), 1.95 mm(axial) in the tenter of field of view, and 2.54 mm, 2.8 mm, 1.61 mm in 2 cm away from the center respectively. Sensitivity was 2.36% at the center of transaxial field of view. Scatter fraction was 20%. Maximal noise equivalent count ratio was 66.4 kcps at 242 kBq/mL. Small animal images were acquired for confirmation of performance. Conclusion: Performance characteristics of microPET R4 were similar with reported value. So this will be a useful tool for small animal imaging.

Dreams of Admiral Yi Sun-sin (1545-1598) in Nanjung Ilgi (Diary in War Time) and Some Aspects of His Personality: From Jungian Viewpoint (≪난중일기≫에서 본 이순신의 꿈과 인격의 몇 가지 측면: 분석심리학적 입장에서)

  • Bou-Yong Rhi
    • Sim-seong Yeon-gu
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    • v.37 no.2
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    • pp.99-148
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    • 2022
  • This study aims at the psychological elucidation of some conscious aspects of the personality of Yi Sun-sin (1545-1598), the Korean national hero, and the unconscious teleologic meanings of his dreams mentioned in Nanjung Ilgi (Diary in War Time) from the viewpoint of analytical psychology of C.G. Jung. Yi Sun-sin was a man of discipline, incorporated with the spirit of Confucian filial piety, hyo (hsiao) and royalty, chung. He was a stern man but with a warm heart. In his diary, Yi Sun-sin poured forth his feelings of suffering, despair, and extreme solicitude caused by slanders of his political opponents, his grief for the loss of mother and son, and his worries about the fate of his country, which the Japanese invaders now plundered. The moon night offered him the opportunity to touch with his inner soul, by reciting poems, playing Korean string, 'Keomungo', and flute. Further, he widened his scope by asking for the answers from the 'Heaven' through divination and dream. Yi Sun-sin's attitude toward his mother who raised the future hero and maternal principles were considered in concern with the Jungian term 'mother complex'. Won Gyun, Yi Sun-sin's rival admiral, who persistently accused Yi Sun-sin of 'slanders,' certainly represents the unconscious shadow image of Yi Sun-sin. The reciprocal 'shadow' projection has intervened in the conflicting relationship between Yi and Won. In concern to the argument for the suicidal death of Yi Sun-sin, the author found no evidence supporting such an argument, No trace of latent suicidal wish was found in his dreams. For Yi Sun-sin, the determination of the life and death depends on Heaven. 32 dreams from the diary and 3 from other historical references were reviewed and analyzed in the Jungian way. Symbols of anima, Self, and individuation process were found. His dream repeatedly suggests that Yi Sun-sin is an extraordinary man chosen by the divine man (神人). In the dream, Yi Sun-sin was a disciple of the divine man receiving instructions on various strategies, and he alone could see the great thing or events. The dream of a beautiful blue and red dragon, whom he was friendly touching, indicates Yi Sun-sin's eligibility for the kingship. Yi Sun-sin seemingly did not aware of this message of the unconscious. Perhaps he sensed something special but did not identify with 'the disciple of gods' and 'royal dragon' in his dream. His modest attitude toward the dream has prevented him from falling into ego inflation. There were warning signals in two dreams that suggested disorders in the dreamer's instinctive feminine drive. Spirits of the dead father and brothers appear in the dream, giving advice or mourning for the death of Sun-sin's mother. Though Yi Sun-sin was a genuine Confucian gentleman, a dream revealed his unconscious drive to destroy the Confucian authoritative 'Persona' by trampling down the cylindrical traditional Korean hat. To the dreams of synchronicity phenomena Yi Sun-sin immediately solves the problem in concrete reality. He understood dreams as valuable messages from the superior entity, for example, the Confucian Heaven (天) or Heaven's Decree (天命). Furthermore, the 'Heaven' presumably arranged for him the way to the national hero and imposed necessary trials upon him. Both his persecutors and advocates of him guided him in the way of a hero. Yi Sun-sin followed his destiny and completed the living myth of the hero. His mother, King Seon-jo, and prime minister Liu Seong Yong, all have contributed to embodying the myth of the hero. Yi Sun-sin died and became god, the divine healer of the nation.