• Title/Summary/Keyword: 상태분할

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Analysis of the Causes of Subfrontal Recurrence in Medulloblastoma and Its Salvage Treatment (수모세포종의 방사선치료 후 전두엽하방 재발된 환자에서 원인 분석 및 구제 치료)

  • Cho Jae Ho;Koom Woong Sub;Lee Chang Geol;Kim Kyoung Ju;Shim Su Jung;Bak Jino;Jeong Kyoungkeun;Kim Tae_Gon;Kim Dong Seok;Choi oong-Uhn;Suh Chang Ok
    • Radiation Oncology Journal
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    • v.22 no.3
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    • pp.165-176
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    • 2004
  • Purpose: Firstly, to analyze facto in terms of radiation treatment that might potentially cause subfrontal relapse in two patients who had been treated by craniospinal irradiation (CSI) for medulloblastoma, Secondly, to explore an effective salvage treatment for these relapses. Materials and Methods: Two patients who had high-risk disease (T3bMl, T3bM3) were treated with combined chemoradiotherapy CT-simulation based radiation-treatment planning (RTP) was peformed. One patient who experienced relapse at 16 months after CSI was treated with salvage surgery followed by a 30.6 Gy IMRT (intensity modulated radiotherapy). The other patient whose tumor relapsed at 12 months after CSI was treated by surgery alone for the recurrence. To investigate factors that might potentially cause subfrontal relapse, we evaluated thoroughly the charts and treatment planning process including portal films, and tried to find out a method to give help for placing blocks appropriately between subfrotal-cribrifrom plate region and both eyes. To salvage subfrontal relapse in a patient, re-irradiation was planned after subtotal tumor removal. We have decided to treat this patient with IMRT because of the proximity of critical normal tissues and large burden of re-irradiation. With seven beam directions, the prescribed mean dose to PTV was 30.6 Gy (1.8 Gy fraction) and the doses to the optic nerves and eyes were limited to 25 Gy and 10 Gy, respectively. Results: Review of radiotherapy Portals clearly indicated that the subfrontal-cribriform plate region was excluded from the therapy beam by eye blocks in both cases, resulting in cold spot within the target volume, When the whole brain was rendered in 3-D after organ drawing in each slice, it was easier to judge appropriateness of the blocks in port film. IMRT planning showed excellent dose distributions (Mean doses to PTV, right and left optic nerves, right and left eyes: 31.1 Gy, 14.7 Gy, 13.9 Gy, 6.9 Gy, and 5.5 Gy, respectively. Maximum dose to PTV: 36 Gy). The patient who received IMRT is still alive with no evidence of recurrence and any neurologic complications for 1 year. Conclusion: To prevent recurrence of medulloblastoma in subfrontal-cribriform plate region, we need to pay close attention to the placement of eye blocks during the treatment. Once subfrontal recurrence has happened, IMRT may be a good choice for re-irradiation as a salvage treatment to maximize the differences of dose distributions between the normal tissues and target volume.

Image Watermarking for Copyright Protection of Images on Shopping Mall (쇼핑몰 이미지 저작권보호를 위한 영상 워터마킹)

  • Bae, Kyoung-Yul
    • Journal of Intelligence and Information Systems
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    • v.19 no.4
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    • pp.147-157
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    • 2013
  • With the advent of the digital environment that can be accessed anytime, anywhere with the introduction of high-speed network, the free distribution and use of digital content were made possible. Ironically this environment is raising a variety of copyright infringement, and product images used in the online shopping mall are pirated frequently. There are many controversial issues whether shopping mall images are creative works or not. According to Supreme Court's decision in 2001, to ad pictures taken with ham products is simply a clone of the appearance of objects to deliver nothing but the decision was not only creative expression. But for the photographer's losses recognized in the advertising photo shoot takes the typical cost was estimated damages. According to Seoul District Court precedents in 2003, if there are the photographer's personality and creativity in the selection of the subject, the composition of the set, the direction and amount of light control, set the angle of the camera, shutter speed, shutter chance, other shooting methods for capturing, developing and printing process, the works should be protected by copyright law by the Court's sentence. In order to receive copyright protection of the shopping mall images by the law, it is simply not to convey the status of the product, the photographer's personality and creativity can be recognized that it requires effort. Accordingly, the cost of making the mall image increases, and the necessity for copyright protection becomes higher. The product images of the online shopping mall have a very unique configuration unlike the general pictures such as portraits and landscape photos and, therefore, the general image watermarking technique can not satisfy the requirements of the image watermarking. Because background of product images commonly used in shopping malls is white or black, or gray scale (gradient) color, it is difficult to utilize the space to embed a watermark and the area is very sensitive even a slight change. In this paper, the characteristics of images used in shopping malls are analyzed and a watermarking technology which is suitable to the shopping mall images is proposed. The proposed image watermarking technology divide a product image into smaller blocks, and the corresponding blocks are transformed by DCT (Discrete Cosine Transform), and then the watermark information was inserted into images using quantization of DCT coefficients. Because uniform treatment of the DCT coefficients for quantization cause visual blocking artifacts, the proposed algorithm used weighted mask which quantizes finely the coefficients located block boundaries and coarsely the coefficients located center area of the block. This mask improves subjective visual quality as well as the objective quality of the images. In addition, in order to improve the safety of the algorithm, the blocks which is embedded the watermark are randomly selected and the turbo code is used to reduce the BER when extracting the watermark. The PSNR(Peak Signal to Noise Ratio) of the shopping mall image watermarked by the proposed algorithm is 40.7~48.5[dB] and BER(Bit Error Rate) after JPEG with QF = 70 is 0. This means the watermarked image is high quality and the algorithm is robust to JPEG compression that is used generally at the online shopping malls. Also, for 40% change in size and 40 degrees of rotation, the BER is 0. In general, the shopping malls are used compressed images with QF which is higher than 90. Because the pirated image is used to replicate from original image, the proposed algorithm can identify the copyright infringement in the most cases. As shown the experimental results, the proposed algorithm is suitable to the shopping mall images with simple background. However, the future study should be carried out to enhance the robustness of the proposed algorithm because the robustness loss is occurred after mask process.