• Title/Summary/Keyword: virtual experiment

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Evaluation of beam delivery accuracy for Small sized lung SBRT in low density lung tissue (Small sized lung SBRT 치료시 폐 실질 조직에서의 계획선량 전달 정확성 평가)

  • Oh, Hye Gyung;Son, Sang Jun;Park, Jang Pil;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.31 no.1
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    • pp.7-15
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    • 2019
  • Purpose: The purpose of this study is to evaluate beam delivery accuracy for small sized lung SBRT through experiment. In order to assess the accuracy, Eclipse TPS(Treatment planning system) equipped Acuros XB and radiochromic film were used for the dose distribution. Comparing calculated and measured dose distribution, evaluated the margin for PTV(Planning target volume) in lung tissue. Materials and Methods : Acquiring CT images for Rando phantom, planned virtual target volume by size(diameter 2, 3, 4, 5 cm) in right lung. All plans were normalized to the target Volume=prescribed 95 % with 6MV FFF VMAT 2 Arc. To compare with calculated and measured dose distribution, film was inserted in rando phantom and irradiated in axial direction. The indexes of evaluation are percentage difference(%Diff) for absolute dose, RMSE(Root-mean-square-error) value for relative dose, coverage ratio and average dose in PTV. Results: The maximum difference at center point was -4.65 % in diameter 2 cm size. And the RMSE value between the calculated and measured off-axis dose distribution indicated that the measured dose distribution in diameter 2 cm was different from calculated and inaccurate compare to diameter 5 cm. In addition, Distance prescribed 95 % dose($D_{95}$) in diameter 2 cm was not covered in PTV and average dose value was lowest in all sizes. Conclusion: This study demonstrated that small sized PTV was not enough covered with prescribed dose in low density lung tissue. All indexes of experimental results in diameter 2 cm were much different from other sizes. It is showed that minimized PTV is not accurate and affects the results of radiation therapy. It is considered that extended margin at small PTV in low density lung tissue for enhancing target center dose is necessary and don't need to constraint Maximum dose in optimization.

How Male and Female Job Seekers Differently React to Favorable/Unfavorable Diversity Cue on Job Postings (채용 공고에 제시된 유리/불리 다양성 단서에 대한 남성과 여성 구직자의 반응 차이)

  • Taekyeong Lee;Hyewon Lee;Jakyung Seo;Jeong Ryu;Young Woo Sohn
    • Science of Emotion and Sensibility
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    • v.26 no.2
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    • pp.67-84
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    • 2023
  • Gender diversity policies aim to reduce institutional discrimination in a male-dominated society and the underutilization of women in terms of the economy. Extant gender diversity literature has focused on gender diversity policies premised on women being treated as a minority. However, since women-centered occupational groups do exist, women cannot be considered an absolute minority. Therefore, we explored the gender difference in job seekers' reactions to a diversity policy favorable to men. The experiment divided participants into 2 (Gender: Male, Female) × 2 (Diversity: Favorable, Unfavorable), canvassing 329 college students (156 male, 173 female). Participants evaluated the organizational justice and organizational attractiveness of the virtual company by looking at the diversity cues presented in the job posting seeking new employees. As a result, it was confirmed that if the diversity cues presented in the job posting were favorable (vs. unfavorable) to the individual, the organization's distribution justice and procedural justice perceptions were generated differently according to the gender of the job seeker. Moreover, female job seekers perceived distribution justice and procedural justice as higher than male job seekers when they encountered diversity cues that were favorable (vs. unfavorable) to them. In addition, the relationship between diversity cues and organizational attractiveness was mediated by the perception of organizational justice, and this mediating effect was moderated by gender. For women, on the one hand, the mediating effect through the perception of distributive justice and procedural justice was significant in the relationship between diversity cues and organizational attractiveness. On the other hand, the mediating effect alone through the perception of procedural justice was significant for men. Our findings suggest that identical diversity managements are distinguished by individuals' social status or affiliation and may even result in differentiated behaviors.

A Study on Promoting Performing Art with Robot Actor : Focusing on EveR (로봇 배우를 활용한 공연예술 활성화 방안 연구 : '에버' 중심으로)

  • Lee, Yoo Sun;Kim, Dong Eon
    • (The) Research of the performance art and culture
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    • no.22
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    • pp.371-411
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    • 2011
  • In the twenty first century of rapid cultural change performing art requires new mode of expression based on imaginative power and creativity as well as establishing its own identity. The modern technological environment support this with advanced technology and bring about the expansion of reason from new experience. The introduction of digital media on artistic expression in particular, expands the physical ability of human body which is the main subject of performing art. A virtual body from digital technology is freed from physical boundaries and goes over space and time. It also suggests the possibility of new mode of communication with audience. This study aims at examining the subject of performing art and its digitalized movement focusing on EveR, the world's first professional robot actor. The robot actor which came on stage according to the new expression medium, a digital body, stands in need not only of technological value but also of cultural and artistic application for expression in art. In this endeavor to meet the demand, this study examines the development process and function of 'EveR' the robot actor. Also it searches into the performance of Ever which replaced human being as well as the historical significance of the title:the world's first. To be more specific, there is a example research on two performances:a pansori play "EveR is simply stunning(2009)" and children's play "The Robot Princess and Seven Dwarfs(2009)." Through this example research, it is enabled to anticipate the influence of robot actors on performing arts and to search for the better way of them to evolve. Furthermore, it aims at finding ways to create high value through promoting robot actors to be familiar to the public as well as supporting them to become active cultural contents. The performance with robotic technology is one of the artistic experiment that may cause the change of the future of performing art by actualizing technological imagination together with human body and machinery. As a consequence, it is expected that the meeting of performing art and robotic technology gives positive influence on activating performing art as one of the integrated cultural phenomenon which satisfies the taste of modern era. Moreover, this study may also be the beginning of the expansion of performing art to stretch to diverse field.

Evaluation of Ovary Dose of Childbearing age Woman with Breast cancer in Radiation therapy (가임기 여성의 방사선 치료 시 난소 선량 평가)

  • Park, Sung Jun;Lee, Yeong Cheol;Kim, Seon Myeong;Kim, Young Bum
    • The Journal of Korean Society for Radiation Therapy
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    • v.33
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    • pp.145-153
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    • 2021
  • Purpose: The purpose of this study is to evaluate the ovarian dose during radiation therapy for breast cancer in women of childbearing age through an experiment. The ovarian dose is evaluated by comparing and analyzing between the calculated dose in the treatment planning system according to the treatment technique and the measured dose using a thermoluminescence dosimeter (TLD). The clinical usefulness of lead (Pb) apron is investigated through dose analysis according to whether or not it is used. Materials and Methods: Rando humanoid phantom was used for measurement, and wedge filter radiation therapy, 3D conformal radiation therapy, and intensity modulated radiation therapy were used as treatment techniques. A treatment plan was established so that 95% of the prescribed dose could be delivered to the right breast of the Rando humanoid phantom 3D image obtained using the CT simulator. TLD was inserted into the surface and depth of the virtual ovary of the Rando hunmanoid phantom and irradiated with radiation. The measurement location was the center of treatment and the point moved 2 cm to the opposite breast from the center of the Rando hunmanoid phantom, 5cm, 10cm, 12.5cm, 15cm, 17.5cm, 20cm from the boundary of the right breast to the center of treatment and downward, and the surface and depth of the right ovary. Measurements were made at a total of 9 central points. In the dose comparison of treatment planning systems, two wedge filter treatment techniques, three-dimensional conformal radiotherapy, and intensity-modulated radiation therapy were established and compared. Treatments were compared, and dose measurements according to the use of lead apron were compared and analyzed in intensity-modulated radiation therapy. The measured value was calculated by averaging three TLD values for each point and converting using the TLD calibration value, which was calculated as the point dose mean value. In order to compare the treatment plan value with the actual measured value, the absolute dose value was measured and compared at each point (%Diff). Results: At Point A, the center of treatment, a maximum of 201.7cGy was obtained in the treatment planning system, and a maximum of 200.6cGy was obtained in the TLD. In all treatment planning systems, 0cGy was calculated from Point G, which is a point 17.5cm downward from the breast interface. As a result of TLD, a maximum of 2.6cGy was obtained at Point G, and a maximum of 0.9cGy was obtained at Point J, which is the ovarian dose, and the absolute dose was 0.3%~1.3%. The difference in dose according to the use of lead aprons was from a maximum of 2.1cGy to a minimum of 0.1cGy, and the %Diff value was 0.1%~1.1%. Conclusion: In the treatment planning system, the difference in dose according to the three treatment plans did not show a significant difference from 0.85% to 2.45%. In the ovary, the difference between the Rando humanoid phantom's treatment planning system and the actual measured dose was within 0.9%, and the actual measured dose was slightly higher. This did not accurately reflect the effect of scattered radiation in the treatment planning system, and it is thought that the dose of scattered radiation and the dose taken by CBCT with TLD inserted were reflected in the actual measurement. In dosimetry according to the with or without a lead apron, when a lead apron was used, the closer the distance from the treatment range, the more effective the shielding was. Although it is not clinically appropriate for pregnancy or artificial insemination during radiotherapy, the dose irradiated to the ovaries during treatment is not expected to significantly affect the reproductive function of women of childbearing age after radiotherapy. However, since women of childbearing age have constant anxiety, it is thought that psychological stability can be promoted by presenting the data from this study.