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Comparative Studies on Absorbed Dose by Geant4-based Simulation Using DICOM File and Gafchromic EBT2 Film (DICOM 파일을 사용한 Geant4 시뮬레이션과 Gafchromic EBT2 필름에 의한 인체 내 흡수선량 비교 연구)

  • Mo, Eun-Hui;Lee, Sang-Ho;Ahn, Sung-Hwan;Kim, Chong-Yeal
    • Progress in Medical Physics
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    • v.24 no.1
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    • pp.48-53
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    • 2013
  • Monte Carlo method has been known as the most accurate method for calculating absorbed dose in the human body, and an anthropomorphic phantom has been mainly used as a method of simulating internal organs for using such a calculation method. However, various efforts are made to extract data on several internal organs in the human body directly from CT DICOM files in recent Monte Carlo calculation using Geant4 code and to use by converting them into the geometry necessary for simulation. Such a function makes it possible to calculate the internal absorbed dose accurately while duplicating the actual human anatomical structure. Thus, this study calculated the absorbed dose in the human body by using Geant4 associating with DICOM files, and aimed to confirm the usefulness by compare the result with the measured dose using a Gafchromic EBT2 film. This study compared the dose calculated using simulation and the measured dose in beam central axis using the EBT2 film. The results showed that the range of difference was an average of 3.75% except for a build-up region, in which the dose rapidly changed from skin surface to the depth of maximum dose. In addition, this study made it easy to confirm the target absorbed dose by internal organ and organ through the output of the calculated value of dose by CT slice and the dose value of each voxel in each slice. Thus, the method that outputs dose value by slice and voxel through the use of CT DICOM, which is actual image data of human body, instead of the anthropomorphic phantom enables accurate dose calculations of various regions. Therefore, it is considered that it will be useful for dose calculation of radiotherapy planning system in the future. Moreover, it is applicable for currently-used several energy ranges in current use, so it is considered that it will be effectively used in order to check the radiation absorbed dose in the human body.

COMPARATIVE STUDY ON THE EARLY DETECTION OF ENAMEL LESIONS USING DIFOTI AND LASER FLUORESCENCE (Digital Imaging Fiber-Optic Trans-Illumination과 Laser Fluorescence를 이용한 법랑질 우식증의 조기 진단에 관한 비교 연구)

  • Maeng, Myoung-Ho;Kim, Seung-Oh;Kim, Jong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.33 no.2
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    • pp.207-220
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    • 2006
  • The newly developed equipments for the early detection of carious lesion are LFD (laser fluorescence device), Ultrasonic diagnostic system, CLSM(confocal laser scanning microscopy), QLF(quantitative light-induced fluorescence) and DIFOTI (digital imaging fiber-optic trans-illumination) system. In this study, DIFOTI system and LFD were used for the detection of early enamel caries. Twenty five primary teeth extracted from twenty one children at around the dentitional exchanging period were selected as samples. The results obtained from DIFOTI imaging and LFD measurement were compared with those of CLSM and comprehensive evaluations were made for the diagnostic capacity of each device. In vitro test, 40 sample teeth with their buccal & lingual surface formed by a window of $2{\times}3mm$ in diameter were immersed in artificial demineralizing solution for the period of 4, 8, 12 and 16 days. The results obtained from the experimental groups (DIFOTI, LFD) were compared to control group (CLSM) and we have reached to the following conclusions. 1. The sensitivity and specificity of DIFOTI system operated in oral environment was 88.2% and 76.9% respectively. 2. The sensitivity and specificity of LFD measured in oral environment was 76.5% and 69.2% respectively. 3, Regression analysis on the light transparent rate of DIFOTI showed its decrease according to the length of primary enamel decalcification performed in vitro(r=-0.96, p<0.05). 4. No statistically significant difference between LFT measurement and the length of in vitro decalcification was found in regression analysis (p>0.05). 5. The correlation coefficient of DIFOTI image transparent rate and the lesion depth of CLMS was -0.6988 (p<0.05), whereas no statistically significant difference was found for LFD measurement.

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EFFECT OF CROSS-SECTIONAL AREA OF 6 NICKEL-TITANIUM ROTARY INSTRUMENTS ON THE FATIGUE FRACTURE UNDER CYCLIC FLEXURAL STRESS: A FRACTOGRAPHIC ANALYSIS (반복 굽힘 스트레스 하에서 전동식 니켈-티타늄 파일의 단면적의 크기가 피로파절에 미치는 영향 : 파절역학 분석)

  • Hwang, Soo-Youn;Oh, So-Ram;Lee, Yoon;Lim, Sang-Min;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • v.34 no.5
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    • pp.424-429
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    • 2009
  • This study aimed to assess the influence of different cross-sectional area on the cyclic fatigue fracture of Ni-Ti rotary files using a fatigue tester incorporating cyclical axial movement. Six brands of Ni-Ti rotary files (ISO 30 size with. 04 taper) of 10 each were tested: Alpha system (KOMET), HeroShaper (MicroMega), K3 (SybronEndo), Mtwo (VDW), NRT (Mani), and ProFile (Dentsply). A fatigue-tester (Denbotix) was designed to allow cyclic tension and compressive stress on the tip of the instrument. Each file was mounted on a torque controlled motor (Aseptico) using a 1:20 reduction contra-angle and was rotated at 300 rpm with a continuous, 6 mm axial oscillating motion inside an artificial steel canal. The canal had a $60^{\circ}$ angle and a 5 mm radius of curvature. Instrument fracture was visually detected and the time until fracture was recorded by a digital stop watch. The data were analyzed statistically. Fractographic analysis of all fractured surfaces was performed to determine the fracture modes using a scanning electron microscope. Cross-sectional area at 3 mm from the tip of 3 unused Ni-Ti instruments for each group was calculated using Image-Pro Plus (Imagej 1.34n, NIH). Results showed that NRT and ProFile had significantly longer time to fracture compared to the other groups (p < .05). The cross-sectional area was not significantly associated with fatigue resistance. Fractographycally, all fractured surfaces demonstrated a combination of ductile and brittle fracture. In conclusion, there was no significant relationship between fatigue resistance and the cross-sectional area of Ni-Ti instruments under experimental conditions.

An Approach to Value Discourse on Translation of Korean Chinese written Classics (한국 한문고전 번역의 가치담론과 번역자상에 대한 시론적 접근)

  • Nam, Ji Man
    • (The)Study of the Eastern Classic
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    • no.73
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    • pp.445-473
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    • 2018
  • This article deals with the reason for translating Korean Chinese written classics and the image of the person performing the translation. The scope of the research was restricted to South Korea and the translation value of translating the Korean classical texts from the 1960s to the 2018. In the 1960s and 1970s, the discourse of national culture and the Classical Sinology(漢學) discourse centered around the Minjokmunwhachujinhwe(民族文化推進會, National Culture Promotion Association). The discourse of the national culture was paired with the modernization, and the discourse of Classical Sinology(漢學) discourse was a certain antagonism to the discourse of modernization. The translator stereotype in this periods was close to a Classical Sinology(漢學) who could wright Korean letters. The discourse of the national culture led to the establishment of The Academy of Korean Studies by pairing with the discourse of the spiritual culture, and then changed into Korean study discourse in the 1980s. Since the mid 80s, the theory of translation has been introduced byo Kim Yong-ok. The translation of the Chosun dynasty annals, which started in the 70s, made the classical translation discourse in the classical translation field into the national project efficiency discourse. To the Early achievement of state-led gigantic project through group translation, they emphasized coherence and efficiency. On the contrary, the individuality of the translators and aspects of in-depth research have weakened. This discourse also influenced until the early 2000s. These large translation projects were produced by professional translator group. With the establishment of the Institute for the Translation of Korean Classics(Hankuk Kojon Bunyukwon) in 2007, he foundation for the stability of the classical translation business was established, and the classical translation discourse was shifted to the academic discourse centered on classical translation sudies. This discussion was expanded to the request of the establishment of an academic institution called the Classical Translation Graduate School, with a discussion on the academic identities of classical translation studies. The imagies of translators, paired with the academic discourse of this period, and that the classical translators must be classical scholars and translators, are begun to be requested. Thus, the classical translation value discourse changed with the passage of time, and the imagies of classical translators have been changed accordingly.

The Korean Girl Group Kara's Differentiation Strategy Which Overcome the Trilemma and Led to the Great Reversal Success (삼중고 탈피 후 대역전의 성공을 이끈 걸 그룹'카라'의 차별화 전략)

  • Kim, Jeong-Seob
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.2
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    • pp.169-178
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    • 2021
  • The Korean girl group "Kara" has suffered the trilemma of its de facto failure to debut, the crisis of team breakup, and the CEO crisis of the agency. But the group has made an outstanding achievement in the history of Korean pop music after overcoming all odds. Their success strategy has never been disclosed by insiders involved in Kara's total music projects. This study has been carried out in the analysis of the strategy to provide academic implications and to honor the contribution of the late CEO Ho-yeon Lee and Kara's key member Ha-ra Gu. Therefore, between Nov. and Dec. 2020, we conducted in-depth interviews with managers, composers, stylists and Ha-ra Gu(Only in 2019, before her death) who took part in the project. The research model is set up by combining Porter's Competitive Advantage Strategy and the music value chain model into categories of "Product Innovation Differentiation (PD)" (producing, album production, performance activities) and "Marketing Differentiation (MD)" (market targeting, image specialization, promotion and communication). The analysis showed that the PD focused on complete rediscovered harmonization and revalued members' personality and sincerity with peppy songs and dainty dances as well as emission of "bright energy" which caused healing effects instead of mimicking other star singers recklessly. In terms of MD, they selected Japan's 10-20s as their main market, increasing intimacy with fans and media with the image of cute+pretty+classy+sexy. The result suggests that Poter's differentiation can function as a meaningful strategy frame in the fostering, hit, and revival of idol groups. In addition, it reaffirmed that spontaneous and passionate activities of early-stage or celebrity fan may serve as a valid catalyst for realizing differentiation, as Kara's caller of Japanese actor Gekidan Hitori caused a strong "priming effect" that drove Kara's unexpected wonderful success in Japan.

A Study on the Interactive Narrative - Focusing on the analysis of VR animation <Wolves in the Walls> (인터랙티브 내러티브에 관한 연구 - VR 애니메이션 <Wolves in the Walls>의 분석을 중심으로)

  • Zhuang Sheng
    • Trans-
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    • v.15
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    • pp.25-56
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    • 2023
  • VR is a dynamic image simulation technology with very high information density. Among them, spatial depth, temporality, and realism bring an unprecedented sense of immersion to the experience. However, due to its high information density, the information contained in it is very easy to be manipulated, creating an illusion of objectivity. Users need guidance to help them interpret the high density of dynamic image information. Just like setting up navigation interfaces and interactivity in games, interactivity in virtual reality is a way to interpret virtual content. At present, domestic research on VR content is mainly focused on technology exploration and visual aesthetic experience. However, there is still a lack of research on interactive storytelling design, which is an important part of VR content creation. In order to explore a better interactive storytelling model in virtual reality content, this paper analyzes the interactive storytelling features of the VR animated version of <Wolves in the walls> through the methods of literature review and case study. We find that the following rules can be followed when creating VR content: 1. the VR environment should fully utilize the advantages of free movement for users, and users should not be viewed as mere observers. The user's sense of presence should be fully considered when designing interaction modules. Break down the "fourth wall" to encourage audience interaction in the virtual reality environment, and make the hot media of VR "cool". 2.Provide developer-driven narrative in the early stages of the work so that users are not confused about the ambiguous world situation when they first enter a virtual environment with a high degree of freedom. 1.Unlike some games that guide users through text, you can guide them through a more natural interactive approach that adds natural dialog between the user and story characters (NPC). Also, since gaze guidance is an important part of story progression, you should set up spatial scene user gaze guidance elements within it. For example, you can provide eye-following cues, motion cues, language cues, and more. By analyzing the interactive storytelling features and innovations of the VR animation <Wolves in the walls>, I hope to summarize the main elements of interactive storytelling from its content. Based on this, I hope to explore how to better showcase interactive storytelling in virtual reality content and provide thoughts on future VR content creation.

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.

Strength Evaluation of Pinus rigida Miller Wooden Retaining Wall Using Steel Bar (Steel Bar를 이용한 리기다소나무 목재옹벽의 내력 평가)

  • Song, Yo-Jin;Kim, Keon-Ho;Lee, Dong-Heub;Hwang, Won-Joung;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.4
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    • pp.318-325
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    • 2011
  • Pitch pine (Pinus rigida Miller) retaining walls using Steel bar, of which the constructability and strength performance are good at the construction site, were manufactured and their strength properties were evaluated. The wooden retaining wall using Steel bar was piled into four stories stretcher and three stories header, which is 770 mm high, 2,890 mm length and 782 mm width. Retaining wall was made by inserting stretchers into Steel bar after making 18 mm diameter of holes at top and bottom stretcher, and then stacking other stretchers and headers which have a slit of 66 mm depth and 18 mm width. The strength properties of retaining walls were investigated by horizontal loading test, and the deformation of structure by image processing (AlCON 3D OPA-PRO system). Joint (Type-A) made with a single long stretcher and two headers, and joint (Type-B) made with two short stretchers connected with half lap joint and two headers were in the retaining wall using Steel bar. The compressive shear strength of joint was tested. Three replicates were used in each test. In horizontal loading test the strength was 1.6 times stronger in wooden retaining wall using Steel bar than in wooden retaining wall using square timber. The timber and joints were not fractured in the test. When testing compressive shear strength, the maximum load of type-A and Type-B was 130.13 kN and 130.6 kN, respectively. Constructability and strength were better in the wooden retaining wall using Steel bar than in wooden retaining wall using square timber.

The Images of Unmarried Single Women as seen from the Viewpoint of Married Men and Women - Focusing on Stereotypes of Unmarried Single Women - (기혼자가 인식하는 30~40대 미혼 여성의 이미지 - 미혼 여성에 대한 고정관념을 중심으로 -)

  • Ryu, Kyung-Hee;Wang, Seok-Soon
    • Journal of Korean Home Economics Education Association
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    • v.22 no.3
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    • pp.37-54
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    • 2010
  • In this work, we investigated the images of (unmarried) single women as seen from the viewpoint of married men and women. In-depth interviews were conducted with twenty-seven (married) men and women of ages from twenties to sixties. By carrying out a content-analysis on the interview results, we could extract three different thematic types of images on single women, which are (1) single women seeking some outlet of their passion instead of forming a family, (2) single women who are enjoying a life of unbound liberty, unlike married men and women, and (3) single women who have distinct personalities from married men and women. Each of these three thematic types could be further classified into narrower themes of specific images. From the first theme of single women who are looking for some outlet of their passion instead of forming a family, one could extract two specific image types in which the single women choose their work as the main outlet of their passion, or else they choose self-development. From the second theme of single women who are leading a life of unbound liberty, four different specific types were found, which are single women with sexual freedom, single women enjoying liberty from the bondage of a family, single women who can freely choose men to go out with, single women who have privileges to enjoy consumption and leisure life only for themselves. From the third theme of single women who have distinct personalities from married men and women, four different types of images were found, that are single women who want to avoid the hard reality of marriage life, single women who are selfish and self-assertive and leading a life that is self-centered or one that is centered around communities of only singles, single women who have secret feelings of emptiness and loneliness, and finally single women who can not find satisfaction in their life style. The images of married men and women on (unmarried) single women are based on the perception that 'those single women are different from us because they are not married'. That is, married men and women look upon the life of single women from the perspective of marriage life that they are experiencing.

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A Study on Detailed Bathymetry and Geophysical Characteristics of the Summit of the Dokdo Volcano (독도 화산체 정상부해역의 정밀해저지형 및 지구물리학적 특성 연구)

  • Kim, Chang Hwan;Park, Chan Hong;Lee, Myoung Hoon;Choi, Soon Young;Jou, Hyeong Tae
    • Economic and Environmental Geology
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    • v.45 no.6
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    • pp.685-695
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    • 2012
  • We studied the detailed bathymetry and the geophysical characteristics of the summit of the Dokdo volcano using mutibeam echosounding and geophysical survey data. The bathymetry around the main east and west islets of the Dokdo volcano shows very shallow within about 10 m water depth. From near islets to about 30 m b.s.l., the shallow water area has very steep slope and many irregular sunken rocks. The area from about 30 m to about 80 m b.s.l. shows gentle rises and falls, and less steep slope. The area from 80 m b.s.l. has gradually flat undulation and smooth slope seabaed and is extended to offshore. The main islets of the Dokdo volcano and the rocky sea bottom elongated from the islets might be the residual part of the eroded and collapsed main crater of the Dokdo volcano. The bathymetry and the seafloor image(from backscattering) data show small craters, assumed to be formed by the eruption of later volcanism. The seafloor images propose that, except some areas with shallow sand sedimentary deposits, there are typical rocky bottom such as rocky protrusions and lack of sediments in the main morphology of the survey area. The stepped slopes of the seabed are deduced to be submarine terraces. The several prominent submarine terraces are found at the summit of the Dokdo volcano, suggesting repetition of sea level changes(transgressions and regressions) in the Quaternary. The results of the magnetic anomaly and the analytic signal have a good coherence with other geophysical consequences regarding to the location of the residual crater.