• Progress in Medical Physics
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• v.14 no.1
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• pp.15-19
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• 2003

High dose rate (HDR) brachytherapy for treating a cervix carcinoma has become popular, because it eliminates many of the problems associated with conventional brachytherapy. In order to improve the clinical effectiveness with HDR brachytherapy, a dose calculation algorithm, optimization procedures, and image registrations need to be verified by comparing the dose distributions from a planning computer and those from a phantom. In this study, the phantom was fabricated in order to verify the absolute doses and the relative dose distributions. The measured doses from the phantom were then compared with the treatment planning system for the dose verification. The phantom needs to be designed such that the dose distributions can be quantitatively evaluated by utilizing the dosimeters with a high spatial resolution. Therefore, the small size of the thermoluminescent dosimeter (TLD) chips with a dimension of <1/8"and film dosimetry with a spatial resolution of <1mm used to measure the radiation dosages in the phantom. The phantom called a pelvic phantom was made from water and the tissue-equivalent acrylic plates. In order to firmly hold the HDR applicators in the water phantom, the applicators were inserted into the grooves of the applicator holder. The dose distributions around the applicators, such as Point A and B, were measured by placing a series of TLD chips (TLD-to-TLD distance: 5mm) in the three TLD holders, and placing three verification films in the orthogonal planes. This study used a Nucletron Plato treatment planning system and a Microselectron Ir-192 source unit. The results showed good agreement between the treatment plan and measurement. The comparisons of the absolute dose showed agreement within $\pm$4.0 % of the dose at point A and B, and the bladder and rectum point. In addition, the relative dose distributions by film dosimetry and those calculated by the planning computer show good agreement. This pelvic phantom could be a useful to verify the dose calculation algorithm and the accuracy of the image localization algorithm in the high dose rate (HDR) planning computer. The dose verification with film dosimetry and TLD as quality assurance (QA) tools are currently being undertaken in the Catholic University, Seoul, Korea.

• Progress in Medical Physics
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• v.21 no.3
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• pp.253-260
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• 2010

Most brachytherapy treatment planning systems employ a dosimetry formalism based on the AAPM TG-43 report which does not appropriately consider tissue heterogeneity. In this study we aimed to set up a simple Monte Carlo-based intracavitary high-dose-rate brachytherapy (IC-HDRB) plan verification platform, focusing particularly on the robustness of the direct Monte Carlo dose calculation using material and density information derived from CT images. CT images of slab phantoms and a uterine cervical cancer patient were used for brachytherapy plans based on the Plato (Nucletron, Netherlands) brachytherapy planning system. Monte Carlo simulations were implemented using the parameters from the Plato system and compared with the EBT film dosimetry and conventional dose computations. EGSnrc based DOSXYZnrc code was used for Monte Carlo simulations. Each $^{192}Ir$ source of the afterloader was approximately modeled as a parallel-piped shape inside the converted CT data set whose voxel size was $2{\times}2{\times}2\;mm^3$. Bracytherapy dose calculations based on the TG-43 showed good agreement with the Monte Carlo results in a homogeneous media whose density was close to water, but there were significant errors in high-density materials. For a patient case, A and B point dose differences were less than 3%, while the mean dose discrepancy was as much as 5%. Conventional dose computation methods might underdose the targets by not accounting for the effects of high-density materials. The proposed platform was shown to be feasible and to have good dose calculation accuracy. One should be careful when confirming the plan using a conventional brachytherapy dose computation method, and moreover, an independent dose verification system as developed in this study might be helpful.

• Progress in Medical Physics
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• v.15 no.2
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• pp.63-69
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• 2004

HDR brachytherapy administers a large dose of radiation in a short time compare with LDR, and its optimization for treatment is related to several complex factors, such as physical, radiation and optimization algorithms, so there is a need for these to be verified for accurate dose delivery. In our approach, a previous study concerning the phantom for dose verification has been modified, and a new pelvic phantom fabricated for the purpose of localization, including a structure enabling the use of a CT or MRI system. In addition, a comparison study was performed to verify an orthogonal method that is commonly used for brachytherapy localization by comparing target coordinates from a CT system. Since the developed phantom was designed to simulate the clinical setups of cervix cancer, it included an air-filled bladder and a rectum structure shaped sphere and cylinder An N-shaped localizer was used to obtain precision coordinates from both CT and films. Moreover, the IDL 5.5 software program for Windows was used to perform coordinates analysis based on an orthogonal algorithm. The film results showed differences within 1.0 mm of the selected target points compare with the CT coordinates. For these results, a Plato planning system (Nucletron, Netherlands) could be independently verified using this phantom and software. Furthermore, the new phantom and software will be efficient and powerful qualify assurance (QA) tools in the field of brachytherapy QA.

• Cartoon and Animation Studies
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• s.29
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• pp.103-128
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• 2012

Study about existence of illusion which human beings feel from imitated image based reality have been continuing by copy theory and conventionalism for a long time. Traditional copy theory which had controlled representation theory from plato have explained illusion by similarity of image and representation objects. According to copy theory, image is natural sign unlike language but the late in the 20th century, conventionalism from N, Goodman insists they are not any special similarity between image and representation objects. They insist image and conventional sign just as language. These opposit theory rearranged conventionalism by the entrance on the cognitive science. The copy theory couldn't explain the problem of representational gap between reality and duplication, but photo media makes new paradigm about theory of the illusion. The problem of representational gap was disappeared by CGI images on the base of digital media. We are exposed exquisite duplication for a example, movie, advertisement, printings. Sometimes duplications are more real than the original works. Digital is a non-material object by 0 and 1. Specially real lighting skill and mechanism are copied perfectly by photon mapping skills and the duplications are produced more real than the original works. By disappearance of representational gap, we need new theory model for explaining of digital illusion and copy theory can be the key.

• Journal of Ocean Engineering and Technology
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• v.13 no.3 s.33
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• pp.68-76
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• 1999

The welding residual stresses produced by the welding frequently caused a crack and promote stress corrosion etc. in HAZ(heat affected zone) contained with external load and weakness of material. Therefore, PWHT(post welding heat treatment) is widely used to reduce wekdubg residuss, to relax hardening of heat affected zone and to get rid of impurity. In this study, in order to define the effect on shappes of T-welded joint, during the post welding heat treatment, we have carried out numerical analyses on the several test pieces by using computer program which was based on thermal-elasto-plato-plasto-creep theories for the study. The main results obtained form this study is as follows: 1) The mechanical difference for change the thickness of plate and groove angle did not appear. 2) The distribution modes of welding residual stresses are same on the all test specimens during the post welding heat treatment. 3) In a mecharical point of view, minimum groove groove angle($40^{circ}$) is more suitable than maximum groove angle($60^{circ}$). 4) Therefore, it is appropriate to minimize the size of groove shape in strength and safety.

• Korean Institute of Interior Design Journal
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• v.22 no.2
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• pp.100-111
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• 2013

The theories of optical/haptic perception provide us contrasting insights into the perception of space in movie and architecture. Through the lenses of these theories, this study aims to analyse the optical and haptical aspect of the medieval library of the film, The Name of the Rose. The dominance of vision over the other senses has been maintained by many philosophers, such as Plato, Aristotle, and Aquinas, and this trend leads to the development of the hierarchical and perspective space of Renaissance and Modern Architecture. Those conceptions of optical space help us not only identify space as clear and distinct three-dimensional entity but also separate the subject and the object. However, tactile/haptic perception is more useful to explain the experience of film and contemporary architecture than optical perception. This haptic space is developed by Alois Riegl, Walter Benjamin, and Gilles Deleuze. This study intends to search for the difference between two perceptions on the architectural space of the movie, examine the relation between architecture and human, space and user.

• Health Policy and Management
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• v.9 no.3
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• pp.149-169
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• 1999

A purpose of this study is to understand Platonic View of Health in $\boxDr$Politeia$\boxUl$. Though Plato was not so much a doctor as a philosopher. he had health care of children at heart. He mapped out an ideal type of nation in $\ulcorner$Politeia$\lrcorner$. and he founded a Akademeia in order to realize his dreams. In his course of education. he put emphasis on the problem of health. He extended poetry education for mental health and physical education for physical health. He placed high value on mental health above physical health. and poetry education corresponds to our reading education of today. He perceived that reading had a considerable influence on mental health promotion. According to his assertion, life style, too. had something to do with health condition. To lead a simple. temperate life makes one' health promote, on the other hand, to lead a complicated, intemperate life makes one' health injure. Morever, he approved of a eugenic marriage and the law of jungle. If one is unable to take care of one' health oneself. he would rather die than live. We cannot accept this proposal by general consent. but we cannot be too careful of our health. We can draw out a philosophy of health from Platonic View of Health. For example. the importance of health education. the preference of mental health. the influence of reading education. and responsibility for self-care, etc. We need to establish a philosophy of health scientifically by lasting study of records.

• Journal of Educational Research in Mathematics
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• v.8 no.2
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• pp.553-563
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• 1998

In this thesis, I examined Bruner's EIS theory from the viewpoint of epistemology based on Piaget's genetic epistemology. Although Bruner's ideal thought which insisted ‘to teach the structure’accepted Piaget's theory in the methodology of realization, it is different from Piaget in understanding knowledge. The difference is shown from understanding the meaning of ‘structure’. Piaget's concept of structure is something that has overcome the realistic viewpoint of the traditional epistemology and is reconstructed through endless self-regulative transformational process. However Bruner's is used as a realistic meaning as we can see in the Plato's recollection theory. Therefore Piaget's ‘stage of development’means the difference of structure which lies in the generative process and it includes the qualitive difference of level. On the other hand, Bruner, who is trying to translate and suggest the fixed structure to the children understood Piaget's stage of development as the difference in the ways of representation. Piaget's operational constructivism insists that the children should ‘construct’the knowledge through their activity, and especially in case of the lohico-mathematical recognition, the source should be internalized activity, that is, operation. In view of this assertion, Burner's idea which insists to accept the structure of knowledge as a fixed reality and to suggest the translated representation proper to the cognitive structure of the children to teach them, has a danger of emphasizing only the functional aspects to deliver the given knowledge ‘quickly’. And it also has the danger of damaging ‘the nature of the knowledge’in the translated knowledge.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.114-121
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• 2012

Gilles Deleuze is a philosopher who replaces the world of representation defined as supremacy of identity with the contemporary reason of non-representation in the history of western philosophy that wants to transcend Plato. Deleuze developed his own philosophical concept through philosophical reason and encounter with arts, for which reason he exerted a great influence on artists and architects in diverse fields. Particularly, 'Logic of Sensation' published in 1981 considers the non-representation painting approach through Francis Bacon's painting theory defined as 'invisible force's visibility'. And it is considered that SANAA's architecture among many contemporary architects accepted the essence of Deleuze's philosophy and continuously reflects it on projects. Hence, objective of the present study is to consider how the non-representation constituting a root for Deleuze's reason has been indicated in paintings and architecture through examining the works by Bacon and SANAA. First, a theoretical consideration will be directed to non-representation, followed by an analysis of Bacon's painting works and SANAA's architecture projects from the viewpoints of the force of isolation, the force of transformation, the force of dissipation and the force of time dealt with by Deleuze in 'Logic of Sensation'. Finally, through such analysis, the characteristics of Deleuze's non-representation indicated in architecture and paintings will be derived.

• Journal of Korea Game Society
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• v.21 no.3
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• pp.25-38
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• 2021

This study examines the possibility of development into a place of existential human meaning and the process of formation of placeness based on the Simulacre theory of digital game space. First of all, the game space related to humans was reinterpreted into the Simulacra theory of Plato, Jean Baudrillard, and Gilles Deleuze, and typified into three simulacra of spaces. The formation process of placeness in the game space is presented by linking the simulacra of space, place theory, and the user's game experience that were reinterpreted. It is hoped that this will contribute to exploring the aspect of the placeness of digital game spaces for authentic experiences of various media.