• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.249-254
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• 2021

This study is about the class model that can demonstrate the modeling ability using the spatial perception capability on basic modeling required for jewelry design majors and the most important perspective method in jewelry design. The outputs were obtained by presenting the topics for creative activities to students after theoretical explaining how to present a spatial sense and presenting practical classes on basic shapes, stereoscopic shapes and perspective methods. While the existing basic molding classes were only practical classes, this study presented students with a class model that allows them to use creativity, basic perspective, and spatial sense together. And it was found out evaluation method that both students and professors can relate to each other through the intensive education effects and clear evaluation standards. I hope that this paper will continue to study more diverse materials and convergent class models.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.11 s.188
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• pp.7-16
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• 2006

• 대한두경부종양학회:학술대회논문집
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• 1998.11a
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• pp.282.2-283
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• 1998

• Progress in Medical Physics
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• v.16 no.4
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• pp.166-175
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• 2005

The purpose of this study is to develop the optimization method for adjusting the film isocenter shift and to suggest the quantitative acceptable criteria for film dosimetry after optimization In the dynamic conformal arc radiation therapy (DCAR). The DCAR planning was peformed In 7 patients with brain metastasis. Both absolute dosimetry with ion chamber and relative film dosimetry were peformed throughout the DCAR using BrainLab's micro-multileaf collimator. An optimization method for obtaining the global minimum was used to adjust for the error in the film isocenter shift, which is the largest pan of systemic errors. The mean of point dose difference between measured value using ion chamber and calculated value acquired from planning system was $0.51{\pm}0.43\%$ and maximum was $1.14\%$ with absolute dosimetry These results were within the AAPM criteria of below $5\%$. The translation values of film isocenter shift with optimization were within ${\pm}$1 mm in all patients. The mean of average dose difference before and after optimization was $1.70{\pm}0.35\%$ and $1.34{\pm}0.20\%$, respectively, and the mean ratios over $5\%$ dose difference was $4.54{\pm}3.94\%$ and $0.11{\pm}0.12\%$, respectively. After optimization, the dose differences decreased dramatically and a ratio over $5\%$ dose difference and average dose difference was less than $2\%$. This optimization method is effective in adjusting the error of the film isocenter shift, which Is the largest part of systemic errors, and the results of this research suggested the quantitative acceptable criteria could be accurate and useful in clinical application of dosimetric verification using film dosimetry as follows; film isocenter shift with optimization should be within ${\pm}$1 mm, and a ratio over $5\%$ dose difference and average dose difference were less than $2\%$.

• The Journal of Korean Society for Radiation Therapy
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• v.12 no.1
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• pp.144-146
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• 2000

삼차원 입체조형치료는 정상조직의 장해를 최소화하고 종양부위에 집중적으로 조사할 수 있는 장점을 가지고 있어 임상 적용범위가 넓어지고 있다. 일반적으로 정상조직의 장해를 줄이기 위해 다양한 방사선 조사방향이 사용되며 특히 비 동일면상에서의 조사가 많이 이루어진다. 따라서 couch 회전이 동반되며 couch는 선형가속기의 다른 기계적 오차보다 많은 오차를 유발할 수 있는 잠재적인 위험을 안고 있다. 저자는 이러한 오차의 정도를 파악하고 이를 개선할 수 있는 방법에 대해 알아보고자 했다. couch 회전에 따른 Isocenter의 변화를 평가하기 위해 3대(Primus, Simens, USA/CL600c & 2100c, Varian, USA)의 선형가속기를 이용하였으며 이중 1대의 장비에는 couch 회전시 오차를 줄이기 위해 고안된 couch 고정장치를 장착하였다. 환자가 테이블에 부하를 주지 않은 상태에서 회전을 실시하여 Isocenter의 변화를 측정하고 환자가 테이블에 누워있는 상황을 재현하기 위해 human phantom을 위치시킨 후 동일한 회전검사를 실시하여 각각의 오차를 비교 분석하였다. 각 실험은 10회씩 반복 측정하여 평균치를 얻었으며 오차의 분석은 AAPM 권고안인 오차중심의 반경으로 표현했다. 3대의 선형가속기를 이용하여 얻은 결과 테이블에 부하를 주지 않은 상태의 회전오차는 평균 2mm, 3.2mm, 2mm로 측정되었으며 휴먼 phantom을 올려놓고 부하를 준 상태에서의 오차는 평균 2.1mm, 4mm, 2.1 mm이였다. 또한 고정장치를 이용한 상태에서의 평균오차는 1.9mm로 나타났다. 삼차원 입체조형치료 시 couch 회전에 따른 Isocenter 오차는 장비의 종류 및 작업자의 사용방법에 따라 다르게 나타났으며 테이블의 부하가 클수록 많은 오차를 보였다. 또한 couch 고정장치를 부착한 장비에서의 결과치 만이 AAPM에서 권고하는 오차의 한계에(${\le}2mm$) 들어감을 알 수 있었다. 따라서 정기적인 QA가 필수적이며 Couch Locking System과 같이 오차를 줄일 수 있는 보조장치의 부착이 많은 도움을 줄 것으로 생각된다. 아울러 이러한 오차를 보정할 수 있는 방법이 강구되어야 할 것으로 사료된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.775-780
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• 2007

Rapid Prototyping (RP) is a technology that produces prototype parts from 3D computer aided design model data without intermediate processing technology rapidly. CAD model data are created from 3D object digitizing systems but presented just as 2D data when they are printed as a hard copy or displayed on a monitor. However, Rapid Prototyping Technology fabricates 3D objects the same that CAD data because it transforms designed 3D CAD data into 2D cross sectional data, and manufactures layer by layer deposition sequentially. But most of all the small and medium scale companies which produce a toothbrush, a toy and such like provisions are in difficult situations to buy RP system because it is very expensive. In this paper, we propose a 3D control system adopting open source programs for implementing Rapid Prototyping Technology in order that RP system can be purchase at a moderate price.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.329-334
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• 2021

This thesis examined the characteristics of constructivism that brought about expanded expression of modern jewelry, and also organized how the constructivism was utilized for jewelry. The objective of this study is to examine the attempts of new materials based on constructivism and various expression styles, and also to understand the concept of constructivism developed into an element of complex formative expression. For this, this study organized the characteristics of constructivism that was initially expanded from Bau Haus in the aspect of expression through the composition of material and space, and also analyzed the jewelry artists' methods and attempts to express various materials. As a result, the constructivism showed the expansion of the formativeness of jewelry in the formative aspect of steric expression and in-depth concept through the composition of architectural pattern, visualization of space, and use of other materials, which becomes an example of basic formative element of modern jewelry design. However, it is limited to the material formative element of constructivism, so the expansion of design would be needed. Thus, there should be more researches on the expansion of various jewelry designs that could express the philosophy of constructivism.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.147-154
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• 2022

This paper evaluated visual function and stereoacuity function after surgery for intermittent exotropia. Subjects of this study were 18 patients (male: n = 10, female: n = 8) mean aged 12.06±5.43 years diagnosed with intermittent exotropia who underwent strabismus surgery. Of these subjects, 72.2% of the subjects underwent strabismus surgery once and 27.8% had it twice. Visual function and stereoacuity function were tested for these subjects. For data analysis, frequency analysis, cross analysis, and correlation analysis were used, and statistical significance was set at p<.05. Regarding the deviation state after strabismus surgery, exodeviation accounted for the most(72.2%), followed by diplopia(50.0%) and suppression(33.3%) for distance sensory fusion. Regarding near sensory fusion, fusion(50.0%) accounted for the most, followed by diplopia(44.4%). After strabismus surgery, subjects with distance stereoacuity blindness were the most at 61.1% and there were no subjects with a normal range of 40-60 arcsec. Near stereoacuity blindness subjects accounted for 33.3% and subjects with 40-60 arcsec accounted for 1.1%. Even after surgery for intermittent exotropia, there were some areas that did not improve in deviation state, stereoacuity, or sensory fusion. Therefore, it is necessary to manage and control strabismus through non-surgical methods before and after surgery for intermittent exotropia.

• Radiation Oncology Journal
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• v.26 no.2
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• pp.91-95
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• 2008

Purpose: To evaluate the response and survival rate after three-dimensional conformal radiation therapy(3D-CRT) of patients with a solitary sternal relapse of breast cancer. Materials and Methods: Seventeen patients between May 1996 and June 2005 were evaluated with the salvage 3D-CRT treatment of a solitary sternal relapse of breast cancer. The treatment fields included the gross tumor volume with 2 cm margins. The total radiation dose was $35.0{\sim}61.5$ Gy(biologic effective dose of $43.7{\sim}76.9Gy_{10}$ using an $\alpha/\beta$ ratio of 10 Gy), with a daily dose of $1.8{\sim}3.0$ Gy. The tumor response was evaluated by the change in maximum tumor size via follow up CT scans $1{\sim}3$ months after the completion of treatment. Results: An objective tumor response was achieved in all patients, with a complete response in 5 patients and a partial response in 12 patients. The 5-year overall survival rate was 51.9%(median survival time: 27 months), and the most important factor affecting overall survival was the disease-free interval(interval from primary surgery of breast cancer to the development of sternal metastasis): The 5-year overall survival rate was 61.8% for patients with a disease-free interval ${\geq}12$ months and 0.0% for patients with disease-free interval <12 months(p=0.03). Conclusion: The response to 3D-CRT was good in patients with solitary sternal relapse of breast cancer. Particularly, patients with long disease-free interval from primary surgery survived significantly longer than patients with short disease-free interval from primary surgery.

• Journal of the Korea Furniture Society
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• v.25 no.3
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• pp.165-172
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• 2014

3D form study is one of basic subjects in industrial design education. There are an array of textbooks of visual art, design and architecture, most of which address basic geometrical form study and abstract forms. With the introduction of computerization, current trends are directed to reduce basic form education and students' participation in classes and their accomplishments. This study was intended to develop works under a theme of furniture design with concrete shapes and functions. This study focused on developing relevant process by fusing 3D form study and furniture design which fall into basic design and design studio subjects, respectively. Among 3D form studies, applied were a concept of 3D configuration that explores the relations between surface forms and 3D forms. Furniture design is a challenge to students at beginner or intermediate level in basic design education from initial devising stage to production in kind. To ease high level of difficulties at designing and producing stages, technical education was systematized in the process of conceptualizing, developing idea and production. This type of challenge was carried out during separate semesters, along with a case study done to develop different types of challenges. This study helped students to be motivated and actively participate in classes and well perform advanced form study and technical training from design to actual production.