• Journal of radiological science and technology
• /
• v.36 no.3
• /
• pp.237-244
• /
• 2013

The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OED(Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ~ 2.02 Gy, 0.36 ~ 5.01 Gy, 0.25 ~ 2.49 Gy, 0.14 ~ 6.92 Gy, 0.03 ~ 2.02 Gy, 0.01 ~ 1.06 Gy, 0.25 ~ 6.08 Gy, 0.08 ~ 0.59 Gy, 0.01 ~ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT.

• Journal of the Korean Society of Radiology
• /
• v.16 no.7
• /
• pp.857-862
• /
• 2022

The purpose of this study was to evaluate a three-dimensional conformal radiotherapy (3D-CRT) treatment plan with regard to head tilting in whole-brain radiotherapy (WBRT) using TomoDirect (TD) mode in Tomotherapy. WBRT 3D-CRT by TD was compared for a total of five head tilt angles (-20°, -10°, 0°. +10° and +20°). The dose homogeneity index (HI) and prescription dose index (CI) were calculated to confirm the target coverage. The maximum and average doses for critical organs such as the lens, eyeball and parotid glands were calculated for different angles of head tilting. The HI and CI were closet to the result value of 1 at the head tilted angle +10° and +20°. At a head tilted angle of +10°, the dose to the lens and eyeballs decreased by about 74% and about 30%, when compared with the reference angle (0°), respectively. The results of this study suggest that a head angle of +10 with chin-up would save adequate target coverage and reduce exposure dose to the lens.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.891-899
• /
• 2009

We need education program and contents that satisfy on-off line's education maximize an initiative spirit development in an absence of UI design for infants and elementary students. For the multiplicity of inflection of these initiative spirit development education program, we need development of contents and teaching materials(Cre-kids) that can educate both in on-line and in off-line. Cre-kids are divided of four areas that are increased fluency, flexibility, originality and delicacy. Four areas are ideas of language, visual, making and computer. Through each area, we can develop children's systematic modeling idea ability. And we divide of fluency, flexibility, originality and delicacy each four areas and evaluate each aspect and mark for index. That is CDQ(Creativity Design Quotient). Through the evaluation result, we will be able to study about a modeling initiative spirit index.

• 한국HCI학회:학술대회논문집
• /
• 2007.02a
• /
• pp.675-680
• /
• 2007

컴퓨터를 활용하는 응용 수많은 가시화 방법론들 중 하나인 3차원 모델링은 경우에 따라 더 구체적인 이해를 위해 모형 형태로 조형작업을 하기도 한다. 그러나, 이러한 입체 모델의 조형은 수작업으로 할 경우에 많은 시간과 노력을 필요로 한다. 이를 해결하기 위하여 Rapid Prototyping기술이 개발 및 보급되어왔다. 이러한 장비와 OS를 포함한 관련 소프트웨어는 고가이기도 하고 동시에 1인 밖에 사용할 수 없는 자원인 경우가 많다. 또한, 사용하기 위하여 장비가 위치한 곳 까지 이동하여야 하는 경우가 많다. 그러나, 원격데스크탑 형태의 인터페이스와 장비 구동과 동작 과정을 모니터링 할 수 있는 인터페이스, 임차를 위한 사용자관리 시스템 등을 포함한 클러스터 컴퓨터 환경으로 구성하고 인터넷을 통하여 제공하면 비록 제한된 수준이기는 하지만, 현업에서 사용하는 고가의 Rapid Prototyping장비를 실제 이용하는데 무리가 없는 임차 및 공유 가능 자원으로 변화 시킬 수 있다. 이 임차 방법론은 고가의 산업 장비와 소프트웨어를 공유할 수 있는 실제적인 예를 제공한다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.04b
• /
• pp.223-227
• /
• 1993

최근 생산성 향상을 위해 용접 자동화가 실용 분야, 특히 GMAW 공정에서 활발히 진행되고있다. 그러 나, 현 수준의 용접 자동화는 완전 자동화에는 이르지 못하고 단지 주어진 용접 조건과 용접 경로로 용 접을 실행하는 로보트 시스템의 채용으로 인간의 작업을 대체하는 정도이다. 이와 같은 로보트 시스템 을 이용한 자동화에 있어서는 예기치못한 공정의 변동에 대처하기 위한 공정 중 용접질 모니터링이 더욱 중요해지고 있다. 본 연구에서는 이 목적으로 표면의 다점 온도를 측정하여 이 중 한점의 온도와 이점 이점 부근의 온도 구배로써 용융지 크기 추정 지수를 구성하였다. 이 지수는 온도 변수들과 대응 용융지 크기 간에 다중 회귀 방법을 이용하여 최소 추정 오차가 발생하도록 설정된 수학적 모델이다. 제안된 지 수의 추정 성능을 평가하기 위해 용접 열전도 모델로 부터 얻은 용융지 크기와 표면 온도분포 data를 이용 하여 일련의 시뮬레이션 연구를 실시하였다. 이 과정에서 지수 구성 온도 변수들의 차수가 추정 성능에 미치는 영향과 온도 측정 위치에 따른 추정 성능의 민감도를 추정 오차와 오차 분산을 통해 분석하고, 지수를 사용하였을 때의 추정성능을 한점 온도를 이용하는 경우와 비교 평가하였다.

• Journal of Welding and Joining
• /
• v.8 no.1
• /
• pp.31-42
• /
• 1990

Arc must be stable during welding first of all other factors for obtaining sound weldment, especially in the automation of welding process. Arc stability is somewhat sophisticated phenomenon which is not clearly defined yet. In consumable electrode welding, the voltage and current variation due to metal transfer enables to assess arc stability. Recently, statistical analyses of the voltage and current waveform factors are performed to assess the degress of arc stability which is assessed and controlled by operator's own experience by now. But, considering the increasing need and the trend of automation of welding process, it is necessary to monitor arc stability in real-time. In this sutdy, the modified stability index composed of two voltage and current wvaeform factors (arc time and short circuit time) reduced from four factors (arc time, short circuit time, average arc current and average short circuit current) in Mita's index by the welding electrical circuit modeling is proposed and verified by experiments to be well estimating arc stability in the static sense. Also, the recursive calculation form estimating present arc stability in the dynamic sense is developed for real-time estimation. The results of applying the recursive index during welding show good estimation of arc stability in real-time. Therefore, the results of this study offers the mean for real-time control arc stability.

• Korean Journal of Food Science and Technology
• /
• v.16 no.3
• /
• pp.273-278
• /
• 1984

Changes in rheological properties of rice starch-water systems during the gelatinization were evaluated with the tube viscometer at temperatures between 50 and $85^{\circ}C$ and for the concentrations ranging from 3-5% rice starch. The flow consistency index increased exponentially with time at a particular temperature while being linearly dependent upon the concentration. The gelatinization rate measured by rheological method followed Arrhenius type equation. The value of activation energy of gelatinization for 5% rice starch was about 25 kcal/g mol.

• Korean Journal of Food Science and Technology
• /
• v.16 no.1
• /
• pp.29-36
• /
• 1984

Flow behaviors of rice starch-water systems containing 3-9% (w/v) of native and gelatinized starch solutions were studied with the capillary tube rheometer in the temperature range of $30-80^{\circ}C$. Flow behaviors of rice starch-water systems showed non-Newtonion behavior which could be expressed as ${\gamma}{\;}=\;{\psi}(^{\tau}g_c-{\tau}_yg_c)^N$. Flow parameters ${\psi}$, N and $^{\tau}_y$ were determined for native and gelatinized solutions. These parameters indicated that native rice starch solution shows a dilatancy and the gelatinized solution ranges from pseudoplastic to mixed type flow behavior with increasing concentrations. The value of flow behavior index for gelatinized solutions was about 1.2 in all samples but for native solutions, the values were 0.87-0.90. The values of yield stress, which were negligible below 5%, were increased with the increase in concentration from 5 to 9%. The value of consistency index was exponentially dependent on concentration and temperature. The values of activation energy for native and gelatinized solutions were 0.13-2.71 and 5.39-9.57 kcal/g mole, respectively.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.148-149
• /
• 2000

유기 고분자는 기존 무기물질의 한계성을 감안해 볼 때, 전기 및 광학적 특성이 우수하여 이에 대한 연구가 매우 활발히 진행되고 있다. 이중에서 Azo 화합물은 특별한 물리적, 광학적 성질과 그 잠재적인 응용성 때문에 계속해서 지금도 많은 관심을 끌고 있다. 그래서 Azo 화합물은 액정과 함께 비선형 광학성질을 가지는 물질에 응용될 수 있으며, 또한 광 유도현상의 이색성(dichroism)및 복굴절(birefringence) 현상 같은 특성을 나타내고 있다.$^{l)2)3)}$ 선형 광학 실험중에서 단순 입사 방법$^{4)}$ 을 이용하여 전기 광학 계수를 측정하였으며, 다시 확장 지수함수(stretched exponential)모델$^{5)}$ 로써 극화(poling)와 완화(relaxation)의 꼴을 보았다. (중략)

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1016-1020
• /
• 2003

In this paper, we present a technology of producing anew chaotic micromixer, named Micromixer with Arranged Blocks(MAB), and the experimental result of the mixing performance. Chaotic mixing was successfully achieved by introducing periodic perturbation in the field of the channel flow by means of slanted blocks. The MAB was made by an RP(Rapid Prototyping) technology. We performed flow visualization experiments for the quantification of the mixing performance with the MAB. Lyapunov exponent was measured to be 0.3557 and 0.1305 for the block height 0.8 and 0.2 times the channel width.