• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.3
• /
• pp.1114-1121
• /
• 2012

There is a cause and effect relationship in that brain injury causes impairment of mental rotation and ultimately independent functional activities. The purpose of this study was to compare the effects of mental rotation on reaction time and precision between the normal adults and chronic hemiparetic stroke patients. Thirty-one patients with chronic hemiparetic stroke and twenty normal adults participated in this study. The participants conducted 2 types of tasks for mental rotation: a comparison task using mirror images, and a rotation task using angular disparity images for 2 different 3-dimensional objects. Each of the 3 possible angled shapes ($90^{\circ}$, $180^{\circ}$, and $270^{\circ}$) appeared in each pair. The test consisted of 6 mirror-reflected image pairs and 6 angular disparity image pairs visualized during angular rotation, and 12 test periods. The subjects were judged on how accurately and rapidly they could distinguish between the mirrored and non-mirrored pairs. The study measured reaction time and precision to compare the effect of mental rotation tasks. Reaction time during all 3 angular conditions were significantly longer in the stroke patients than that in the normal adult during the comparison tasks and the rotation tasks. In addition, precision during mental rotation tasks was not significantly different between normal adults and stroke patients. Our results suggest that rehabilitation therapists should keep in mind that mental rotation is more difficult in stroke population than in normal adults.

• The Journal of Korean Society for Radiation Therapy
• /
• v.33
• /
• pp.117-125
• /
• 2021

Purpose: To purpose of this study is to find the correlation of the Set-up error according to the couch rotation and suggest additional margin setting for the GTV. Target and Method: Each scenario treatment plan was created by making the frequency of non-coplanar beams different among all beams. The set-up error value was measured by using the Exact System and the dose accuracy was evaluated by creating a re-treatment plan. Results: When the couch was rotated by 30°, 45°, 60°, and 90°, the mean of the X-axis values was measured to be 0.29 mm, 0.26 mm, 0.51 mm, and 0.08 mm, respectively. The mean of the Y-axis values was measured to be 0.75 mm, 0.5mm, 0.35 mm, and 0.29 mm, respectively. The mean of the Z-axis values was measured to be 0.5 mm, 0.28 mm, 0.22 mm, and 0.1 mm, respectively. There were dose reductions of 0.1%, 3.1%, 1.9% in D99 for 1-NC VMAT, 2-NC VMAT, and 3-NC VMAT, respectively. Conclusion: When treating with 50% or more of non-coplanar beams among total beams, image verification is required. And it is considered to make the treatment plan by adding a 1.5 mm margin to the GTV.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.2D
• /
• pp.209-215
• /
• 2011

Roundabout has circular traffic island in the intersection center and is kind of intersection where the automobile bypass circular traffic island. In Korea, the provisional Roundabouts Design Guidelines were published in 2004 by MLTM (Ministry of Land, Transport and Maritime Affairs). This guideline did not discussed domestic traffic circumstance. It just only introduced foreign instances and their guidelines. In addition, the recent National Competitiveness roundabouts as part of the green growth has been concentrated on the interest. In this paper, 90 degree of the 4-legged roundabout was compared with 72 degree, 45 degree, and 30 degree 5-legged roundabouts by micro simulation VISSIM. As a result of analysis, average travel time is decreased when the inscribed circle diameter become bigger the roundabout. 5-legged roundabout until 2,000 volume per hour evaluated to be similar effect at 90 degree of 4-legged roundabout.

• The Journal of Korean Society for Radiation Therapy
• /
• v.28 no.1
• /
• pp.1-5
• /
• 2016

A dosimetric evaluation of volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy for the lower extremity soft tissue sarcoma For the lower extremity soft tissue sarcoma, volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy were evaluated to compare these three treatment planning technique. The mean doses to the planning target volume and the femur were calculated to evaluate target coverage and the risk of bone fracture during radiation therapy. Volumetric modulated arc therapy can reduce the dose to the femur without compromising target coverage and reduce the treatment time compared with intensity modulated radiation therapy.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1992.04b
• /
• pp.237-246
• /
• 1992

본 연구는 선삭공정에서 CAD 인터페이스된 자동공정계획시스템개발에 관한 연구의 계속으로 작업준비계획(Setup Planning)을 자동적으로 수행하는 기법을 개발함이 주된 목적이다. 연구의 대상은 기계가공부품들 중 많은 비중을 차지하는 NC선반가공용 회전형상부품을 대상으로 하였다. 연구의 내용은 공작물고정방법의 결정, 작업준비횟수의 결정, 클램핑(Clamping)면 및 공작물고정구의 선정에 관한 기법과 알고리즘을 개발하였으며, 소프트웨어는 개인용 컴퓨터를 이용하여 Turbo-C(Version 2.0)를 사용하여 개발하였고, 사례연구를 통하여 개발된 시스템의 유효성을 평가하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.4
• /
• pp.54-67
• /
• 2016

All roundabouts are designed based on "Roundabout Design Guideline, Ministry of Land and Transportation, 2014" in Korea. The guideline also provides the traffic volume criteria to convert from signalized intersections to roundabouts. While the criteria are based on capacity of roundabouts, left-turn ratio and the number of lane on approaches are not considered to calculate the capacity of roundabouts. Therefore it is difficult to apply the traffic volume criteria in the real world. In this study, we studied the impact of left-turn ratio and the number of lane on approaches into capacity of roundabouts using micro-simulation. It was found that the capacity of roundabouts is changed according to left-turn ratio and the number of lane on approaches.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2004.11a
• /
• pp.75-77
• /
• 2004

Stereotactic radiosurgery(SRS) is a technique to deliver a high dose to a particular target region and a low dose to the critical organ using only one or a few irradiations while the patient is fixed with a stereotactic frame. The optimized plan is decided by repetitive work to combine the beam parameters and identify prescribed doses level in a tumor, which is usually called a trial and error method. This requires a great deal of time, effort, and experience. Therefore, we developed the automatic arrangement of multi-isocenter within irregularly shaped tumor. At the arbitrary targets, which is this method based on the voxel unit of the space, well satisfies the dose conformity and dose homogeneity to the targets relative to the RTOG radiosurgery plan guidelines

• Progress in Medical Physics
• /
• v.24 no.4
• /
• pp.284-289
• /
• 2013

A study was performed comparing dosimetric characteristics of volumetric modulated arc and intensity modulated radiatio therapy on patients with bilateral breast cancer. For 5 patients, 3 plans were made for each patient; IMRT beams 8 and 12 of the beam intensity modulated radiation therapy, volumetric modulated arc therapy plan. The average PTVs volumes and $D_{98}$ for 12-IMRT were $51.04{\pm}0.57$ Gy (right), $50.80{\pm}1.07$ Gy (left), $42.94{\pm}16.16$ Gy (right), $42.56{\pm}2.09$ Gy (left). HI ($D_5{\sim}D_{95}$) and $CI_{90,95}$, even 12-IMRT has shown excellent results. In OAR, 3 plans showed excellent results. But the lowest dose of 12-IMRT. 12-IMRT achieved similar PTV coverage and sparing of organs at risk than 8-IMRT and VMAT.

• Journal of radiological science and technology
• /
• v.34 no.1
• /
• pp.51-58
• /
• 2011

The aim of the study is to analyze the dose delivery error depending on the depth variation according to target positions and arc trajectories by comparing the simulated treatment planning with the actual dose delivery in conformal arc therapy. We simulated the conformal arc treatment planning with the three target positions (center, 2.5 cm, and 5 cm in the phantom). For the experiments, IMRT body phantom (I’mRT Phantom, Wellhofer Dosimetry, Germany) was used for treatment planning with CT (Computed Tomography, Light speed 16, GE, USA). The simulated treatment plans were established by three different target positions using treatment planning system (Eclipse, ver. 6.5, VMS, Palo Alto, USA). The radiochromic film (Gafchromic EBT2, ISP, Wayne, USA) and dose analysis software (OmniPro-IMRT, ver. 1.4, Wellhofer Dosimetry, Germany) were used for the measurement of the planned arc delivery using 6 MV photon beam from linear accelerator (CL21EX, VMS, Palo Alto, USA). Gamma index (DD: 3%, DTA: 2 mm) histogram and dose profile were evaluated for a quantitative analysis. The dose distributions surrounded by targets were also compared with each plans and measurements by conformity index (CI), and homogeneity index (HI). The area covered by 100% isodose line was compared to the whole target area. The results for the 5 cm-shifted target plan show that 23.8%, 35.6%, and 37% for multiple conformal arc therapy (MCAT), single conformal arc therapy (SCAT), and multiple static beam therapy, respectively. In the 2.5 cm-shifted target plan, it was shown that 61%, 21.5%, and 14.2%, while in case of center-located target, 70.5%, 14.1%, and 36.3% for MCAT, SCAT, and multiple static beam therapy, respectively. The values were resulted by most superior in the MCAT, except the case of the 5 cm-shifted target. In the analysis of gamma index histogram, it was resulted of 37.1, 27.3, 29.2 in the SCAT, while 9.2, 8.4, 10.3 in the MCAT, for the target positions of center, shifted 2.5 cm and 5 cm, respectively. The fail proportions of the SCAT were 2.8 to 4 times as compared to those of the MCAT. In conclusion, dose delivery error could be occurred depending on the target positions and arc trajectories. Hence, if the target were located in the biased position, the accurate dose delivery could be performed through the optimization of depth according to arc trajectory.

• Journal of Aerospace System Engineering
• /
• v.17 no.6
• /
• pp.133-143
• /
• 2023

This paper describes the system integration laboratory's requirement analysis, implementation, and verification for multiple-scenario unmanned aerial vehicle operation and control technology using a manned rotorcraft for Manned-Unmanned Teaming. System integration laboratory consists of manned rotorcraft flight simulation, unmanned aerial vehicle flight and mission equipment simulation, ground control system simulation for unmanned aerial vehicle control and change in the control authority between the ground control system and manned rotorcraft, and operation and control system for mission plan's writing and transmission. Each implemented simulation verified the requirements through software and hardware integration test.