• Progress in Medical Physics
• /
• v.33 no.4
• /
• pp.37-52
• /
• 2022

Over the past decades, radiation therapy combined with imaging modalities that ensure optimal image guidance has revolutionized cancer treatment. The two major purposes of using imaging modalities in radiotherapy are to clearly delineate the target prior to treatment and set up the patient during radiation delivery. Image guidance secures target position prior to and during the treatment. High quality images provide an accurate definition of the treatment target and the possibility to reduce the treatment margin of the target volume, further lowering radiation toxicity and improving the quality of life of cancer patients. In this review, the various types of image guidance modalities used in radiation therapy are distinguished into ionized (kilovoltage and megavoltage image) and nonionized imaging (magnetic resonance image, ultrasound, surface imaging, and radiofrequency). The functional aspects, advantages, and limitation of imaging using these modalities are described as a subsection of each category. This review only focuses on the technological viewpoint of these modalities and any clinical aspects are omitted. Image guidance is essential, and its importance is rapidly increasing in modern radiotherapy. The most important aspect of using image guidance in clinical settings is to monitor the performance of image quality, which must be checked during the periodic quality assurance process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.500-504
• /
• 2002

The purpose of this paper is to implement a guidance system for an object on the road. A watch camera equipped on the auto door recognizes the direction for the destination of an object, after that it determines whether opening or closing the door, and then the door is opened automatically, based on the decision. The motion of the moving object is approximated by using the technique of the image processing of tracking images and the affine model. The direction of the moving object is predicted from image information obtained by applying linear Kalman filter to the motion estimation in order to reduce the search region, the moving position, and the direction of the center of the object. Along with the guidance function, the system has the announcing function to the object. The experimental results confirm the veridity and applicability of the proposed system.

• Journal of the Semiconductor & Display Technology
• /
• v.21 no.3
• /
• pp.17-21
• /
• 2022

A variety of techniques have been proposed in the literature for depth improvement in depth from focus method. Unfortunately, these techniques over-smooth the depth maps over the regions of depth discontinuities. In this paper, we propose a robust technique for improving the depth map by employing a nonconvex smoothness function that preserves the depth edges. In addition, the proposed technique exploits the mutual structures between the depth map and a guidance map. This guidance map is designed by taking the mean of image intensities in the image sequence. The depth map is updated iteratively till the nonconvex objective function converges. Experiments performed on real complex image sequences revealed the effectiveness of the proposed technique.

• The Journal of Korea Robotics Society
• /
• v.9 no.3
• /
• pp.147-153
• /
• 2014

In this paper, we proposed a new algorithm of the guidance line extraction for autonomous weeding robot based on infrared vision sensor in wet paddy. It is the critical process for guidance line extraction which finds the central point or area of rice row. In order to improve accuracy of the guidance line, we are trying to use the morphological characteristics of rice that the direction of rice leaves have convergence to central area of rice row. Using Hough transform, we were represented the curved leaves as a combination of segmented straight lines on binary image that has been skeletonized and segmented object. A slope of the guidance line was gotten as calculate the average slope of all segmented lines. An initial point of the guidance line was determined that is the maximum pixel value of the accumulated white columns of a binary image which is rotated the slope of guidance line in the opposite direction. We also have verified an accuracy of the proposed algorithm by experiments in the real wet paddy.

• Korean Journal of Community Nutrition
• /
• v.8 no.6
• /
• pp.831-839
• /
• 2003

This study was conducted to investigate whether there were any differences in the body image perception, dietary behavior and maternal dietary guidance between an obese group (“OG”) and a normal weight group (“NWG”), and furthermore, to provide basic informations for comprehensive educational programs for obese children. For this purpose, the questionnaire method was used. The subjects were 1,501 elementary school children, in the 4th to the 6th grades in Seoul, Busan, Daegu, Gwangju, and Andong, and their mothers (1,459). The percentage of the children who misperceive their body image was higher among the girls (30.4%) than the boys (22.6%) The average scores for balanced dietary behavior as assessed by the children was higher in the OG than in NWG; the average scores for dietary control as assessed by their mothers was higher in the NWG than in the OG. The scores for dietary behavior as assessed by the children was different from those as assessed by their mothers. Assuming that the mothers would give more correct and balanced answers, the development of a reliable questionnaire for dietary behavior that could be more accurately answered by the children is necessary. Maternal dietary guidance for dietary control was more frequently given in the OG as compared with the NWG and more frequently in girls as compared with boys ; while that for balanced diet was more in the NWG as compared with the OG. The worse the mothers estimate of the dietary behavior for their children, the more they tried to guide their children in dietary behavior. It is recommended that the children should be taught to correctly recognize the degree of their obesity, and receive the appropriate educational program accordingly, including the maternal dietary guidance.

• Journal of the Korea Society of Computer and Information
• /
• v.9 no.1
• /
• pp.63-70
• /
• 2004

This paper describes modeling, design and performance test results of infrared thermal image target system which can generate infrared thermal image on aircraft. The system is designed to control image shape and intensity so that the infrared image shape and its emitting intensity are so similar to that of real aircraft. When applying the technique suggested in this paper, the system consumes only small electric power energy about 30(㎾) to generate infrared thermal image which is equivalent to that of real aircraft under full power operation. After verifying performance test, the system developed here has been used as a target for korean potable surface to air missile(KPSAM) at the stage of evaluation test such as target adaptive guidance test and auto-pilot logic test.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.12
• /
• pp.93-102
• /
• 2011

This paper presents a walking guidance system for blind pedestrians in an outdoor environment using just one single camera. Unlike many existing travel-aid systems that rely on stereo-vision, the proposed system aims to get necessary information of the road environment by using just single camera fixed at the belly of the user. To achieve this goal, a top-view image of the road is used, on which obstacles are detected by first extracting local extreme points and then verified by the polar edge histogram. Meanwhile, user motion is estimated by using optical flow in an area close to the user. Based on these information extracted from image domain, an audio message generation scheme is proposed to deliver guidance instructions via synthetic voice to the blind user. Experiments with several sidewalk video-clips show that the proposed walking guidance system is able to provide useful guidance instructions under certain sidewalk environments.

• Journal of International Society for Simulation Surgery
• /
• v.1 no.2
• /
• pp.62-66
• /
• 2014

Image registration is the process for finding the correct geometrical transformation that brings one image in precise spatial correspondence with another image. There are limitations on the visualization of simple overlay between two different modality images because two different modality images have different anatomical information, resolution, and viewpoint. In this paper, various image registration methods and their applications are introduced. With the recent advance of medical imaging device, image registration is used actively in diagnosis support, treatment planning, surgery guidance and monitoring the disease progression.

• The Journal of Korea Robotics Society
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2016

In this paper, we propose a new algorithm of the guidance line extraction for autonomous agricultural robot based on vision camera in paddy field. It is the important process for guidance line extraction which finds the central point or area of rice row. We are trying to use the central region data of crop that the direction of rice leaves have convergence to central area of rice row in order to improve accuracy of the guidance line. The guidance line is extracted from the intersection points of extended virtual lines using the modified robust regression. The extended virtual lines are represented as the extended line from each segmented straight line created on the edges of the rice plants in the image using the Hough transform. We also have verified an accuracy of the proposed algorithm by experiments in the real wet paddy.

• Journal of Korean Society of Transportation
• /
• v.27 no.2
• /
• pp.207-214
• /
• 2009

This study proposed an advanced warning information system based on real-time traffic conflict analysis. An algorithm to detect and analyze unsafe traffic events associated with car-following and lane-changes using individual vehicle trajectories was developed. A positive guidance procedure was adopted to provide warning information to alert drivers to hazardous traffic conditions derived from the outcomes of the algorithm. In addition, autoregressive integrated moving average (ARIMA) analyses were conducted to investigate the predictability of warning information for the enhancement of information reliability.