• Proceedings of the KSR Conference
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• 2009.05a
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• pp.472-475
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• 2009

Nowadays, Short headway is a requirement of Signaling System applied to subway and Light Rail Transit (LRT) being constructed in Korea. To satisfy this Systematic Requirement, the accuracy of train position information on the line is one of the main element to improve ATC system safety and performance. On-board ATC system performs feasibility of Train Position as comparing data from balise installed along the track with data from tachometer installed at both axles of train.

• Progress in Medical Physics
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• v.22 no.1
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• pp.12-17
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• 2011

This study has its own goal to deliver the accurate dose on the target volume by calculating and modifying the attenuation rate of photon beam transmitting the couch top with geometric model. The experiment was that the transmission rate and attenuation rate of photon beam transmitting the couch top was predicted by the geometric model, then compared and analyzed with what was measured experimentally based on that. The result showed that the predicted value by the geometric model accorded closely with the experimental value. In addition, in order to judge whether the practical clinical application is available, the point dose, measured after modifying the attenuation rate modelinged according to the treatment plan of a patient of spine radiosurgery, was compared with the one done nothing. The result was that the former showed decreased error range with treatment planned one than the latter. This papers calculated the transmission and attenuation rate with the geometric model transmitting the couch top and verified it experimentally. This method is expected to be very useful in not only the radiosurgery using Novalis but also the general radiation therapy.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.3
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• pp.335-342
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• 2014

In this paper We study on test methods and procedures for Hybrid Track Circuit's practicalization. It's possible to apply to HTC's Seoulmetro and high-speed train by proposing test method considering special rail environment and RFID tag and leader, antenna We also present the test methods and procedures for safe and reliable of interface among the Hybrid track circuit devices.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.8
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• pp.743-750
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• 2016

The conventional track to train communication is commonly using radio based equipment such as transponder or balise to transmit the data. However, there are some drawbacks of the conventional equipment, for example multipath fading, source of bandwidth limitation, and interference from other users. Moreover, the radio based equipment is very expensive when installed in large numbers. To address these problems, we propose infrared system for trackside to train communication system. Infrared system offers a transmission of data to train and it can be processed to obtain at least a train location. Infrared communication protocol provides practical wireless data communication for direct dedication configuration. Furthermore, on the pole configuration the infrared system provides an abundant bandwidth, an economically sensible, minimalized installation of equipment on the trackside and reliability for heavy rain environment. This paper concentrates on the communication function and measurement performance evaluation. The proposed trackside to train communication system covers about 6 meters between infrared receiver and infrared transmitter, whereas the half angle of the transmitter is set to $19.65^{\circ}$ and the receiver angle is $15^{\circ}$.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.633-639
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• 2007

This study proposes an optimal condition to recognize a train using RFID. In order to recognize a moving train, bandwidth, an angle of antenna and the location of a tag should be considered. In this study, a field test was conducted using two different bandwidths (900MHz and 2.45GHz), four angles of antenna(0, 30, 45, and $60^{\circ}$), different velocities (10, 30 and 50km), and three different locations of tags. The field test verified the optimal condition for recognition of a train, The present study convinced that location detection and tracking of rail freight can be monitored in real time. The present technology can be applied to railway signals including detecting and tracking such as EURO Balis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.23-30
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• 2016

ccording to the airport railroad linkage facility expansion project constructing a connecting line to the airport railway and improving the signal system and Gyeongui Susaek Station, a high-speed train is able to run directly from Gyeongbu and Honam to the airport railway. According to mixed operation of high-speed Korea Train Express (KTX) and Airport Railroad Express (AREX) trains, to establish ERTMS/ETCS L1 ATP to operate the KTX train, the signaling system of the AREX train is the same as the existing ATC/ATO, but its operation became impossible because the high-speed train causes mutual interference between the "high-speed train (KTX) and AREX ground signaling equipment" and between the "AREX train and KTX (high-speed train) ATP ground equipment." Thus, it was necessary to have a supplemental technical interference analysis comparing the characteristics of the AREX beacon and the KTX balise. So, we resolve the problems of mutual interference between the "high-speed train (KTX) and AREX ground signaling equipment" and between the "AREX train and KTX (high-speed train) ATP ground equipment" with a test using an actual train, and we confirm the technical validity with three types of test module.

• Progress in Medical Physics
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• v.13 no.4
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• pp.218-223
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• 2002

Stereotactic radiosurgery for intracranial lesion is well established since the Lars Leksell first introduced radiosurgery concept in 1951 Its use in the treatment of spinal lesion has been limited by the availability of effective immobilization devices. The first clinical experience of the spinal stereotactic radiosurgery technique was reported by Hamilton AJ. in 1995. Recently, Optic-guided patient positioning technique for extracranial stereotactic radiosurgery was developed and reported. This study is for assess the target positioning accuracy of the optic guided patient positioning system Exactrac (BrainLab., Inc, Germany). We have designed phantom for assess the accuracy of spinal stereotactic radiosurgery The infrared reflective body markers attached to the relatively immobile part of the body and a series of 2 mm CT images was taken. The image sets were transferred to the planning computer. During the radiosurgery treatment, we measure the real-time display showing the positioning values from Exactrac computer. And we compare the isocenter deviation from irradiated center point of the film which was mounted on the lesion site of the phantom and pin hole site of that film. The accuracy of the ExacTrac system in positioning a target point shows enough for the clinical applications.

• Progress in Medical Physics
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• v.13 no.3
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• pp.135-138
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• 2002

Fractionated stereotactic radiosurguy (FSRS) requires precise and reproducible patient set up. For these reasons non-invasive mask fixation methods have been used in Linac based FSRS. In this study, we measured and assessed the isocenter reproducibility using a commercial head mask fixation system based on thermoplastic materials. For the verification and the measurement of isocenter deviation a special acrylic brain phantom was designed. The designed phantom has 22 vertical rods and each rod has different lengths. At the end of the 8 rods, the monochromic film is attached and irradiated due to planned target position. Deviations of isocenter were measured separately for each direction. The mean deviation showed 0.4 mm in longitudinal direction, 0.1 mm in the lateral direction, 0.1 mm in the anterior-posterior direction of the treatment couch. The data demonstrates the high accuracy and reproducibility. This study reinforces previous literature published.

• Progress in Medical Physics
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• v.24 no.4
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• pp.265-270
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• 2013

Correct target volume delineation is an important part of radiosurgery treatment planning process. We designed head phantom and performed target delineation to evaluate the volume differences due to radiosurgery treatment planning systems and image acquisition system, CT/MR. Delineated mean target volume from CT scan images was $2.23{\pm}0.08cm^3$ on BrainSCAN (NOVALS), $2.13{\pm}0.07cm^3$ on Leksell gamma plan (Gamma Knife) and $2.24{\pm}0.10cm^3$ on Multi plan (Cyber Knife). For MR images, $2.08{\pm}0.06cm^3$ on BrainSCAN, $1.94{\pm}0.05cm^3$ on Leksell gamma plan and $2.15{\pm}0.06cm^3$ on Multi plan. As a result, Differences of delineated mean target volume due to radiotherapy planning system was 3% to 6%. And overall mean target volume from CT scan images was 6.36% larger than those of MR scan images.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.1
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• pp.33-39
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• 2010

Purpose: It is very important to confirm conformance of dose distribution that is formed with treatment planning from IMRS or IMRT. It has been a problem dropped accuracy and conformance when the field size is getting smaller because of character of the 2D ion chamber. Verification of MatriXX Phantom dose distribution with a change in the SAD. Dose distribution measurement and analysis to improve the accuracy and should be useful to evaluate the award. Materials and Methods: A use of Novalis linear accelerator 6 MV photon beams. In general, IMRS were 25 patients with small field size. The selected patients were divided into three groups on the basis of the field size. SAD was changed from 80 to 130 cm and field size to determine the dose distribution to the change, each dose was measured using MatriXX Phantom. Analysis of measured values obtained from the program for each patient through the treatment planning system comparison and analysis of the dose distribution and gamma values were expressed. Result: SAD 80, 100, and 120 cm in size in the gamma value to the investigation of patients less than $3\;cm^2$ average 0.939, 0.969, and 0.979, respectively. Patients with more than $5\;cm^2$ 0.962, 0.983, and 0.988, respectively. $5\;cm^2$ or more patients 0.982, 0.990, and 0.992, respectively. Conclusion: The error rate of less than $3\;cm^2$ field size is increased rapidly. If the field size is increased, resolution is increased by 2D ion chambers. It has been approved that it can be credible if it is around $3\;cm^2$ when measuring dose distribution using MatriXX. Adjusting geometric field size by changing SAD is likely to be very useful when you measure dose distribution using MatriXX.