• Progress in Medical Physics
• /
• v.24 no.4
• /
• pp.230-236
• /
• 2013

Our purpose is to present a novel technique for delivering craniospinal irradiation in the supine position using a perfect match, field-in-field (FIF) intrafractional feathering, and simple forward-optimization technique. To achieve this purpose, computed tomography simulation was performed with patients in the supine position. Half-beam, blocked, opposed, lateral, cranial fields with a collimator rotation were matched to the divergence of the superior border of an upper-spinal field. Fixed field parameters were used, and the isocenter of the upper-spinal field was placed at the same source-to-axis distance (SAD), 20 cm inferior to the cranial isocenter. For a lower-spinal field, the isocenter was placed 40 cm inferior to the cranial isocenter at a constant SAD. Both gantry and couch rotations for the lower-spinal field were used to achieve perfect divergence match with the inferior border of the upper-spinal field. A FIF technique was used to feather the craniospinal and spinal-spinal junction daily by varying the match line over 2 cm. The dose throughout the target volume was modulated using the FIF simple forward optimization technique to obtain homogenous coverage. Daily, image-guided therapy was used to assure and verify the setup. This supine-position, perfect match craniospinal irradiation technique with FIF intrafractional feathering and dose modulation provides a simple and safe way to deliver treatment while minimizing dose inhomogeneity.

• ETRI Journal
• /
• v.24 no.2
• /
• pp.97-108
• /
• 2002

Optical Border Gateway Protocol (OBGP) is an extension to BGP for Optical Cross Connects (OXCs) to automatically setup multiple direct optical lightpaths between many different autonomous domains. With OBGP, the routing component of a network may be distributed to the edge of the network while the packet classification and forwarding is done in the core. However, it is necessary to analyze the stable convergence functions of OBGP in case of lightpath failures. In this paper, we first describe the architecture of the OBGP model and analyze the potential problems of OBGP, e.g., virtual BGP router convergence behavior in the presence of lightpath failure. We then propose an OBGP convergence model derived from an inter-AS (Autonomous System) relationship. The evaluation results show that the proposed model can be used for a stable OBGP routing policy and OBGP routing convergence under lightpath failures of the optical Internet.

• Journal of Cadastre & Land InformatiX
• /
• v.50 no.2
• /
• pp.117-132
• /
• 2020

The study studied ways to improve the adjustment of the cadastral reform project after analyzing and evaluating the method of determining the boundaries and the overall status of the adjustment, focusing on cases of complaints in the business district in Sejong City, where the re-investigation project was completed. Measures to improve the adjustment amount of the cadastral reform project were largely divided into boundary adjustment and improvement measures according to the scope of area allowance and institutional improvement. According to an analysis of the status of boundary adjustment in Sejong City, the boundary of the cadastral reform project was being adjusted in various ways, and among them, it was found that it is simple to adjust, to formalize parcels, and that many adjustments are being made centering on resolving blind areas by establishing new roads. When setting such a boundary, it is necessary to establish an efficient and reasonable boundary by actively encouraging sufficient consultation with owners and an adjustment boundary that reflects the personal will of landowners to minimize disputes over the adjustment amount. In terms of improvement measures based on the area limit, it is necessary to accurately record and preserve the results of the cadastral resurvey in numerical data and to ease or exempt the adjustment amount if it is within the area permissible scope of the Spatial Data Management Act when calculating the adjustment amount. Finally, in relation to the adjustment, it was judged that it would be necessary to provide long-term low-interest loans to their own land to landowners, and that it would be necessary to calculate the adjustment through appraisal calculated by third parties fairly and objectively based on value judgment.