• Spatial Information Research
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• v.10 no.1
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• pp.61-76
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• 2002

Mobile map services using PDA are prevailing because of the rapid developments of techniques of the internet and handhold devices recently. While the volume of spatial data is tremendous and the spatial operations are time-intensive, the PDA has small size memory and a low performance processor. Therefore, the spatial index for PDA should be small size and efficiently filter out the candidate objects of spatial operation as well. This paper proposes a spatial index far PDA called MHF(Multilevel Hashing File). The MHF has simple structure for storage efficiency and uses a hashing technique, which is direct search method, for search efficiency. This paper also designs a compression technique for MBR. which occupies almost 80% of index data in the two dimensional case. We call it HMBR. Although the HMBR technique reduces the MB\ulcorner size to almost a third, it shows good filtering efficiency because of no information loss by quantization in case of small objects that occupy a major portion. Our experimental tests show that the proposed MHF index using HMBR technique is appropriate for PDA in terms of the size of index, the Number of MBR comparisons, the filtering efficiency and the execution time of spatial operations.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.189-193
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• 2022

Hemorrhage after pancreaticobiliary surgery is an infrequent but fatal complication. It is primarily caused by rupture of the pseudoaneurysm, and treatment options include endovascular coil embolization or endovascular stent-graft placement. Herein, we report a case of migration of an arterial stent-graft that was placed in the common hepatic artery to treat pseudoaneurysm after pylorus-preserving pancreaticoduodenectomy. The stent-graft migrated to the jejunum and was eventually excreted from the body.