• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.175-175
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• 2000

In this Paper we propose a navigation algorithm which can be used to estimate state vectors such as position and velocity for its motion control using multi-sensor output measurements. The output measurement we will use in estimating the state is a series of known multi-sensor asynchronous outputs with measurement noise. This paper investigates the Extended Kalman Filtering method to merge asynchronous heading, heading rate, velocity of DVL, and SSBL information to produce a single state vector. Different complexity of Kalman Filter, with biases and measurement noise, are investigated with theoretically data from KRISO's AUV. All levels of complexity of the Kalman Filters are shown to be much more close and smooth to real trajectories then the basic underwater acoustic navigation system comment)'used aboard underwater vehicle.

• Journal of Korean Neurosurgical Society
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• v.52 no.2
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• pp.126-132
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• 2012

Objective : The purpose of this study was to present the MRI and CT findings of solitary spinal bone lesions (SSBLs) with the aims of aiding the differential diagnoses of malignant tumors and benign lesions, and proposing a diagnostic strategy for obscure SSBLs. Methods : The authors retrospectively reviewed the imaging findings of 19 patients with an obscure SSBL on MRI at our hospital from January 1994 to April 2011. The 19 patients were divided to benign groups and malignant groups according to final diagnosis. MRI and CT findings were evaluated and the results of additional work-up studies were conducted to achieve a differential diagnosis. Results : At final diagnoses, 10 (52.6%) of the 19 SSBLs were malignant tumors and 9 (47.4%) were benign lesions. The malignant tumors included 6 metastatic cancers, 3 multiple myelomas, and 1 chordoma, and the benign lesions included 4 osteomyelitis, 2 hemangiomas, 2 nonspecific chronic inflammations, and 1 giant cell tumor. No MRI characteristics examined was found to be significantly different in the benign and malignant groups. Reactive sclerotic change was observed by CT in 1 (10.0%) of the 10 malignant lesions and in 7 (77.8%) of the 9 benign lesions (p=0.005). Conclusion : Approximately half of the obscure SSBLs were malignant tumors. CT and MRI findings in combination may aid the differential diagnosis of obscure SSBLs. In particular, sclerotic change on CT images was an important finding implying benign lesion. Finally, we suggest a possible diagnostic strategy for obscure SSBLs on MRI.