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Calibration of a Mobile-Gantry CT Scanner for Surgical NavigationBelkova, Anna 05 September 2013 (has links)
In image-guided surgical navigation, instruments tools are tracked by a position sensor and their locations rendered along with the patient's anatomy. Conventional methods require an invasive, time-consuming and potentially uncertain process of intra-operative registration of the images to the patient. In a direct navigation system, such an intra-operative registration is replaced with pre-operative patient-independent calibration in a process that determines the relationship between the coordinate frame of imaging equipment and the coordinate frame of the position sensor.
This dissertation presents a method for pre-operatively calibrating a direct navigation system that used an optical position sensor and a mobile gantry CT scanner. A custom bi-local calibration device was designed and manufactured, after which existing navigation software was augmented with components that used the pre-operatively determined transformation to provide image-guided surgical navigation. The resulting system was tested in an image-guided operating suite using plastic bone models. In the validation stage, the inherent error was less than 0.4 mm and the target registration error was approximately 1.6 mm for a ceiling-mounted position sensor and 0.7 mm for a portable position sensor. This accuracy is consistent with the best intra-operative registrations reported in the literature and this calibration method may be useful in future surgical systems. / Thesis (Master, Computing) -- Queen's University, 2013-09-05 12:53:08.994
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After WTO The Strategy of Taiwan Shipping Industry Enter Into the Mainland China -Hansen Group as the Case StudyWang, Chia-Hua 22 July 2003 (has links)
Taiwan is a small island and there are more than 90% of the ex/import trade of the country is dominated by the shipping transportation. The shipping transportation is very important to the existence and development of the country. Taiwan and China being an official member of WTO since from the year 2002, the coastal shipping transportation between Taiwan and China is still very busy and even if more frequent than before.
The direct navigation between Taiwan and China ports is still strict prohibited by the Taiwan government. All the ships must be direct sailing for the third port such as Hong Kong, Ishigaki Jima, Busan for only port clearance purpose after sailed from China or Taiwan ports, vice versa. The exact effect of the mini three links between China and Taiwan is quite limited, when the major three links will come true is still unclear under the political issue across the Taiwan Strait so far.
Taiwan shipping industry is encountering some challenges or obstacles in the current circumstance regarding how to penetrate or break through the existing barriers to be successfully survived in the market or develop their business connection in China those are either coming from Taiwan government or China administration being installed to the Taiwan shipping forwarders.
Shipping industry is including the ship owners¡Bshipping agents¡Bfreight forwarders (NVOCC). This study will explore the result of the Taiwan shipping industry can better utilize the company¡¦s core competence to smooth run the business in Taiwan and develop its connection in mainland China. Will use Hansen Group as an individual case by using the company¡¦s strategy of its several different stream business divisions to ¡§think global, act locally¡¨, standing in Taiwan¡Bgo to China and take the world.
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