DSpace Community:
https://dspace.ewha.ac.kr/handle/2015.oak/171851
2024-03-28T14:51:33Z
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A hybrid solid-state storage architecture for the performance, energy consumption, and lifetime improvement
https://dspace.ewha.ac.kr/handle/2015.oak/230590
Title: A hybrid solid-state storage architecture for the performance, energy consumption, and lifetime improvement
Ewha Authors: 주용수
Abstract: In recent years, many systems have employed NAND flash memory as storage devices because of its advantages of high I/O performance, increasing capacity, and falling cost. On the other hand, the performance of NAND flash memory is limited by its erase-before-write requirement. Log-based structures have been used to alleviate this problem by writing updated data to the clean space. Log-based methods, however, cannot completely overcome the inherent limitation of NAND flash memory. It cannot avoid excessive erase operations when there are frequent updates, which quickly consume free pages, especially when some data are updated repeatedly. In this paper, we propose a hybrid architecture for the NAND flash memory storage, of which the log region is implemented using phase change random access memory (PCRAM). Compared to traditional log-based architectures, it has the following advantages: (1) the PCRAM log region allows in-place updating and byte-granularity access so that it significantly improves the usage efficiency of log pages by eliminating out-of-date log records; (2) it greatly reduces the traffic of reading from the NAND flash memory storage since the size of logs loaded for the read operation is decreased; (3) the energy consumption of the storage system is reduced as the overhead of writing and reading log data is decreased with the PCRAM log region; (4) the lifetime of NAND flash memory is increased because the number of erase operations are reduced. To facilitate the PCRAM log region, we propose several management policies. The simulation results show that our proposed methods can substantially improve the performance, energy consumption, and lifetime of the NAND flash memory storage. © 2014 Springer Science+Business Media New York. All rights are reserved.
2014-01-01T00:00:00Z
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Use of a handheld, computerized device as a decision support tool for stroke classification
https://dspace.ewha.ac.kr/handle/2015.oak/222371
Title: Use of a handheld, computerized device as a decision support tool for stroke classification
Ewha Authors: 박은정
Abstract: Background: The Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification has been widely used to determine etiology of ischemic stroke. However, interrater reliability is known to be modest. The complexity of abstraction and the interpretation of various clinical and laboratory data might limit the accuracy of the TOAST classification. In this study, we developed a computerized clinical decision support system for stroke classification that can be used in a handheld device and tested whether this system can improve diagnostic accuracy and reliability. Methods: Based on the TOAST classification, a logical algorithm was developed and implemented on a handheld device, named iTOAST. After answering six questions using the touch interface, the stroke subtype result is displayed on the screen. Four neurology residents were randomly assigned to classify stroke subtypes using iTOAST or the conventional method (cTOAST). Using a crossover design, they classified the stroke subtypes of 70 patients. The standard subtypes were determined by three stroke experts. Correlated kappa coefficients using iTOAST compared with cTOAST were determined. Results: The kappa (SE) value of iTOAST [0.790 (0.041), 95% CI: 0.707-0.870] was higher than that of cTOAST [0.692 (0.046), 95% CI: 0.600-0.782] (P<0.001). Neither sequence (P=0.857) nor period effect (P=0.999) was observed. Conclusions: The stroke classification tool using a handheld, computerized device was easy, accurate, and reliable over the conventional method. It may have additional benefit because a handheld, computerized device is accessible anytime and anywhere. © 2011 The Author(s). European Journal of Neurology © 2011 EFNS.
2012-01-01T00:00:00Z
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Size variability of handwriting in healthy Korean older adults
https://dspace.ewha.ac.kr/handle/2015.oak/227659
Title: Size variability of handwriting in healthy Korean older adults
Ewha Authors: 박은정
Abstract: Aging; Elderly; Handwriting; Visuomotor integration
2014-01-01T00:00:00Z
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Development of smartphone application that aids stroke screening and identifying nearby acute stroke care hospitals
https://dspace.ewha.ac.kr/handle/2015.oak/227470
Title: Development of smartphone application that aids stroke screening and identifying nearby acute stroke care hospitals
Ewha Authors: 박은정
Abstract: Emergency delivery service; Smartphone; Stroke; Thrombolysis
2014-01-01T00:00:00Z