• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.133-139
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• 2009

This paper has proposed Flow Holding Time based Link State Update(LSU) Algorithm that has minimized the LSU message overhead in QoS routing and has not had a strong influence on the depreciation of QoS routing performance. We apply a flow holding time in order to decrease the number of LSU message. We have evaluated the performance of the proposed model and the existing algorithms on MCI simulation network using the performance metric as the QoS routing blocking rate and the mean update rate per link, it thus appears that we have verified the performance of this algorithm.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.4
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• pp.286-293
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• 2019

This study compares and analyzes online update techniques, which estimate the parameters of battery equivalent circuit models in real time. Online update techniques, which are based on extended Kalman filter and recursive least square methods, are constructed by considering the dynamic characteristics of batteries. The performance of the online update techniques is verified by simulation and experiments. Each online update technique is compared and analyzed in terms of complexity and accuracy to propose a suitable guide for selecting algorithms on various types of battery applications.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.55-67
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• 2012

Real-time image georeferencing is required to generate spatial information rapidly from the image sequences acquired by multi-sensor systems. To complement the performance of position/attitude sensors and process in real-time, we should employ on-line aerial triangulation based on a sequential estimation algorithm. In this study, we thus attempt to derive an efficient on-line aerial triangulation algorithm for real-time georeferencing of image sequences. We implemented on-line aerial triangulation using the existing Given transformation update algorithm, and a new inverse normal matrix update algorithm based on observation classification, respectively. To compare the performance of two algorithms in terms of the accuracy and processing time, we applied these algorithms to simulated airborne multi-sensory data. The experimental results indicate that the inverse normal matrix update algorithm shows 40 % higher accuracy in the estimated ground point coordinates and eight times faster processing speed comparing to the Given transformation update algorithm. Therefore, the inverse normal matrix update algorithm is more appropriate for the real-time image georeferencing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1571-1576
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• 2018

Recently, the attractive changes of mobile device are a improvement of the computing performance, dramatic improvement of storage capacity, constant connection to the internet, and sophisticated development of display technology. As a result, database applications utilizing mobile devices are emerging. These applications include databases for mobile servers, databases for edge computing, and fog computing. Therefore, it is important to pay attention to the current mobile database and pay attention to whether it has suitable performance for the applications. In this paper, the most common mobile database, SQLite3 is selected and experimented to test and understand the update performance and characteristics. The results of experiment are compared with the one of Oracle database at the same condition to evaluate the experiment. As a result, Insert Performance of SQLite3 has a lot of points to be improved and Update performance is very good. Especially, the performance of Range Query is excellent.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.1 s.307
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• pp.35-44
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• 2006

Recently, a lot of index techniques for storing and querying XML document have been studied so far and many researches of them used coordinate-based methods. But update operation and query processing to express structural relations among elements, attributes and texts make a large burden. In this paper, we propose an efficient BitmapInvert index technique based on Relative Position Coordinate (RPC). RPC has good preformance even if there are frequent update operations because it represents relationship among parent node and left, right sibling nodes. BitmapInvert index supports tort query with bitwise operations and does not casue serious performance degradations on update operations using PostUpdate algerian. Overall, the performance could be improved by reduction of the number of times for traversing nodes.

• Journal of information and communication convergence engineering
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• v.13 no.1
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• pp.42-49
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• 2015

In laser pointer interaction systems, laser spot detection is one of the most important technologies, and most of the challenges in this area are related to the varying backgrounds, and the real-time performance of the interaction system. In this paper, we present a robust dictionary construction and update algorithm based on a sparse model of background subtraction. In order to control dynamic backgrounds, first, we determine whether there is a change in the backgrounds; if this is true, the new background can be directly added to the dictionary configurations; otherwise, we run an online cumulative average on the backgrounds to update the dictionary. The proposed dictionary construction and update algorithm for laser spot detection, is robust to the varying backgrounds and noises, and can be implemented in real time. A large number of experimental results have confirmed the superior performance of the proposed method in terms of the detection error and real-time implementation.

• The KIPS Transactions:PartC
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• v.10C no.6
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• pp.755-762
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• 2003

For the route optimization in the MIPv6, MN(Mobile Node) sends CN(Correspondent Node) a binding update message to notify the binding of is HoA(Home Address) with its new CoA(Care-of Address). However, unautenticated binding updates expose the involved MN and CM to various sucurity attacks. Thus, protecting the binding update process becomes of paramount importance in the MIPv6, and several secure binding update protocols, and the performance of packet exchanges and cryptographic operations. Then, we analyze the four typical binding update protocols based on the presented criterions. In addition, we propose some improvement tips for secure binding updates.

• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.27-36
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• 2004

Frequent occurrence of binding update messages may incur high overhead in Mobile IP supporting users mobility. Thus, it needs to develop algorithms to deal with the situation. In this paper, we propose new lifetime assignment schemes for dynamic binding update considering the locality property related with mobile node's movement. Each mobile node maintains a profile which is based on log containing useful information about its visiting subnets. That is, it determines dynamic binding update lifetime for currently visiting subnet by computing past mean resident time recorded in the profile. In addition, we note that the resident time depends on the time when each node enters a subnet and thus, we devise another lifetime assignment algorithm. Extensive experiments are made to compare our schemes with existing Mobile IPv6 where major facts for performance comparison are both the number of binding update messages and the number of binding request messages. From the results, we come to know that our schemes obtain highly considerable performance improvements in terms of communication cost by decreasing the number of those messages.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2245-2252
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• 1999

Since DSM provides a user a simple shared memory abstraction, the user does not have to be concerned with data movement between hosts. Each node in DSM systems has processor, memory, and connection to a network. Memory is divided into pages, and a page can have multiple copies in different nodes. To maintain data consistency between nodes, two conventional protocols are used : write-update protocol and invalidate protocol. The performance of these protocols depends on the system parameters and the memory access patterns. for adapting to memory access patterns, competitive update protocol updates those copies of a page that are expected to be used in the near future, while selectively invalidating other copies. We present weighted competitive update protocols that consider different communication bandwidth for each connection a of two nodes. Test result by simulation show that the weighted competitive update protocol improves performance.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.5
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• pp.365-373
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• 2013

Tile caching technology is a commonly used method that optimizes the delivery of map imagery across the internet in modern WebGIS systems. However the poor performance of the map tile cache update is one of the major causes that hamper the wider use of this technique for datasets with frequent updates. In this paper, we introduce a new algorithm, namely, Partial Area Cache Update (PACU) that significantly minimizes redundant update of map tiles where the update frequency of source map data is very large. The performance of our algorithm is verified with the cadastral map data of Pyeongtaek of Gyeonggi Province, where approximately 3,100 changes occur in a day among the 331,594 parcels. The experiment results show that the performance of the PACU algorithm is 6.6 times faster than the ESRI ArcGIS SERVER$^{(r)}$. This algorithm significantly contributes in solving the frequent update problem and enable Web Map Tile Services for data that requires frequent update.