• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10a
• /
• pp.210-212
• /
• 2000

In this paper, we present a comcurrency control scheme over the index structure in main memory databases using multiversion mechanism, and implement it on T-tree. As a well-known idea for comcurrency control, multiversion allows multiple transactions to reat and write different versions of the same data item, each transaction sees a consistent set of versions for all the data items it accesses[1]. Logical versioning and physical versioning techniques are used to keep versions of data item and versions of index node respectively. The main features of this multiversion indexing approach are (1)update operations and rotations on T-tree can take place concurrently, (2)the number of locking and latching requirement is sharply reduced because read-only transactions do not obtain any locks or latches and update transactions obtain latches only when actually performing the update, (3)it reduces storage overhead for tracking version and reclaims storage in time, and (4)it provides complete isolation of read-only transactions from update transactions, so the read-only transactions can get response information without any block.

• Journal of Korean Institute of Industrial Engineers
• /
• v.40 no.1
• /
• pp.43-51
• /
• 2014

Statistical process control (SPC) is an important technique for monitoring and managing the manufacturing process. In spite of its easiness and effectiveness, some problematic sides of application exist such that the SPC techniques are hardly reflect the changes of the process conditions. Especially, update of control limits at the right time plays an important role in acquiring a reasonable performance of control charts. Therefore, we propose the control chart performance evaluation index (CPEI) based on count data model to monitor and manage the performance of control charts. The CPEI could indicate the degree of control chart performance and be helpful to detect the proper update cycle of control limits in real time. Experiments using real manufacturing data show that the proper update intervals are made by proposed method.

• Journal of Life Science
• /
• v.18 no.3
• /
• pp.318-322
• /
• 2008

This paper deals with an efficient management and automatic update sub-system for WASPIFA (Web-based Assistant System for Protein-protein Interaction and Function Analysis) system that had been developed in the past and now provides the comprehensive information on protein-protein interaction and protein function. Protein interacting data has increased exponentially, so that it costs enormous time and effort. In other words, it is actually impossible to manually update and manage an analysis system based on protein interacting data. Even though there exists a good analysis system, it could be useless if it was able to be updated timely and managed properly. Unfortunately, in most cases, biologists without professional knowledge on their analysis systems have to cope with a great difficulty in running them. In this respect, the efficient management and automatic update subsystem of protein interacting and its related data has been developed to facilitate experimental biologists as well as bioinformaticians to update and manage the WASPIFA system.

• Journal of KIISE:Databases
• /
• v.31 no.6
• /
• pp.567-584
• /
• 2004

As XML becomes popular as the way of presenting information on the web, how to secure XML data becomes an important issue. So far study on XML security has focused on security of data communications by using digital sign or encryption technology. But, it now requires not just to communicate secure XML data on communication but also to manage query process to access XML data since XML data becomes more complicated and bigger. We can manage XML data queries by access control technique. Right now current XML data access control only deals with read operation. This approach has no option to process update XML queries. In this paper, we present XML access control model and technique that can support both read and update operations. In this paper, we will propose the operation for XML document update. Also, We will define action type as a new concept to manage authorization information and process update queries. It results in both minimizing access control steps and reducing memory cost. In addition, we can filter queries that have no access rights at the XML data, which it can reduce unnecessary tasks for processing unauthorized query. As a result of the performance evaluation, we show our access control model is proved to be better than other access control model in update query. But it has a little overhead to decide action type in select query.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2006.04a
• /
• pp.411-417
• /
• 2006

As NGIS project has been implemented in 1995 and effectiveness of spatial information increased, Digital maps serve several purpose in administrative, living, and industrial fields. But, Digital maps have many differences with real world information and difficulties in application of managing urban facilities due to high update cost and long generation period. In this study, We suggest methodology to update a building layer of digital map in urban area as regenerating a building layer by detection of changed buildings in the existing digital map anf extraction using LIDAR data and Aerial images, more easier to acquire data and available to guarantee accuracy. Experimental results are expected to applied for constructing 3D urban model in a broad expensive urban area.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.29B no.7
• /
• pp.11-22
• /
• 1992

In this paper, a new indexing technique is proposed for efficient evaluation of nested queries on aggregation hierarchy in object-oriented data model. As an index data structure, an extended $B^{+}$ tree is introduced in which instance identifier to be searched and path information used for update of index record are stored in leaf node and subleaf node, respectively. the retrieval and update algorithm on the introduced index data structure is provided. Comparisons under a variety of conditions are given with current indexing techniques, showing improved performance in cost, i.e., the total number of pages accessed for retrieval and update.

• Journal of the Korean Mathematical Society
• /
• v.57 no.2
• /
• pp.401-414
• /
• 2020

It is computationally expensive to compute principal components from scratch at every update or downdate when new data arrive and existing data are truncated from the data matrix frequently. To overcome this limitations, incremental principal component analysis is considered. Specifically, we present a sliding window based efficient incremental principal component computation from a covariance matrix which comprises of two procedures; simultaneous update and downdate of principal components, followed by the rank-one matrix update. Additionally we track the accurate decomposition error and the adaptive numerical rank. Experiments show that the proposed algorithm enables a faster execution speed and no-meaningful decomposition error differences compared to typical incremental principal component analysis algorithms, thereby maintaining a good approximation for the principal components.

• Asia pacific journal of information systems
• /
• v.13 no.4
• /
• pp.191-206
• /
• 2003

More views in data warehouse, can respond to the users more rapidly because the user's requests might be processed by accessing only the materialized views with higher probabilities rather than accessing base relations. But, the update duration for maintaining materialized views limits the number of materialized views in data warehouse. In this paper, we propose the algorithm for reducing update duration of materialized views, of which aggregation functions are maintained by self-maintenance. We also implement the proposed algorithm and evaluate the performance of the algorithm.

• Journal of the military operations research society of Korea
• /
• v.29 no.1
• /
• pp.28-42
• /
• 2003

The simplex method requires basis update in each iteration, which is the most time consuming process. Several methods have been developed for the update of basis which is represented in LU factorized form, such as Bartels-Golub's method, Forrest-Tomlin's method, Reid's method, Saunders's method, etc. In this research, we compare between the updating methods in terms of sparsity, data structure and computing time issues. The analysis is mainly based on the computational experience.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.4
• /
• pp.909-916
• /
• 2010

In ubiquitous GIS services is possible to use the spatio-temporal data using a mobile device at anytime. Also, client is transmitted latest spatio-temporal data from server. But traditional systems have a problem that the time of transmitting latest information from server to client takes long time because of collecting data periodically. In this paper, we proposed Two-way Synchronization system supporting field update to solve the existing problem. This system uses mobile device for collecting changed data in the real world and sending collected data to server.