• The Transactions of the Korea Information Processing Society
• /
• v.1 no.2
• /
• pp.172-183
• /
• 1994

In the multidatabase systems(MDBS), local autonomy and global consistency are important issues. Global consistency could be maintained by a global concurrency control algorithm and a global recovery algorithm. In this thesis, we propose a global concurrency control algorithm to ensure local autonomy and to guarantee global serializability, and a global recovery algorithm which is possible to recover the multudatabase from any failures. The proposed global concurrency control algorithm uses bottom-up approach, based on three-level transaction processing model. It can produce a local history that the execution order of subtransactions is identical to their serialization order by using dummy-operations in the server when an indirect conflict is caused between subtransactions due to local transactions. At the global module, it can efficiently validate global serializability of global transactions by checking global serializability only for the global transactions which conflict with each other.

• The Journal of the Korea Contents Association
• /
• v.20 no.3
• /
• pp.267-274
• /
• 2020

Click-through rate (CTR) prediction is an estimate of the probability that a user will click on a given item and plays an important role in determining strategies for maximizing online ad revenue. Recently, research has been performed to utilize CNN for CTR prediction. Since the CTR data does not have a meaningful order in terms of correlation, the CTR data may be arranged in any order. However, because CNN only learns local information limited by filter size, data arrays can have a significant impact on performance. In this paper, we propose a multi-array CNN model that generates a data array set that can extract all local feature information that CNN can collect, and learns features through individual CNN modules. Experimental results for large data sets show that the proposed model achieves a 22.6% synergy with RI in AUC compared to the existing CNN, and the proposed array generation method achieves 3.87% performance improvement over the random generation method.

• Journal of the Korea Institute of Building Construction
• /
• v.15 no.6
• /
• pp.631-639
• /
• 2015

In the unit modular construction, the unit module prefabricated in a factory with a high level of accuracy does not fit completely onto the ground-joint junction due to the low accuracy of the ground work. This difference in the level of accuracy can cause diverse problems, such as twisting the upper unit modules and loosening the connection between the module and the footing. On this background, the aim of this study is to develop a technique for adjusting the height of the prefabricated individual footing. To accomplish the aim, a height adjustment method using bolts and nuts is proposed, and a shop drawing and the construction sequence are also presented in this study. The structural safety is verified through a structure simulation. In the future, research will be conducted on a mock-up test of the height adjustment method developed in this study, and an analysis of economic feasibility will be performed in order to verify its constructability and usability.

• Proceedings of the Korea Contents Association Conference
• /
• 2006.11a
• /
• pp.172-175
• /
• 2006

Hamel has a scholastic value as the first person, who announces Jeju and Korea to Europe. However, there has been little research on developing digital contents except a few books about Hamel. We develop an educational game on PDA using Hamel, based on Hamel character, Jeju's unique culture, multimedia technology, and so on. Compared with the previous games, it is different from the form of gathering points and has various game scenarios through interactions between Hamel character and game space. The structure of this game, which connects Jeju culture and cyber space together, represents the form of a digital storytelling. You can study through this game. It uses quizzes about Jeju culture, crossword puzzles, finding a sequence, finding differences between two pictures to teach users, and fixing pieces of a figure, etc. When we made the game, we divided it into some independent modules to make new game series easily using contents of the other provinces.

• Journal of the Korean Vacuum Society
• /
• v.5 no.4
• /
• pp.284-291
• /
• 1996

We have implemented a fast pressure control system for the transport chamber of a high vacuum cluster tool for advance semiconductor fabrication and evaluated its performance. To overcome the typically slow response of mass flow controllers, the modified experimental method is used very effectively to optimize the pressure control procedure. We successfully obtained quite fast pressure control by adjusting the starting time and eht tuning constants by the Ziegler-Nichols method. In the transport pressure $10\times 10^{-5}$ torr, actual pressure control starts from 4 sec after an initial gas load of 2.1 sccm. As a result, optimum conditions for the tuning constants are the rise rate of 0.02 torr/sec, the lag time of 0.15 sec, and the sampling period of 0.5 sec. Then the settling time is about 9 sec within about $\pm$0.5% for the referenced value. This settling time is enhanced above 75 percents in comparison with conventional experimental method. To account for the experimental effects observed, a theoretical model was developed. This experimental result has a tendency to fit with the theoretical result of $\omega$=-1.0.

• Convergence Security Journal
• /
• v.7 no.1
• /
• pp.77-82
• /
• 2007

Supporting Quality of Service (QoS) for multimedia services in heterogeneous mobile networks is a part of key issue for Beyond Three Generation (B3G) development. In particular, if QoS degradation are occurred because cell overload and error late patterns of wireless links during the transmission of multimedia data, the efficient QoS management is necessary to maintain the same QoS of transmitted multimedia data because the QoS may be defected by some delay and information loss. This paper deals with QoS Degradation reason Intra-System Handover (D-ISHO) for handling QoS of multimedia services over heterogeneous mobile networks. For this aim, the function modules for supporting QoS of D-ISHO are proposed. The sequence diagram showing interaction between the modules is described and then a scenario for D-ISHO is considered. Simulation is focused on the average delay and packet loss rate. The proposed heterogeneous mobile system using the QoS-Guaranteed Resource Management (QGRM) provides a better performance than each different access system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.8
• /
• pp.1169-1174
• /
• 2002

In this paper, we implemented the sign board system that displays user's image, user's sentence, the information from DARC. The existing sign board is displaying only user's image and sentence. Or other existing sign board is displaying the information via CDMA network. However, our system is also able to display the user's message like other system and gain the information more cheap by DARC. This system includes the main processor, the program memory, the external memory, the DARC module and the LED display module. The external memory stores the user's message files and the order file that decides the displaying order of user's file and the DARC information The DARC module extracts the DARC information from FM signal. From the experiment, we could confirm that this system display the DARC information and the user's message by the order file.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.4
• /
• pp.111-120
• /
• 2009

In this paper, we propose ubiWarehouse system which can efficiently manages mass and many kinds of parts such as automotive parts. First, user's work situation is defined systematically as context type of 5W1H, context-aware system is separated on function, and each module operates independently. An efficient route is selected and relevant parts frequently treated at the same time are gathered by calculating the suitability of parts and racks. If other users currently are on a visit or are supposed to visit soon, the hun of visit is changed making a concession for preventing collision. As a result, the proposed system with avoiding competition can provide users with routes for inbound or outbound parts, and can effectively use spaces of a warehouse by arranging racks to gather relevant parts to near location. Also, individual service can be offered by evaluating user propensity using history of the warehouse job, and the accuracy of stock information can be improved by processing of unexpected context and real-time renewing of warehousing and delivering.

• KIPS Transactions on Software and Data Engineering
• /
• v.8 no.4
• /
• pp.145-152
• /
• 2019

Unlike a single value from a sensor device, a massive data set has characteristics for various processing aspects; input data may be formed in a different format, the size of input data varies, and the processing time of analyzing input data is not predictable. Therefore, context aware systems may contain complex modules, and these modules can be implemented and used in different ways. In order to solve these problems, we propose a method to handle context information from the result of analyzing massive data. The proposed method considers analysis work as a different type of abstracting context and suggests the way of representing context information. In experiment, we demonstrate how the context processing engine works properly in a couple of steps with healthcare services.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.5
• /
• pp.1067-1072
• /
• 2014

As the service continuity of mobile multimedia service is affected by packet loss and delay, the efficient handover control is essentially required. This paper proposes a handover admission control scheme to satisfy service continuity of mobile multimedia services in LTE-Advanced System. In this method, based on context information of mobile terminal and base station changes, the sequence diagrams between the function modules for controlling new sessions and ISHO sessions are proposed. Simulation is done for performance analysis with the measure of transmission delay and packet loss rate.