• Information Systems Review
• /
• v.10 no.3
• /
• pp.223-255
• /
• 2008

This study explores the determinants and processes of IT consolidation of Korean conglomerates. Through an extensive analysis of cases, this study identifies the drivers, benefits and critical success factors of IT consolidation, and observes the transition of vision for the IT service subsidiaries in the conglomerates. The results show that most firms in this analysis have completed the organizational, physical, and logical consolidation of their IT resources, and currently some of them are preparing for the next stage of IT consolidation such as rational consolidation and virtualization. It is also found that the strategic factor was one of the most significant determinants in consolidating IT resources which leaded the transition of vision of the IT service firms in the conglomerates from "cost center" to "profit center". The results of this study can provide a fundamental and empirical basis for building a theory of IT consolidation, and be used as a valuable benchmarking model for the organizations which consider starting a project of IT consolidation.

• Nuclear Engineering and Technology
• /
• v.18 no.3
• /
• pp.218-227
• /
• 1986

Studies were conducted to determine the extent of oxidation and same of the mechanical property changes of Zircaloy-4 fuel cladding after it was exposed to hot steam environment. The purpose of these tests was to provide some informations on the embrittlement behavior of CANDU type fuel cladding, which could be experienced under the loss-of-coolant accident conditions. The Zircaloy fuel cladding tubes were exposed in a steam environment at the temperature of 90$0^{\circ}C$, 1,00$0^{\circ}C$. The growth of the ZrO$_2$ layer combined with an oxygen rich $\alpha$-phase layer into the Zircaloy tube material was found as a function of time t and temperature of steam exposure, E=1.1√Dt+0.002 where D is a temperature dependent diffusion coefficient. The tensile strength of the specimens exposed for a short period increased but decreased continuously with further exposure. The circumferential elongation was drastically changed with the exposure time while the hoop strength did't decrease greatly. The X-ray measurement of preferred orientation of the Zircaloy tube material indicated that grains in the as received tube were oriented such that the poles of the basal (0001) planes were predominantly radial, while the poles of the basal plane in the tube materials heattreated at 1,00$0^{\circ}C$ were oriented tangentially. It appears that this reoriented texture may contribute to lessening the decrease of the hoop strength of the heat treated Zircaloy tube material.

• Cartoon and Animation Studies
• /
• s.15
• /
• pp.221-235
• /
• 2009

Most of the sounds used in animated films are artificially made. A large number of the sounds used are either actual sound recordings or diversely processed artificial sounds made with professional sound equipments such as synthesizers. One animation episode contains numerous amounts of sounds, resulting in significant sound production costs. These sounds have full potential to be reused in different films or animations, but in reality we fail to do so. This thesis discusses ways these sound sources can be acknowledged as added new values to the present market situation as a usable 'digital content'. The iTunes Music Store is an American Apple company product that is acknowledged as the most successful digital content distribution model at the time being. Its system's sound library has potential for application in the Korean sound industry. In result, this system allows the sound creator to connect directly to the online store and become the initiative content supplier. At the same time, the user can receive a needed content easily at a low price. The most important part in the construction of this system is the search engine, which allows users to search for data in short periods of time. The search engine will have to be made in a new manner that takes into consideration the characteristics of the Korean language. This thesis presents a device incorporating the Wiki System to allow users to search and build their own data bases to share with other users. Using this system as a base, the Korean animation sound library will provide development and growth in the sound source industry as a new digital sound content.

• Journal of KIISE:Information Networking
• /
• v.34 no.5
• /
• pp.348-359
• /
• 2007

The conventional mobile VPN services assumed the mobile communications occur between the MN in foreign networks and the CN in the home network. However, if a MN wants to communicate with another MN in a foreign network, it could degrade the performance of the mobile VPN service because of the triangular routing problem. In this paper, we propose a route optimization mechanism based on the mobile VPN using an x-HA allocated by diameter MIP in order to support the efficient communication between the mobile VPN users in foreign networks. The i-HA maintains the VPN-TIA as well as the x-HoA as the CoAs to solve the security problem and to provide an efficient route optimization simultaneously. Moreover, we proposed revised IPSec tunnel configuration to reduce the IPSec tunnel overheads at a MN when the MN communicates with several MNs in the foreign networks at the same time. The VPN server, a security management entity in the home network, notifies an additional IPSec tunnel establishment between the x-HAs where the communication peers are registered. The simulation result showed that the proposed scheme decreases the end-to-end packet delay time and improves the throughput after the handoff compared to the existing mechanism.

• Science of Emotion and Sensibility
• /
• v.12 no.3
• /
• pp.267-278
• /
• 2009

Today an embodied agent generates a large amount of interest because of its vital role for human-human interactions and human-computer interactions in virtual world. A number of researchers have found that we can recognize and distinguish between various emotions expressed by an embodied agent. In addition many studies found that we respond to simulated emotions in a similar way to human emotion. This study investigates interpretation of mismatched emotions expressed by an embodied agent (e.g. a happy face with a sad voice); whether audio-visual channel integration occurs or one channel dominates when participants judge the emotion. The study employed a 4 (visual: happy, sad, warm, cold) $\times$ 4 (audio: happy, sad, warm, cold) within-subjects repeated measure design. The results suggest that people perceive emotions not depending on just one channel but depending on both channels. Additionally facial expression (happy face vs. sad face) makes a difference in influence of two channels; Audio channel has more influence in interpretation of emotions when facial expression is happy. People were able to feel other emotion which was not expressed by face or voice from mismatched emotional expressions, so there is a possibility that we may express various and delicate emotions with embodied agent by using only several kinds of emotions.

• Journal of KIISE:Computing Practices and Letters
• /
• v.6 no.5
• /
• pp.513-527
• /
• 2000

This paper describes our experience to design and implementation of a collaborative system framework that allows to develop certain collaborative applications such as 3D animation, computer game, and industrial design. The collaborative system enables users, who located in geographically long distance, to do collaborative work in a single virtual space. The proposed system basically consists of client and server system. The goal of proposed system is to support scalability, portability, and platform independent. In order to achieve these, the server is implemented in Java platform and is adopted to the hybrid architecture which takes the advantages both in centralized and decentralized collaborative system. We construct the server base on its functional characteristics so called User Manager Server (UMS), Session Manager Server (SMS), and Information Server (IS), The UMS manages the users who are taking part in the collaborative operations. The SMS supports the conferencing in the proposed system. The IS provides the connection methods among the UMSs. For user's convenience, we implement the client using Visual C++ in Windows. We also expend the functions of 3D Studio Max to distributed environment by means of the plug-in module, and facilitate the chatting and white board functions as well.

• Journal of KIISE:Information Networking
• /
• v.32 no.4
• /
• pp.452-461
• /
• 2005

In the star VPN (Virtual Private Network) topology, the traffic between the communicating two CPE(Customer Premise Equipment) VPN GW(Gateway)s nay be inefficiently transferred. Also, the Center VPN GW nav erperience the overload due to excessive packet processing overhead. As a solution to this problem, a direct tunnel can be established between the communicating two CPE VPN GWs using the IKE (Internet Key Exchange) mechanism of IPSec(IP Security). In this case, however, the tunnel establishment and management nay be complicated. In this paper, we propose a mechanism called' SVOT (Star VPN On-demand Tunnel)', which automatically establishes a direct tunnel between the communicating CPE VPN GWs based on demand. In the SVOT scheme, CPE VPN GWs determine whether it will establish a direct tunnel or not depending on the traffic information monitored. CPE VPN GW requests the information that is necessary to establishes a direct tunnel to the Center VPN GW Through a simulation, we investigate the performance of the scheme performs better than the SYST scheme with respect to scalability, traffic efficiency and overhead of Center VPN GW, while it shows similar performance to the FVST with respect to end-to-end delay and throughput.

• Journal of KIISE:Information Networking
• /
• v.33 no.3
• /
• pp.231-246
• /
• 2006

A server load balancer is used to accept and distribute client requests to one of servers in a wireless internet proxy server cluster. LVS(Linux Virtual Server), a software based server load balancer, can support several load balancing algorithms where client requests are distributed to servers in a round robin way, in a hashing-based way or in a way to assign first to the server with the least number of its concurrent connections to LVS. An improved load balancing algorithm to consider server performance was proposed where they check upper and lower limits of concurrent connection numbers to be allowed within each maximum server performance in advance and apply the static limits to load balancing. However, they do not apply run-time server load information dynamically to load balancing. In this paper, we propose a dynamic load balancing scheme where the load balancer keeps each server CPU load information at run time and assigns a new client request first to the server with the lowest load. Using a cluster consisting of 16 PCs, we performed experiments with static content(image and HTML). Compared to the existing schemes, experimental results show performance improvement in the cases of client requests requiring CPU-intensive processing and a cluster consisting of servers with difference performance.

• Journal of KIISE:Software and Applications
• /
• v.33 no.1
• /
• pp.69-83
• /
• 2006

This paper describes an image disparity estimation method using a segmented-region based stereo matching. Segmented-region based disparity estimation yields a disparity map as the unit of segmented region. However, there is a problem that it estimates disparity imprecisely. The reason is that because it not only have matching errors but also apply an identical way to disparity estimation, which is not considered each type of matched regions. To solve this problem, we proposes a disparity estimation method which is considered the type of matched regions. That is, the proposed method classifies whole matched regions into similar-matched region, dissimilar-matched region, false-matched region and miss-matched region by analyzing the type of matched regions. We then performs proper disparity estimation for each type of matched regions. This method minimizes the error in estimating disparity which is caused by inaccurate matching and also improves the accuracy of disparity of the well-matched regions. For the purpose of performance evaluations, we perform tests on a variety of scenes for synthetic, indoor and outdoor images. As a result of tests, we can obtain a dense disparity map which has the improved accuracy. The remarkable result is that the accuracy of disparity is also improved considerably for complex outdoor images which are barely treatable in the previous methods.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.4
• /
• pp.1-11
• /
• 2013

Dynamic Software Update(DSU) is a technique, which updates a new version of the software to a running process without stopping. Many DSU systems that update C application programs are introduced. However, these DSU systems differ in implementation method or in main features. In this paper, we propose a new DSU system that can solve some disadvantages of existing DSU systems. DSU system presented in this paper splits existing program to code, global data and local data and then updates each part of the program considering the characteristics of the respective parts. The proposed system in this paper is implemented and tested on Linux. Also, we compared our DSU system with other DSU systems and we could find some strength of our DSU system. First, the code memory usage of our DSU system can be efficient since our system does not need to maintain code of an old version. Second, the global data memory waste is small because our system does not need to allocate the global data again which is not modified in the new version. Finally, we restore local data of old version in stack area of the new version using stack reconstruction technique. This paper is meaningful since we proposed a new DSU method and we implemented a full DSU system using the method.