• Journal of Korean Tunnelling and Underground Space Association
• /
• v.14 no.2
• /
• pp.107-116
• /
• 2012

The experiment was performed to analyze the intersectional ventilation efficiency by intersection structure and Jet Fan in network-form road tunnel. For this, the size of real road tunnel was reduced by 1/45. To apply traffic inertia force when driving, blower fan was used to form an airflow in model tunnel and the intersectional efficiency was also investigated by measuring the speed at local point of the tunnel. To improve the reduction of ventilation caused by the structure character, Jet Fan was installed to optimize ventilation efficiency in tunnel.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.2
• /
• pp.426-436
• /
• 2000

Given a linear arrangement of n base stations which generate multiple types of traffic among themselves, we consider the problem of finding a set of disjoint clusters to cover n base statons so that a cluster is assigned a location server. Our goal is to minimize the total communication cost for the entire network where the cost of intra-cluster communication is usually lower than that of intercluster communication for each type of traffic. The optimization problem is transformed into an equivavalent problem using the concept of relative cost, which generates the difference of communication costs between intracluster and intercluster communications. Using the relative cost matrix, an efficient algorithm of O($mm^2$), where m is the number of clusters in a partition, is designed by dynamic programming. The algorithm also finds all thevalid partitions in the same polynomial time, given the size constraint on a cluster, and the total allowable communication cost for the entire network.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.21 no.2
• /
• pp.101-110
• /
• 2011

Recently, an attack to an application incapacitates the intrusion detection rule, the defense policy for a network and database and induces intrusion incidents. Thus, it is necessary to study integration security to ensure the security of an internal network and database from that attack. This article is about building an integration security system to prevent an attack to an application set with intrusion detection rules. It responds to network-based attack through detection, disperses attack with the internal integration security system through virtual clustering and load balancing, and sets up defense policy for attacking destination packets, analyzes and records attack packets, and updates rules through monitoring and analysis. Moreover, this study establishes defense policy according to attacking types to settle access traffic through virtual machine partition policy and suggests an integration security system applied to prevent attack and tests its defense. The result of this study is expected to provide practical data for integration security defense for hacking attack from outside.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.3
• /
• pp.99-106
• /
• 2023

In this paper, we propose subregion-based area of interest management techniques for MMORPG(massively multiplayer online role playing games) integrating P2P(peer-to-peer) networking and cloud computing. For the crowded region, the proposed techniques partition it into several subregions and assign a player to manage each subregion as a coordinator. These techniques include a load balancing mechanism which regulates communication and computation overhead of such player below the specified threshold. We also provide a mechanism for satisfying the criterion, where subregions overlapped with each player's view must be switched quickly and seamlessly as the view moves around in the game world. In the proposed techniques where an efficient provisioning of resources is realized, they relieve a lot of computational power and network traffic, the load on the servers in the cloud by exploiting the capacity of the players effectively. Simulation results show that the MMORPG based on cloud and P2P architecture can reduce the considerable bandwidth at the server compared to the client server architecture as the available resources grow with the number of players in crowding or hotspots.