• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.12
• /
• pp.5723-5743
• /
• 2018

The evolving internet-based services demand high-speed data transmission in conjunction with scalability. The next generation optical network has to exploit artificial intelligence and cognitive techniques to cope with the emerging requirements. This work proposes a novel way to solve the dynamic provisioning problem in optical network. The provisioning in optical network involves the computation of routes and the reservation of wavelenghs (Routing and Wavelength assignment-RWA). This is an extensively studied multi-objective optimization problem and its complexity is known to be NP-Complete. As the exact algorithms incurs more running time, the heuristic based approaches have been widely preferred to solve this problem. Recently the software-defined networking has impacted the way the optical pipes are configured and monitored. This work proposes the dynamic selection of path computation algorithms in response to the changing service requirements and network scenarios. A software-defined controller mechanism with a novel packet matching feature was proposed to dynamically match the traffic demands with the appropriate algorithm. A software-defined controller with Path Computation Element-PCE was created in the ONOS tool. A simulation study was performed with the case study of dynamic path establishment in ONOS-Open Network Operating System based software defined controller environment. A java based NOX controller was configured with a parent path computation element. The child path computation elements were configured with different path computation algorithms under the control of the parent path computation element. The use case of dynamic bulk path creation was considered. The algorithm selection method is compared with the existing single algorithm based method and the results are analyzed.

• KIPS Transactions on Computer and Communication Systems
• /
• v.10 no.4
• /
• pp.93-100
• /
• 2021

The Ethereum shard system for solving the scalability problem of the blockchain has a load balancing issue, which is modeled as a graph partitioning problem. In this paper, we propose an adaptive online weighted graph partitioning algorithm that can negotiate between two utility of the shard system using the game theory's bargaining solution. The bargaining solution is an axiomatic solution that can fairly determine the points of conflict of utility. The proposed algorithm was improved to apply the existing online graph partitioning algorithm to the weighted graph, and load balancing was performed efficiently through the design considering the situation of the sharding system using the extension of Nash bargaining solution, which is extended to apply solution to non-convex feasible set of bargaining problem. As a result of the experiment, it showed up to 37% better performance than typical load balancing algorithm of shard system.

• Korean Journal of Computational Design and Engineering
• /
• v.17 no.2
• /
• pp.123-131
• /
• 2012

The requirements for computational resources to perform the structural analysis are increasing rapidly. The size of the current analysis problems that are required from practical industry is typically large-scale with more than millions degrees of freedom (DOFs). These large-scale analysis problems result in the requirements of high-performance analysis codes as well as hardware systems such as supercomputer systems or cluster systems. In this paper, the pre- and post-processing system for supercomputing based large-scale structural analysis is presented. The proposed system has 3-tier architecture and three main components; geometry viewer, pre-/post-processor and supercomputing manager. To analyze large-scale problems, the ADVENTURE solid solver was adopted as a general-purpose finite element solver and the supercomputer named 'tachyon' was adopted as a parallel computational platform. The problem solving performance and scalability of this structural analysis system is demonstrated by illustrative examples with different sizes of degrees of freedom.

• Journal of the Korea Society of Computer and Information
• /
• v.9 no.3
• /
• pp.45-53
• /
• 2004

The fact that the end-user response time could become unacceptable in the 2-tier C/S system has been well known to C/S system developers. But inexperienced new developers who want to provide mobile solutions using PDA sometimes do not realize the ominous consequences of the 2-tier C/S systems. Except for the easy of development. the 2-tier C/S system has many weak points like in application deployment, security, scalability, application reuse, heterogeneous DBMS support, availability. and response time. This paper analyzes the response time in the 2-tier and 3-tier C/S systems through simulation. Although the problem space is confined to the 2 and 3 tiers, the result could be equally applied to any multi-tier systems.

• Journal of the Korea Computer Industry Society
• /
• v.5 no.9
• /
• pp.891-902
• /
• 2004

Membership changing is deeply associated with scalability problem for group key management. If members of the group join or leave, new group key has to be geneerated and distributed to all remaining members of group. Group key changing is perform for group controller. The following parameters are important evaluating criteria of multicast key management scheme that generate and deliver new keys for rekeying: the number of keys stored by both controller and member, messages to deliver, keys to initially be delivered by controller, blocking capability of collusion attacks, messages to deliver at the batch rekeyng. Batch rekeying can reduce messages to deliver and operation costs of generation for message rather than removing members sequentially in fashion one after another. We propose efficient batch rekeying scheme applicable to Pegueroles scheme using random number and prove to be a efficient group key scheme for enhanced Pegueroles model with batch rekeying capability.

• The Journal of the Korea Contents Association
• /
• v.3 no.3
• /
• pp.63-73
• /
• 2003

Today, in exponential growth of internet, the importance of file caching which could reduce the sun load, the volume of network traffic, and the latency of response has emerged. Actually, in one network, the traffic has reduced by using the cache and this means that file caching can improve the internet environment by cost a fraction of link upgrades. In this paper, we address a dynamic cache group configuration policy, to solve the scalable problem. The simulation result shows that the cache group using our proposal policy reduces the latency of response time and it means that out cache group configuration is more scalable than the static cache configuration.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2000.04a
• /
• pp.691-694
• /
• 2000

기존 LAN 환경에서 인터넷을 이용한 멀티미디어 실시간 전송과 같은 QoS 보장형 서비스에 대한 요구가 증대되면서, 고속의 ATM 기술을 LAN에 적용하는 기술들이 등장하였다. LANE(LAN Emulation)은 그러한 기술 대안들 중에서 campus network와 enterprise network에 많이 보급되고 있는 기술이다. 그러나 이러한 급격한 LANE 도입에 비하여 이의 효과적인 운용에 대한 연구는 많지 않은 실정이다. 본 논문에서는 LANE을 도입한 campus network의 최적 운영방안에 대하여 논한다. Broadcast 데이터 트래픽 관리에서 발생하는 규모성(Scalability) 문제로 인하여 전체 LANE망은 여러 개의 ELAN으로 나뉘어 관리된다. 이 때 하나의 ELAN은 마치 단위 LAN로써, Broadcast 데이터의 전송범위를 제한한다. 즉, 서로 다른 ELAN에 속하는 노드간에는 Broadcast 방식으로 데이터를 전송할 수 없게 된다. 그런데, IPX 등을 사용하는 대화형 시뮬레이션 게임 등과 같은 응용프로그램에서는 Broadcast 방식이 이용되므로, 서로 다른 ELAN에 속하는 노드간의 데이터 전송은 불가능하게 되거나 별도의 복잡한 과정을 개입시켜야 하는 비용이 발생한다. 따라서 규모성 문제해결을 위한 ELAN 구성(configuration)에는 위와 같은 비용이 수반된다. 본 연구에서는 LANE망을 여러 개의 ELAN으로 분할하는 경우에 블로킹(blocking) 되는 Broadcast 트래픽 규모를 해당 ELAN 구성의 비용으로 간주한다. 이 경우에 규모성을 고려한 ELAN의 최적 구현방안(optimal configuration)은 ELAN 구성을 위한 기술적 제약하에서 블로킹되는 Broadcast 트래픽을 최소화시키는 문제로 요약된다. 이는 다시 그래프 분할문제(graph partition problem)의 변형된 형태로 모형화 될 수 있다. 본 논문에서는 이러한 사항들을 고려하여 제시된 수리적 모형을 대상으로, genetic algorithm을 이용하여 최적 ELAN 구성을 위한 여러 파라미터들의 효과를 살펴보고, 이러한 결과들이 LANE 운영과 관련하여 가지는 함축적인 의미를 고찰한다.

• Genomics & Informatics
• /
• v.1 no.2
• /
• pp.65-74
• /
• 2003

Data mining differs primarily from traditional data analysis on an important dimension, namely the scale of the data. That is the reason why not only statistical but also computer science principles are needed to extract information from large data sets. In this paper we briefly review data mining, its characteristics, typical data mining algorithms, and potential and ongoing applications of data mining at biopharmaceutical industries. The distinguishing characteristics of data mining lie in its understandability, scalability, its problem driven nature, and its analysis of retrospective or observational data in contrast to experimentally designed data. At a high level one can identify three types of problems for which data mining is useful: description, prediction and search. Brief review of data mining algorithms include decision trees and rules, nonlinear classification methods, memory-based methods, model-based clustering, and graphical dependency models. Application areas covered are discovery compound libraries, clinical trial and disease management data, genomics and proteomics, structural databases for candidate drug compounds, and other applications of pharmaceutical relevance.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.11
• /
• pp.2869-2885
• /
• 1996

There werer many researches on the switch system for high speed netowrk such as B-ISDN and the server system for the multimedia services respectively. But, in case of simple connection of these two systems, we have to suffer the bottlenck problem of data transmission, and pay the wasteful expenditure because of duplicated architecture of both systems such as interconnecting network at the switch and the server. Therefore, we propse the unified architecture of switehces and servers, which can be used as switches and servers simultaneously. This is based on the hybercube structure. The links are used iterconnection network of switch system, and each node has the subscriber subsystem and the server subsystem. The proposed architecure has the benifits as follows; the easy espansion of capacity due to the scalability,the simple system development and maintenance because of the equivalance of each nodes, the high reliability against the fault of nodes and links due to the existence of the many alternative links between nodes, the easy flow and QoS managment due to the non-blocking data transmission between any two nodes, the flexible adaptation for additional new services owing to simple insertion server board to node. In this paper, we present overal configuration and node component of proposed architecture, and the procesing flow for the various services.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.10
• /
• pp.620-629
• /
• 2005

In this paper, a new protocol-based approach was proposed for development of a ubiquitous vision system. It is possible to apply the approach by regarding the ubiquitous vision system as a multiagent system. Thus, each vision sensor can be regarded as an agent (vision agent). Each vision agent independently performs exact segmentation for a target by color and motion information, visual tracking for multiple targets in real-time, and location estimation by a simple perspective transform. Matching problem for the identity of a target during handover between vision agents is solved by the Identified Contract Net (ICN) protocol implemented for the protocol-based approach. The protocol-based approach by the ICN protocol is independent of the number of vision agents and moreover the approach doesn't need calibration and overlapped region between vision agents. Therefore, the ICN protocol raises speed, scalability, and modularity of the system. The protocol-based approach was successfully applied for our ubiquitous vision system and operated well through several experiments.