• Journal of Internet Computing and Services
• /
• v.22 no.1
• /
• pp.1-11
• /
• 2021

Estimation of distribution algorithm (EDA) is a popular stochastic metaheuristic algorithm. EDA has been widely utilized in various optimization problems. However, it has been shown that the diversity of the population gradually decreases during the iterations, which makes EDA easily lead to premature convergence. This article introduces a hybrid estimation of distribution algorithm (EDA) with differential evolution (DE) based on self-adaptive strategy, namely HEDADE-SA. Firstly, an alternative probability model is used in sampling to improve population diversity. Secondly, the proposed algorithm is combined with DE, and a self-adaptive strategy is adopted to improve the convergence speed of the algorithm. Finally, twenty-five benchmark problems are conducted to verify the performance of HEDADE-SA. Experimental results indicate that HEDADE-SA is a feasible and effective algorithm.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04a
• /
• pp.4-6
• /
• 2003

시스템의 구조는 확장 또는 부하 균형을 위해 재구성 및 재구조화가 필요하다. 이러한 상황에서, 다수의 새로운 시스템이 기존의 시스템에 추가되며 이전의 시스템이 담당하고 있던 역할의 일부분이 새로 추가된 시스템으로 분산된다. 이러한 자원 관리는 몇 가지 문제를 야기시키는데, 가장 큰 문제점은 일부 시스템 또는 전체 시스템의 재구조화를 위해 일정기간 동안 서비스 제공이 중단된다는 점이다. 이 논문에서는 동적인 자원관리가 요구되는 변화하는 환경에서 자동적으로 새로운 시스템을 추가하고 적응적으로 시스템의 부하를 재조정할 수 있는 이동 컴퓨팅 모델을 제안한다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2000.04b
• /
• pp.449-457
• /
• 2000

The paper describes the study of global approximate optimization utilizing soft computing techniques such as genetic algorithms (GA's), neural networks (NN's), and fuzzy inference systems(FIS). GA's provide the increasing probability of locating a global optimum over the entire design space associated with multimodality and nonlinearity. NN's can be used as a tool for function approximations, a rapid reanalysis model for subsequent use in design optimization. FIS facilitates to handle the quantitative design information under the case where the training data samples are not sufficiently provided or uncertain information is included in design modeling. Properties of soft computing techniques affect the quality of global approximate model. Evolutionary fuzzy modeling (EFM) and adaptive neuro-fuzzy inference system (ANFIS) are briefly introduced for structural optimization problem in this context. The paper presents the success of EFM depends on how optimally the fuzzy membership parameters are selected and how fuzzy rules are generated.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.10a
• /
• pp.61-64
• /
• 2015

데스크톱 가상화 기반 대규모 가상 플랫폼 인프라 시스템은 다양한 모바일 및 경량 단말 사용자에게 네트워크를 통해 가상 플랫폼 서비스를 끊김 없이 제공하는 것을 목적으로 한다. 대규모 사용자 지원 및 적응형 가상 플랫폼 서비스를 위해서는 가상 플랫폼 전송 프로토콜의 경량화를 통한 서비스 부하를 감소시켜 서버당 가상 플랫폼 서비스 댓수의 증가 및 모바일 사용자 지원을 위한 네트워크 대역폭 부하 감소가 필요하다. 본 논문에서는 클라우드 인프라 상에서 사용자의 컴퓨팅 환경에 최적화된 가상 플랫폼 서비스 제공 및 서비스 부하 감소를 위한 네트워크 경량 프로토콜 전송 시스템을 설계 및 구현한다.

• Journal of KIISE:Computing Practices and Letters
• /
• v.9 no.4
• /
• pp.431-438
• /
• 2003

In this study, we have developed a web-based adaptive testing system using item response theory´s computerized adaptive testing to diagnose underachievers, and to check the evaluation results immediately. Adaptive testing system simple is not the fact that it presents a question to students. It calculates information of a question and presents the question to students. It controls the response of the students under extraction conditions of the next question. It extracts the question which is the most suitable it presents. In this adaptive testing system, you can extract questions according to the level of the students, and adjust the length and the level of the difficulty according to the response of the students.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.8
• /
• pp.823-829
• /
• 2003

For high frequency microstrip line modelling, a fast inductance extraction technique using an adaptive PEEC(partial element equivalent circuit) grid is proposed. The grid refinement technique is based on the current distribution depend on the excitation frequencies and the geometry of the microstrip lines. The adaptive ids are refined mainly in the area where heavy currents reside. This technique is applied to the inductance extraction of the microstrip lines. The results show fast convergence, and this adaptive technique is efficient to reduce computing time and the number of grids.

• Nuclear Engineering and Technology
• /
• v.43 no.6
• /
• pp.531-546
• /
• 2011

The backward differentiation formula (BDF) method is applied to a three-dimensional reactor kinetics calculation for efficient yet accurate transient analysis with adaptive time step control. The coarse mesh finite difference (CMFD) formulation is used for an efficient implementation of the BDF method that does not require excessive memory to store old information from previous time steps. An iterative scheme to update the nodal coupling coefficients through higher order local nodal solutions is established in order to make it possible to store only node average fluxes of the previous five time points. An adaptive time step control method is derived using two order solutions, the fifth and the fourth order BDF solutions, which provide an estimate of the solution error at the current time point. The performance of the BDF- and CMFD-based spatial kinetics calculation and the adaptive time step control scheme is examined with the NEACRP control rod ejection and rod withdrawal benchmark problems. The accuracy is first assessed by comparing the BDF-based results with those of the Crank-Nicholson method with an exponential transform. The effectiveness of the adaptive time step control is then assessed in terms of the possible computing time reduction in producing sufficiently accurate solutions that meet the desired solution fidelity.

• Journal of Internet Computing and Services
• /
• v.9 no.3
• /
• pp.51-58
• /
• 2008

Wireless sensor networks are used by various application areas to implement smart data processing and ubiquitous system. In the recent research of parking management system based on wireless sensor networks, adaptive sensing and efficient data processing are not considered. The effectiveness of implementing these distributed computing devices affects the performance of the applications in parking management. This paper proposes an adaptive sensing using fuzzy wireless sensor for the ubiquitous networks of parking management system. The fuzzy inference system is encoded in the sensor for efficient car presence detection. Moreover, a rule base adaptive module is proposed which wirelessly transmit the new values to each sensor for adapting the environment of car park area. The result of experiments shows that the fuzzy wireless sensor provides more throughputs and less time delays compared to a normal method of data gathering by wireless sensors.

• The KIPS Transactions:PartA
• /
• v.12A no.6 s.96
• /
• pp.485-492
• /
• 2005

Currently workflows in business processes and distributed computing environments have provided service automation by connecting many tasks with rules and/or orderings. The services in ubiquitous computing environments have to automatically provide users with adaptive services according to dynamically changing contort information, which is obtained from both the users and their environment. To adapt these workflows to ubiquitous computing, we must specify the situation information on the transition conditions. In this paper, we propose uWDL, Ubiquitous Workflow Description Language, based on Web Services to use the situation information on the transition constraints of workflow's services. uWDL can select adaptive services according to contexts, profiles, and events information, which are situation information. Furthermore, we verified the execution of a scenario document described with uWDL using the parser and the context handler for uWDL. The scenario developers can use the uWDL scenario editor for a design of scenarios, and they can easily specify the transition condition of the services according the situation information of ubiquitous environments using the uWDL.

• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.9
• /
• pp.719-727
• /
• 2002

We proposed a decoupled adaptive fuzzy sliding-mode control scheme for a class of fourth-order nonlinear systems. The system is decoupled into two second-order systems such that each subsystem has a separate control target expressed in terms of sliding surface. For these sliding surfaces, we define main and sub target conditions. and, we made intermediate variables which are interconnected both surface conditions from the sub target sliding surface. Then, Two sets of fuzzy rule bases are utilized to represent the equivalent control input with unknown system functions of the main target sliding surface including intermediate variables. The membership functions of the THEN-part, which is used to construct a suitable equivalent control of sliding-mode control, are changed according to the adaptive law. With such a design scheme, we not only maintain the distribution of membership functions over state space but also reduce the computing time considerably. We apply the decoupled adaptive sliding-mode control to a nonlinear Cart-Pole system and confirms the validity of the proposed approach.