• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.48 no.4
• /
• pp.365-370
• /
• 1999

This paper describes the Weekly Load Forecasting Expert System(Named WLoFy) which was developed and implemented for Korea Electric Power Corporation(KEPCO). WLoFy was designed to provide user oriented features with a graphical user interface to improve the user interaction. The various forecasting models such as exponential smoothing, multiple regression, artificial nerual networks, rult-based model, and relative coefficient model also have been included in WLofy to increase the forecasting accuracy. The simulation based on historical data shows that the weekly forecasting results form WLoFy is an improvement when compared to the results from the conventional methods. Especially the forecasting accuracy on special days has been improved remakably.

• Journal of Preventive Medicine and Public Health
• /
• v.33 no.2
• /
• pp.215-225
• /
• 2000

Objective : The purpose of this study was to examine the therapeutic compliance and its related factors in the rural hypertensives. Method : A questionnaire survey and blood pressure measurement were performed to 3,876 residents of a rural area, and 660 hypertensives were selected as subjects of study. The study employed a hypothetical model which was composed of constructs from the health belief model and KAP model. The analysis techniques employed included contingency table analysis and structural equation modeling. Result : The proportion of those who were compliant to the treatment of hypertension was 44.2% of subjects. As the result of structural equation modeling, when patients had more favorable attitude toward treatment, higher perceived benefit, or lower perceived barriers to treatment, the therapeutic compliance was significantly higher(T>2.0). When patients had more knowledge about hypertension, or higher perceived severity of hypertension, the attitude toward the treatment of hypertension was more favorable significantly(T>2.0). And when patients had the support for treatment from family or neighbor, the attitude toward treatment was more favorable(T>2.0). When patients had experience of health education, they had more knowledge, higher perceived susceptibility of complication, perceived severity for hypertension, and perceived benefit of treatment, compare to patients without health education(T>2.0). Conclusion : In consideration of above findings, in order to improve the therapeutic compliance in the rural hypertensives, it would be necessary to change attitude, perception, knowledge about hypertension and its treatment, by various methods such as effective health education and programs for maintaining the supportive environment for hypertension treatment.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.1
• /
• pp.19-26
• /
• 2015

This paper proposes a design method for improving the frequency-domain performance reliability of dynamic systems with uncertain and degrading components. Discrete frequencies are used in this method as surrogates for the frequency band of interest, and the conformance of the frequency responses to the specification at these frequencies is utilized to model the frequency-domain performance reliability. A meta-model for the frequency responses, an extreme-value event, and the set-theory are integrated to improve the computational efficiency of the reliability estimation. In addition, a sample-based approach is presented to evaluate and optimize the estimated performance reliability. A case study of a vibration absorber system showed that the proposed design method has engineering applications.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.6 s.38
• /
• pp.279-286
• /
• 2005

The objective of this study is to suggest a credit scoring model of a capital company's customers by integration of multiple classifiers using genetic algorithm. For this purpose , an integrated model is derived in two phases. In first phase, three types of classifiers MLP (Multi-Layered Perceptron), RBF (Radial Basis Function) and linear models - are trained, in which each type has three ones respectively so htat we have nine classifiers totally. In second phase, genetic algorithm is applied twice for integration of classifiers. That is, after htree models are derived from each group, a final one is from these three, In result, our suggested model shows a superior accuracy to any single ones.

• The KIPS Transactions:PartD
• /
• v.12D no.2 s.98
• /
• pp.211-218
• /
• 2005

This study presents an integrated data mining model for the credit evaluation of the customers of a capital company. Based on customer information and financing processes in capital market, we derived individual models from multi-layered perceptrons(MLP), multivariate discrimination analysis(MDA), and decision tree. Further, the results from the existing models were compared with the results from the integrated model using genetic algorithm. The integrated model presented by this study turned out to be superior to the existing models. This study contributes not only to verifying the existing individual models but also to overcoming the limitations of the existing approaches.

• The Journal of the Korea Contents Association
• /
• v.10 no.5
• /
• pp.351-359
• /
• 2010

Recently, interesting of U-city with ubiquitous computing technologies has increased and u-city services can improve people's quality of life. Among the u-city services, traffice service is actively developed in our lives. In this paper, we propose the business model and business model process in u-intelligence traffic service. To propose the research purpose, we examined the prior business model and investigated u-intelligence traffic information and control services. And also, we draw scenario and used it to identify business model. To efficiently understand proposed business model, we built business model process of u-intelligence traffic information and control services. The results of study, we draw 4 representative U-intelligence traffic information and control service. Based on representative services, we proposed business model and business model process with stakeholder, benefiter and value model. This study concludes with implications of the study results as well as limitations and future research directions.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.59 no.1
• /
• pp.44-54
• /
• 2023

In this study, the second-order Nomoto's nonlinear expansion model was implemented as a Tagaki-Sugeno fuzzy model based on the heading angular velocity to design the automatic steering system of a ship considering nonlinear elements. A Tagaki-Sugeno fuzzy PID controller was designed using the applied fuzzy membership functions from the Tagaki-Sugeno fuzzy model. The linear models and fuzzy membership functions of each operating point of a given nonlinear expansion model were simultaneously tuned using a genetic algorithm. It was confirmed that the implemented Tagaki-Sugeno fuzzy model could accurately describe the given nonlinear expansion model through the Zig-Zag experiment. The optimal parameters of the sub-PID controller for each operating point of the Tagaki-Sugeno fuzzy model were searched using a genetic algorithm. The evaluation function for searching the optimal parameters considered the route extension due to course deviation and the resistance component of the ship by steering. By adding a penalty function to the evaluation function, the performance of the automatic steering system of the ship could be evaluated to track the set course without overshooting when changing the course. It was confirmed that the sub-PID controller for each operating point followed the set course to minimize the evaluation function without overshoot when changing the course. The outputs of the tuned sub-PID controllers were combined in a weighted average method using the membership functions of the Tagaki-Sugeno fuzzy model. The proposed Tagaki-Sugeno fuzzy PID controller was applied to the second-order Nomoto's nonlinear expansion model. As a result of examining the transient response characteristics for the set course change, it was confirmed that the set course tracking was satisfactorily performed.

• Journal of Korean Public Health Nursing
• /
• v.7 no.1
• /
• pp.17-29
• /
• 1993

Nursing centers are nurse-managed organizations that give the client direct access to professional nursing services. Academic nursing centers are faculty-created and -organized nursing centers integrated into nursing school or cooperated with community nursing center. Academic nursing centers are needed for providing services to the forgotten or underserved populations in the community, providing learning opportunities for nursing students and practice opportunities for faculties. The intent of this study is to identify the elements needed in developing process and operations of acedemic nursing center for elderlies and the disabled, and to present the desired model for academic nursing center. The processes of my study were : 1) The articles of the academic nursing centers in U. S. were reviewed and analysed. 2) The academic nursing center for elderlies and the disabled was developed and operated in my paper. 3) Desired model for academic nursing center was presented in my paper. The followings are the results of my study: 1. Elements needed in developing process of academic nursing center were philosophy and goals, the community support, assessment of the validity of the service and health needs, identification of the service contents, roles and responsibilities, communication lines, finances for facilities and operations, cooperation with resources, and developing record system. 2. Elements needed in operations of academic nursing center were the structural organizations, realization of the above philosophy and goals, development of policy and nursing standards, faculty participation, continuity of services, and financial solutions. 3. The desired model was presented according to the process and operations.

• 한국연소학회:학술대회논문집
• /
• 2005.10a
• /
• pp.58-63
• /
• 2005

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.37 no.6
• /
• pp.15-24
• /
• 2000

This paper presents an output feedback robust H$\infty$ control problem for a class of uncertain nonlinear systems, which can be represented by an fuzzy dynamic model. The nonlinear system is represented by Takagi-Sugeno fuzzy model, and the control design is carried out on the basis of the fuzzy model. Using a single quadratic Lyapunov function, the globally exponential stability and disturance attenuation of the closed-loop fuzzy control system are discussed. Sufficient conditions for the existence of robust H$\infty$ controllers are given in terms of linear matrix inequalities(LMIs). Constructive algorithm for design of robust H$\infty$ controller is also developed. The resulting controller is nonlinear and automatically tuned based on fuzzy operation.