• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2283-2286
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• 2000

Sliding control is a powerful approach to controlling nonlinear and uncertain systems. Conventional sliding mode control suffer' from high control gain and chattering problem. also it needs mathematic! modeling equations for control systems. A Fuzzy controller is endowed with control rules and membership function that are constructed on the knowledge of expert, as like intuition and experience. but It is very difficult to obtain the exact values which are the membership function and consequent parameters. In this paper, without mathematical modeling equations, the plant parameters in sliding mode are estimated by the indirect adaptive fuzzy method. the proposed algorithm could analyze the system's stability and convergence behavior using Lyapunov theory. so sliding modes are reconstructed and decreased tracking error. moreover convergence time took a short. An example of inverted pendulum is given for demonstration of the robustness of proposed methodology.

• Genomics & Informatics
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• v.13 no.3
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• pp.90-92
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• 2015

Biological diversity, also known as biodiversity, is an important criterion for measuring the value of an ecosystem. As biodiversity is closely related to human welfare and quality of life, many efforts to restore and maintain the biodiversity of species have been made by government agencies and non-governmental organizations, thereby drawing a substantial amount of international attention. In the fields of biological research, biodiversity is widely measured using traditional statistical indices such as the Shannon-Wiener index, species richness, evenness, and relative dominance of species. However, some biologists and ecologists have difficulty using these indices because they require advanced mathematical knowledge and computational techniques. Therefore, we developed VBioindex, a user-friendly program that is capable of measuring the Shannon-Wiener index, species richness, evenness, and relative dominance. VBioindex serves as an easy to use interface and visually represents the results in the form of a simple chart and in addition, VBioindex offers functions for long-term investigations of datasets using time-series analyses.

• Journal of the Semiconductor & Display Technology
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• v.10 no.3
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• pp.95-98
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• 2011

System to urinalysis using FT-IR instruments is presented based on fuzzy logic knowledge. Linguistic expressions of the possibility of infection and the importance were quantified and membership functions were determined based on general quantitative criteria. Diseases considered were Diabetes Mellitus, Proteinuria, Microalbuminuria. Glucose, Protein, Albumin, Creatinine in 30 samples were analyzed by the present system, which resulted in 74% accuracy. The simple mathematical formulation of present system would enable an easy implementation in commercial analysis instruments. Also, the identical fuzzy logic can be applied to similar diagnostic environments in general.

• YAKHAK HOEJI
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• v.18 no.1
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• pp.49-58
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• 1974

Tablet product design problem was structured as constrained optimization problem and subsequently solved by multiple regression analysis and Lagrangian method of optimization. Aluminum flufenamate was the drug chosen and microcrystalline cellulose nad starch were the binder and disintegrant, respectivley. The effect of the binder and disintegrant concentration on tablet hardness, friability, volume, in vitro release rate, and urinary excretion rate of drug in human subjects was recorded. Since a reasonably rapid release rate of drug is generally an important objective in the design of solid dosage form, optimization of this parameter was employed in studying the applicability of constrained optimization to a pharmaceutical product design problem. In addition to finding optimal sitivity analysis studies to such problems was also illustratd. It would appear that prediction of the in vivo t$_{50%}$ response from a knowledge of the incitro t$_{50%}$ response can be made fairly accurately for the tablet system used in this study.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.10
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• pp.59-68
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• 1992

In this paper, we proposed coordinator description and ambiguity on the hybrid controller for position/force control of robot manipulator. When the hybrid controller is desiged based on the PID control conception, the parameter sharing problem must be considered. However, selection problem of coordinate system on n-DOF robot manipulator control is unsolved. Moreover, contact force on object and change of shape make another problems. And it is very difficult to figure out the accurate mathematical model of manipulator on account of ambiguity and nonlinearity of actuator. Therfore, we design a new hybrid controller, FPID(Fuzzy PID). For verifying the validity of the controller, we tried computer simulation of this system. As a result, we can get remarkable improvement of overdamping and overshooting. Also we can solve compicance problem effectively. Furthermore, ambiguity problem is solved by adding control knowledge based compensator. So robust controller can be acheived, too.

• Education of Primary School Mathematics
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• v.9 no.2 s.18
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• pp.107-118
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• 2005

The purposes of this study were to investigate the practice of performance assessment in elementary mathematics classes especially focused on 4th grade. To achieve this, three research questions were posed as follow: First, What do they prepare for performance assessment? Second, What kinds of tests do they use in mathematics performance assessment? Third, What kinds of difficulties do they have for performance assessment and what should be changed for a successful performance assessment in mathematics? To Answer the research questions, three 4th grade classes were selected from three different elementary schools in seoul and three teachers were interviewed. From the data analysis, several conclusion were drawn. First, a plan for mathematics performance assessment was not set by the class teacher who are in charge of the class. The main reason was lack of time. Second, in most of the assessment, written tests were used and the items in the tests were skill-oriented. Third, teachers thought that performance assessment was needed in mathematics. But lack of their time, knowledge and competency, it is difficult to do performance assessment in mathematics.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.9
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• pp.646-654
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• 1988

In this paper, a speed controller using a microcomputer is implemented and applied to a DC Servo Motor. Adaptive control is applied to a system for which a priori knowledge to its mathematical model is insufficient, on the basis of input and output data an apropriate controller is constructed through which the system input is synthesized. The pole-placement PID self tuning control algorithms as a control algorithm is used to compare the performance of the controller with that of the classical PID controller through computer simulations and experiments.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.5
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• pp.35-42
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• 2011

This study examined emergency exit location with the most representing school floor type with a mathematical model that applied optimized algorithm in the field of engineering. Recent school buildings became much more diverse in floor planning than the old days. Nevertheless, architect's approach to building prevention against fire related emergency planning still relies on an personal experience and knowledge. Therefore, since school buildings are much more likely to be exposed to any fire related events, emergency exit planning has to be seriously evaluated with a scientific method. The algorithm, which acquires the number of persons in each spatial type(node) and the minimum physical distance between spatial types(arc), can propose the most optimized emergency exit locations. Consequently, this study compared an architect's fire exit planning with the scientific outcome of this study and suggested the most reliable emergency exit locations.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.295-304
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• 1994

This paper describes some preliminary attempts to formulate simple mathematical models of the transmission dynamics of HIV infection in homosexual communities. In conjunction with a survey of the available epidemiological data on HIV infection and the incidence of AIDS, the model is used to assess how various processes influence the course of the initial epidemic following the introduction of the virus. Models of the early stages of viral spread provide crude methods for estimating the basic reproductive rate of the virus, given a knowledge of the incubation period of AIDS and the initial doubling time of the epidemic. More complex models are formulated to assess the influence of heterogeneity in sexual activity. This latter factor is shown to have a major effect on the predicted pattern of the epidemic.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.113-120
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• 1994

The dynamic characteristics of turning processes are complex, non-linear and time-varying. Consequently, the conventional techniques based on crisp mathematical model may not guarantee cutting force regulation. This paper presents a fuzzy controller which can regulate cutting force in turning process under varying cutting conditions. The fuzzy control rules are extablished from operator experience and expert knowledge about the process dynamics. Regulation which increases productivity and tool life is achieved by adjusting feedrate according to the variation of cutting conditions. The performance of the proposed controller is evaluated by cutting experiments in the converted conventional lathe. The results of experiments show that the proposed fuzzy controller has a good cutting force regulation capability in spite of the variation of cutting conditions.