• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.701-706
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• 1998

A design method of rule -based fuzzy modeling is presented for the model identification of complex and nonlinear systems. The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of " IF..., THEN,," statements. using the theories of optimization and linguistic fuzzy implication rules. The improved complex method, which is a powerful auto-tuning algorithm, is used for tuning of parameters of the premise membership functions in consideration of the overall structure of fuzzy rules. The optimized objective function, including the weighting factors, is auto-tuned for better performance of fuzzy model using training data and testing data. According to the adjustment of each weighting factor of training and testing data, we can construct the optimal fuzzy model from the objective function. The least square method is utilized for the identification of optimum consequence parameters. Gas furance and a sewage treatment proce s are used to evaluate the performance of the proposed rule-based fuzzy modeling.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.108-121
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• 2008

Dispatching rule for parallel machines with multi product is proposed in this paper, In current market,customer's request for higher quality is increasing, In accordance with such demand, manufacturers are focusingon improving the quality of the products. Such shift in production objective is risky. The possibility ofneglecting another important factor in customer satisfaction increases, namely due dates. From the aspect ofimproving quality, frequency of product assignment to limited number of high performance machines willincrease. This will lead to increased waiting time which can incur delays, In the case of due date orientedproduct dispatch, Products are assigned to machines without consideration for quality. Overall deterioration ofproduct quality is inevitable, In addition, Poor products will undergo rework process which can increase delays.The objective of this research is dispatching products to minimize due date delays while improving overallquality. Quality index is introduced to provide means of standardizing product quality. The index is used toassure predetermined quality level while minimizing product delays when dispatching products. Qualitystandardization method and dispatching algorithm is presented. And performance evaluation is performed withcomparison to various dispatching methods.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.5
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• pp.691-697
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• 2010

Reliability-based topology optimization (RBTO) is to get an optimal topology satisfying uncertainties of design variables. In this study, reliability-based topology optimization method is applied to the inner reinforcement of vehicle's hood based on BESO. A multi-objective topology optimization technique was implemented to obtain optimal topology of the inner reinforcement of the hood. considering the static stiffness of bending and torsion as well as natural frequency. Performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints. To evaluate the obtained optimal topology by RBTO, it is compared with that of DTO of the inner reinforcement of the hood. It is found that the more suitable topology is obtained through RBTO than DTO even though the final volume of RBTO is a little bit larger than that of DTO. From the result, multiobjective optimization technique based on the BESO can be applied very effectively in topology optimization for vehicle's hood reinforcement considering the static stiffness of bending and torsion as well as natural frequency.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.105-114
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• 2008

In this study, the sizing and performance analysis program is developed for the canard rotor wing(CRW) aircraft which operates in dual modes (fixed wing mode and rotary wing mode). The developed program is verified for both fixed wing and rotary wing modes using the existing aircraft data and the design optimization formulation is made to perform the reconnaissance mission. For the canard rotor wing aircraft optimization , multi-objective function is constructed to consider both the fixed wing mode and rotary wing mode the weighting factor. For six design cases with different weighting factors and different design constraints, the optimization is performed and improved rotor design results are derived.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.84-90
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• 2010

This paper presents the shape optimization process for the automotive wheel bearing seal lip using the finite element method and the response surface method. First, to predict performance of the bearing seal lip, we used the non-linear finite element analysis. And then, we compared the analysis results with the test results to verify the finite element model. The objective function in optimizing process was obtained from results of the mud slurry test, which is one of many tests for evaluating performance of wheel bearing. After the mud slurry test for the four models which have the similar cross-sectional shape, we measured the wear area of the seal lip and the moisture content in grease. The objective function has been chosen by comparing the results of mud slurry test and characteristics of seal lip, such as contact force, contact area, contact pressure, and interference. Finally, within limited design parameters, we suggested the optimized shape of seal lip, which is expected to improve the wear and the sealing effect of it.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.101-105
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• 1989

The iterative learning controller makes the system output follow the desired output over a finite time interval through iterating trials. In this paper, first we discuss that the design problem of learning controller is originally the design problem of the inverse model. Then we show that the tracking error which is the difference between the desired output and the system output is reduced monotonically by properly modeled inverse system if the magnitude of the learning operator being introduced is bounded within the unit circle in complex domain. Also it would be shown that the conventional learning control method is a kind of extremely simplified inverse model learning control method of the objective controlled system. Hence this control method can be considered as a generalization of the conventional learning control method. The more a designer model the objective controlled system precisely, the better the performance of the approximated inverse model learning controller would be. Finally we compare the performance of the conventional learning control method with that of the approximated inverse model learning control method by computer simulation.

• Journal of Korean Association for Spatial Structures
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• v.14 no.3
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• pp.75-84
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• 2014

When adjacent tall buildings experience earthquake excitation, structural pounding may happen. In order to mitigate seismic pounding damage to adjacent structures, many studies have been done to date. Tuned mass dampers (TMD) are widely used for reduction of dynamic responses of building structures subjected to earthquake excitations. If a TMD is shared between adjacent buildings and it shows good control performance, it will be effective and economic means to reduce seismic responses of adjacent structures. In this study, control performance of a shared tuned mass damper (STMD) for seismic response reduction of adjacent buildings has been evaluated. For this purpose, two 8-story example buildings were used and multi-objective genetic algorithms has been employed for optimal design of the stiffness and damping parameters of the STMD. Based on numerical analyses, it has been shown that a STMD can effectively control dynamic responses and reduce the effect of pounding between adjacent buildings subjected to earthquake excitations in comparison with a traditional TMD.

• Structural Monitoring and Maintenance
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• v.3 no.1
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• pp.51-69
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• 2016

Monitoring the performance and estimating the remaining useful life of aging civil infrastructure in the United States has been identified as a major objective in the civil engineering community. Structural health monitoring has emerged as a central tool to fulfill this objective. This paper presents a review of the major structural monitoring programs that have been recently implemented in the United States, focusing on the integrity and performance assessment of large-scale structural systems. Applications where response data from a monitoring program have been used to detect and correct structural deficiencies are highlighted. These applications include (but are not limited to): i) Post-earthquake damage assessment of buildings and bridges; ii) Monitoring of cables vibration in cable-stayed bridges; iii) Evaluation of the effectiveness of technologies for retrofit and seismic protection, such as base isolation systems; and iv) Structural damage assessment of bridges after impact loads resulting from ship collisions. These and many other applications show that a structural health monitoring program is a powerful tool for structural damage and condition assessment, that can be used as part of a comprehensive decision-making process about possible actions that can be undertaken in a large-scale civil infrastructure system after potentially damaging events.

• Asia-Pacific Journal of Business
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• v.9 no.2
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• pp.15-37
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• 2018

The purpose of this paper was to explain on the conceptualisation of the Halal Orientation strategy (HOS) based on operation strategy perspective. The four variables constitute in HOS are staffing, materials, production process and storage together with transportation. By focusing on HOS, the manufacturers reinforce improvement in quality, cost control, time and flexibility of the production Halal food industry in Malaysia which is the performance objective of market competitiveness in Malaysia context. A self-administered questionnaire was designed and used to assess the significant of HOS that lead to improve quality, cost control, reduction in time and the flexibility among Halal food manufacturers in Malaysia. From a total of 443 Halal food manufacturers were involved in this study, only 137 respondents are usable for this research. The study showed significant results for the manufacturers to focus in Halal Orientation strategy (HOS) which have positive impacts on quality, cost control, time and flexibility. This research aimed to measure the HOS among food firms in Malaysia and to determine HOS in relation with the performance objective of operational outcomes.

• Journal of Korean Medicine for Obesity Research
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• v.7 no.1
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• pp.1-7
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• 2007

Background : Use of Ma Huang is controversial. Multiple reports of adverse effects led the U.S. Federal Drug Administration (FDA) to announce about prohibiting dietary supplements containing ephedrine alkaloids/Ma Huang. Objective : The objective of the study was to review the evidence from literature and rigorous clinical trials on the dosage, effectiveness, and adverse effects. Methods : Literature searches were conducted in U.S. FDA database after 2003 and digital Uibujeonok(醫部全錄). Hand searches of medical journal and bibliographies of identified articles were conducted. Results : Ma Huang has been used in Korean Oriental Medicine to treatment asthma and other ailments. Recently, Ephedrine/Ma Huang are used for weight loss or to enhance athletic performance in Europe and America, Korea. Ephedrine/Ma Huang are associated with increased risk of psychiatric, autonomic, or gastrointestinal symptoms, and heart palpitations. In addition to that, a risk of serious adverse events, including heart attack, stroke, epilepsy and psychiatric problem are also have been reported. Therefore, max dose of total alkaloids of ephedrine is studied in need of a specialist's part. Conclusion : In most reports, Ma Huang effectively promoted short-term weight loss and enhancement of athletic performance, But, safety with long-term use requires further investigation.