• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.415-424
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• 1995

Combined models, specified by two or more modeling formalisms, can represent a wide variety of complex systems. This paper describes a methodology for the development of combined models in two model types of discrete event and continuous process. The methodology is based on transformation of continuous state space into discrete one to homomorphically represent dynamics of continuous processes in discrete events. This paper proposes a formal structure which can combine model of the DES and the CS within a framework. The structure employs the DEVS formalism for the DES models and differential or polynomial equations for the CS models. To employ the proposed structure to specify a DEVS/CS combined model, a modeler needs to take the following steps. First, a modeler should identify events in the CS and transform the states of the CS into the DES. Second, a modular employs the formalism to specify the system as the DES. Finally, a moduler developes sub-models for the CS and continguos states of the DES and establishs one-to-one correspondence between the sub-models and such states. The proposed formal structre has been applied to develop a DEVS/CS combined model for the human cardiovascular system. For this, the cardiac cycle is partitioned into a set of phases based on events identified through observation. For each phase, a CS model has been developed and associated with the phase. To validate the DEVS/CS combined model developed, then simulate the model in the DEVSIM + + environment, which is a model simulation results with the results obtained from the CS model simulation using SPICE. The comparison shows that the DEVS/CS combined model adequately represents dynamics of the human heart system at each phase of cardiac cycle.

• Journal of the Korean Home Economics Association
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• v.23 no.1
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• pp.59-69
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• 1985

Consumer satisfaction/dissatisfaction is a concept which is receiving increased attention from consumers, public policy makers, and marketers alike. The literature in this field is still meager, has been growing rapidly byt with diversity of direction. The purpose of this study is to review the conceptualization and taxonomy of CS/D in consumer research. Three types of the basic process in a general theory of CS/D are suggested; system CS/D, enterprise CS/D and product-service CS/D. It is also classified into macro marketing system CS/D, micro marketing system CS/D and consuming mix CS/D. The conceptualization of CS/D begins with a basic model of how CS/D results from the individual product purchase experience of individual consumer. Basic CS/D models are classified into process model which contains experience, information search, prepurchase evaluation and comparison process variables and psychological model which is derived from cognitive dissonance theory. Theoretical and empirical foundations about expectation model are asimilatin, contrast, generalized negativity and assimilation contrast theories.

• Journal of Korean Society for Quality Management
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• v.49 no.3
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• pp.421-431
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• 2021

Purpose: For improving outgoing quality, this study presents a novel sampling framework based on predictive analytics. Methods: The proposed framework is composed of three steps. The first step is the variable selection. The knowledge-based and data-driven approaches are employed to select important variables. The second step is the model learning. In this step, we consider the supervised classification methods, the anomaly detection methods, and the rule-based methods. The applying model is the third step. This step includes the all processes to be enabled on real-time prediction. Each prediction model classifies a product as a target sample or random sample. Thereafter intensive quality inspections are executed on the specified target samples. Results: The inspection data of three Samsung products (mobile, TV, refrigerator) are used to check functional defects in the product by utilizing the proposed method. The results demonstrate that using target sampling is more effective and efficient than random sampling. Conclusion: The results of this paper show that the proposed method can efficiently detect products that have the possibilities of user's defect in the lot. Additionally our study can guide practitioners on how to easily detect defective products using stratified sampling

• Computers and Concrete
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• v.21 no.1
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• pp.103-110
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• 2018

This study introduces the supervised committee fuzzy model as a hybrid fuzzy model to predict compressive strength (CS) of geopolymers prepared from alumina-silica products. For this purpose, more than 50 experimental data that evaluated the effect of $Al_2O_3/SiO_2$, $Na_2O/Al_2O_3$, $Na_2O/H_2O$ and Na/[Na+K] on (CS) of geopolymers were collected from the literature. Then, three different Fuzzy Logic (FL) models (Sugeno fuzzy logic (SFL), Mamdani fuzzy logic (MFL), and Larsen fuzzy logic (LFL)) were adopted to overcome the inherent uncertainty of geochemical parameters and to predict CS. After validating the model, it was found that the SFL model is superior to MFL and LFL models, but each of the FL models has advantages to predict CS. Therefore, to achieve the optimal performance, the supervised committee fuzzy logic (SCFL) model was developed as a hybrid method to combine the benefits of individual FL models. The SCFL employs an artificial neural network (ANN) model to re-predict the CS of three FL model predictions. The results also show significant fitting improvement in comparison with individual FL models.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.2
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• pp.66-73
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• 2017

This study was to evaluate the influential parameters such as intial Cs concentration, reaction temperature, contact time and pH variation of solution on Cs adsorption. Using the experimental data, adsorption kinetics, isotherms and thermodynamic properties were analyzed. The Cs ion adsorption of the zeolite X was effective in the range from pH 5 to 10 and reached equilibrium after 60 minutes. The adsorption kinetics and isotherms of Cs ion with the zeolite X was described well by the pseudo-second-order kinetic and Langmuir isotherm model. The maximum adsorption capacities of Cs ion calculated from Langmuir isotherm model at 293~333 K were from 303.03 mg/g to 333.33 mg/g. It was found that thermodynamic property of Cs ion absorption on the zeolite X was spontaneous and endothermic reaction. The experimental data were fitted a second-order polynomial equation by the multiple regression analysis. The values of the dependent variable calculated by this best fitted model equation were in very good agreement with the experimentally obtained values.

• The Korea Journal of Herbology
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• v.22 no.3
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• pp.57-65
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• 2007

Objectives : We examined to know the effect of Cordyceps sinensis(CS) on arthritis mouse induced by type II collagen. Methods : To analyse immunomodulatory effects of CS, arthritis index, incidence, hind paw edema, DTH, spleen weight, the number of hemocytes, and surface-receptor expression of CD4+, CD8+ and CD19+ cells in DBA/IJ mice which is experimental model of arthritis induced by collagen were measured in vivo. Results: CS reduced arthritis index, incidence, hind paw edema and DTH significantly as compared with the control group in experimental model of arthritis induced by collagen. CS enhanced the spleen weight significantly as compared with the control group but didn't enhanced the number of leukocytes and thrombocytes in experimental model of arthritis. CS enhanced the number of activating cells and surface-receptor expression of CD4+, CD8+ cells as compared with the control group but didn't enhanced those of CD19+ cells in experimental model of arthritis. Conclusion : We found out that CS may have a suppressing effect againist auto-immune disease and will be need continuous research in looking for the more effective mechanism in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.2
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• pp.366-385
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• 2013

In this paper, we propose a compressed sensing (CS) based Wyner-Ziv (WZ) codec using motion-aligned auto regressive model (MAAR) based side information (SI) extrapolation to improve the compression performance of low-delay distributed video coding (DVC). In the CS based WZ codec, the WZ frame is divided into small blocks and CS measurements of each block are acquired at the encoder, and a specific CS reconstruction algorithm is proposed to correct errors in the SI using CS measurements at the decoder. In order to generate high quality SI, a MAAR model is introduced to improve the inaccurate motion field in auto regressive (AR) model, and the Tikhonov regularization on MAAR coefficients and overlapped block based interpolation are performed to reduce block effects and errors from over-fitting. Simulation experiments show that our proposed CS based WZ codec associated with MAAR based SI generation achieves better results compared to other SI extrapolation methods.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.8
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• pp.450-457
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• 2015

In this research a adsorbent, PVA-Zeolite bead, was prepared by immobilizing zeolite with PVA. The results of XRD and SEM analysis showed that the prepared PVA-Zeolite beads had porous structure and the zeolite particles were in mobilized within the internal matrix of the beads. The adsorption properties of Sr ion and Cs ion with the adsorbent were studied by different parameters such as effect of pH, adsorption rate, and adsorption isotherm. The adsorption of Sr ion and Cs ion reached equilibrium after 540 minutes. The adsorption kinetics of both ions by the PVA-Zeolite beads were fitted well by the pseudo-second-order model more than pseudo-first-order model. The equilibrium data fitted well with Langmuir isotherm model. The maximum adsorption capacities of Sr ion and Cs ion calculated from Langmuir isotherm model were 52.08 mg/g and 58.14 mg/g, respectively. The external mass transfer step was very fast compared to the intra-particle diffusion step in the adsorption process of Cs ion and Sr ion by the PVA-Zeolite beads. This result implied that the rate controlling step was the intra-particle diffusion step.

• Journal of Environmental Science International
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• v.28 no.6
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• pp.561-570
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• 2019

A zeolitic material (Z-Y2) was synthesized from Coal Fly Ash (CFA) using a fusion/hydrothermal method under low-alkali condition (NaOH/CFA = 0.6). The adsorption performance of the prepared zeolite was evaluated by monitoring its removal efficiencies for Sr and Cs ions, which are well-known as significant radionuclides in liquid radioactive waste. The XRD (X-ray diffraction) patterns of the synthesized Z-Y2 indicated that a Na-A type zeolite was formed from raw coal fly ash. The SEM (scanning electron microscope) images also showed that a cubic crystal structure of size $1{\sim}3{\mu}m$ was formed on its surface. In the adsorption kinetic analysis, the adsorption of Sr and Cs ions on Z-Y2 fitted the pseudo-second-order kinetic model well, instead of the pseudo-first-order kinetic model. The second-order kinetic rate constant ($k_2$) was determined to be $0.0614g/mmol{\cdot}min$ for Sr and $1.8172g/mmol{\cdot}min$ for Cs. The adsorption equilibria of Sr and Cs ions on Z-Y2 were fitted successfully by Langmuir model. The maximum adsorption capacity ($q_m$) of Sr and Cs was calculated as 1.6846 mmol/g and 1.2055 mmol/g, respectively. The maximum desorption capacity ($q_{dm}$) of the Na ions estimated via the Langmuir desorption model was 2.4196 mmol/g for Sr and 2.1870 mmol/g for Cs. The molar ratio of the desorption/adsorption capacity ($q_{dm}/q_m$) was determined to be 1.44 for Na/Sr and 1.81 for Na/Cs, indicating that the amounts of desorbed Na ions and adsorbed Sr and Cs ions did not yield an equimolar ratio when using Z-Y2.

• Clean Technology
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• v.23 no.4
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• pp.413-420
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• 2017

The batch experiments and response surface methodology (RSM) have been applied to the investigation of the Cs adsorption with zeolite X synthesized using coal fly ash generated from the thermal power plant. Regression equation formulated for Cs adsorption was represented as a function of response variables. The model was highly relevant because the decision coefficient ($r^2$) was 0.9630. It was confirmed from the statistical results that the removal efficiency of Cs was affected by the order of experimental factors as pH > Cs concentration > temperature. The adsorption kinetics were more accurately represented by a pseudo second-order model. The maximum adsorption capacity calculated from the Langmuir isotherm model was $151.52mg\;g^{-1}$ at 293 K. Also, according to the thermodynamic parameters calculated from Vant Hoff equation, it could be confirmed that the adsorption reaction was an endothermic reaction and a spontaneous process.