• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.35-41
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• 2020

This study was conducted to develop the efficient system for starch hydrolysis suppression using rutin, quercetin and dietary fiber through the statistical mixture design. The three components were replaced with wheat flour at the level of 10% and the mixed gel with three components was characterized by in vitro starch digestion. The mixture design was applied by simplex-centroid experimental model. The quadratic model (R²=0.86) was well fitted and the obtained regression equation indicated that the significant positive effects was observed in the quercetin and fiber mixture. Based on the statistical results, the best mixing ratio of quercetin and fiber was 72: 28 that led to the lowest predicted glycemic index (pGI). Their interactions on the pGI of starch digestibility were clearly visualized in the 3D surface plot. These results suggested that the mixture of quercetin and fiber interact strongly with wheat flour, consequently retarding starch hydrolysis by 15%.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.5
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• pp.555-565
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• 1999

The optimal identification algorithm of fuzzy systems is presented for rule-based fuzzy modeling of nonlinear complex systems. Nonlinear systems are expressed using the identification of structure such as input variables and fuzzy input subspaces, and parameters of a fuzzy model. In this paper, the rule-based fuzzy modeling implements system structure and parameter identification using the fuzzy inference methods and hybrid structure combined with two types of optimization theories for nonlinear systems. Two types of inference methods of a fuzzy model are the simplified inference and linear inference. The proposed hybrid optimal identification algorithm is carried out using both a genetic algorithm and the improved complex method. Here, a genetic algorithm is utilized for determining initial parameters of membership function of premise fuzzy rules, and the improved complex method which is a powerful auto-tuning algorithm is carried out to obtain fine parameters of membership function. Accordingly, in order to optimize fuzzy model, we use the optimal algorithm with a hybrid type for the identification of premise parameters and standard least square method for the identification of consequence parameters of a fuzzy model. Also, an aggregate performance index with weighting factor is proposed to achieve a balance between performance results of fuzzy model produced for the training and testing data. Two numerical examples are used to evaluate the performance of the proposed model.

• KSBB Journal
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• v.26 no.5
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• pp.427-432
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• 2011

In this study, a EXGA gene code for exo-β-1,3-glucanase from Aspergillus oryzae was overexpressed and secretory produced in Saccharomyces cerevisiae. To overexpress the β-1,3-glucanase, pGInu-exgA and pAInu-exgA plasmids having GAL10 and ADH1 promoter, respectively, and exoinulinase signal sequence (Inu s.s) were constructed and introduced in S. cerevisiae SEY2102 and 2805. The recombinant β-1,3-glucanase was successfully expressed and secreted into the medium and the β--1,3-glucanase activity in 2102/pGInu-exgA and 2102/pAInu-exgA strain were 5.01 unit/mL and 4.09 unit/mL, respectively. In the 2805/pGInu-exgA and 2805/pAInu-exgA strain, the β-1,3-glucanase activity showed 3.23 unit/mL and 3.22 unit/mL, respectively. Secretory efficiency in each strain reached 95% to 98%. Subsequently, the recombinant β1,3-glucanase was used for ethanol production. Ethanol productivity in 2102/pAInu-exgA strain was 0.83 g/L when pre-treated Laminaria japonica which has initial reducing sugar of 1.4 g/L was used as substrate. It is assumed that the polysaccharides of Laminaria japonica was effectively saccharified by recombinant β-1,3-glucanase, resulting in increase of ethanol productivity. These results suggested that recombinant β-1,3-glucanase was efficiently overexpressed and secreted in S. cerevisiae SEY2102 as host strain by using ADH1 promoter-Inu s.s system.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.167-174
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• 2007

This study proposes a practical and realistic method to establish an optimal lifetime maintenance strategy for deteriorating bridges by considering the life-cycle performance as well as the life-cycle cost. The proposed method offers a set of optimal tradeoff maintenance scenarios among other conflicting objectives, such as minimizing cost and maximizing performance. A genetic algorithm is used to generate a set of maintenance scenarios that is a multi-objective combinatorial optimization problem related to the and the life-cycle cost and performance as separate objective functions. A computer program, which generates optimal maintenance scenarios, was developed based on the proposed method. The subordinate relation between bridge members has been considered to decide optimal maintenance sequence. The developed program has been used to present a procedure for finding an optimal maintenance scenario for steel-girder bridges on the Korean National Road. Through this bridge maintenance scenario analysis, it is expected that the developed method and program can be effectively used to allow bridge managers an optimal maintenance strategy satisfying various constraints and requirements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.2
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• pp.108-121
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• 1986

In this paper, the development of a simulator for the performance estimation and parameter optimization of an integrates voice/data packet communication network is described. The simulator implemented is capable of simulating the integrated voice/data network that handles packet voice terminals as well as data terminals and hosts operating under standard CCITT protocols. Of the three descrete event simulation approaches presently known, the process interaction method has been chose. With this approach one can implement a simulator that is related most Closely with the real system. The simulator has been implemented in PL/I and GPSS simulation languages, resulting in a software package of about 4,000 lines. To reduce the computer run time of the simulator, we have used a method of reducing conditional events based on a GPSS LINK block. We describe various aspects of the simulation model developed. We then investigate the performance of a 7-node network using the simulator, and present the results. For validation of the simulator developed, we construct a simulation model for a simple voice/ data multiplexer, and compare the results of simulation with those of an analytical model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.285-297
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• 2015

In this paper, Ulta-WideBand (UWB) channel measurement and modeling based on compressive sampling (CS) are proposed. The sparsity of the channel impulse response (CIR) of the UWB signal in frequency domain enables the proposed channel measurement to have a low-complexity and to provide a comparable performance compared with the existing approaches especially used for the indoor geo-localization purpose. Furthermore, to improve the performance under noisy situation, the soft thresholding method is also investigated in solving the optimization problem for signal recovery of CS. Via numerical results, the proposed channel measurement and modeling are evaluated with the real measured data in terms of location estimation error, bandwidth, and compression ratio for indoor geo-localization using UWB system.

• Steel and Composite Structures
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• v.25 no.1
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• pp.117-126
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• 2017

The component method is an analytical approach for investigating the moment-rotation relationship of steel connections. In this study, the component method was improved from two aspects: (i) load analysis of mechanical model; and (ii) combination of spring elements. An optimized component method with more reasonable component models, spring arrangement position, and boundary conditions was developed using finite element analysis. An experimental testing program in two major-axis and two minor-axis connections under symmetrically loading was carried out to verify this method. The initial rotational stiffness obtained from the optimized component method was consistent with the experimental results. It can be concluded that (i) The coupling stiffness between column and beam flanges significantly affects the effective height of the tensile-column web. (ii) The mechanical properties of the bending components were obtained using an equivalent t-stub model considering the bending capacity of bolts. (iii) Using the optimized mechanical components, the initial rotational stiffness was accurately calculated using the spring system. (iv) The characteristics of moment-rotation relationship for beam to column connections were effectively expressed by the SPRING element analysis model using ABAQUS. The calculations are simpler, and the results are accurate.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.617-636
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• 2017

Many businesses have adopted the standard security management structure such as ISO27001 and K-ISMS for strengthening business's security management structure to protect their core information assets and have acquired partial output from such effort. However, many risk factors such as recent advances in Information Technology and evolution of intrusion methods have increased exponentially requiring the businesses to response even more quickly with better accuracy. For such purpose, a study of 'Real Time Security Management Structure for Business' based on security management process optimization, defining a set of security index for managing core security area and calculation of risk indices for precognition of intrusion risk area has been made. Also, a survey on opinions of an expert panel has been conducted. The effectiveness of studied structure was analyzed using AHP method as well. Using this study, security personnels of a company can improve efficiency of the preemptive responsive and quicker measure from the current security management structure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.4
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• pp.602-610
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• 2018

The model predictive control is an effective method to optimize the current control input that predicts the current control state and the future error using the predictive model of the control system when the reference trajectory is known. Since the control input can not have a physically infinitely large value, a predictive controller design with constraints should be considered. In addition, the reference model $A_r$ and the weight matrices Q, R that determine the control performance of the predictive controller are not optimized as arbitrarily designated should be considered in the controller design. In this study, we construct a predictive controller of a mobile robot by transforming it into a quadratic programming problem with constraints, The control performance of the mobile robot can be improved by optimizing the control parameters of the predictive controller that determines the control performance of the mobile robot using genetic algorithm. Through the computer simulation, the superiority of the proposed method is confirmed by comparing with the existing method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1586-1592
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• 1999

In DWMT, CMFB is employed in the synthesis/analysis part. The CMFB uses filters of greater length than the DFT, resulting in reduced interference between the carriers. In addition, the CMFB system is computationally efficient and fast algorithms are available for their implementation. Traditional designs for the prototype filters of CMFB usually involve nonlinear optimizations. Thus the required design time is considerably large even for small filter orders. In this paper, a prototype filter design method for CMFB is presented using optimal window method. The design process is reduced to the optimization of a single parameter and consequently the required design time is much less than those of the existing methods. It is shown that the stopband performance of the proposed method is better than that of the Kaiser window method.