• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.25 no.3
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• pp.93-106
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• 2021

In this paper, an efficient hybrid numerical method for solving two-asset option pricing problem is presented based on the Crank-Nicolson and the radial basis function methods. For this purpose, the two-asset Black-Scholes partial differential equation is considered. Also, the convergence of the proposed method are proved and implementation of the proposed hybrid method is specifically studied on Exchange and Call on maximum Rainbow options. In addition, this method is compared to the explicit finite difference method as the benchmark and the results show that the proposed method can achieve a noticeably higher accuracy than the benchmark method at a similar computational time. Furthermore, the stability of the proposed hybrid method is numerically proved by considering the effect of the time step size to the computational accuracy in solving these problems.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.2
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• pp.121-137
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• 2022

In this paper, we investigate an efficient hybrid method for solving two-asset time fractional Black-Scholes partial differential equations. The proposed method is based on the Crank-Nicolson the radial basis functions methods. We show that, this method is convergent and we obtain good approximations for solution of our problems. The numerical results show high accuracy of the proposed method without needing high computational cost.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1387-1392
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• 1990

In this paper, an iterative learning control algorithm for unknown linear discrete systems is proposed by employing a parameter estimator together with an inverse system model. Regardless of initial error and inherent parameter uncertainty, a good tracking control performance is obtained using the proposed learning control algorithm characterized by recursive operations. A sufficient condition for convergency is provided to show the effectiveness of the proposed algorithm. To investigate the performance of the algorithm a series of simulations and experiments were performed for the tracking control of a servo motor.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1415-1419
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• 1990

A novel type of a play-back servo system with high precision is designed using an iterative learning control method by employing the model algorithmic control concept together with an inverse model. A sufficient condition is also provided for the convergency. It is shown by simulation that the proposed control algorithm yields a good performance even in the presence of a periodic load disturbance and proved by experiments using microprocessor-based play-back servo system.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.308-324
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• 2012

The aim of this study is to develop and construct the elements of a new evaluation tool to assess the effectiveness of a horticultural therapy. Delphi method was applied to classify the realms of evaluation and specify their components and constituting items. Delphi process was performed through three rounds and 24 professionals attended all the rounds as panel members. Some of the items were revised or removed according to the results of such tests as content validity ratio, agreement rate, convergency and stability of each item. On the contrary, a few new items were added by accepting the opinions of the professional panels. Previous to the Delphi, the realms of evaluation were classified into physical, cognitional, psycho-emotional and social ones on the basis of literature review, professionals' consultation and in-depth interview with practitioners. At the first round, 112 items constituting four realms were reviewed. The numbers of items to be reviewed were reduced to 107 at the second round and to 102 at the third round. As a result, 98 items in 4 realms were decided as proper evaluation points of horticultural therapy. The compositions of the four respective realms are as follows: 5 components and 27 items in physical realm; 4 components and 25 items in cognitional realm; 2 components and 24 items in psycho-emotional realm; and 4 components and 22 items in social realm. These realms, components and specific items derived from this study constitute indices to evaluate the effectiveness of horticultural therapy. In addition, they might be utilized as good guidelines for planning horticultural therapy programs.

• Journal of the Korea Society of Computer and Information
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• v.15 no.9
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• pp.77-85
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• 2010

As various convergency products have been actively developed, the study on user interface has been conducted a lot, and for more specific direction, users' experience-oriented user interface from user-oriented studies is recently developed. Such a tendency aiming to focus on product development to express users' emotion, the next step in the user-oriented development had difficulties in an objective approach, so the data based on previous users' experiences were presented as the basic data to establish user interface design process with grounds and design direction, and therefore it is available to show more specific and objective grounds. From this perspective, such psychological variables showing users' experiences like age and job are studied through surveys of users at the development of products, and products according to the variables are released. On the other hand, the products considering psychological difference distinguishing users' experiences as the cultural cap are not progressed yet. Despite the understanding of cultural difference, its decisive grounds are hard to distinguish like age, and job. Therefore, the cognitive concept about how to design menu information structure according to accident types that can be considered regarding user interface design among theoretical backgrounds about cultural difference. As the category according to the range of things among accident types, it is divided into analytical type and relational type to conduct a test on similarity and relations about the representative digital TV's menu information of the convergency product. As the result, analytical type and relational type showed difference and this study aims to use menu information concept considering this difference as explanatory variables of the users' experience-oriented development.

• Journal of Welding and Joining
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• v.32 no.4
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• pp.69-74
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• 2014

Welding distortions of large steel structures had mainly been estimated with some simplified formula obtained by lots of experience and numerical analyses for small steel structures. However, the large structures would have different characteristics of distortion with welding because of their own stiffness coming from the size itself. Therefore, in order to find some measures for preventing welding distortion of large structure, it is requite in advance to precisely analysis thermal stress and distortion during welding of the structure. Numerical analysis for larger structure has been known to take large amount of calculation time and have a poor convergency problem during the thermo-elasto-plastic calculation. In this study, a hybrid method is proposed to analysis the thermal stress and distortion of a large steel plate with the finite element analysis by incorporating with temperature distribution of the plate calculated by an analytical solution. The proposed method revealed that the thermo-mechanical analysis for welding of the large structure could be performed with a good convergence and produced precise results with much reduced time consumption.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.4
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• pp.435-444
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• 2001

Even todays, accurate and efficient algorithms for the large deformation analysis of elastoplastic frame structures lack due to the complexities of kinematics, material nonlinearities and numerical methods to cater for. The author suggests appropriate beam element based upon the incremental formulation from the 3D rod theory where Cauchy stress and engineering strain are variables to incorporate plasticity equations so that objectivity may be satisfied. A rectum mapping methods which can integrate and satisfy yield criteria efficiently is suggested and a continuation method which has global convergency and quadratic speed is developed as well. leading-unloading example problems are tested and the ideas are proved to be valuable.

• Journal of the Society of Disaster Information
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• v.14 no.1
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• pp.43-50
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• 2018

This study presented 3D Finite Element (FE) analysis of curved beam structures subjected to static and dynamic loading conditions, which is particularly strong ground motions. It was shown that the results obtained from 3D FE analyses was similar to the theoretical solution within 1% convergency error, in order to validate the 3D solid FE models in this study. In particular, it was focusing on development of dynamic characteristics of curved beam structures subjected to three-different seismic ground motions: GyeongJu, Lomaprieta and Northridge earthquakes. Consequently, It was interesting to find that the results obtained from GyeongJu earthquake was detuned due to high frequency effect, but the Von-Mises of the curved beam structure under Lomaprieta earthquake was 647.824 MPa at 45 curvature degree.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.187-190
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• 2015

Recently, most of people wants to have smart life for themselves like smart phones. In this paper, we propose the smart elevator based on the laser screen, speakers and air fresheners. Using this elevator, we could enjoy the various screen inside, and we could keep contacting with manager for wifi in the emergency situation. Also, the elevator could be operated with user's motion for Kinect. Finally, we did the survey for understanding preference of smart elevator. The grops are elevator manufacturing company, elevator distribution corporation and consumers, each group have 200 people.