• Research in Mathematical Education
• /
• v.15 no.1
• /
• pp.15-30
• /
• 2011

We study to design educational Logo-based microworld environment equipped with 3D construction capability, 3D manipulation, and web-based communication. Extending the turtle metaphor of 2D Logo, we design simple and intuitive symbolic representation system that can create several turtle objects and operations. We also present various mathematization activities applying the turtle objects and suggest the way to make good use of them in mathematics education. In our microworld environment, the symbolic representations constructing the turtle objects can be used for web-based collaborative learning, communication, and assessments.

• Proceedings of the KIEE Conference
• /
• 2002.07d
• /
• pp.2531-2533
• /
• 2002

In this paper, we evaluate feasibility of an object-oriented method in a distributed real-time control environment through the prediction of delay expected. We adopt CAN as the distributed network and the application layer of the CAN is composed of client/server communication model of COM and surroundings for the support of real-time capability of the COM. Mathematical models formalizing delays which are predicted to invoke in the COM architecture are proposed. Sensors and actuators which are widely used in distributed network-based systems are represented by COM objects in this paper. It is expected that the mathematical models can be used to protect distributed network-based systems from violation of real-time features by the COM.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1661-1664
• /
• 1994

In designing $SF_6$ puffer circuit breakers, analyzing are behavior during current zero region and thermal recovery characteristics after current interrupt ion is very important. In this paper, a mathematical are model based on the integral method has been based to analyze them. The pressure rise in the puffer chamber and the distributions of pressure, density, velocity and enthalpy inside nozzle are calculated and analyzed at current zero region. The influence of fault current magnitude and change of di/dt at current zero on the interruption capability of puffer circuit breakers is investigated. Finally, the calculated results are compared with the available results from experiment.

• Architectural research
• /
• v.15 no.4
• /
• pp.207-214
• /
• 2013

A form-finding technique is proposed for three-dimensional spatial structures. Two-step discrete finite element (FE) mesh generator based on computer aided geometric design (CAGD) is introduced and used to control the shape of three-dimensional spatial structures. Mathematical programming technique is adopted to search new forms (or shapes) of spatial structures. For this purpose, the strain energy is introduced as the objective function to be minimized and the initial volume (or the initial weight) is considered as constraint function. Numerical examples are carried out to test the capability of the proposed form-finding techniques and provided as benchmark tests.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.177-180
• /
• 2000

An algorithm for modeling of yeast fermentation process using genetic-fuzzy algorithm is presented in this work. The algorithm involves developing the fuzzy modeling of the process and model update capability against the system change. The membership functions of state variables and specific rates and the decision table were generated using genetic algorithm. This algorithm could replace the complex mathematical model to simple fuzzy model and cope with the change of process characteristics well.

• Proceedings of the IEEK Conference
• /
• 2000.06e
• /
• pp.167-170
• /
• 2000

In this paper, we develope a intelligent monitoring system of Coastal Ocean Environment based on WWW(World Wide Web) and PCS(Personal Communication System). This system have capability of real time processing of enviromental variable from various sensors. The system is composed of three part. The first part is mathematical modeling of real ocean. The second is construction server for real time web page. And the third is developing the measurement system which has wireless(PCS) interface to server.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.06a
• /
• pp.257-261
• /
• 2005

The helicopter system is non-linear and complex. Futhermore, because of absence of accurate mathematical model, it is difficult accurately to control its attitude. therefore, we propose a WAVENET control technique to control efficiently its elevation angle and azimuth one. Wavelet neural network(WAVENET) can construct systematically initial neural network as applying wavelet theory to feedforward network. It is proved through computer simulation that WAVENET has more excellent approximation capability than existing neural network. The simulation results using MATLAB are introduced.

• Journal of Educational Research in Mathematics
• /
• v.18 no.1
• /
• pp.1-24
• /
• 2008

The purpose of this study is to uncover weaknesses in the constructivism in mathematics education and to search for ways to complement these deficiencies. We contemplate the relationship between the capability of construction and the performance of it, with the view of the 'Twofold-Structure of Mind.' From this, it is claimed that the construction of mathematical knowledge should be to experience and reveal the upper layer of Mind, the Reality. Based on the examination on the conflict and relation between the structuralism and the constructivism, with reference to the 'theory of principle' and the 'theory of material force' in Neo-Confucianist theory, it is asserted that the construction of mathematical knowledge must be the construction of the structure of mathematical knowledge. To comprehend the processes involved in the construction of the structure of mathematical knowledge, the epistemology of Michael Polanyi is studied. And also, the theory of mathematization, the historico-genetic principle, and the theory on the levels of mathematical thinking are reinterpreted. Finally, on the basis of the theory of twofold-structure, the roles and attitudes of teachers and students are discussed.

• Journal of Korean Institute of Industrial Engineers
• /
• v.34 no.3
• /
• pp.362-372
• /
• 2008

Manufacturers, or vendors, and their customers continue to adopt vendor-managed inventory(VMI) program to improve supply chain performance through collaboration achieved by consolidating replenishment responsibility upstream with vendors. In this paper, we construct a mixed integer linear programming model and propose a genetic algorithm for the integrated inventory and routing problems with lost sales maximizing the total profit in the VMI supply chains which comprise of a single manufacturer and multi-retailer. The proposed GA is compared with the mathematical model on the various sized test problems with respect to the solution quality and computation time. As a result, the GA demonstrates the capability of reaching solutions that are very close to those obtained by the mathematical model for small problems and stay within 3.2% from those obtained by the mathematical model for larger problems, with a much shorter computation time. Finally, we investigate the effects of the cost and operation variables on the total profit of the problem as well as the GA performance through the sensitivity analyses.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1994.11a
• /
• pp.288-302
• /
• 1994

A security risk analysis provides all information system with the capability to investigate and estimate the status of its security, and gives a guideline for establishing a safeguard against any means of security threats. The information system needs tile judicious and accurate why for performing a risk analysis since security policy and risk analysis of tile information system are based on risk analysis, The risk analysis is composed of two methods. mathematical approach and diagramming technique. Mathematical approach cannot yield a precise description of the real world. However, diagramming technique is more pragmatic since it overcomes this limitation. In this paper, we studied tile security risk analysis methods proposed in overseas such as INFOSEC [4], SRAG [5], FIPS65[6], and JRAM[7].