• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1330-1341
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• 1993

The kinematic synthesis deals with the systematic design of mechanisms for a given performance. The area of synthesis may be grouped into two categories to determine the type and to size the dimensions of a mechanism for a specified task. In this paper, using a database of mechanisms a designer can determine the type of mechanism conveniently and design equations are automatically generated for a given input performance. The solving method of design equations utilizes an optimization routine to obtain roots effectively. The linkages of 4, 6, and 8bars with revolute joints are considered in this study but may be extended to linkages of more bars.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.168-175
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• 2001

Reduction of structure-borne noise of the compartment in a car is an important task in automotive engineering. Transfer path analysis using vibroacoustic reciprocity technique or multiple path decomposition method has generally been used for structure-borne noise path analysis. These methods are useful in solving particular problem but do net quantify the effectiveness of vibration isolation of each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow has been used for a simple isolation system or a laboratory based isolation system. It is often difficult to apply the vibrational power flow technique to the complex isolation system like a car. In this paper, a simple equation is derived for calculation of the vibrational power flow of an isolation system with multiple isolators such as a car. It is successfully applied to not only quantifying the relative contributions of eighteen isolators but also reducing structure-borne noise of a passenger car. According to the results, the main contributor of eighteen isolators is the rear roll mount of an engine. The reduced structure-borne noise level is about 5dBA.

• Journal of Gifted/Talented Education
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• v.11 no.2
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• pp.87-106
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• 2001

Identification and selection the mathematically gifted child must be based on it's definition. So, we have to consider not only IQ or high ability in mathematical problem solving, but also mathematical creativity and mathematical task commitment. Furthermore, we must relate our ideas with the programs to develop each student's hidden potential. This study is focused on the discrimination of the candidates who would like to enter the elementary school level mathematics gifted education program. To fulfill this purpose, I considered the criteria, principles, methods, and tools. Identification is not exactly separate from selection and education. So, it is important to have long-term vision and plan to identify the mathematically gifted students.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.862-868
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• 2007

The planar motion of the index finger in general human hands is usually implemented by the actuation of three joints. This task requires a technique to determine the joint combination for each fingertip position which is well-known as the inverse kinematics problem in robotics. Especially, it is an essential work for grasping and manipulation tasks by robotic and humanoid fingers. In this paper, an intelligent neural learning scheme for solving such inverse kinematics is presented. Specifically, a multi-layered neural network is utilized for effective inverse kinematics, where a dynamic neural learning algorithm is employed for fast learning. Also, a bio-mimetic feature of general human fingers is incorporated to the learning scheme. The usefulness of the proposed approach is verified by simulations.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.368-389
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• 2014

There are many agendas and discussion subjects for BIM-based Criteria Design phase. At that time, some problems are occurred by software compatibility, simple repetitive tasks, rework caused by missing information etc. In this study, we focus on solving that problems by applying API(Application Programming Interface) method. For effective study, we construct Criteria Design process by using DSM (Dependency Structure Matrix) and study applicability of API. It will be effective for time-consuming task and simply labor-intensive tasks by applying API. we expect improving BIM-based Design Process and Data quality, work productivity without missing information and shapes for using API.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.103-107
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• 2009

PI controller is widely used as voltage control system of generator. However when a generator system has various characters of continuance, a new PI parameter decision for accurate control is a hard task as method of solving this problem, in this paper, the method to generator voltage control using Neural Network self adaptive control is presented. A property continuous feedback control gain of voltage control system is decided by a rule of delta learning. The function of proposed control method is verified by voltage control experiment results of DC generator.

• The Journal of Korean Association of Computer Education
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• v.14 no.5
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• pp.71-79
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• 2011

We designed and implemented a cooperative learning system using social network service which can be utilized on a smart phone for users to read each other's posting once they upload posting and to give feedback concerning the posting in real time without the need for accessing a relevant website, through the installation of a necessary application which makes it possible for learners to interact at any time in any place on a smart phone. The developed program is used as an intermediate tool for real-time communications so as to aid in solving the task of learners, and it was made to boost academic achievement as well as interest in learning through real-time interactions and feedback. Furthermore, the program was designed in such a way that an instructor actually helps learners by closely identifying their levels based on accumulated data.

• School Mathematics
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• v.2 no.1
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• pp.203-241
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• 2000

This study aims to suggest a model of task development for mathematics performance assessment and to develop performance tasks for the fifth graders in the primary school on the basis of this model. In order to achieve these aims, the following inquiry questions were set up: (1) to develop open-ended tasks and projects for the fifth graders, (2) to develop checklists for measuring the abilities of mathematical reasoning, problem solving, connection, communication of the fifth graders more deeply when performance assessment tasks are implemented and (3) to examine the appropriateness of performance tasks and checklists and to modify them when is needed through applying these tasks to pupils. The consequences of applying some tasks and analysing some work samples of pupils are as follows. Firstly, pupils need more diverse thinking ability. Secondly, pupils want in the ability of analysing the meaning of mathematical concepts in relation to real world. Thirdly, pupils can calculate precisely but they want in the ability of explaining their ideas and strategies. Fourthly, pupils can find patterns in sequences of numbers or figures but they have difficulty in generalizing these patterns, predicting and demonstrating. Fifthly, pupils are familiar with procedural knowledge more than conceptual knowledge. From these analyses, it is concluded that performance tasks and checklists developed in this study are improved assessment tools for measuring mathematical abilities of pupils, and that we should improve mathematics instruction for pupils to understand mathematical concepts deeply, solve problems, reason mathematically, connect mathematics to real world and other disciplines, and communicate about mathematics.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.559-562
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• 2003

In this paper, we introduce a new method detecting thyristor faults of the power converter module in Control Rod Control System. When we control the currents in each coil of Control Rod Drive Mechanism by using the current control method, the current value can follow the current reference despite the faults like the missing phase or the diode acting. Comparing the fault current values with the normal current values, the bad transient characteristics of the abnormal current can make the operations of control rods incorrect. In this case, the information from the current trends cannot be enough to detect the fault occurrence in thyristors. Instead of the coil currents, the state of thyristors can be watched by measuring the coil voltages. In the existing system of Westinghouse type, the ripple detector takes charge of this task. But this detector has some shortcomings in the point of time for fault detection, we come to devise a new fault detection method solving the problems which belong to the ripple detector.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.4
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• pp.391-398
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• 2005

In this investigation, turbulent premixed combustion and flame front propagation in a gas turbine combustion chamber is studied. Direct numerical simulation of turbulent reacting flows demands extremely high computational resources, especially in more complicated geometry. The alternative choice may be left for Large Eddy Simulation (LES) by which only large scales are solved directly. In combustion problems, capturing the large scales' behavior without solving the details of small scales is a difficult task. Using a transport equation for description of the flame front propagation and therefore avoiding the calculation of inner flame structure is the basic idea of this study. For this purpose. the so-called G-equation has been used by which any iso-level of the G variable provides the flame location. A comparison with the experiment indicates that the present method can predict a turbulent velocity field and also capture a instantaneous 3-dimensional flame structure.