• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.11a
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• pp.17-20
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• 2006

In the remote welding system using $CO_2$ laser, laser beam is rapidly deflected by moving mirrors of scanner system and has focusable distance over 1000mm from workpiece. From such arrangement, various advantages and disadvantages arise. Remote welding is a highly efficient laser process. As the mirrors of the scanner system allow positioning speeds exceeding 700m/s, it becomes possible to reduce the welding cycle time. On the other hand, as there no the provision of shielding gas which is normally required for beam powers exceeding 3kW, may become difficult task. Therefore, In this study, the influence of the various penetration of back bead by the different laser welding speed on the weld seam formation without shielding gas was investigated.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.321-329
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• 2012

Providing variable load for testing a motor in high speed conditions is usually a difficult task. The eddy current brake can be used in application of load testing of motors. This paper deals with construction of a novel claw pole eddy current brake which is employed as a load for a DC counter rotating motor (CRM). These kinds of motors have two inner and outer shafts that rotate in opposite directions simultaneously, which are particularly suitable for under water propulsion systems. The prototype 45KW eddy current brake consists of two parts. One of them is installed on the inner shaft of the 60KW DC CRM and the other one is installed on its outer shaft. The simulation and experimental results with prototype brakes are also analyzed by using MATLAB/Simulink and the operational characteristic of the brake is demonstrated as a function of the motor speed and current of the magnetic poles.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.2
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• pp.279-284
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• 2009

In swarm robot systems, each robot must behaves by itself according to the its states and environments, and if necessary, must cooperates with other robots in order to carry out a given task. Therefore it is essential that each robot has both learning and evolution ability to adapt the dynamic environments. In this paper, reinforcement learning method using many SVM based on structural risk minimization and distributed genetic algorithms is proposed for behavior learning and evolution of collective autonomous mobile robots. By distributed genetic algorithm exchanging the chromosome acquired under different environments by communication each robot can improve its behavior ability. Specially, in order to improve the performance of evolution, selective crossover using the characteristic of reinforcement learning that basis of Cascade SVM is adopted in this paper.

• Journal of the Korean Institute of Educational Facilities
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• v.22 no.2
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• pp.15-22
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• 2015

The latest educational curriculum in Korea started in 1997, and the 'Departmentalized Classroom System', which is a distinguishing modern concept compared with conventional pedagogy, has already been used in several high schools since 2009 and will be expanded to all middle school and high schools by 2014. However, most Korean schools are not yet physically ready to implement the new system. Moreover, despite many trials during the last three years, the characteristic and architectural function of a place called 'Home-base' is still vague and has caused many controversial arguments. In fact, a large number of home-base designs failed to accomplish their original task and there are counter evidences that shows reality was quite different over architect's personal and subjective radical plan. Therefore, this study seeks to introduce and objective scientific method based on an mathematical model of an optimized algorithm for planning a home-base area in a school design. The algorithm developed in this study is designed to determine the most efficient location for a home-base area to minimize the distance students typically need to walk.

• Journal of the Korean Chemical Society
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• v.41 no.10
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• pp.524-534
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• 1997

Analysis of additives in cured rubber is often a difficult task for analytical chemists because of a wide variety of complex components. Conventional analyses of additives and rubbers have been done in multistep, off-line processes with large sample size and extensive sample preparations. The coumarone-indene resin, resorcinol-formaldehyde resin, and prevulcanization inhibitor have been characterized by their pyrolysis pathways and mass spectra of characteristic pyrolyzates. Pyrolysis Gas Chromatography/Mass Spectrometry (Py-GC/MS) was used in the identification of additives without any sample pretreatment. This result shows that several organic additives in cured rubber can be directly analyzed.

• Smart Structures and Systems
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• v.9 no.6
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• pp.535-547
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• 2012

Controlling the balance of motion in a context involving a biped robot navigating a rugged surface or a step is a difficult task. In the present study, a $3{\times}5$ flexible piezoelectric tactile sensor array is developed to provide a foot pressure map and zero moment point for a biped robot. We introduce an innovative concept involving structural electrodes on a piezoelectric film in order to improve the sensitivity. The tactile sensor consists of a polymer piezoelectric film, PVDF, between two patterned flexible print circuit substrates (FPC). Additionally, a silicon rubber bump-like structure is attached to the FPC and covered by a polydimethylsiloxane (PDMS) layer. Experimental results show that the output signal of the sensor exhibits a linear behavior within 0.2 N ~ 9 N, while its sensitivity is approximately 42 mV/N. According to the characteristic of the tactile sensor, the readout module is designed for an in-situ display of the pressure magnitudes and distribution within $3{\times}5$ taxels. Furthermore, the trajectory of the zero moment point (ZMP) can also be calculated by this program. Consequently, our tactile sensor module can provide the pressure map and ZMP information to the in-situ feedback to control the balance of moment for a biped robot.

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.1
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• pp.43-58
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• 1999

To instruct in accordance with learner's trait & preceding knowledge, letting the learner control the learning activities is the important task of educator & major goal of the Education Department this year. This article intends to provide useful Instructional Model for the teachers in fisheries marine high school, when they design the individualized teaching model using motivation. One of the major reason for the fisheries marine high school students' low learning achievement is due to the neglecting motivation elements in teaching - learning processes. Recently, with assistance of the information communication technology development, various teaching methods such as Individualized Multimedia Mediated Instruction, Internet Instruction, have come to the major method in activating motivation and computer-mediated instruction considering the learner's individual difference is the useful tools for the instructional efficiency. Because current navigation text book of fisheries marine high school have special characteristic considering the spacial context & time series from departing port to entering port, Teachers can maximize learner's learning accomplishment by using individualized multimedia & providing similar situation like a real navigation(simulating), representing this text characteristics. Thus this paper searches for the specifications of Keller's Motivation Model & Sweeter's Tutorial Model to solve instructional efficiency problems in fisheries marine high school & developed an efficient instructional design by integrating two models.

• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.113-118
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• 2021

Objective: The purpose of this study was to investigate differences of landing strategy between people with or without chronic ankle instability (CAI) during double-leg drop landing. Method: 34 male adults participated in this study (CAI = 16, Normal = 18). Participants performed double-leg drop landing task on a 30 cm height and 20 cm horizontal distance away from the force plate. Lower Extremities Kinetic and Kinematic data were obtained using 8 motion capture cameras and 2 force plates and loading rate was calculated. Independent samples t-test were used to identify differences between groups. Results: Compared with normal group, CAI group exhibits significantly less hip internal rotation angle (CAI = 1.52±8.12, Normal = 10.63±8.44, p = 0.003), greater knee valgus angle (CAI = -6.78±5.03, Normal = -12.38 ±6.78, p = 0.011), greater ankle eversion moment (CAI = 0.0001±0.02, Normal = -0.03±0.05, p = 0.043), greater loading Rate (CAI = 32.65±15.52, Normal = 18.43±10.87, p = 0.003) on their affected limb during maximum vertical Ground Reaction Force moment. Conclusion: Our results demonstrated that CAI group exhibits compensatory movement to avoid ankle inversion during double-leg drop landing compared with normal group. Further study about how changed kinetic and kinematic affect shock absorption ability and injury risk in participants with CAI is needed.

• Journal of Korean Society of Rural Planning
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• v.28 no.2
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• pp.11-20
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• 2022

As a portal to rural town, Myeon near large cities is expected to represent image of the rural area. But, the landscape are changing rapidly due to development pressure and to the expansion of the transportation network. For visitors and transit traffic, Recognizing that the characteristics of the streetscape is an important task for the vitalization of the rural district. In particular, it was found that the visual quantity of the central street in the location of the town was closely related to the preference of the streetscape, and the visual quantity of trees and the visual quantity of the building showed an inverse relationship of + and - respectively. Since this is not a simple ratio of the sky to the building, but a relative factor, the possibility of landscape improvement can be improved through management of public facilities or green spaces and maintenance of open spaces or gaps between buildings. It seems that it is necessary to secure separate means for the management of the architectural landscape, such as the establishment of a special landscape plan or establishment of ordinances.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.244-250
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• 2022

Reforming social relations requires changing the system of relations between state executive bodies, institutions subordinate to them and a citizen, which is characteristic for most of the country, in which the latter is a petitioner even if his indisputable rights and legitimate interests are satisfied. One of the most important areas of public administration reform is the formation and development of a system of administrative services and appropriate information support. The result of the implementation of this direction should be the creation of such a legal framework and its real implementation in administrative and legal practice, in which consumers of administrative services will have broad rights and powers and will not be passive subjects manipulated by civil servants.Thus, the main task of the study is to analyze the normative legal aspects of information support for the provision of administrative services in the field of public administration. As a result of the study, the main aspects of normative legal aspects of information support for the provision of administrative services in the field of public administration were investigated.