• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.929-934
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• 2015

Because of the recent rapid advances in the development of ships with a larger proportion of electrical and electronic equipment, The usable frequency spread spectrum on ships is global trend. Therefore, concerns have been raised regarding the possible hazardous health effects of electromagnetic fields radiating from electronic devices. Although studies and investments on electro-magnetic fields in terrestrial areas are being conducted, they are not applied to a ship. In this paper, we measured electromagnetic fields in ship propulsion systems, and we analyzed the measured values against Korean and international standards. While the measured results satisfied the Korean standard, the Italian standard was not met in the switchboard area. However, the measured values were close to meeting the Italian standard. Therefore, further studies should be conducted for performing a comparative analysis of data in order to specify a standard of electromagnetic fields in propulsion systems that can be applied in the construction of government infrastructures.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.989-997
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• 2002

This paper presents a new technique that enhances the performance of the smart antenna system especially in signal environments of wide angular spread by adopting a weight vector obtained from two eigenvectors of theautocovariance matrix of the received data. While the conventional beamformingtechnique employs only one eigenvector corresponding to the largest eigenvalue, the proposed algorithm uses two eigenvectors corresponding to the largest and second largest eigenvalue in such a way that it can be robust enough to the signal environments of wide angular spread. An efficient adaptive procedure is shown to verify that the optimal weight vector consisting of the two eigenvectors is obtained with a reasonable complexity(3.5$N_2$+ 12N) and accuracy. it is also shown in this paper that the numerical results obtained from the proposed adaptive procedure well agree with those obtained from a commercial tool computing the eigen-function of MATLABTM.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.13-20
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• 2008

Magnetic method is rapid, cheap and simple geophysical exploration technique, and has wide range of applications such as resources prospecting, geological structure investigation and even geotechnical and environmental problems. Documents during Japanese occupation says that magnetic method was used for exploring metallic ore deposits and hot spring, and that a geomagnetic observatory was operated. From mid 1950's, magnetic explorations for natural resources such as metallic ore, uranium, coal, and groundwater were intensively executed for industrialization. Magnetic survey techniques were rapidly advanced during 1970's and 1980's with improvements of instruments, growth of geophysical manpower, and availability of computers. Decline of mining industry since mid 1980's moved the exploration objects from traditional resources to new ones such as groundwater and geothermal resources. Recently appeared applications such as natural hazard assessment, and engineering and environmental studies increased the magnetic method's utility in the realm of exploration.

• Journal of The Korean Association of Information Education
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• v.17 no.4
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• pp.497-506
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• 2013

The purpose of this study is to explore and develop a new instructional approach to a technology-enhanced, collaborative learning environment called Smart technology-enhanced Team-Based Learning (S-TBL). We designed a novel instructional model that combines mobile technology, collaborative teamwork, a problem-solving process, and a variety of evaluation techniques from the viewpoint of a conventional team-based model. Based on the traditional TBL model, we have integrated smart learning technologies: 1) to provide a holistic learning environment that integrates learning resources, assessment tools, and problem solving spaces; and 2) to enhance collaboration and communication between team members and between an instructor and his or her students. The S-TBL instructional approach combines: 1) individual learning and collaborative team learning; 2) conceptual learning and problem-solving & critical thinking; 3) both individual and group assessment; 4) self-directed learning and teacher-led instruction; and 5) personal reflection and publication.

• Journal of The Korean Association of Information Education
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• v.13 no.2
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• pp.127-134
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• 2009

As wireless-internet and mobile computer revitalizes, various teaching and learning strategies are appearing. In this study, we suggest a new integrated teaching method in u-learning environment effectively. First of all, to apply information technique to education effectively, we grasped various educational factors centered on learners. And then, we categorized them into contents, time and space as three vital factors and analyzed. Next, by combining the important factors, we suggested the new integrated teaching and learning strategy. We also operated personalized the integrated teaching for elementary school students and verified the effect. As a result, we learned that the integrated teaching was effective in the area of higher-level thinking presented as an effectiveness index, learning motivation and self-directed learning. That is, this study will promote excellence in education centered on learners in the hereafter u-learning environment and support general integrated education effectively.

• 전자공학회논문지 IE
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• v.48 no.1
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• pp.36-44
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• 2011

The purpose of this study was to develop the basic design principles for the engineering mathematics teaching model that supported college students to become collaborative problem solvers. For this purpose, the following four design principles were drawn from the steps of systems approach, especially with consideration of needs of engineering students, professors, curriculum and relevant research on mathematical education. As a result, the four design principles for the engineeering mathematics teaching model were drawn as follows: (1) Improve students' basic mathematical learning abilities through repetition and elaborative practice of the basic mathematical concepts and principles, (2) Develop students' problem solving abilities through collaborative projects or learning activities with peers, (3) Facilitate students' reflection and provide teacher's monitoring and prompt feedback during their learning process, and (4) Build up online learning environments that enable students to become self-regulated learners.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.699-705
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• 2009

This paper is represented to research of driving control for the forklift AGV. The related works that were studied about AGV as heavy equipment used two methods which are magnet-gyro and wire guidance for localization. However, they have weaknesses that are high cost, difficult maintenance according to change of environment. In this paper, we develop localization system through sensor fusion with laser navigation system and encoder, gyro for robustness. Also we design driving controller using fuzzy and proportional control. It considers distance and angle difference between forklift AGV and pallet for engaging work. To analyze performance of the proposed control system, we experiment in same working condition over 10 times. In the results, the average error was presented with 54.16mm between simulation of control navigation and real control navigation. Consequently, experimental result shows that the performance of proposed control system is effective.

• Economic and Environmental Geology
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• v.52 no.5
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• pp.357-366
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• 2019

Deposition of the Daedong Supergroup has been considered to be related with the Triassic Songrim and Jurassic Daebo orogenies. The Chungnam Basin fills is an important sedimentary succession to understand the geological evolution of the Early to Middle Mesozoic Korean Peninsula. Previous paleontological and paleomagnetic studies have suggested the Late Triassic to Early Jurassic sedimentation of the Chungnam Basin fills. However, the orogenic model of the basin development has remained controversial because recently reported zircon U-Pb isotopic ages are not harmonious with the previous studies. This paper aims to review the stratigraphy, depositional age, and composition of the Chungnam Basin fills, together with test of the basin development models.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.43-52
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• 2021

This study investigated the influence of clinical physical therapist's perception of their work environment and their attitude toward professionalization on individual job satisfaction. This study is a cross-sectional survey of clinical physical therapists 356 working in hospital, and utilized a structured questionnaire. As a result of this study, in their twenties, women, physical therapist with low clinical experience, and physical therapists working at hospital level showed low job satisfaction. Most of the physical therapists said that they needed a system for professionalism, and the lower the job satisfaction was, the higher the attitude toward the necessity of introducing a professional system. The variables affecting job satisfaction were academic background and annual salary. Therefore, in order to improve the job satisfaction of physical therapists, improvement of salary and learning for professionalism played an important role in improving job satisfaction. Self-development and job specialization through the introduction of a system for equipping expertise appear to be important to improve the job satisfaction.

• Journal of Internet Computing and Services
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• v.23 no.4
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• pp.65-72
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• 2022

In this paper, a zero trust-based complex biometric authentication was proposed in a passwordless environment. The linkage of FIDO 2.0 (Fast IDENTITY Online) transaction authentication platforms was designed in conjunction with metaverse. In particular, it was applied with the location information of a smart terminal according to a geomagnetic sensor, an accelerator sensor, and biometric information for multi-factor authentication(MFA). At this time, a FIDO transaction authentication platform was presented for adaptive complex authentication with user's environment through complex authentication with secondary authentication based on situational awareness such as illuminance and temperature/humidity. As a result, it is possible to authenticate secondary users based on zero trust with behavior patterns such as fingerprint recognition, iris recognition, face recognition, and voice according to the environment. In addition, it is intended to check the linkage result of the FIDO platform for complex integrated authentication and improve the authentication accuracy of the linkage platform for transaction authentication using FIDO2.0.