• Convergence Security Journal
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• v.11 no.1
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• pp.11-18
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• 2011

Wireless mesh network technology with transmission speeds similar to wired and wireless technology means to build, compared with wired networks, building a more efficient network to provide convenience and flexibility. The wireless mesh network router nodes in the energy impact of the mobility is less constrained and has fewer features entail. However, the characteristics of various kinds due to network configuration settings and the choice of multiple paths that can occur when the system overhead and there are many details that must be considered. Therefore, according to the characteristics of these network routing technology that is reflected in the design and optimization of the network is worth noting. In this paper, a multi-path setting can be raised in order to respond effectively to the problem of the router node data loss and bandwidth according to traffic conditions and links to elements of the hop count evaluation by using a genetic algorithm as a workaround for dynamic routing the routing metric for wireless mesh network scheme is proposed.

• Journal of Advanced Navigation Technology
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• v.18 no.3
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• pp.215-222
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• 2014

In this paper, parafoil airdrop system has been designed and analyzed. 6-degrees of freedom (6-DOF) model of the parafoil system is set up. Nonlinear model predictive control (NMPC) and Proportion integration differentiation (PID) methods were separately applied to adjust the flap yaw angle. Compared the results of setting time and overshoot time of yaw angle, it is found that the of yaw angle is more stable by using PID method. Then, trajectory following controller was designed based on the simulation results of trajectory following effects, which was carried out by using MATLAB. The lateral offset error of parafoil trajectory can be eliminated by its lateral deviation control. The later offset deviation reference was obtained by the interpolation of the current planning path. Moreover, using the designed trajectory, the trajectory following system was simulated by adding the wind disturbances. It is found that the simulation result is highly agreed with the designed trajectory, which means that wind disturbances have been eliminated with the change of yaw angle controlled by PID method.

• Journal of the Korean earth science society
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• v.38 no.4
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• pp.251-262
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• 2017

The system of magnetic exploration with a drone flight was constructed and applied to the iron mine site. The magnetic probe system installed on the drone used a sensor as Bartington's fluxgate type magnetometer, Mag639 and the A/D converter to collect magnetic intensity values on the tablet PC. The drone flight control module is a highly expandable Pixhawk with allowing 15 minutes of flight by loading 3kg. Experiments on the magnetic field interference range were performed to remove the erroneous effect from the drone with applying RTK GPS to obtain the magnetic intensity value at the accurate position. The accurate location information enabled to obtain the gradient measurement of magnetic field by measuring twice at different altitudes. Also, by using the terrain information, we could eliminate the terrain effect by setting the flight path to fly along the terrain. These results are in line with the field experiments using the nuclear proton magnetometer G-858 of Geometrics Co., Ltd, which adds to the reliability of the drone based aeromagnetic survey system we constructed.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.233-244
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• 2002

The purpose of this study is to assess the ability of balance control in moving surround using head mount device and force platform and to examine the clinical usefulness of COP parameters. Fifteen patients with stroke and healthy persons were participated. COP parameters were obtained as total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) in comfortable standing with opened or closed eyes, (2) in virtual moving surround delivered using HMD to four different moving pattern. In virtual moving surround setting, moving pattern was composed of close-far, superior-inferior tilting(pitch), right-left tilting(roll) and horizontal rotation(yaw) movement. In all parameters, the reliebility of COP analysis system was significantly high. Also, the construct validity compared between fifteen patients with stroke and normal persons was excellent in virtual moving surround condition(p

• Journal of Distribution Science
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• v.12 no.10
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• pp.85-97
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• 2014

Purpose - This study aims to clarify through which process asset specificity and supplier development project (SDP) affect performance. Cooperation, partnership, the level of information exchange, and the importance of information sharing are considered significant variables as mediators related to the process. Finally, the performance formation model of the supply chain through asset specificity and supplier development project would be suggested as being a result of this study. Research design, data, and methodology - Data collection was as follows: questionnaires were distributed to 250 companies that have business ties with H Company. The empirical study to test our hypothesis was based on statistical analysis (using SPSS 19.0 and AMOS 19.0). The hypothesis of this paper is that the asset specificity and supplier development project variables have positive effects on the following variables: mediators such as cooperation and partnership (reliability and dependence); and the cooperation and partnership variables have a positive effect on the following variables: level of information sharing, the importance of information sharing, and level of information sharing; the importance of information sharing has a positive effect on supply chain performance. We tested our hypothesized model utilizing path analysis with latent variables. Results - First, it was found that asset specificity has significant positive effects on cooperation (H1), reliability (H2), and dependability (H3). Second, it was proved that the level of comprehension on the purpose of SDP has positive effects significantly on cooperation (H4), reliability (H5), and dependability (H6). Third, the hypotheses related to cooperation were all significantly accepted. The relationships of cooperation with the level (H7) and importance (H8) of information sharing were significant. Fourth, the hypotheses related to reliability were all significantly accepted. The relationships of reliability with the level (H9) and importance (H10) of information sharing were significant. In terms of dependability, however, the hypotheses were partially accepted. The effect of dependability was significant on the importance of information sharing (H12), but insignificant on the level of information sharing (H11). Finally, the causal relationships from the level of information sharing to SCM performance (H13) and from the importance of information sharing to SCM performance (H14) were both significantly accepted. Conclusion - First, with rapid changes in the business environment, enterprises should acquire the right information to properly implement SCM. For successful SCM, firms should understand the supplier development project. Second, asset specificity and the level of comprehension on SDP have significant effects both on cooperation and partnership (reliability and dependability). Third, mediators such as cooperation, reliability, and dependability significantly affect the level and importance of information sharing. Fourth, the level and importance of information sharing have significant impacts on SCM performance. This paper makes a meaningful contribution to further the understanding of how SDP affects SCM performance. Finally, successful SCM performance is achieved by information sharing through a collaborative environment and partnership (confidence & dependence) rather than by investing only in setting up an information system.

• Journal of the Korean earth science society
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• v.30 no.1
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• pp.127-140
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• 2009

The purpose of this study was to explore the characteristics of children's interactive learning focusing on the Vygotsky's ZPD (the zone of proximal development) in a natural history museum as a representative free-choice learning context. We focused on the understanding of peer dyadic discourses and data were collected from 13 peer groups of children (3rd and 4th graders) who were videotaped all conversations occurred as they visited around the exhibits with no predetermined path. The transcribed data were analyzed by the developmental level of ZPD system and the discourse within an ADL (an actual developmental level) was overwhelmingly common in the conversations between child-child dyads. The representative discourse by discourse types were parsed according to three constructs of ZPD. Children formed the intersubjectivity through semiotic mediation such as conversations and exhibits and ended up with the similar situation definition. In conclusion, the details of discourses of the most impressive dyad were looked into focusing on the scientific concept. The study implies that a natural history museum becomes a meaningful resource to offer a deeper understanding of the nature of children's learning as an informal learning setting.

• Journal of Practical Engineering Education
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• v.12 no.1
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• pp.117-125
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• 2020

According to the government's smart factory promotion project for small and medium-sized enterprises, more than 10,000 intelligent factories are scheduled or already built in the country and the government-led goal is to nurture 100,000 skilled workers by 2022. Smart Factory introduces numerous types of education and training courses from the supplier's point of view, such as training institutions belonging to local governments, some universities, and public organizations, in the form of an efficient resource management system and ICT technology convergence in the automated manufacturing equipment. The lack of linkage with the NCS, the standard for training, seems to have room for rethinking and direction. Results of survey is provided for the family companies of K-University in the metropolitan area and Chungnam area, and analyzes job demands by identifying whether or not they want to introduce smart factories. Defining the practitioners who will serve as a window for the introduction of smart factory technology within the company, setting up a training goal in consideration of the career path, and including the level of training required competency units, optional competency units, and training time suitable for introducing and operating smart factories. Author would like to present an NCS-based qualification design plan.

• Journal of the Korean earth science society
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• v.42 no.6
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• pp.717-733
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• 2021

This study is aimed to provide basic data to set the direction of polar literacy education and to raise awareness of the importance of polar research. Elementary, middle, and high school students' perception of the polar region was examined in terms of current status of polar information, impression regarding polar regions, and awareness of related issues. The study included 975 students from nine elementary, middle, and high schools, who responded to 16 questions, including close-ended and open-ended items. The results suggest that students had more experiences regarding the polar region on audiovisual media, but relatively limited learning experiences in school education. The impression they had of the polar region was confined to the monotonous image of a polar bear in crisis, following the melting of the glacier due to global warming. The students formed powerful images by combining scenes they saw in audiovisual media with emotions. In terms of recognizing problems in the polar region, the students were generally interested in creatures, natural environment, and climate change, but their interests varied depending on their school level and their own career path. The students highly valued the scientist's status as agents to address the problems facing the region, and gave priority to global citizenship values rather than practical standards. Based on the results, we suggest the following: introducing and systematizing content focusing on the polar region in the school curriculum, providing a differentiated learning experience through cooperation between scientists and educators, establishing polar literacy based on concepts that are relevant to various subjects, earth system-centered learning approach, setting the direction for follow-up studies and the need for science education that incorporates diverse values.