• Journal of the Korean earth science society
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• v.25 no.8
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• pp.656-662
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• 2004

The purposes of this study was to analyze the knowledge sources and of high school students' responses on tasks in scientific context and tasks in everyday context, and was to investigate the relationship between the consistency of responses and cognitive style. One hundred fifteen students participated in study. The students were asked to solve ten paris of problems about several concepts of circulation of atmosphere and water. Each pair of the problems consisted of two questions which were about the same concept but were about different context. That is to say, one questions related to scientific context and the other related to everyday context. Every questions included one subquestion in other to investigate the students' sources of knowledge. The students' responses on two questions in each problem were analyzed in order to compare the sources of knowledge and examine the influence of task context. The results of the study can be summarized as follows: First, students' knowledge sources varied by task contexts. That is to say, the students selected 'Science activities in school' as main source in questions related scientific context and chose 'Experience in daily life' as main source in questions related to everyday context. Second, inconsistency score on all paris of problem was significantly higher than consistency score (p<.01). This result indicated students' responses were much dependent on context. third, field-dependent students were more dependent on context, considering higher inconsistency score than field-dependent ones.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.670-691
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• 2018

This study presents the research results of the BMT(Benchmark Model Test) simulations of the DECOVALEX-2019 project Task B. Task B named 'Fault slip modelling' is aiming at developing a numerical method to predict fault reactivation and the coupled hydro-mechanical behavior of fault. BMT scenario simulations of Task B were conducted to improve each numerical model of participating group by demonstrating the feasibility of reproducing the fault behavior induced by water injection. The BMT simulations consist of seven different conditions depending on injection pressure, fault properties and the hydro-mechanical coupling relations. TOUGH-FLAC simulator was used to reproduce the coupled hydro-mechanical process of fault slip. A coupling module to update the changes in hydrological properties and geometric features of the numerical mesh in the present study. We made modifications to the numerical model developed in Task B Step 1 to consider the changes in compressibility, Permeability and geometric features with hydraulic aperture of fault due to mechanical deformation. The effects of the storativity and transmissivity of the fault on the hydro-mechanical behavior such as the pressure distribution, injection rate, displacement and stress of the fault were examined, and the results of the previous step 1 simulation were updated using the modified numerical model. The simulation results indicate that the developed model can provide a reasonable prediction of the hydro-mechanical behavior related to fault reactivation. The numerical model will be enhanced by continuing interaction and collaboration with other research teams of DECOVALEX-2019 Task B and validated using the field experiment data in a further study.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1020-1023
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• 1996

Fieldbus provides real-time data communication among field devices in the process control and manufacturing automation systems. This paper presents an implementation method of Profibus in the experimental model of manufacturing automation system. The manufacturing automation system considered in this paper consists of robots, NC machines, sensors, conveyers and PCs. The application task programs are developed on the basis of FMS/FMA7 communication services which are provided by Profibus application layer. The communication and application programs are developed in the real-time environment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.290-291
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• 2018

The purpose of this study is to analyze the trends and changes in the environment of construction technology and industry through big data analysis and to draw out implications. Based on this research, this study will be used as a basic research for the vision of industrial competitiveness in the field of construction engineering technology and the policy task.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.307-311
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• 2003

Taegu subway fire accident happened on 18th February this year, which was recorded as the 2nd biggest subway accident in the world. The accident was inspected and reviewed by Task Force Team of MOCT and KRRI, which results in the integrated safety plan for subway system. Among the safety plan. this report describes the analysis of the accident causes and safety plan in the field of rolling stock.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.599-602
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• 2007

Generally, the mobile robot navigation with obstacle avoidance is one of the key issues to be looked into for successful applications of autonomous mobile robots. In this paper, the Univector field based method is proposed for mobile robot to accomplish the obstacle avoidance and the robot orientation at the target position. Univector field method guarantees the desired posture of the robot at the target position. But it is not effective Univector to avoid obstacles. To solve this problem, modified univector field is used. With this proposed method, robot navigation task becomes easier and effectively.

• International Journal of Automotive Technology
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• v.6 no.5
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• pp.545-554
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• 2005

Passive velocity field control (PVFC) was previously developed for fully mechanical systems, in which the motion task was specified by behaviors in terms of a velocity field and the closed-loop was passive with respect to the supply rate given by the environment input. However, the PVFC was only applied to a single manipulator. The proposed control law was derived geometrically and the geometric and robustness properties of the closed-loop system were also analyzed. In this paper, we propose a virtual passivity-based algorithm to apply decentralized control to multiple 3­wheeled mobile robotic systems whose subsystems are under nonholonomic constraints and convey a common rigid object in a horizontal plain. Moreover, it is shown that multiple robot systems ensure stability and the velocities of augmented systems converge to a scaled multiple of each desired velocity field for cooperative mobile robot systems. Finally, the application of proposed virtual passivity-based decentralized algorithm via system augmentation is applied to trace a circle and the simulation results is presented in order to show effectiveness for the decentralized control algorithm proposed in this research.

• Korean Journal of Environmental Agriculture
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• v.41 no.2
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• pp.125-134
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• 2022

BACKGROUND: It is a very important task to block distribution of the agricultural products contaminated with pesticides in advance to protect consumers from residual pesticides among the agricultural products. Therefore, this study was performed to determine residual characteristics of pesticides in time-dependent manner and present scientific evidences for pre-harvest residue limit (PHRL) setting. METHODS AND RESULTS: The tested pesticides, chromafenozide and pyridalyl were sprayed onto the kale twice (seven day intervals) and then the plant samples were collected at 0 (after 3 hours), 1, 2, 3, 5, 7, and 10 days after the last spraying. Residual concentration of chromafenozide in kale decreased with 74.9% (of decreased fraction, field 1) and 85.3% (field 2) and pyridalyl decreased with 81.2% (field 1) and 85.8% (field 2), calculated by comparisons of the concentrations at 0 day and 10 days. Also biological half-lives of chromafenozide in kale were 5.6 day (field 1) and 3.4 day (field 2), and those of pyridalyl were 4.3 day (field 1) and 3.5 day (field 2). CONCLUSION(S): If the residues of chromafenozide and pyridalyl in kale from 10 days before harvest are less than 37.6 mg/kg and 58.9 mg/kg, respectively, it is expected that safe kale below MRL can be supplied on the pre-harvest day.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.355-357
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• 2005

This paper describes the architecture and modeling of adaptive and reconfigurable OS in wireless distributed sensor networks. Before initial sensor nodes are deployed in a sensor field, minimum functions including basic OS and routing algorithms are required for these nodes to send request messages for dynamic reconfigurations and receive response messages from a task manager. When the downloading is finished, each sensor node can reconfigure the initial state and be ready to start its functions. By applying this reconfigurable modeling, sensor nodes can be easily deployed in the sensor field and dynamically programmed during a bootstrap process.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.11a
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• pp.213-218
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• 2007