• The Journal of Korean Association of Computer Education
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• v.23 no.2
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• pp.31-39
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• 2020

As the importance of software education is emphasized, various educations for improve the computational thinking of elementary school students are being provided. However, there are many limitations that apply to the school at preceding studies. because they were invented for specific environment or students. Therefore, in this study, software education was conducted by constructing teaching-learning activities in consideration of the characteristics of students such as teaching aids and level of computational thinking ability, which can influence students based on the contents of textbooks. Through the comparison about computational thinking improvements, this study tried to suggest the direction of effective software education method. As a result, there are differences in computational thinking improvements according to the student's level and used teaching aids. Specifically, visual programming and unplugged type teaching-learning activities were more effective in teaching aids, and according to the level of students, students with low level of computing thinking in pre-inspection showed relatively high improvement. This tendency suggests that it is necessary to consider various learning factors in designing teaching-learning activities in elementary software education.

• Korean Journal of Childcare and Education
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• v.16 no.5
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• pp.1-26
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• 2020

Objective: This study investigated 5-year-old children's developmental levels for creative and social personalities according to gender, and whether participation in STEAM-based unplugged robotic activities can improve their creative and social personalities. Methods: Participants were 5-year-old children (N=125) from 11 child care centers. The experimental group included 29 boys and 24 girls enrolled in classrooms that implemented an unplugged activities curriculum over five weeks. The control group consisted of 38 boys and 34 girls. Data were analyzed using a t-test and analysis of covariance, and Hedges' g was used to measure effect size. Results: First, the participating children's mean scores on creative and social personalities were 3.20 and 3.53 on a 5-point Likert scale, respectively. Girls scored higher than boys in sensitivity-various interests and imagination-playfulness domains of creative personality and all three domains of social personality. Second, children in the experimental group showed improvement in all domains of social personality and the effect size was large. They also improved in three domains (openness-humor, imagination-playfulness, independency-immersion) of creative personality, although the effect size was small. Conclusion/Implications: The results imply that implementing a robotics curriculum with unplugged play activities in early childhood classrooms contributes to 5-year-old children's development of creative and social personalities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.561-563
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• 2015

The majority of current streaming services are particular S/W I a separate setup program supports real-time streaming service a reality, will be stored until the end of the video, save for a video about editing and is not available. In this paper, allows the user to save and apply the multi threaded techniques for video based on a system without a separate plug-ins, or installation of programs HTML5 by taking advantage of Web content authoring, real-time streaming system using a Web browser. This saves the video streaming in real time can be used for editing and, on real-time communications and media sharing and streaming Web service you need and will be utilized in the field.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.629-631
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• 2015

Recently, the actual demand for electricity usage to out of demand forecasting demand appears to be based on the power of Government to address the insecurity is there are a lot of efforts on a more efficient energy management. In 2011, the first major outage, blackout since the current rate of no more than 10% of our power plants, such as power supply and demand crisis is being repeated. In addition, energy management systems, the demand for care and social areas are being expanded. In this paper, Building power supply and wired/wireless router and to optimize the DDNS (Dynamic Domain Name Service) for remote control and monitoring device for electric consumption Presonal Energy Management System offers a way to implement it. In the future, remote control and access the user's can minimize the settings for additional research is needed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.7
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• pp.671-677
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• 2010

In the present study, we designed a microfluidic platform for generating monodisperse droplets with diameters ranging from hundreds of nanometers to several micrometers. To generate fine droplets, T-junction and flow-focusing geometry are integrated into the microfluidic channel. Relatively large aqueous droplets are generated at the upstream T-junction and transported to the flow-focusing geometry, where each droplet is broken into smaller droplets of the desired size by the action of pressure and viscous stress. In this configuration, the flow rate of the inner fluid can be made very low, and the ratio of the inner- and outer-fluid flow rates in the flow-focusing region can be made very high. It has been shown that the present microfluidic device can generate droplets with diameters of approximately $1\;{\mu}m$ (standard deviation: <3%).

• Fire Science and Engineering
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• v.30 no.6
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• pp.71-77
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• 2016

The electrolyte of the capacitor in mobile phone chargers leaks to the power input terminal resulting in tracking on the PCB board to form a carbonized conductive path. As a result of structural analysis of the cause of the tracking, It occurred when the power input terminal and the PCB board were connected directly using the connector. The larger the amount of electrolyte leaked from the capacitor into the power input terminal, or the lower the height of the partition provided between the plug pins of the power input terminal, the higher the tracking occurrence rate. Accordingly, to lower the occurrence rate of tracking in the charger, it is necessary to provide a partition on the capacitor or increase the height of the partition provided on the power input terminal so that the leaked electrolyte does not flow to the power input terminal. In addition, the tracking occurrence rate will be reduced further if the shape of the PCB board touching ther power connection terminal is changed to ${\Pi}$.

• Spatial Information Research
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• v.18 no.4
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• pp.141-149
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• 2010

One of recent trends in Web-based GIS is the system development using FOSS (Free and Open Source Software). Open Source software is independent from the technologies of commercial software and can increase the reusability and extensibility of existing systems. In this study, we developed a Web-based GIS for interactive visualization of geographic information using Google Earth and spatial DBMS(database management system). Google Earth Plug-in and Google Earth API(application programming interface) were used to embed a geo-browser in the Web browser. In order to integrate the Google Earth with a spatial DBMS, we implemented a KML(Keyhole Markup Language) generator for transmitting server-side data according to user's query and converting the data to a variety of KML for geovisualization on the Web. Our prototype system was tested using time-series of LAI(leaf area index), forest map, and crop yield statistics. The demonstration included the geovisualization of raster and vector data in the form of an animated map and a 3-D choropleth map. We anticipate our KML generator and system framework will be extended to a more comprehensive geospatial analysis system on the Web.

• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.101-115
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• 2011

PECOLE (Peer-to-Peer Collaborative Environment) is a P2P-based multimedia distributed collaborative environment supporting a collaborative workspace which is composed of a variety of collaborative applications such as multi-chat, video conferencing, screen sharing and etc. Unfortunately, due to the PECOLE's simple group management, it is impossible to perform collaboration activities while joining multiple groups. In this paper, we present the design and implementation of PECOLE+ which is an extension of PECOLE. PECOLE+ resolves the drawback of PECOLE by providing the Group Management Service and the Workspace Management Service. The Group Management Service provides functionalities such as creating groups, joining multiple groups, and searching groups, and etc. The Workspace Management Service provides each group with an associated workspace, supporting the execution of collaborative applications over the workspace. In addition, any collaborative applications with the provided plug-in interfaces can be executed over the workspace as a PECOLE+ collaborative application.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.157-165
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• 2011

As the contents of information were reinforced the rules of computer science, it was necessary to develop the new teaching and learning plans and various education materials that encourage students and easy to access. So, in this study developed a wide ran of play activities and educational materials without using a computer for the area of information representation and applied to 68 students, second grade of middle school for 4 weeks. After the class, the effect on the learning achievement was verified by the t-test. As a result, it was shown that there was a significant difference between learning with play activities materials and the traditional lecture-type. It means that learning with play activities materials in the information representation influences a positive effect to the learning achievement.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.201-207
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• 2012

This study was conducted to investigate the effect of supporting material and ionic strength of the MS medium on growth of strawberry plantlets cultured in vitro for the rapid mass production. Explants of $Fragaria$ $ananassa$ 'Houkouwase' in vitro were planted in the agar or Tosilee (commercial plug medium) medium as the supporting material and supplied with 1/4 MS, 1/2 MS or basal (as the control) MS medium in an autotrophic micropropagation. Plant height and root length were significantly greater when they were cultured in 1/2 MS medium as compared to those grown in the agar medium. Also, shoot fresh and dry weights, and leaf area in the 1/2 MS medium were greater than in 1/4 MS or basal MS medium. When plantlets were cultured in Tosilee medium and fed with the basal MS medium, plant height, root length, shoot fresh and dry weights, root fresh and dry weights, and leaf area were promoted and greater than those in plantlets cultured in the agar medium.