• Journal of the Korean earth science society
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• v.31 no.7
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• pp.772-784
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• 2010

'Science festival' is an annual public event featuring a variety of science- and technology-related workshops and live demonstrations of experiments by student presenters. This study was to explore the student presenters' and student visitors' perceptions of the science festival. The subjects were 323 student presenters who managed laboratory booths and 495 student visitors who attended the festival for six days. We developed a questionnaire based on the modified items of ones both from Ahn & Park (2009) and Lee et al. (2010). Data included students' participation backgrounds, differences of their perceptions about the educational effects according to participation types and school levels, and student presenters' perceptions of scientific inquiry that they had through the preparation of the festival. Findings suggested that student presenters perceived their experience of preparing for the festival as meaningful scientific inquiry process such as asking and solving problems. Based on the results, discussion and implications for communitybased programs as an informal science education were presented.

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1483-1495
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• 2007

Thanks to IEEE 802.11 technique, accessing Internet through a wireless LAN(Local Area Network) is possible in the most of the places including university campuses, shopping malls, offices, hospitals, stations, and so on. Most of the APs(access points) for wireless LAN are supporting 2.4 GHz band 802.11b and 802.11g protocols. This paper is introducing a C# library function which can be used to read RSSIs(Received Signal Strength Indicator) from APs. An LBS(Location Based Service) estimates the current location of the user and provides useful user's location-based services such as navigation, points of interest, and so on. Therefore, indoor, LBS is very desirable. However, an indoor LBS cannot be realized unless indoor position ing is possible. For indoor positioning, techniques of using infrared, ultrasound, signal strength of UDP packet have been proposed. One of the disadvantages of these techniques is that they require special equipments dedicated for positioning. On the other hand, wireless LAN-based indoor positioning does not require any special equipments and more economical. A wireless LAN-based positioning cannot be realized without reading RSSIs from APs. Therefore, our C# library function will be widely used in the field of indoor positioning. In addition to providing a C# library function of reading RSSI, this paper introduces implementation of indoor positioning modules making use of the library function. The methods used in the implementation are K-NN(K Nearest Neighbors), Bayesian and trilateration. K-NN and Bayesian are kind of fingerprinting method. A fingerprint method consists of off-line phase and realtime phase. The process time of realtime phase must be fast. This paper proposes a decision tree method in order to improve the process time of realtime phase. Experimental results of comparing performances of these methods are also discussed.

• Journal of KIISE:Databases
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• v.30 no.3
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• pp.296-309
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• 2003

One of commercial applications of mobile computing is ATIS(Advanced Traveler Information Systems) in ITS(Intelligent Transport Systems). In ATIS, a primary mobile computing task is to compute the shortest path from the current location to the destination. In this paper, we have studied the shortest path re-computation problem that arises in the DRGS(Dynamic Route Guidance System) in ATIS where the cost of topological digital road map is frequently updated as traffic condition changes dynamically. Previously suggested methods either re-compute the shortest path from scratch or re-compute the shortest path just between the two end nodes of the edge where the cost change occurs. However, these methods we trivial in that they do not intelligently utilize the previously computed shortest path information. In this paper, we propose an efficient approximate shortest path re-computation method based on the dynamic window scheme. The proposed method re-computes an approximate shortest path very quickly by utilizing the previously computed shortest path information. We first show the theoretical analysis of our methods and then present an in-depth experimental performance analysis by implementing it on grid graphs as well as a real digital road map.

• Korean Journal of Cognitive Science
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• v.24 no.1
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• pp.49-69
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• 2013

While we interact with other people or objects, the brain continuously updates our own body schema to recognize the agent of observed actions. The Extrastriate Body Area (EBA) provides an initial interface for the sense of agency by integrating visual inputs of body parts with internal signals related to self-generated body movements. Less is known, however, about how the functional use of tools contributes to such processes. Here, we investigated whether tool-specific affordance would differentially affect the neural responses in the EBA depending on the agency of imaginary actions. In each trial we presented a picture of an object in a rectangular frame. Objects were either the tools typically brought towards the body (body tools; e.g., telescope, earphones) or away from the body (world tools; e.g., pen, dice; Rueschemeyer, Pfeiffer, & Bekkering, 2010). Depending on the color of the frame, participants imagined either themselves or the other person using the tool (self vs. other conditions). These four types of trials were randomly intermixed with blank trials. As results, independently localized right EBA regions of interest showed greater activation when participants imagined themselves using body tools than using world tools whereas no such differential activations were found when they imagined the other person using the tools. The postscan test revealed no significant difference in vividness of imagery between the self and other conditions. Our results suggest that the EBA incorporates functional affordance of tools into the body schema in order to enhance the sense of agency and to guide our own actions.

• Journal of The Korean Association For Science Education
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• v.40 no.1
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• pp.77-87
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• 2020

Scientific inquiry has emphasized its importance in various aspects of science learning and has been performed according to various methods and purposes. Among the various aspects of science learning, it is emphasized to develop core competencies with science, such as scientific thinking. Therefore, it is necessary to support students to be able to formulate scientific reasoning properly. This study attempts to explore problem-finding and scientific reasoning in the process of performing scientific inquiry. This study also aims to reveal what factors influence this complex process. For this purpose, this study analyzed the inquiry process and results performed by two groups of college students who conducted the inquiry related to osmosis. To analyze, research plans, presentations, and group interviews were used. As a result, it was found that participants used various scientific reasoning, such as deductive, inductive, and abductive reasoning, in the process of problem finding for their inquiry about osmosis. In the process of inquiry and reasoning complexly, anomalous data, which appear regularly, and the characteristics of experimental instruments influenced their reasoning. Various reasons were produced for the purpose of constructing the best explanation about the phenomena observed by participants themselves. Finally, based on the results of this study, several implications for the development context of programs using scientific inquiry are discussed.

• Journal of The Korean Association For Science Education
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• v.40 no.4
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• pp.415-427
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• 2020

This study aims to understand science education conducted in North Korea by analyzing the PCK components shown in two science teacher's guidebooks: (1) Guidebook for 1^st grade elementary school and (2) Guidebook for 1^st grade middle school. These were published after 2013, when "the first 12-year Universal Compulsory Curriculum" was implemented in North Korea. The analysis shows that both elementary and middle school guidebooks had the highest percentage of content in "Knowledge of Subject Matter", followed by "Knowledge of Instructional Strategies in Science" and "Knowledge of Science Curriculum". On the other hand, "Knowledge of Assessment in Science" and "Knowledge of Students" were significantly low in content. Within the "Knowledge of Subject Matter", both elementary and middle schools had the highest proportion of content in "Concepts and Theories", along with "Experiments and Inquiries" that was also significantly higher than other PCK components. Science teacher's guidebooks in North Korea advocates constructivist teaching style by using "discussions" as the main activity when conveying scientific concepts and theories to students or conducting scientific inquiry classes. Furthermore, "Knowledge of Instructional Strategies in Science" was mainly focused on guiding the "Instruction sequence and method" from the "Topic-specific Strategies", while only a small part of the "Subject-specific Strategies" was being presented. Also, Science teacher's guide books in North Korea included only a few theoretical elements of science education in both the general outline and the particular sections of guidebooks. "Knowledge of Science Curriculum" was mainly composed of "Lesson Objectives" with some inclusion of "Vertical Articulation" and "Horizontal Articulation". "Knowledge of Assessment in Science" and "Knowledge of Students" accounted for a small portion compared to the science teacher's guidebooks in South Korea.

• Korean Journal of Childcare and Education
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• v.11 no.3
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• pp.149-167
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• 2015

This study aims to propose the future direction of research of the Nuri-Curriculum, a national level curriculum, analyzing the subjects, the research methods, and the contents of Nuri-Curriculum studies, and current research trends. For these purposes, 102 Nuri-Curriculum articles in major child care-related journals from 2012-2015 are reviewed. PASW 18.0 program was used to calculate frequency and percentage rate. The major findings are as follows. First, a considerable amount of research has been carried out despite a relatively short implementation period. Second, many research topics dealt with include curriculum-related material. Third, 74.5 percent of the articles used quantitative methods, and content-analysis was the most widely used method among them. On the contrary, there was relatively less research which used the experimental method applying the curriculum to real practice, observational or qualitative method. Fourth, most of the research contents focus on the direction of making of the curriculum. Therefore, this paper proposes the necessity of supplementary research including its application to real practice as the research approaches on the Nuri-Curriculum performed so far have been limited.

• Journal of Science Education
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• v.38 no.3
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• pp.490-508
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• 2014

The objective of this study is to describe the status of operation of after-school science activities in elementary school and offer suggestions for the activation of such programs by targeting parents who participated in an open class, and examining their recognition of the program. To achieve this, announcement sheets for after-school science activities in 809 elementary schools in Gyeonggi-do were collected to examine the class names, class fees, material costs, and management status of class hours. In addition, 36 parents who participated in an open class were targeted, and their recognition of the program was analyzed using the results of a questionnaire. A draft of the questionnaire was developed by revising and complementing the 2013 customer satisfaction survey of the living science class of the Korea Foundation for the Advancement of Science & Creativity. The final questionnaire was completed by consulting 1 science education professor and 12 Master's candidates in science education for advice on the validity of the questionnaire content and terminology. The collected data were analyzed using a statistical program. Based on the results of the study, the following suggestions are proposed for the activation of after-school science activities in elementary school. First, the needs of education consumers (parents) should be identified and reflected persistently to activate after-school science activities in elementary school. Second, a science program that reflects the demand and choice of education consumers (parents) needs to be developed for the continuous activation of after-school science activities in elementary school.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.655-663
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• 2017

With the development of ICT technology, the indoor utilization of robots is increasing. Research on transportation, cleaning, guidance robots, etc., that can be used now or increase the scope of future use will be advanced. To facilitate the use of mobile robots in indoor spaces, the problem of self-location recognition is an important research area to be addressed. If an unexpected collision occurs during the motion of a mobile robot, the position of the mobile robot deviates from the initially planned navigation path. In this case, the mobile robot needs a robust controller that enables the mobile robot to accurately navigate toward the goal. This research tries to address the issues related to self-location of the mobile robot. A robust position recognition system was implemented; the system estimates the position of the mobile robot using a combination of encoder information of the mobile robot and the absolute space coordinate transformation information obtained from external video sources such as a large number of CCTVs installed in the room. Furthermore, vector field histogram method of the pass traveling algorithm of the mobile robot system was applied, and the results of the research were confirmed after conducting experiments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.4
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• pp.326-335
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• 2014

Aerodynamic characteristics of the small two-stage turbo blower were investigated using commercial CFD tool(ANSYS CFX Ver. 14.5) in this paper. Turbo blower, which is a centrifugal type of turbomachinery, is used in various industries. It is used for application that required high static pressure rising at relatively small volumetric flow rate. In order to understand the mechanism of static pressure rising, the aerodynamic characteristics of the small two-stage turbo blower are analyzed at high rotating speed in this study. The k-${\omega}$ SST turbulence model, which is good at prediction of adverse pressure gradient flows, was applied. The CFD results of the turbo blower are validated by performance test. The static pressure rising of the turbo blower is nonlinearly increased over the first stage and the second stage. The secondary flow occurred at guide vanes, between the casing and the first impeller shroud, and the bottom of the impeller disk. As a result, It is required that whole fluid area is analyzed to predict aerodynamic characteristics of small two-stage turbo blower. and the result should be selected with considering for error from experiment and CFD.