• Journal of The Korean Association For Science Education
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• v.35 no.2
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• pp.247-258
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• 2015

Students are engaged in classroom learning, and classroom learning occurs not only through conversation but also through nonverbal behavior. In science classrooms especially, there are meaningful nonverbal behaviors such as practical activities like observation and measurement. But these behaviors have not been properly investigated by existing instruments that try to measure students' engagement. This study aims to develop a new instrument for analyzing students' behavioral engagement especially in science classrooms. The method of developing the instrument was structured along three steps. First, student behaviors have been classified into fourteen categories through literature review and a series of observation of elementary science classroom. Second, based on these, a framework for analyzing student behavioral engagement has been developed. With the framework, every student moment could be labeled as Participatory Speech or Participatory Silence or Non-Participatory Speech or Non-Participatory Silence. Third, an instrument to which the framework is applied has been developed by using Microsoft Excel. As a trial, two fourth-grade students in elementary science class were analyzed with this instrument. The results of the trial analysis shows that the longest period of a science lesson was occupied by Participatory Silence (63% and 72%). Among the participatory silence, 'listening' was the most common (51% and 42% of the trial lesson) and 'observing' which is a specific behavior to science was the fourth position (17% and 17% of the trial lesson). It is expected that the developed instrument could be used in improving our understanding of the patterns of student engagement in science classrooms.

• Economic and Environmental Geology
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• v.36 no.2
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• pp.123-131
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• 2003

Geophysical surveys(electrical resistivity, self-potential, seismic refraction, GPR) were conducted to investigate the physical properties of the subsurface, and to delineate the flow channel of leachate from a AMD(acid mine drainage), buried rock wastes and tailings, and drainage pipes at an abandoned mine(Kwangyang mine). Especially in rainy season the sites appear to be abundant in AMD leachate, characterized by electrical conductivities of 0.98-1.10 ms/S. Electrical resistivity sections indicate that the leachate flows running in two directions at southern part rise up through the narrow fracture zones at the central part and contaminates the surrounding soil and stream. Such schematic features at the anomalous zone are well correlated with negative peaks in self-potential data, the limited penetration depth in GPR data and low velocity zone in seismic refraction data. Shallow high-resistivity zone is associated with the buried rock wastes which cause the diffractions in GPR image. In addition, the events at depth of approximately 1-1.25 m in GPR sections must be the metal pipes through which AMD is drained off to the inner bay.

• Journal of Engineering Education Research
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• v.8 no.4
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• pp.52-63
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• 2005

National competitiveness is related directly to the strength of educational competitiveness of universities. Seoul National University (SNU) has been taking efforts to improve its competitiveness in University education in variety of ways and the classroom assessment is one key example of those. The current classroom assessment system practiced at universities is being used to evaluate courses and professors in charge by the university administration or evaluation committee. The classroom assessment system is not intended to put students and professors as the subject of the evaluation. In this case, the evaluation is intended wrongfully to rank the courses and evaluate professors' achievement by assigning grades on the lectures. Instead, a proper classroom assessment system should be targeted to improve the quality of lectures by encouraging communication among professor and students in the classroom. In this study, it was intended to investigate a suitable classroom assessment system to enhance the effectiveness of education, not to rank the courses and evaluate professors' achievement. For this purpose, research has been carried out to investigate opinions of professors at SNU on the criteria of classroom assessment and to analyze the criteria of classroom assessment at other domestic universities in Korea. The inquiries for feedback on the lecture by the student in the class was analyzed. The current classroom assessment system at SNU was reviewed and an improvement plan was devised to evaluate liberal art courses of engineering and science schools at SNU. In this research, the problems in the classroom assessment system was reviewed and improvement points were searched to utilize the classroom assessment system more effectively for the improvement of lecture quality.

• Journal of Gifted/Talented Education
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• v.20 no.1
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• pp.369-388
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• 2010

A Discourse Analysis tool has been developed and has been applied in the cooperative group inquiry activities in order to derive the characteristics of elementary gifted students in science. We recorded and videotaped the whole group problem-solving processes where 4 elementary students worked together to solve given problems as a group for one year in a gifted education center attached to a university in Seoul. We analyzed recorded discourses using systemic functional linguistics with a focus on the structure of information and topic. The discourse analysis tool was developed with the cooperation of science education and gifted education experts. In discourse analysis, we focused on meaning development processes rather than grammatical analysis. Through application of newly developed discourse analysis tool, we confirmed that the tool is useful in understanding the characteristics of science-gifted elementary students. We also founded that the interaction between students has significant effects on problem-solving processes by comparing two students who showed contradictory features in the share of dialogue. In addition, the result suggested that we need to provide students with proper training for ways to communicate with others for effective science-gifted instruction.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.5
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• pp.189-196
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• 2022

Skyline query is a scheme for exploring objects that are suitable for user preferences based on multiple attributes of objects. Existing skyline queries return search results as batch processing, but the need for real-time search results has increased with the advent of interactive apps or mobile environments. Online algorithm for Skyline improves the return speed of objects to explore preferred objects in real time. However, the object navigation process requires unnecessary navigation time due to repeated comparative operations. This paper proposes a Pre-processing Online Algorithm for Skyline Query (POA) to eliminate unnecessary search time in Online Algorithm exploration techniques and provide the results of skyline queries in real time. Proposed techniques use the concept of range-limiting to existing Online Algorithm to perform pretreatment and then eliminate repetitive rediscovering regions first. POAs showed improvement in standard distributions, bias distributions, positive correlations, and negative correlations of discrete data sets compared to Online Algorithm. The POAs used in this paper improve navigation performance by minimizing comparison targets for Online Algorithm, which will be a new criterion for rapid service to users in the face of increasing use of mobile devices.

• Research in Plant Disease
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• v.28 no.1
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• pp.1-18
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• 2022

Volatiles exist ubiquitously in nature. Volatile compounds produced by plants and microorganisms confer inter-kingdom and intra-kingdom communications. Autoinducer signaling molecules from contact-based chemical communication, such as bacterial quorum sensing, are relayed through short distances. By contrast, biogenic volatiles derived from plant-microbe interactions generate long-distance (>20 cm) alarm signals for sensing harmful microorganisms. In this review, we discuss prior work on volatile compound-mediated diagnosis of plant diseases, and the use of volatile packaging and dispensing approaches for the biological control of fungi, bacteria, and viruses. In this regard, recent developments on technologies to analyze and detect microbial volatile compounds are introduced. Furthermore, we survey the chemical encapsulation, slow-release, and bio-nano techniques for volatile formulation and delivery that are expected to overcome limitations in the application of biogenic volatiles to modern agriculture. Collectively, technological advances in volatile compound detection, packaging, and delivery provide great potential for the implementation of ecologically-sound plant disease management strategies. We hope that this review will help farmers and young scientists understand the nature of microbial volatile compounds, and shift paradigms on disease diagnosis and management to aromatic (volatile-based) agriculture.

• Geophysics and Geophysical Exploration
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• v.21 no.3
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• pp.171-182
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• 2018

We performed the seismic field data processing using an open-source software (Madagascar) to verify if it is applicable to processing of field data, which has low signal-to-noise ratio and high uncertainties in velocities. The Madagascar, based on Python, is usually supposed to be better in the development of processing technologies due to its capabilities of multidimensional data analysis and reproducibility. However, this open-source software has not been widely used so far for field data processing because of complicated interfaces and data structure system. To verify the effectiveness of the Madagascar software on field data, we applied it to a typical seismic data processing flow including data loading, geometry build-up, F-K filter, predictive deconvolution, velocity analysis, normal moveout correction, stack, and migration. The field data for the test were acquired in Gunsan Basin, Yellow Sea using a streamer consisting of 480 channels and 4 arrays of air-guns. The results at all processing step are compared with those processed with Landmark's ProMAX (SeisSpace R5000) which is a commercial processing software. Madagascar shows relatively high efficiencies in data IO and management as well as reproducibility. Additionally, it shows quick and exact calculations in some automated procedures such as stacking velocity analysis. There were no remarkable differences in the results after applying the signal enhancement flows of both software. For the deeper part of the substructure image, however, the commercial software shows better results than the open-source software. This is simply because the commercial software has various flows for de-multiple and provides interactive processing environments for delicate processing works compared to Madagascar. Considering that many researchers around the world are developing various data processing algorithms for Madagascar, we can expect that the open-source software such as Madagascar can be widely used for commercial-level processing with the strength of expandability, cost effectiveness and reproducibility.

• Sijohaknonchong
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• v.43
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• pp.177-206
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• 2015

This paper is written in order to research for the contents and expression of HanYongUn's Sijo. HanYongUn is very famous as monk and independent campaigner, modern poet in Korea. He wrote many kinds of literary works, for example, many modern poetry, modern novels, Sijo, Chino-Korean Poetry etc. It's very exceptional that he wrote a lot of Korean traditional Sijo and Chino-Korean Poetry. Because he was a many modern poet as same as modern novelist. So studying on his Sijo can help someone to understand the essence of HanYongUn's all literature. That's why I'm studying on HanYongUn's Sijo. The firstly, in aspect of the the contents of HanYongUn's Sijo, HanYongUn was expressing three kinds of themes, that is ideology, reality, daily life in his Sijo. The ideology consists of Buddhism and Confucianism and the reality is related with social conditions, the daily life is deeply connected with Nim. These features of his Sijo are different from his modern poetry and Chino-Korean Poetry which had a simple theme, for example, love with Nim, daily life. The secondly, in aspect of the expression of HanYongUn's Sijo, I studied the expression of HanYongUn's Sijo in three angles, that is, vocabulary and the developing of poet thinking, rhetorics. HanYongUn used essential words for expressing three kinds of themes effectively in his Sijo. And he was developing of his poet thinking by three steps in his Sijo. He applied several representative rhetorics to his Sijo, those are question and answer, exclamation, irony, distich etc. Even though I studied the characteristics of HanYongUn's Sijo in two aspects But there could be the other things to study about these kinds of theme. I might continue researching the other kinds of theme next time in the near future.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.286-298
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• 2002

The Remote Procedure Call(RPC) has been traditionally used for Inter Process Communication(IPC) among precesses in distributed computing environment. As distributed applications have been complicated more and more, the Mobile Agent paradigm for IPC is emerged. Because there are some paradigms for IPC, researches to evaluate and compare the performance of each paradigm are issued recently. But the performance models used in the previous research did not reflect real distributed computing environment correctly, because they did not consider the evacuation elements for providing security services. Since real distributed environment is open, it is very vulnerable to a variety of attacks. In order to execute applications securely in distributed computing environment, security services which protect applications and information against the attacks must be considered. In this paper, we evaluate and compare the performance of the Remote Procedure Call with that of the Mobile Agent in IPC paradigms. We examine security services to execute applications securely, and propose new performance models considering those services. We design performance models, which describe information retrieval system through N database services, using Petri Net. We compare the performance of two paradigms by assigning numerical values to parameters and measuring the execution time of two paradigms. In this paper, the comparison of two performance models with security services for secure communication shows the results that the execution time of the Remote Procedure Call performance model is sharply increased because of many communications with the high cryptography mechanism between hosts, and that the execution time of the Mobile Agent model is gradually increased because the Mobile Agent paradigm can reduce the quantity of the communications between hosts.

• Journal of Korea Foundry Society
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• v.42 no.6
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• pp.337-346
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• 2022

In order to optimize the solution treatment conditions of Al-7Si-(0.3~0.5)Mg-(0~0.5)Cu alloys, a series of heat treatment experiments were conducted under various solution treatment times up to 7 hours at 545℃, followed by a microstructural analysis using optical microscopy, FE-SEM, and Brinell hardness measurements. Rapid coarsening of eutectic Si particles was observed in the alloys during the first 3 hours of solution treatment but the size of those Si particles did not change at longer solution treatment conditions. Meanwhile, the degree of spheroidisation of eutectic Si particles increased until the solution treatment time was increased up to 7 hours. Q-Al5Cu2Mg8Si6 andθ-Al2Cu were observed in as-cast Cu-containing Al alloys but the intermetallic compounds were dissolved completely after 3 hours of solution treatment at 545℃. Depending on the initial Mg composition of the Al alloys, π-Al8FeMg3Si either disappeared in the alloy with 0.3wt% of Mg content after 5 hours of solution treatment or remained in the alloy with 0.5wt% of Mg content after 7 hours of solution treatment time. Mg and Cu content in the primary-α phase of the Al alloys increased until the solution treatment time reached 5 hours, which was in accordance with the dissolution behavior of Mg or Cu-containing intermetallic compounds with respect to the solution treatment time. From the results of microstructural changes in the Al-7Si-Mg-Cu alloys during solution treatment, it was concluded that at least 5 hours of solution treatment at 545℃ is required to maximize the age hardening effect of the present Al alloys. The same optimal solution treatment conditions could also be derived from Brinell hardness values of the present Al-7Si-Mg-Cu alloys measured at different solution treatment conditions.