• Bulletin of the Korean Chemical Society
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• v.9 no.6
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• pp.338-341
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• 1988

Two crystal structures of fully dehydrated silver and potassium exchanged zeolite A, stoichiometries of $Ag_{9.3}K_{{2.7}^-}A$ (${\alpha}$ = 12.282(2) ${\AA}$) and $Ag_{10.7}K_{{1.3}^-}{\AA}$ (${\alpha}$ = 12.287(2) A) per unit cell, have been determined from 3-dimensional x-ray diffraction data gathered by counter methods. All structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}C$ . The crystals of $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$ were prepared by flow method using exchange solutions in which mole ratios of $AgNO_3$ and $KNO_3$ were 1:10 and 1:5, respectively, with total concentration of 0.05M. The structures of the dehydrated $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$ were refined to yield the final error indices $R_1$ = 0.037 and $R_2$ = 0.040 with 321 reflections, and $R_1$ = 0.042 and $R_2$ = 0.043 with 371 reflections, repectively, for which I > 3${\sigma}$(I). In both structures, eight $Ag^+$ ions are found nearly at 6-ring centers and each $Ag^+$ ion is nearly in the (1 1 1) plane at its O(3) ligands. The 8-ring sites are preferentially occupied by $K^+$ ions in both structures. 1.3 and 1.7 reduced silver atoms per unit cell were found inside of sodalite units of $Ag_{9.3}K_{{2.7}^-}A$ and that of $Ag_{10.7}K_{{1.3}^-}A$, respectively. These reduced silver species were presumably formed from the reduction of $Ag^+$ ions by oxide ions of residual water molecule or of the zeolite framework. These two crystals may be presented as hexasilver cluster in 21.7% and 28.3% of sodalite unit cells for $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$, repectively.

• Ecology and Resilient Infrastructure
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• v.9 no.4
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• pp.237-246
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• 2022

Owing to their high bioproductivity and unique physical environment, estuarine wetlands are gaining importance in national biodiversity management and habitat conservation. With regard to conservation and management of estuarine wetlands, this study analyzed the ecological characteristics of Gahwacheon Estuarine Wetland, an open estuary with various habitat types. Data from vegetation and biotic surveys have shown that 12 plant communities of five physiognomic vegetation types, including lentic herbaceous vegetation, halophytic herbaceous vegetation, and chasmophytic herbaceous vegetation. Due to the discharge of Namgang Dam and the effect of the tide, vegetation are distributed along the narrow waterside area. In terms of biodiversity, a total of 715 species, including 12 endangered wildlife species, were identified. Species diversity was relatively high in sections I and III where various riverbed structures and microhabitats were distributed. Due to the effect of the brackish water area following the inflow of seawater, endangered wildlife of various functional groups were also found to be distributed, indicating the high conservation value of that area. The collection of ecological information of the Gahwacheon Estuarine Wetland can be used as a framework for establishing the basis for conservation and management of the estuarine ecosystem and support policy establishment.

• Journal of The Korean Association For Science Education
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• v.27 no.1
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• pp.70-83
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• 2007

Reflection in teacher education is one reform effort that has taken hold in many teacher preparation programs. However, how to define it and how to foster it in a teacher's education are problematic issues. In this study, on the basis of literature review, science teachers' reflective thinking is defined as a process of thinking that deliberates on alternatives to solve conflict between one's previous knowledge/belief/practice and internal/external factors in science teaching context. Based on this definition, three types of science teachers' reflective thinking (i.e. technical reflection, professional reflection and critical reflection) were proposed. In addition, a framework of classifying the reflective thinking's types was also developed. To investigate science teachers' reflective thinking, two pre-service science teachers who majored in physics education participated in this study. The participants presented the monthly report on reflective practice, pre/post questionnaire, and education practicum journals. Individual interviews with them were conducted before and after their teaching activities. From the analysis of the data, it was possible to categorize the reflective thinking of the participants into three types. The major type of their reflective thinking was the technical reflection. However, it was difficult to find examples of the critical reflection.

• Journal of The Korean Association For Science Education
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• v.30 no.8
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• pp.953-970
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• 2010

The purpose of this study was to investigate the change of teacher-student interaction in a beginner secondary science teachers' class through collaborative mentoring program. Three experienced science teachers as mentors and three beginner science teachers as mentees were participated in this study. Mentors have been teaching science secondary school for more than 13 years with specialty in science education, and mentees have been teaching less than three years in secondary schools. They were matched one-toone on grounded characteristics that were revealed from pre-interview. Data collection consisted of lesson plans of mentees' classes, videotaped lessons of mentees, consultation meetings between mentors and mentees, and interviews with mentees as well as mentors. The consultation meetings and interviews were audiotaped and then transcribed with the videotaped lessons. To examine the change in teacher-student interactions, the lesson observed after four sessions of mentoring was compared to the lesson before mentoring on the basis of the analytical framework that was developed based on the interpretative approach. The analytical framework addresses the four aspects of teacher-student interaction, which include beginner of interaction (initiation), the types of the question, the student response and the feedback. After four sessions of collaborative mentoring, the beginner science teacher's classroom interactions were initiated by students more often. Teachers' questions increasingly turned into thought-provoking queries that required higherorder thinking. The students responded in the form of statements instead of asking question more frequently. Also, teachers provided more delayed feedback than immediate feedback. These changes of interaction patterns showed that students took a leading role in classroom interaction and they were encouraged to think. From this result, we argue that the beginner science teachers developed the ability to make students think and to support them in coming to an understanding of knowledge through a collaborative mentoring program.

• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.75-86
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• 2016

The purpose of the present study is to develop and validate an instrument to assess STEM career motivation. We developed 32 items for 7 constructs (i.e. education experience, career value, academic self-efficacy, career self-efficacy, career interest, parents' support, and career motivation) on STEM career motivation based on Social Cognitive Career Theory (SCCT; Lent et al.,1994). 767 first year high school students participated in this study. The items were validated by Messick's framework (1995). In this study, we examined the validity of items in four aspects (i.e. content, substantive, structural and generalizability of validity). Methodologically, we used Rasch analysis, Exploratory factor analysis, confirmative factor analysis based on structural equation modelling. We confirmed that our instrument with 32 items as valid and reliable for measuring the STEM career motivation. In addition, we tested the STEM career motivation model based on SCCT. Our model explained the data well, suggesting that external factors (education experience and parents' support) and cognitive factors (perception of value, self-efficacy and interest) were significantly related to STEM career motivation.

• Korean journal of communication and information
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• v.53
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• pp.5-28
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• 2011

This research examines the recent increasingly intensified non-reporting phenomenon by the press in South Korea and its legitimacy and validity. Non-reporting denotes cases in which the press does not report on significant issues in society. Although journalism scholars have raised this question, it remains unaddressed through case studies and formal criticism. This research compares the reporting and non-reporting by major media groups of cases related to the surveillance of civilians by the National Intelligence Service and the Defense Security Command under the Ministry of National Defense. This research specifies that the non-reporting phenomenon relates not to the ability to report, but to willingness to report, due to intervention by political factionalism of media groups. The non-reporting phenomenon results from the press ignoring their basic responsibility stemming from journalistic ethics and their social responsibility to fulfill their readers' right to know. Accordingly, this research revealed that the non-reporting phenomenon cannot be justified through diverse theoretical discussions and the journalistic code of ethics. Through the logical framework of public opinions and diverse empirical data to support it, this research demonstrates that the non-reporting phenomenon produces not unhelpful, but harmful effects to resolutions to ideological dissent in South Korean society.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.151-160
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• 2015

As a lexical meaning, casino is defined as "a certified gambling house, equipped with recreational facilities such as dance and music, etc., where people play roulette or cards." Casinos started from 17th to 18th century for European nobility and their social meetings and established a casino industry framework in the United States in the 1930s. The success of the casino business leads to the increase of sales; it became very helpful for the local and national government revenues and also for the related incidental tasks. Casino operations include a variety of fields, such as general customer management, dealer game management, security, account management, currency exchange, re-exchange management, marketing management, comp management and placement management, etc. These operations should be organically connected to each other by information systems such as a groupware, ERP and Customer Relationship Management (CRM), etc. In addition, in order to effectively manage comprehensive entertainment service, including accommodation and tourism, it is necessary to develop an information system which supports casino business and collateral entertainment service, collects the data generated throughout the business and provides information about the situations of management. Thus, this study will propose a casino information system designed and implemented, considering these details.

• Journal of the Korean Chemical Society
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• v.59 no.6
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• pp.520-532
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• 2015

The purposes of this study were to examine what kinds of educational activities were carried out during the practice teaching based on CoRe and to identify the role of CoRe and its influence on the development of expertise of student teachers. This study was performed as qualitative case study. The subjects of this study were one practice supervisor teacher and two student teachers. Data were collected through recording CoRe discussion process, student teachers' instructional scene, and semi-constructed interview, and analyzed by an inductive method. Student teachers noticed their own misconceptions, and clarified the concepts based on CoRe during the discussion with supervisor teacher. They also supplemented their lack of knowledge and made up new strategies through the process of sharing their ideas. During the discussion, the supervisor teacher conveyed his teaching experience based on his own orientations toward science teaching. In this course, CoRe plays roles as follows. Firstly, CoRe played a role as guiding supervisor teacher's coaching process. Secondly, CoRe helped for the supervisor teacher to recognize their own PCK. Thirdly, CoRe served as a tool of helping their communication. In turn CoRe proved to be a useful frame for teaching student teachers during practice teaching. Student teachers were provided with a useful framework for preparing lessons by developing CoRe for the topic they teach. Developing CoRe with supervisor teacher at the planning stage of lessons enhenced student-teachers' subject matter knowledge and their PCK including knowledge of science curricula and knowledge of student's understanding of science. Also student teachers understood the components of PCK and experienced the positive understanding toward students, teaching activities, and themselves as a science teacher.

• Journal of Science Education
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• v.39 no.1
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• pp.113-131
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• 2015

The purpose of this study was to analyze the interactive patterns between teacher and students in middle school earthh science classroom, identify difference of discourse types between earthh science classes taught by majored and non-majored teacher, find the relationship between the discourse pattern and the type of teachers' questions. For that purpose, the participants in this study included four teachers and their students of three middle schools in Seoul. The data consisted of two parts. First, we categorized interaction between teacher and students into the types of discourses by the use of Mortimer and Scott's analytical framework(2003). Second, we classified teachers' questions into four different types of question based on MNeill & Pimentel's classification scheme(2009) to examine for the relationship between the discourse pattern and the type of teachers' questions. As a result, all teachers used interactive/authoritative discourse most in middle school earth science class. Therefore, there was more authoritative discourse to non-majored teacher in comparison with majored teacher. And study demonstrated that the discourse pattern was more related to feedback about student's response rather than the type of teachers' question. In other words, the dialogic discourse showed up more frequently when the teacher used delayed feedback with positive and accepting attitude.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.181-192
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• 2013

Given both structural safety and economic benefits of aging facilities, remodelling of the existing facilities is preferable to reconstruction. This recognition provides an opportunity to reduce the commitment of resources and national budget. However, when a subordinate troop asks for remodeling or reconstruction of a deteriorated facility, it is difficult to ensure the consistency and objectivity in the process of decision making for the alternatives due to the absence of systematic and quantitative rating methodology. Their economic evaluation methodology only exists in a manual format. Thus, further research is required for converting the methodology into an automated system in view of practicality such as rapid and accurate data processing. The contributions of this study are as follows: 1) Literature review found out a representative economic evaluation model focused on military facilities, and comparative analysis with a similar study identified the strength and weakness. 2) this study presented how to convert the theoretical framework which enables to solve a specific subject matter into an automated system. 3) it developed a user friendly interfaces which consist of four functional modules by considering the usability and accessibility of the system user. 4) the developed system was verified by a case study in terms of four kinds of performance indicators.