• Korean Journal of Ecology and Environment
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• v.35 no.2 s.98
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• pp.92-102
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• 2002

This study was conducted to compare filtering abilities of three species of freshwater mussels (Cobicula fluminea, Corbicula leana and Unio douglasiae) and to evaluate their filter feeding effects on water quality change in experimental enclosure systems. Mussel feeding in both laboratory and enclosure resulted in decrease of particulate material, such as chlorophyll, total P, SS. In the treatment with 600 individuals of mussels, chllorophyll concentration and net primary productivity decreased from $87.3{\pm}4.5\;{\mu}g/L$ and $106.3{\pm}8.8\;{\mu}gC\;L^{-1}\;hr^{-1}$ to nearly the same level as the mussel-free enclosure ($25.0{\pm}0.5\;{\mu}g/L$ and $15.6{\pm}13.3\;{\mu}gC\;L^{-1}\;hr^{-1}$, respectively)(P< 0.05, n = 6, ANOVA). In concert with the decrease of chlorophyll concentration, not only was the transparency enhanced from 0.48 m to 1.2m but also the suspended solids and total phosphorus decreased from $22.0{\pm}1.0\;mg/L$ to $7.5{\pm}0.5\;mg/L$ and $133{\pm}0.8\;{\mu}g/L$ to $70{\pm}0.0\;{\mu}g/L$, respectively (P<0.001, $r^2$>0.71, n = 11). Although slight decrease of SRP concentration and the increase of inorganic nitrogen ($NH_3-N$ and $NO_2-N$) were observed in the mussel addition enclosure, there was no statistical difference between two enclosures. Based on the filtering rate on phytoplankton and nutrient release rate in forms of feces and pseudofeces, Corbicula leana appeared to be the most efficient filter-feeder among three mussel species. These results inidicate that Cobicula play an important role in controlling particulate sestons and thus it could be applied as a biocontroler for the water quality management in lakes and reservoirs with algal blooms.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.539-550
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• 2016

The purpose of the study is to conceptualize SSI-PCK by identifying major components and sub-components to promote science teachers' confidence and knowledge on teaching SSIs. To achieve this, I conducted extensive literature reviews on teachers' perceptions on SSI, case studies of teachers addressing SSIs, SSI instructional strategies, etc. as well as PCK. Results indicate that SSI-PCK include six major components: 1) Orientation for Teaching SSI (OTS), 2) Knowledge of Instructional Strategies for Teaching SSI (KIS), 3) Knowledge of Curriculum (KC), 4) Knowledge of Students' SSI Learning (KSL), 5) Knowledge of Assessment in SSI Learning (KAS), and 6) Knowledge of Learning Contexts (KLC). OTS refers to teachers' instructional goals and intentions for teaching SSIs. Teachers often present a) activity-driven, b) knowledge and higher order thinking skills, c) application of science in everyday life, d) nature of science and technology, e) citizenship and f) activism orientations for teaching SSIs. KIS indicates teachers' instructional knowledge required for effectively designing and implementing SSI lessons. It includes a) SSI lesson design, b) utilizing progressive instructional strategies, and c) constructing collaborative classroom cultures. KC refers to teachers' knowledge on a) connection to science curriculum (horizontal/vertical) and b) connection to other subject matters. KSL refers to teachers' knowledge on a) learner experiences in SSI learning, b) difficulties in SSI learning, and c) SSI reasoning patterns. KAS indicates teachers' knowledge on a) dimensions of SSI learning to assess, and b) methods of assessing SSI learning. Finally, KLC refers to teachers' knowledge on the cultures of a) classrooms, b) schools, and c) community and society where they are located when teaching SSIs.

• 대한공업교육학회지
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• v.41 no.1
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• pp.128-146
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• 2016

The purpose of this study was to provide a basic research data for increasing the quality of 'creative engineering design' lesson and the teaching learning capability of high school teachers by analyzing the teaching learning management status and improvement plan of 'technology home economics subject' lesson for high school teachers. In order to investigate the teaching learning management status, the survey questionnaires from 63 teachers were collected from high school teachers who teach technology home economics subject currently and analyzed by statistical program SPSS 20. The main results of this study were as follows: First, for the contents of 'creative engineering design' lesson, the highest mean of response was 'creative thinking method'(M=4.22). In the learning activities, the teachers perceived the importance of the 'idea concept' highly. Second, in the management of 'creative engineering design' lesson, the teachers perceived the importance of the secure of tool, material budget, and practice space for the lesson highly. In the teaching capabilities, the teacher perceived the importance of the preparing teaching learning strategy most($$M{\frac{._-}{.}}4.14$$). Third, the teachers preferred to product for making uncomfortable things better in life and the other production outside from the content of textbook. Fourth, in the ratio of practice:theory lesson, they perceived the ratio of 3:7(36.5%), 4:6(25.4%), and 2:8(23.8%) are appropriate. In the assessment, the combination of production, portfolio, and presentation was preferred most. Fifth, there were statistically significant difference in teachers' interest and satisfaction and contents about 'creative engineering design' lesson between groups divided by the existence of practice space, certification held(technology teacher, non technology teacher), etc. Therefore, in order to improve the interest and satisfaction about the 'creative engineering design' lesson, the secure of space for technology practice and material budget were required. In addition, training and seminars program for improving the teaching capability for 'creative engineering design' lesson were required.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.128-136
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• 2011

This study was carried out to investigate the factors of food service satisfaction of the elderly in Busan. The survey was conducted from September 1 to October 15, 2009 by questionnaires and data analyzed by SPSS program. Fifty point nine percent of the subjects lived alone and the source of living expenses of 70.5% of the subjects was subsidy from government. The most important reason for the elderly to participate in meal service was 'economic difficulty' and 'to meet friend'. The subjects had various chronic degenerative diseases, such as arthritis, hypertension, diabetes, osteoporosis and cardiac disease. Sixty-six point eight percent of the subjects needed diet therapy for their diseases, but 87.1% of them don't want to pay the extra fee. Thirty six point five percent of the subjects attained information about lunch program because it was 'close to home' but 20.7% was 'from public officials'. The reasons for the use of the meal service were 'economic difficulty' (40.0%), 'to meet friends' (22.6%), and 'bother to prepare meal' (16.50%). The services provided by welfare center were health care, physical exam and haircut. The score given by the subjects on the satisfaction of meal service was 3.84 on the 5-point maximum scale. Higher satisfaction on kindness of staff, satisfaction of social support and awareness of support resulted in higher satisfaction of food service. It would be effective to provide food service models that meet specific needs of the elderly according to social welfare service and social community activities.

• Journal of Educational Research in Mathematics
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• v.24 no.3
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• pp.333-357
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• 2014

This study resulted from a study regarding creative STEAM System based upon an experiment with the center of gravity. The results of the study are constructed by a fusion of mathematics and physics, showing that they are the same as mathematical calculations. Also, students can find that center of gravity of an object is in equilibrium on a metal rod when the center of gravity exactly is placed on the rod. The fact that an experimental results are correspond to calculations can maximize the effectiveness of teaching. And also this study has the following effectiveness. First, the exact construction and calculations arouses good competition among students. Second, this experiment can give students a motivation for study and increase their thinking in classes because the theoretical background of center of gravity experiment is basically attributed to math and science classes in school. This study includes three different types of center-of-gravity experiments. One is a simple type of experiment in which center of gravity exists inside of an object. Another is a complicated one in which the center of gravity is also inside of an object. However, the third type is an experiment in where the center of gravity is outside of an object. Therefore, it gives students an opportunity to discuss how to confirm equilibrium on a metal rod when the object has its center of gravity outside. Having discussions in class will allow students to have a critical way of thinking. In addition, searching for a way to solve a problem will increase creativity of students as well. And the last type is finding the center of gravity of a big acrylic panel where multiple objects are on the panel. According to the survey and interview conducted by students who participated in this program, teaching based on creative STEAM system helps students to get a better understanding and more fast acquisition of knowledge. We can expect that a well-planned creative STEAM system through a continuous study will be both effective and efficient in educating critical and creative students.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.344-354
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• 2004

A pilot study was performed from September 2000 to April 2004 to examine the feasibility of the wetland-pond system for the agricultural reuse of reclaimed water. The wetland system was a subsurface flow type, with a hydraulic residence time of 3.5 days, and the subsequent pond was 8 $m^3$ in volume (2 m ${\times}$ 2 m ${\times}$ 2 m) and operated with intermittent-discharge and continuous flow types. The wetland system was effective in treating the sewage; median removal efficiencies of $BOD_5$ and TSS were above 70.0%, with mean effluent concentrations of 27.1 and 16.8 mg $L^{-1}$, respectively, for these constituents. However, they did often exceed the effluent water quality standards of 20 mg $L^{-1}$. Removal of T-N and T-P was relatively less effective and mean effluent concentrations were approximately 103.2 and 7.2 mg $L^{-1}$, respectively. The wetland system demonstrated high removal rate (92 ${\sim}$ 90%) of microorganisms, but effluent concentrations were in the range of 300 ${\sim}$ 16,000 MPN 100 $mL^{-1}$ which is still high for agricultural reuse. The subsequent pond system provided further treatment of the wetland effluent, and especially additional microorganisms removal in addition to wetland-pond system could reduce the mean concentration to 1,000 MPN 100 $mL^{-1}$ from about $10^5$ MPN 100 $mL^{-1}$ of wetland influent. Other parameters in the pond system showed seasonal variation, and the upper layer of the pond water column became remarkably clear immediately after ice melt. Overall, the wetland system was found to be adequate for treating sewage with stable removal efficiency, and the subsequent pond was effective for further polishing. This study concerned agricultural reuse of reclaimed water using natural systems. Considering stable performance and effective removal of bacterial indicators as well as other water quality parameters, low maintenance, and cost-effectiveness, wetland- pond system was thought to be an effective and feasible alternative for agricultural reuse of reclaimed water in rural area.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.3
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• pp.335-344
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• 2022

This study was conducted for 4 weeks on the preparation of the science teaching/learning course plan for 109 students in 4 classes of the 2nd year intensive course at B University of Education. Pre-service elementary teachers attended a two-week field training practice after listening to a lecture on how to write a science teaching and learning course plan. Pre-service elementary teachers tried to find out about the selection of materials and the degree of connection between the course plan and the class to prepare the science teaching/learning course plan. The researcher completed the questionnaire by reviewing and deliberation on the questionnaire questions together with 4 pre-service elementary teachers. The questionnaire related to the writing of the science teaching and learning course plan consists of 8 questions. Preferred reference materials when writing the course plan, the level of interest in learning, the success or failure of the science course plan and class, the science preferred model, the evaluation method in unit time, and the science teaching and learning One's own efforts to write the course plan, the contents of this course are the science faculty. It is composed of the preparation of the learning process plan and how helpful it is to the class. The results of this study are as follows. First, it was found that elementary school pre-service elementary teachers preferred teacher guidance the most when drafting science teaching and learning curriculum plans. Second, it is recognized that the development stage is very important in the teaching and learning stage of the science department. Third, Pre-service elementary teachers believe that the science and teaching and learning process plan has a high correlation with the success of the class. Fourth, it was said that the student's level, the teacher's ability, and the appropriate lesson plan had the most influence on the class. Fifth, it was found that pre-service elementary teachers prefer the inquiry learning class model. Sixth, it was found that reports and activity papers were preferred for evaluation in 40-minute classes. Seventh, it was stated that the teaching and learning process plan is highly related to the class, so it will be studied and studied diligently. Eighth, the method of writing a science teaching and learning course plan based on the instructional design principle is interpreted as very beneficial.

• The Korean Journal of Archival Studies
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• no.79
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• pp.5-32
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• 2024

The Korean government ranked 3rd among 193 UN member countries in the UN's 2022 e-Government Development Index. Korea, which has consistently been evaluated as a top country, can clearly be said to be a leading country in the world of e-government. The lubricant of e-government is data. Data itself is neither information nor a record, but it is a source of information and records and a resource of knowledge. Since administrative actions through electronic systems have become widespread, the production and technology of data-based records have naturally expanded and evolved. Technology may seem value-neutral, but in fact, technology itself reflects a specific worldview. The digital order of new technologies, armed with hyper-connectivity and super-intelligence, not only has a profound influence on traditional power structures, but also has an a similar influence on existing information and knowledge transmission media. Moreover, new technologies and media, including data-based generative artificial intelligence, are by far the hot topic. It can be seen that the all-round growth and spread of digital technology has led to the augmentation of human capabilities and the outsourcing of thinking. This also involves a variety of problems, ranging from deep fakes and other fake images, auto profiling, AI lies hallucination that creates them as if they were real, and copyright infringement of machine learning data. Moreover, radical connectivity capabilities enable the instantaneous sharing of vast amounts of data and rely on the technological unconscious to generate actions without awareness. Another irony of the digital world and online network, which is based on immaterial distribution and logical existence, is that access and contact can only be made through physical tools. Digital information is a logical object, but digital resources cannot be read or utilized without some type of device to relay it. In that respect, machines in today's technological society have gone beyond the level of simple assistance, and there are points at which it is difficult to say that the entry of machines into human society is a natural change pattern due to advanced technological development. This is because perspectives on machines will change over time. Important is the social and cultural implications of changes in the way records are produced as a result of communication and actions through machines. Even in the archive field, what problems will a data-based archive society face due to technological changes toward a hyper-intelligence and hyper-connected society, and who will prove the continuous activity of records and data and what will be the main drivers of media change? It is time to research whether this will happen. This study began with the need to recognize that archives are not only records that are the result of actions, but also data as strategic assets. Through this, author considered how to expand traditional boundaries and achieves reterritorialization in a data-driven society.