• Journal of the Korean earth science society
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• v.18 no.6
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• pp.464-472
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• 1997

The purpose of training science teachers is to bring up the ideality and the most excellent science teachers whom our society needs. So, teacher training college curriculums of science education should be the ones that will train competent and respectable science teachers who have the technical and practical theory and knowledge through the process of high level academic experiences and activities. Accordingly, the training system and improvement plan for the problems in employment of science teachers in secondary schools should be as follows: 1. The employment examination for teachers should be abolished instead, the system of an apprentice teacher should be brought in, or private schools as well as public schools should bring in employment examination system. 2. With the modification of science teacher training curriculums, the cooperative studies of science major subjects and science education subjects should be strengthened and the connection between real needs of secondary schools and curriculums of secondary school science teacher training should be embodied. 3. Bringing up excellent science teachers should be facilitated through the establishment of administrative and financial aiding system about teacher training college.

• Journal of the Korean earth science society
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• v.23 no.2
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• pp.166-179
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• 2002

This study investigated preservice teachers' perceived constraints in implementing their ideal pedagogies and the influence of the teacher education program on their pedagogical beliefs changes. Unique features that the university-based coursework and field experiences had on preservice teachers' learning to teach were also explored. This preservice teacher education program employs constructivist aspects of teacher education and generates applications of constructivism to the practice of teaching. Major findings include: preservice teachers' having traditional pedagogy as the default, recovery of prior beliefs, constraints on implementing constructivist pedagogy, and being overly confident in themselves as teachers. With the influence of constructivist epistemology, these preservice teachers' pedagogical beliefs evolved and were refined over time as they incorporated various constructivist ideas. The benefits and influences of the M.Ed. program's theoretical coursework and the field experiences on these teachers' learning-to-teach experiences are addressed with rich data. The implications for teacher educators as well as for the instructional practices of preservice teacher education programs are discussed. Recommendations for future research are also presented.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.269-274
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• 1998

In order to develop of support medla for bloom reactor, physicochemical properties and attachability of surface of activated carbon, clay mineral, non-clay mineral, and waste mold sand were enamined. Measured physicochemical properties of materials were surface roughness, mean particle size, surface area, hydrophobicity, and surface charge. At a tested materials, activated carbon was the best attachable material and microorganisms were attached $20.1{\times}10^7CFU/cm^2$ at surface, compared with diatomaceous earth which were attached of $9.2{\times}10^7CFU/cm^2$ in our research, surface area and hydrophobicity show- ed more Influence than any other factor on attachment of microorganisms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.980-998
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• 2023

In Low Earth Orbit (LEO) satellite networks, satellites operate fast and the inter-satellite link change period is short. In order to sense the spectrum state in LEO satellite networks in real-time, a space-based satellite network intelligent spectrum sensing algorithm based on artificial neural network (ANN) is proposed, while Geosynchronous Earth Orbit (GEO) satellites are introduced to make fast and effective judgments on the spectrum state of LEO satellites by using their stronger arithmetic power. Firstly, the visibility constraints between LEO satellites and GEO satellites are analyzed to derive the inter-satellite link building matrix and complete the inter-satellite link situational awareness. Secondly, an ANN-based energy detection (ANN-ED) algorithm is proposed based on the traditional energy detection algorithm and artificial neural network. The ANN module is used to determine the spectrum state and optimize the traditional energy detection algorithm. GEO satellites are used to fuse the information sensed by LEO satellites and then give the spectrum decision, thereby realizing the inter-satellite spectrum state sensing. Finally, the sensing quality is evaluated by the analysis of sensing delay and sensing energy consumption. The simulation results show that our proposed algorithm has lower complexity, the sensing delay and sensing energy consumption compared with the traditional energy detection method.

• Journal of the Korean earth science society
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• v.25 no.4
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• pp.242-250
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• 2004

The purpose of this study is to examine the interactive effects of teaching methods (expository and discovery) and learner's cognitive styles on the retention of learned content in Earth Science three weeks after an instruction is given. The subjects of this study were 1st graders of a boys' high school (n = 185) and co-educational high school (n = 189) in Gwangiu Metropolitan City of Korea. 92 students of the boys' high school and 95 students of the co-ed high school were assigned to the expository teaching group, and the rest of the boys' high school students and the co-ed high school students were to the discovery teaching group. The students were classified into field-independent learners, medium learners, and field-dependent learners based on their cognitive styles. The results of the study can be summarized as follows: First, the discovery teaching was more effective than expository teaching in terms of comprehension and application related to post-instruction retention of learned content. But there was no noticeable difference in knowledge domain. Second, the field-independent cognitive style was more effective than its counterpart, the field dependent cognitive style. Third, in the post-instruction retention test, not so much relevance was found between teaching methods and learner's cognitive style.

• Journal of the Korean earth science society
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• v.27 no.3
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• pp.313-327
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• 2006

This study investigated the geochernical characteristics of Mn scale formed in groundwater wells at the Damyang area. The composition of Mn scale consists mainly of MnO and $SiO_2$. The content of Mn ranges from56.61wt.% to 68.69wt.%, and $SiO_2$ content ranges from 1.56wt.% to 10.45wt.%. The contents of Mo and Ba in Mn scale increased with increased depth; whereas, the content of Zn and Pb decreased with increased depth. Birnessite, quartz and feldspars were identified in Mn scales using x-ray powder diffraction studies. The IR absorption bands for Mn scales show major absorption band due to OH stretching, adsorbed molecular water, and birnessite stretching, respectively. In the SEM and EDS analysis, the Mn scale consists of botryoidal, spherical, spherulite, and empty straw structure. Those structure may be precipitated simply due to oversaturation with concentrated Mn content or may be formed through biogenic precipitation by Lepthothrix discophora. Under microanalysis using EDS on those structure surface of Mn scales, the Mn atomic percent range from 28 to 44, and such elements revealed the presence of Si, K, Na, Ca, Cl, Cu, Zn, and Ba.

• 한국해양학회지
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• v.16 no.1
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• pp.12-23
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• 1981

A numerical experiment is made in order to clarify the mechanism of the upwelling phenomenon along the coast near the poleward edge of the western boundary current. The possibility of the upwelling is suggested from the analysis of the observational data in the east of Honshu, Japan, and in the south eastern coast of Korean Peninsula. This upwelling phenomenon is very deep and can be traced to the bottom layer. The upwelling phenomenon seems to be a general oceanic feature which characterizes the region along the west coast near the poleward edge of the western boundary current. This experiment is simulating the oceanic condition of the transition region between Kuroshio front and the Oyashio front in the east of Honshu, Japan. The possible explanations of the causes of the upwelling are as follows;In the interior of the modeled ocean the cold heavy water supplied from the north and the warm light water from the south make the north-south gradient of the pressure field and accelerate the eastward current to produce the h-orizontal divergence feld near the west coast. The divergence is compensated by the upwelling near the separation region. Another one is that the upwell-ed cold water strengthen constantly the pressure gradient which is balanced by the northward current and is weakened by the horizontal diffusion.

• Journal of the Korean earth science society
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• v.25 no.5
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• pp.336-347
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• 2004

This study investigated the effects of the application of a variety of ICTs cause the effects on self-directed learning capability, creativity and problem-solving ability. In order to achieve the above aim, Web-Based Instructions(WBI) and instructions using CD-ROM Titles for the unit of 'the solar system and the galaxy' were applicated and analyzed which belongs to the area of 'the earth' in the subject 'science' for high school students. Instructions using WBI materials and CD-ROM titles were found to be effective on 'self-conception', 'creativity', 'future inclination', 'self-assessment ability', 'openness' and' initiative' improvement all of which belong to self-directed learning characteristics. They did not, however, show meaningful effect on improving 'learning eagemess' and 'responsibility' improvement. On looking into self-directed learning characteristics according to prerequisite learning levels, both groups and these for instruction using CD-ROM learning materials were found to have no effect on interaction. With respect to problem-solving ability improvement which is characteristic of the instruction using ICTs, WBI proved more fruitful than instruction using CD-ROM titles on improving scholastic achievement level. WBI was effective on 'fluency', 'originality' and 'resistance to premature closure'. It on the other hand, was of no use on 'abstraction of titles' and 'elaborateness' These results came from the following characteristics: WBI came into effect on 'fluency' and 'originality' in the areas of variety and vitality, which are characteristic of WBI. In the area of resistance to premature closure WBI was effective on organizing learning contents owing to the animation of picture materials which are variously presented in the web site. As a result of WBI questionnaire about WBI, an excellent effect on the structure of display, quantity of information, indication and instruction, supplementary study and further study were discussed.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.9
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• pp.542-547
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• 2017

This paper was to analyze the membrane characterization of hydrophilicity, surface morphology and membrane chemical anlysis of three commercial microfiltration/ultrafiltration membranes, and evaluate the filtration performance of a seawater to assess the availability for pretreatment of desalination process. From the results of contact angle, Mem-3, fabricated with polyacrylonitrile, was highly hydrophilic. It find out that Mem-3 has more anti-biofouling property. In Field emission scanning electron microscope (FESEM), Mem-1 (polyethylene) and Mem-2 (Polyvinylidenefluoride) showed the sponge-like shape and Mem-3 showed finger-like shape. Membrane chemical analysis by energy dispersive spectrometer (EDS) presented that Mem-2 was mostly fluoride and Mem-3 had s high ratio of N (32.47%) due to the nitrile group. The permeation flowrate per time on suction pressures using deionized water (D.I. water) tends that permeation rate of Mem-3 more increased when the pressure was increased compared to other membranes. From the results of turbidity and total suspended solids (TSS) removal, turbidity of permeate was 0.191 NTU to 0.406 NTU and TSS was 2.2 mg/L to 3.0 mg/L in all membranes, indicating that it was not suitable for the pretreatment of seawater desalination by short-term experiments.

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.309-323
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• 2002

This qualitative study investigated preservice teachers' understandings of the ontology and epistemology underlying constructivist notions of learning through four in-depth interviews. Of the sixteen participants in a larger study, five significantly changed ontological and epistemological beliefs and eleven did not. This study focused on these eleven teachers who have hardly changed their philosophical beliefs throughout the teacher education program. Ten teachers who consistently maintained the scientific realist beliefs were presented as a composite case (Young's case). Among the eleven teachers, there was one outlier who had consistently maintained an idealist and relativist epistemological position from the beginning of the study and was subjected to another case analysis (Ben's case). These cases corroborated the assertion that each individual's deeply entrenched ontological and epistemological beliefs are very hard to change. For researchers, this study offers insights into the reasons that preservice teachers give for non-changes in their thinking about learning to teach. The study also examines preservice teachers' perceived constraints in implementing their ideal pedagogies and the influence of the teacher education program on their pedagogical beliefs changes. The benefits and influences of the M.Ed. program's theoretical coursework and the field experiences on these teachers' learning-to-teach experiences are addressed with rich data. The implications for teacher educators as well as for the instructional practices of preservice teacher education programs are discussed. This research emphasize necessity of the field-based teacher education program and the need of empowering experienced school teachers as teacher educators in teacher preparation and professional development.