• Journal of The Korean Association For Science Education
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• 제36권1호
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• pp.177-190
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• 2016

The purpose of this study is to validate learning progressions for Earth's motion and solar system from two different perspectives of validity. One is construct validity, that is whether a hypothetical pathway derived from our study of LPs is supported by empirical evidence of children's substantive development. The other is consequential validity, which refers to the impact of LP-based adaptive instruction on children's improved learning outcomes. For this purpose, 373 fifth-grade students and 17 teachers from six elementary schools in Seoul, Kangwon province, and Gwangju participated. We designed LP-based adaptive instruction modules delving into the unit of 'Solar system and stars.' We also employed 13 ordered multiple-choice items and analyzed the transitions of children's achievement levels based on the results of pre-test and post-test. For testing construct validity, 64 % of children in the experimental group showed improvement according to the hypothetical pathways. Rasch analysis also supports this results. For testing consequential validity, the analysis of covariance between experimental and control groups revealed that the improvement of experimental group is significantly higher than the control group (F=30.819, p=0.000), and positive transitions of children's achievement level in the experimental group are more dominant than in the control group. In addition, the findings of applying Rasch model reveal that the improvement of students' ability in the experimental group is significantly higher than that of the control group (F=11.632, p=0.001).

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제30권2호
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• pp.47-54
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• 2020

To develop the bright-vivid red- and yellow-inorganic fluorescent pigments with high luminescence properties, A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ inorganic pigments were synthesized by a water assisted solid state reaction (WASSR) method and a conventional solid state reaction method. Although impurity peaks corresponding to the AVO₃ and AV₃O₈ (A = K, Rb, and Cs) were observed in all samples prepared, the trigonal structure A₃V₅O₁₄ (A = K and Rb) and orthorhombic structure Cs₂V₄O₁₁ were successfully obtained as a main phase. These inorganic pigments showed the broad absorption band (under 550 nm) originated from CT transitions of VO₄ polyhedron, and the strong broad red- and green-emission bands due to ³T₂ → ¹A₁ and ³T₁ → ¹A₁ transitions of the [VO₄]^3- group. The A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ pigments showed a bright-vivid red- and yellow-body color, where the a* values of the A₃V₅O₁₄ (A = K and Rb) were +35.5 and +45.9, respectively, and b* value of Cs₂V₄O₁₁ pigments was +50.3. The L* values of the A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ inorganic pigments were over +45. These results indicate that the A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ inorganic pigments could be an attractive candidate as a bright-vivid red- and yellow inorganic pigments.

• Journal of Oral Medicine and Pain
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• 제37권1호
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• pp.33-45
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• 2012

This study was designed to assess follow-up study of condylar bone changes using cone beam computed tomography in patients with osteoarthritis. The author performed clinical examination for osteoarthritis patients who visited Orofacial Pain Clinic, Department of Oral Medicine, Pusan National University Hospital. CBCT(Cone beam computed tomography) was taken for 228 joints in 114 subjects. After average 10 months, CBCT was retaken. A Oral medicine and Oral radiologist evaluated CBCT each other. Condyle bone changes were classified by no bone change, flattening, erosion, osteophyte and sclerosis. The obtained results were as follow. 1. The condylar bone changes of osteoarthritis in temporomandibular disorder were as follow: 1) The transitions of each types of condylar bone changes was maintained at the initial state of the majority. 2) The transition of erosion was distributed erosion, flattening, sclreosis, osteohyte in order. 3) The transition of flattening was distributed flattening, osteohyte, normal, sclreosis in order. 4) The transition of osteohyte was distributed osteohyte, erosion, sclreosis, flattening in order. 5) The transition of sclreosis was distributed sclreosis, osteohyte, erosion, normal in order. 2. The signs and symptoms according to transition of each types of condylar bone changes were as follow 1) In the transition of condylar bone changes from erosin to erosion, pain, noise, LOM and MCO had symptomatic improvement. In the transition of condylar bone changes from erosin to flattening, pain, LOM, MCO had symptomatic improvement. In the transition of condylar bone changes from erosin to no bony change, pain, noise, LOM had symptomatic improvement. In the transition of condylar bone changes from erosion to flattening than the maintenance of eosion, MCO had symptomatic improvement. 2) In the transition of condylar bone changes from flattening to flattening, pain, noise and MCO had symptomatic improvement. In the transition of condylar bone changes from flattening to sclerosis, LOM had symptomatic improvement. 3) In the transition of condylar bone changes from osteophyte to osteophyte, pain, LOM and MCO had symptomatic improvement.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제30권4호
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• pp.239-250
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• 1994

The vertical distribution and activity patterns of fishes during the evening and morning transitions between day and night were studied acoustically and by bottom trawling in November 1990-1992 in thermally stratified waters of the East China Sea. The acoustic data were collected from six stations with a scientific echo-sounder operating at two frequencies of 25 and 100kHz, and the echograms were used to determine the vertical distributions of fish. Biological sampling was accomplished by bottom trawling to identify fish species recorded on the echograms, and the species and length compositions were determined. At each station, vertical profiles of water temperature, salinity and dissolved oxygen were taken with a CTD system and were related to the diel movements and the depth distributions of fish. During the day most fish were within several meters above bottom, but began to migrate upwards just before sunset, and during the night they were dispersed in midwater. Prior to sunrise with a thermocline present, one group of the fish aggregation occurred in dense schools slightly above the thermocline, while the other group occurred with the numerous single fish-traces bellow it. These groups of aggregations rapidly began to migrate toward the bottom across the thermocline from about 40 min before sunrise. Trawl hauls in the bottom strata below the thermocline with the characteristic single fish traces yieled invariably catches dominated by snailfish and fishing frog with minor quantities of other species in all stations. Hence, the results indicate that snailfish and fishing frog were the dominated scatterers in the depth strata below the thermocline, and the single-fish recordings were mainly snailfish. The fish species such as anchovy and juvenile mackerel in bottom trawl catches is poorly represented in relation to the mesh selectivity of the trawl net, but their occurrence suggest that the fish-school recording above the thermocline were due to these species which migrated vertically across the thermocline, with a temperature gradient of about 8$^{\circ}C$, from the water layers near the bottom at night. Accordingly, we conclude that the vertical distribution and activity patterns of snailfish were strongly temperature dependent and in the termally stratified waters, the upper limit to diel activity was closely linked to the position of the thermocline.

• 대한공업교육학회지
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• 제39권2호
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• pp.37-57
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• 2014

This study investigated perception of first-year college students who recently experienced technology education in their secondary education for describing contemporary technology classrooms. To accomplish this goal, survey and in-depth interview on their technology classrooms were employed. Participants in this study were 427 first-year college students who began their college life in 2013 and consisted of 224 students enrolled in 10 departments of educational major and 203 students who enrolled in 9 departments of other colleges. The instrument of this study consisted of preference toward technology classrooms and teachers, experience in the secondary technology classrooms, perception toward technology teachers, and suggestions for technology classrooms with five point Likert scales and open-ended questionnaires. And individual in-depth interviews with 22 volunteers who answered the instrument and consented the interview process were conducted. Based on the collected data, statistical and theme analyses were performed and the key findings were as follows. First-year students' experiences for technology classrooms were described with the theme of 'learning contents or activities'(54.4%). And the negative perception toward technology classrooms(29.1%) was larger than he positive perception(16.5%). The perception toward technology classrooms was also presented with two themes of teaching methods and subject interest. The perception toward technology teachers presented a medium level preference with several themes of teachers' teaching methods, teachers' personality, and subject interest. Lecture style method(60.48%) was largely used in the participants' technology classrooms and problem solving or collaborative methods was not frequent(19.31%). The participants indicated a need for improving teaching methods in technology education and suggested sufficient administration and curriculum supports and transitions of the learning contents. Further studies investigating the diverse public's perception toward technology and technology classrooms could be recommended.

• Ecology and Resilient Infrastructure
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• 제7권1호
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• pp.1-14
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• 2020

In fluvial and riparian ecosystems, biogeomorphological research has considered the complex, multi-way relationships between biological and hydro-geomorphological components over a wide range of spatial and temporal scales. In this review, we discussed the scope and processes of fluvial biogeomorphology by explaining (1) the multi-lateral interactions between organisms and hydrogeomorphic conditions, (2) the relationships between biodiversity and habitat heterogeneity, and (3) the effects of disturbance on ecosystem patterns. Over time, an organism-landform complex along streams transitions in the sequences of geomorphic, pioneer, biogeomorphic, and ecological stages. Over space, water flow and sediment distributions interact with vegetation to modify channel topography. It is the habitat heterogeneity in streams that enhances riparian biodiversity. However, in the areas downstream of a dam, habitat types and conditions are substantially damaged and biodiversity should be reduced. In South Korea, riparian vegetation flourishes in general and, in particular, invasive species actively colonize in accordance with the changes in the fluvial conditions driven by local disturbances and global climate change. Therefore, the importance of understanding reciprocal relationships between living organisms and hydrogeomorphic conditions will ever increase in this era of rapid climate change and anthropogenic pressure. The fluvial biogeomorphic framework reviewed in this article will contribute to the ecological management and restoration of streams in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• 제45권1호
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• pp.1-15
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• 2017

This study investigated the process of change of 32 urban parks designated during the period of Japanese colonial rule according to growth and development of the city in Busan. Particularly, researching included analyizing books, notification, data, and documents relevant to the history of urban planning published by Busan city. As a result, Daejeong Park, Gokwan Park, and Yongdusan Park had been utilized by Japanese residents under the Japanese colonial rule before planning of urban parks, and 32 parks legally specified in 1944 were planned by considering the prevention against disasters. After emancipation, there were an unauthorized building, housing construction, business district, public office, and school facility in the sites of the parks due to the influence of the Korean War and reorganization of urban planning. The majority of parkways and small parks downtown were eliminated. However, unexecuted parks that the government had designed on the edge of town during the Japanese colonial period have become major parks downtown through the city's growth. Yeonji Park, Yangjeong Park, and Danggok Park have been being building as a business of parks for a comfortable city, forming downtown along with the Green-Busan Policy. Thus, 32 parks designated under the Japanese colonial rule have made or got out of use reflecting on the phases of the times of modern Korean society. It turns out that these parks need an investigation about condition for land possession and purchase of the site of the parks in order for social common capital.

• Journal of Korean Elementary Science Education
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• 제24권5호특별호
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• pp.546-557
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• 2005

The purpose of this study was to analyze the characteristics of the geology-related contents in the 1st~7th elementary science curriculum. Our analysis was based on the analytical frameworks of geology-related contents (the structure of the contents, the amount of teaming, the contents of the experimental activities, the transitions of the terminology, and the change in the number of illustrations). The results are as follows: 1. Consistently covered contents were limited to weathering of the rock and soil, igneous rock, sedimentary rock, metamorphic rock, and the change of the earth's, fold and fault, earthquake and volcano, geologic stratum and fossil. 2. The geological contents account for (average), 11.5% (maximum), and 5.1% (minimum) of the elementary science curriculum. Most contents covered in the curriculum were rock and soil, and the change of the earth's surface. 3. Continuously covered experimental contents were the weathering and soil, igneous rock, change of the earth's surface, geologic stratum and fossil. 4. The terminology on the rock was the most frequently changed. Whenever the curriculum changed, the addition, deletion, or renaming of terminology led to confusions. 5. In terms of the transition of illustrations, the pictures replaced the figures or diagrams as the representative illustration methods as the science or the textbook compilation skill develope. The cartoons or tables were also used increasingly in order to help the children to understand and pay attention to study.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제29권3호
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• pp.186-191
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• 2016

The effects of $Eu^{3+}$ doping on the structural, morphological, and optical properties of $MgMoO_4:Dy^{3+},Eu^{3+}$ phosphors prepared by solid-state reaction technique were investigated. XRD patterns exhibited that all the synthesized phosphors showed a monoclinic system with a dominant (220) diffraction peak, irrespective of the content of $Eu^{3+}$ ions. The surface morphology of $MgMoO_4:Dy^{3+},Eu^{3+}$ phosphors was studied using scanning electron microscopy and the grains showed a tendency to agglomerate as the content of $Eu^{3+}$ ions increased. The excitation spectra of the phosphor powders were composed of a strong charge transfer band centered at 294 nm in the range of 230~340 nm and two intense peaks at 354 and 389 nm, respectively, arising from the $^6H_{15/2}{\rightarrow}^6P_{7/2}$ and $^6H_{15/2}{\rightarrow}^4M_{21/2}$ transitions of $Dy^{3+}$ ions. The emission spectra of the $Mg_{0.85}MoO_4$:10 mol% $Dy^{3+}$ phosphors without incorporating $Eu^{3+}$ ions revealed a strong yellow band centered at 573 nm resulting from the $^4F_{9/2}{\rightarrow}^6H_{13/2}$ transition of $Dy^{3+}$. As the content of $Eu^{3+}$ was increased, the intensity of the yellow emission was gradually decreased, while that of red emission band located at 614 nm began to appear, approached a maximum value at 10 mol%, and then decreased at 15 mol% of $Eu^{3+}$. These results indicated that white light emission could be achieved by controlling the contents of the $Dy^{3+}$ and $Eu^{3+}$ ions incorporated into the $MgMoO_4$ host crystal.

• Journal of Ginseng Research
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• 제44권1호
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• pp.105-114
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• 2020

Background: Exploring the pharmacokinetic (PK) changes of various active components of single herbs and their combinations is necessary to elucidate the compatibility mechanism. However, the lack of chemical standards and low concentrations of multiple active ingredients in the biological matrix restrict PK studies. Methods: A putative multiple reaction monitoring strategy based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to extend the PK scopes of quantification without resorting to the use of chemical standards. First, the compounds studied, including components with available reference standard (ARS) and components lacking reference standard (LRS), were preclassified to several groups according to their chemical structures. Herb decoctions were then subjected to ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry analysis with appropriate collision energy (CE) in MS² mode. Finally, multiple reaction monitoring transitions transformed from MS² of ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were used for ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry to obtain the mass responses of LRS components. LRS components quantification was further performed by developing an assistive group-dependent semiquantitative method. Results: The developed method was exemplified by the comparative PK process of single herbs Radix Ginseng (RG), Radix Polygala (RP), and their combinations (RG-RP). Significant changes in PK parameters were observed before and after combination. Conclusion: Results indicated that Traditional Chinese Medicine combinations can produce synergistic effects and diminish possible toxic effects, thereby reflecting the advantages of compatibility. The proposed strategy can solve the quantitative problem of LRS and extend the scopes of PK studies.