• Journal of the Korean Ceramic Society
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• v.51 no.3
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• pp.145-149
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• 2014

A hydroxyapatite microsphere was prepared using a spray-drying method. The change in the shape as a function of the slurry concentration and the change in the degree of shrinkage according to the heat-treatment temperatures were observed. To obtain biomaterials with improved bio-stability, $CaHPO_4{\cdot}2H_2O$ and $Ca(OH)_2$ were mixed at a ratio of 6 : 4 and then ball-milled to synthesize hydroxyapatite. The hydroxyapatite microsphere was prepared using 30 wt% ~ 80 wt% hydroxyapatite slurry by a spray-drying method. For concentrations lower than 50 wt% or higher than 80 wt%, doughnut-shaped microspheres were produced. However, perfect microspheres were produced when using slurry concentrations of 50 wt% ~ 70 wt%. A dense microstructure was observed after a heat treatment at temperatures higher than $1100^{\circ}C$ and the size was reduced by 24.3% at these temperatures.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.6
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• pp.548-557
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• 2020

Purpose: To better understand the benefits and harms of engagement with online pediatric liver disease communities within social media. Methods: We conducted a survey of caregivers of children with liver disease participating in online pediatric liver disease communities within social media, as well as a survey of healthcare providers (e.g., physicians, surgeons, nurse coordinators) from this field to better understand the perceived benefits and harms of participation. Results: Among 138 caregivers of children with liver disease that completed the survey, 97.8% agreed social media was a good place to learn about patient experiences and 88% agreed it was a good source of general information. Among caregivers, 84.8% agreed social media helps them to better advocate for their child. While 18% agreed that the information over social media was equal to the information from their healthcare team and 19% neither agreed/disagreed, only 3% indicated they would use this information to change care without telling their provider; in contrast, among 217 healthcare providers, 55% believed social media may lead caregivers to change management without telling their team. Conclusion: Engagement with online disease-specific communities in social media yields several benefits for caregivers and, in contrast to healthcare providers' concerns, participation is unlikely to lead to problems including caregivers changing the treatment plan without first discussing these plans with their team. Openness between caregivers and medical teams about the role for social media can help to improve trust and maximize the potential benefits of engagement with these groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.433-445
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• 2019

This study was designed to create an innovative Korean school space plan. This was done by performing an analysis of cases of student-tailored class operations and the composition of school space in Sweden's Vittra Telefonplan School. To this end, the research team analyzed prior studies, the Vittra school space and the student-tailored classes through an analysis of the literature, documents and video images. First, the OpenSpace was operating classes tailored to each student's academic growth and needs. Second, the open-space school space played a role as the space for student life. Third, the teacher played a role as an active guide and facilitator of students. Forth, the students' individual learning management team actively conducted coding classes by utilizing IT-based learning platforms. The implications of the Vittra School are as follows. When designing a new school, it is recommended to design a small school as small as possible, organize an open space according to the grade and not by the class, and operate the curriculum around the students' grade. When reorganizing existing schools, it is proposed that standardized classrooms be modified for schools with spare classrooms to create learning spaces that can vary for large to small and to practice project-oriented classes at the grade level.

• Hwankyungkyoyuk
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• v.13 no.1
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• pp.75-86
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• 2000

The purpose of this study is to analyze the content of environmental inquiry activities and values of elementary school students written in their reports of the Energy Environment Inquiry Activity Contest which is a unit contest of the Youth Science Festival held annually in Korea and get some ideas for the valuable way of Korean environmental education. 10 teams' reports were gathered and the locality, class study area, inquiry theme, inquiry method and values were analyzed and introduced as case studies to get some insights to teach elementary school students environmental values through inquiry activities of science subject approach. Each teams set various inquiry themes in the content domain of energy resources and earth environment conservation focusing on each team's geographical characteristics and occurring environmental problems in their local areas. There were 16 sentences representing technocentrism and 12 sentences representing ecocentrism. 5 of 10 teams showed both of technocentrism and ecocentrism in their reports. But their was only scientific knowledge without any environmental values in one team's report. Inquiry activity is a good teaching-learning method to develop environmental literacy. There should be environmental values involved as far as it is the environmental inquiry activities using environmental subject matter. The result of this study proposes that environmental educators should actively intervene for inquirers to set a stage in the whole process to search for an alternative to solve environmental problems involved in their project activities. The reason is because the environmental education in the elementary school is established to operate by the infusion way into various subjects already existed in the Korean curriculum.

• Korean Journal of Materials Research
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• v.24 no.12
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• pp.715-719
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• 2014

(PDDA/$SiO_2$) thin films that consisted of positively charged poly (diallyldimethylammonium chloride) (PDDA) and negatively charged $SiO_2$ nanoparticles were fabricated on a glass substrate by an applying voltage layer-by-layer (LBL) self-assembly method. In this study, the microstructure and optical properties of the (PDDA/$SiO_2$) thin films coated on glass substrate were measured as a function of the applied voltage on the Pt electrodes. When 1.0 V was applied to a Pt electrode in a PDDA and $SiO_2$ solution, the thickness of the $(PDDA/SiO_2)_{10}$ thin film increased from 79 nm to 166 nm. The surface roughness also increased from 15.21 nm to 33.25 nm because the adsorption volume of the oppositely charged PDDA and $SiO_2$ solution increased. Especially, when the voltage was applied to the Pt electrode in the $SiO_2$ solution, the thickness increase of the (PDDA/$SiO_2$) thin film was larger than that obtained when using the PDDA solution. The refractive index of the fabricated (PDDA/$SiO_2$) thin film was ca. n = 1.31~1.32. The transmittance of the glass substrate coated by (PDDA/$SiO_2$)6 thin film with a thickness of 106 nm increased from ca. 91.37 to 95.74% in the visible range.

• Journal of Korean Elementary Science Education
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• v.31 no.3
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• pp.311-320
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• 2012

The purpose of this study was to examine the effect of peer mentoring activity in elementary school. For this study, an experimental group was conducted for peer mentoring activity in science class. The mentoring team was organized by mento-mentee team according to the scores of science process skill and achievement. The objects of this study were the sixth grade of both an experimental group (28 students) and a control group (27 students) located in Incheon. The results of this study were as follows. First, the experimental group was shown more significant effect for improvement of science process skills than the control group (p<.05). As the result of analysis by groups, both of mento and mentee showed significant effect for improvement of science process skills. Second, the peer mentoring activity showed more significant effect for improvement of achievement (p<.05). As the result of analysis by groups, mentee showed significant effect for improvement achievement. But mento group didn't show significant effect. Third, the peer mentoring activity showed the effect for positive changes of scientific attitude. If matching the mentoring object effectively and conducting the classes applying peer mentoring activity based on the results of this study, it's expected to draw student' improvement of science academic, achievement and positive changes of scientific attitude.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.154-161
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• 2005

As disasters in the modem era become a large scale and complexity, no single entity can manage them. Instead collective cooperation between civilian, enterprise, school and government sectors is significantly needed, along with a well prepared mechanism. Thus, I attempt to construct the applicable network of civilian, enterprise, school and government sectors for disaster management through exemplary case studies of established countries as well as Korea's current operations and its drawbacks, based upon a networking design of disaster management organizations as belows: Firstly, it is cooperation and coordination among relevant organizations that are required essentially in the new era, in view of formative condition of necessary environment for civil participation. The cooperation and coordination can be made only through the network of civilian, enterprise, school and government sectors. Secondly, in order to build up the network, major roles and tasks which should be done by civilian, enterprise, school and government sectors respectively are listed based upon a stage of disaster management. Thirdly, operation models of a safety monitoring unit, a disaster prevention unit, a emergency response unit, and a rehabilitation unit are proposed in line with the network of civilian, enterprise, school and government sectors in regional base.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.1
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• pp.119-126
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• 2022

Mini-implant has been reported as an alternative method to conventional diameter implants in the treatment of mandibular anterior region with narrow ridge. However, one-piece type mini-implant showed biological and technical complications, such as peri-implantitis by residual cement and prosthetic detachment. Recently, one-piece type mini-implant with additional retentive structure has been introduced to increase the retention and stability of the mini-implant. The mini-implant is based on spreading the upper retentive structure with a spreader and connected it with the inner surface of the zirconia prosthesis. In two cases, we tried to reduce these complications through the mini-implant on the narrow mandibular anterior region, and it was possible to reduce the overall treatment period through a digital system. In this case report, restoration using the digital mini-implant system showed improvement of patient satisfaction on the aspect of function and esthetic in the narrow mandibular anterior region.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.286-290
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• 2011

Syngas was produced out of pellet refuse derived fuel (RDF) produced from an RDF production facility of W city, Korea. A two-stage gasification system was developed to use the RDF char as an auxiliary heat source for gasification reaction. The composition and heating value of syngas as well as the heating value of residual product (char) were measured at a different residence time to investigate the optimal operating condition of the two-stage gasification system for syngas production. The optimal char residence time to minimize the energy cost due to an external heat source supply was also deduced.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.178-182
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• 2002

For action selection as well as teaming, simple associations between stimulus and response have been employed in most of literatures. But, for successful task accomplishment, it is required that artificial life system can team and express behavioral sequences. In this paper, we propose a novel action-selection-mechanism to deal with behavioral sequences. For this, we define behavioral motivation as a primitive node for action selection, and then hierarchically construct a tree with behavioral motivations. The vertical path of the tree represents behavioral sequences. Here, such a tree for our proposed ASM can be newly generated and/or updated, whenever a new behavioral sequence is learned. To show the validity of our proposed ASM, three 2-D grid world simulations will be illustrated.