• Journal of the Korea Society of Computer and Information
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• v.25 no.1
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• pp.93-99
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• 2020

With the development of digital technology and the increasing demand for learning how to improve one's ability to solve problems through play and participation interactions, a variety of edutainment game contents are being developed. The edutainment game contents developed until recently have received a large number of contents for intelligence development and transfer of knowledge such as Korean and English mathematics for children and children. Recently, there have been various researches on the necessity and effect of STEAM education that foster convergent science and technology talents with comprehensive thinking ability and scientific inquiry spirit through the fusion education method among the subjects including science, technology, engineering, mathematics, And there is a growing need for the development of a parish suitable for STEAM education. However, there is a lack of STEAM educational content development that incorporates the technology of creative convergence talent training to develop talented people who can think and solve problems by crossing various academic boundaries. Therefore, this study develops game contents for early childhood education by combining STEAM education which foster convergent science and technology talents with comprehensive thinking ability and scientific inquiry spirit. And we designed and implemented STEAM game contents for infant learning education which can induce the interest of children and have fun by using gyroscope sensor of smartphone.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.691-702
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• 2019

Flood inundation map has various important roles in terms of municipal planning, timely dam operation, economic levee design, and building flood forecasting systems. Considering that the riparian areas adjacent to national rivers with high potential flood vulnerability conventionally imposed special cares to justify applications of recently available two- or three-dimensional flood inundation numerical models on top of digital elevation models of dense spatial resolution such as LiDAR irrespective of their high costs. On the contrary, local streams usually could not have benefits from recent technological advances, instead they inevitably have relied upon time-consuming manual drawings or have accepted DEMs with poor resolutions or inaccurate 1D numerical models for producing inundation maps due mainly to limited budgets and suitable techniques. In order to efficiently and cost-effectively provide a series of flood inundation maps dedicatedly for the local streams, this study proposed an OpenGIS-based flood mapping tool named Open Flood Mapper (OFM). The spatial accuracy of flood inundation map derived from the OFM was validated throughout comparison with an inundation trace map acquired after typhoon Nari in Hancheon basin located in Jeju Island. Also, a series of inundation maps from the OFM were comprehensively investigated to track the burst of flood in the extreme flood events.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.715-720
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• 2016

This paper proposes a PWM (Pulse Width Modulation) voltage mode DC-DC step-up converter for portable devices. The converter, which is operated with a 1 MHz switching frequency, is capable of reducing the mounting area of passive devices, such as inductor and capacitor, and is suitable for compact mobile products. This step-up converter consists of a power stage and a control block. The circuit elements of the power stage are an inductor, output capacitor, MOS transistors Meanwhile, control block consist of OPAMP (operational amplifier), BGR (band gap reference), soft-start, hysteresis comparator, and non-overlap driver and some protection circuits (OVP, TSD, UVLO). The hysteresis comparator and non-overlapping drivers reduce the output ripple and the effects of noise to improve safety. The proposed step-up converter was designed and verified in Magnachip/Hynix 0.18um 1-poly, 6-metal CMOS process technology. The output voltage was 5 V with a 3.3 V input voltage, output current of 100 mA, output ripple less than 1% of the output voltage, and a switching frequency of 1 MHz. These designed DC-DC step-up converters could be applied to the Personal Digital Assistants(PDA), cellular Phones, Laptop Computer, etc.

• Economic and Environmental Geology
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• v.52 no.6
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• pp.637-645
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• 2019

Due to the transformation to the intelligent information society, the rapid change of our life and environment is expected. The Ministry of Science and ICT (MSIT) and the National Research Council of Science and Technology (NST) introduced a five-year government supported research institution's planning and evaluation based on the mid-to long-term perspective. This study collects international benchmarking information including industry, academia, and research fields by collecting mid- and long-term strategy reports from public research institutes, surveys by experts from abroad universities and research institutes, and analyzing overseas market information reports. The British Geological Survey (BGS), the U.S. Geological Survey (USGS) and the japanese geological survey related institutes (AIST-GSJ) plans for three-dimensional national geological information, predictions of geological environmental disasters, and development of important metals and material in the low carbon economic transformation and in the era of the Fourth Industrial Revolution. The mid- and long-term program emphasizes basic and public research on geological information through abroad experts survey such as the IPGP-CNRS etc. The market analysis of the mining automation and digital map sectors has been able to derive the fields in which the role of public research institutes by the market is expected such as data collection on land and in the air, mobile or three-dimensional information production, smooth/fast/real-time maps, custom map design, mapping support to various platforms, geological environmental risk assessment and disaster management information and maps.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.21-31
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• 1999

In accordance with the completion of the spatial database building works in the central and/or local government authorities as well as the rapid popularization of various information services through internet, it is heavily required to provide spatial information services through World Wide Web. To provide a qualified spatial information service, it is crucial to have a Web-based GIS (Geographic Information Service) service system equipped with the publicity, the convenient accessibility, and the easy-to-use user interface. In this paper, we introduce a new component system for Web-based spatial information services based on the OpenGIS Simple Feature specification for OLE/COM[3] and OLE DB specification[4]. The important functionality of a Web-based spatial information service system includes its accessibility of various existing GIS server system and huge databases in addition to the resolution of response-time delay problems caused by transmitting a large amount of digital maps via internet[6]. To cope with these problems, our component system has been designed to access heterogeneous databases in transparent manner and to support vector-based and/or image-based image production techniques for shortening transmission time.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.503-518
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• 2003

Statement of problem : There have been previous studies about considerable variations in machining accuracy and consistency in the implant-abutment-screw interfaces. Purpose : The purpose of this study was to evaluate the machining accuracy and consistency of implant/abutment/screw combinations on two randomly selected implants from each of four manufactures. Material and methods : In this study, screws were respectively used to secure a cemented abutment, to a hexlock implant fixture ; teflon coated titanium alloy screw(Torq-Tite) and titanium alloy screw in Steri--Oss system, gold-plated gold-palladium alloy screw(Gold-Tite) and titanium alloy screw in 3i system gild screw ana titanium screw in AVANA Dental Implant system, and titanium screws in Paragon System. The implants were perpendicularly mounted in polymethyl methacrylate autopolymerizing acrylic resin block(Orthodontic resin, Densply International Inc. USA) by use of dental surveyer. Each abutment screw was secured to the implant with recommended torque value using a digital torque controller. Each screw was again tightened after 10 minutes. All samples were cross sectioned with grinder-polisher unit(Omnilap 2000 SBT Inc) after embeded in liquid unsaturated polyester (Epovia, Cray Valley Inc) Results : There were the largest gaps in the neck areas of screws in hexagonal extension implants which were examined in this study. The leading edge of the abutment screw thread (superior surface) was in contact with the implant body thread, and the majority of the contacting surfaces were localized to the middle portion of the mating threads. Considerable variation in the contacting surfaces was noted in the samples evaluated. Amounts of contact in the abutment screw thread were larger for assemblies with Gold-Tite screw, gold alloy screw. Torq-Tite screw than those with titanium screws. The findings of intimate contact between the screw and screw seat were seen in all samples, regardless of manufacturers. However, microgap between the head and lateral neck surface of the screw and the abutment could be dectected in all samples. The findings of intimate contact between the platform of the implant and the bottom of the abutment were consistent in all samples, regardless of manufacturers. However, microgaps between the lateral surface of external hex of the fixture and the abutment could be dectected in all samples. Conclusion : Considerable variations in machining accuracy and consistency were noted in the samples and the implant-abutment-screw interfaces were incomplete. From the results of this study, further development of the system will be required, including improvements in pattern design.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.2
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• pp.192-209
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• 2004

Purpose : The purpose of this study was to evaluate the machining accuracy and consistency of implant/abutment/screw combination or internal connection type. Material and methods: In this study, each two randomly selected internal implant fixtures from ITI, 3i, Avana, Bicon, Friadent, Astra, and Paragon system were used. Each abutment was connected to the implant with 32Ncm torque value using a digital torque controller or tapping. All samples were cross-sectioned with grinder-polisher unit (Omnilap 2000 SBT Inc) after embeded in liquid unsaturated polyester (Epovia, Cray Valley Inc). Then optical microscopic and scanning electron microscopic(SEM) evaluations of the implant-abutment interfaces were conducted to assess quality of fit between the mating components. Results : 1) Generally, the geometry of the internal connection system provided for a precision fit of the implant/abutment into interface. 2) The most precision fit of the implant/abutment interface was provided in the case of Bicon System which has not screw. 3) The fit of the implant/abutment interface was usually good in the case of ITI, 3I and Avana system and the amount of fit of the implant/abutment interface was similar to each other. 4) The fit of the implant/abutment interface was usually good in the case of Friadent, Astra and Paragon system. The case of Astra system with the inclined contacting surface had the most Intimate contact among them. 5) Amount of intimate contact in the abutment screw thread to the mating fixture was larger in assembly with two-piece type which is separated screw from abutment such as Friadent, Astra and Paragon system than in that with one-piece type which is not seperated screw from abutment such as ITI, 3I and Avana system. 6) Amount of contact in the screw and the screw seat of abutment was larger in assembly of Friadent system than in asembly of Astra system of Paragon system. Conclusion: Although a little variation in machining accuracy and consistency was noted in the samples, important features of all internal connection systems were the deep, internal implant-abutment connections which provides intimate contact with the implant walls to resist micro-movement, resulting in a strong stable interface. From the results of this study, further research of the stress distribution according to the design of internal connection system will be required.

• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.33-39
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• 2007

Because of the cognitive overload which is caused by the complicated information structure, Digital Convergence product interferes with the effective retrieval of the information from the menu. Two methods have been used to alleviate that cognitive overload by making an effective menu structure; physical menu structure method which is related with the width and depth of the menu, semantic menu structure method which is related with the menu title. In this research, we tried to demonstrate the effectiveness of the menu structure designing method by suggesting a new semantic methodology which uses the Fixation and Fixation duration which are accompanied by the visual search. Because the Fixation is automatically processed by the human cognitive model, we could easily recognize whether the information structure is correspond to the cognitive model or not. From this fact we established the hypothesis that the number of cognitively well established menu structures are fewer than that of the wrongly designed menu structures in terms of the Fixation number and Duration. To verify this hypothesis, we compared the Fixation number and Duration of the modified menu structures with those of the original menu structures by using the Eye-Tracking experiment. As a result, we could find the significant decrease of the Fixation number and Duration after modification. Therefore we could recognize that the modified menu structure was more effective than the original menu structure. In sum, the newly suggested menu structure designing methodology which uses the Fixation and Fixation Duration accompanied by the visual search was proved to be a very effective method.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.19-26
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• 2008

This paper is related to a new technology allowing a user to have a 360 degree viewpoint of the virtual wearing object, and to an object VR(Virtual Reality)-based 2D virtual textile wearing system using viewpoint vector estimation and textile texture mapping. The proposed system is characterized as capable of virtually wearing a new textile pattern selected by the user to the clothing shape section segmented from multiview 2D images of clothes model for object VR, and three-dimensionally viewing its virtual wearing appearance at a 360 degree viewpoint of the object. Regardless of color or intensity of model clothes, the proposed system is possible to virtually change the textile pattern with holding the illumination and shading properties of the selected clothing shape section, and also to quickly and easily simulate, compare, and select multiple textile pattern combinations for individual styles or entire outfits. The proposed system can provide higher practicality and easy-to-use interface, as it makes real-time processing possible in various digital environment, and creates comparatively natural and realistic virtual wearing styles, and also makes semi -automatic processing possible to reduce the manual works to a minimum. According to the proposed system, it can motivate the creative activity of the designers with simulation results on the effect of textile pattern design on the appearance of clothes without manufacturing physical clothes and, as it can help the purchasers for decision-making with them, promote B2B or B2C e-commerce.

• Korean Journal of Social Welfare
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• v.55
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• pp.27-54
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• 2003

This study examines the problems of children exposed to family violence. As a result, the children exposed to family violence exhibit various emotional, behavioral and social problems and distorted perceptions and inappropriate reactions toward family violence. Based on these results and existing programs for children exposed family violence, an integrative group program has been devised. The program was applied to two groups of the children and an experimental study was conducted to examine its effectiveness on emotional problems, aggressiveness, social skills and perceptions/reactions toward family violence. As a result, the experimental groups have shown an overall significant improvement in scores on emotional problems, aggressiveness, social skills and perceptions/reactions toward family violence. The study offers the following recommendations for clinical social work practice. First, great efforts to alleviating the problems of children exposed to family violence should be made continually. Second, special attention should be paid to reflect the characteristics of our own culture in clinical social work intervention and to do so, various practical intervention skills suitable to our culture should be developed. Finally, many different intervention models for children exposed family violence should be developed and researches comparing those models should be carried out.