• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.267-274
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• 2018

Though the wet bottom ash has been used as a type of lightweight aggregate, dry bottom ash, new type bottom ash from coal combustion power plant, has scarcely researched. It is excellent lightweight aggregate in the view point of construction material. This study is performed to check the applicability of dry bottom ash as a fine aggregate in lightweight aggregate concrete, by analyzing various properties of fresh and hardened concrete. We get results that the slump of concrete is within the target range at less than 75% replacement rate of dry bottom ash, the air content is not affected by the replacement rate of dry bottom ash, the bleeding capacity is less than $0.025cm^3/cm^2$ at 75% under of the replacement rate of dry bottom ash, and the compressive strength of concrete show 90% or more comparing the base mix while initial strength development is a little low. Oven dry unit weight of concrete is reduced by 8.9% when replaced 100% dry bottom ash, and dry shrinkage tends to decrease depending on increase of replacement rate of dry bottom ash. Modulus of elasticity of concrete shows no decease at 50% over of the replacement rate of dry bottom ash, while modulus of elasticity of concrete decreases when the replacement rate increases further. The dry bottom ash, when used as a fine aggregate in lightweight concrete, can be used effectively without any deterioration in quality.

• Journal of Korean Home Economics Education Association
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• v.33 no.3
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• pp.173-187
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• 2021

The purpose of this research was to develop instructions for making upcycled clothing accessories related to the 'clothing management and recycling' unit of middle school home economics applying the design thinking technique. Teaching and learning process plans were developed according to the ADDIE model which includes the following process: analysis, design, development, implementation, and evaluation. The design thinking process includes understanding the related knowledge, sympathizing, problem identification(sharing perspectives) and idea development, making prototypes, testing, and making the actual product. Thirteen home economics teachers served as critics. Student feedbacks were collected to evaluate whether the course objectives were attained after the implementation. As a result, teaching and learning process plans, course materials, and evaluation rubrics for ten class sessions were developed. Student feedbacks confirmed the attainment of following five course objectives: improvement of ethical responsibilities through the exploration of various clothing recycling techniques, practice of creative and eco-friendly clothing culture, acquisition of the skills to use sewing tools safely, improvement of abilities to think, sympathize, and communicate, and exploration of aesthetic activities and fashion careers.

• Journal of Korean Society of Archives and Records Management
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• v.21 no.3
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• pp.99-118
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• 2021

As the importance of data grows because of the advent of the next industrial revolution, foreign countries are pushing for long-term data preservation technology research. On the other hand, in Korea, administrative information data sets have been legislated as records management areas without specific long-term preservation measures. As a response, this study conducted basic, cross-validation tests on the Software Independent Archiving of Relational Database (SIARD), which was proposed as an administrative information data set preservation format in several prior works. First, the underlying verification test focuses on deriving the data, structure, and functionality of the data set that SIARD can preserve. The second cross-validation test aimed at verifying the interoperability of SIARD independent of the DBMS class. In addition, two verification tests have confirmed the SIARD feature delivery range. Consequently, the differences between the feature types specified in the SIARD 2.0 standard and those provided by the actual SIARD Suite have been derived. Based on verification test results, we are proposing a development plan to broaden SIARD functionality and set a direction to efficiently enhance SIARD for local situations.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.301-307
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• 2011

Optimal culture conditions of Spirulina platensis NIES 39 have been established using different types of light sources. Several types of photobioreactors were designed and the increase of biomass, the amount of $CO_2$, fixation and the production of chlorophyll content were studied. The result revealed that the input conditions of a 10 min period per 4 h at the condition of 5% $CO_2$ and 0.1 vvm, were excellent in the growth. The growth showing the maximum biomass accumulation is limited to 1.411 g/L when using the fluorescent bulb and the low powered surface mount device (SMD) type LEDs which were equipped-inside in the photobioreactor. However, the biomass exceeded up to 1.758 g/L level when a high powered red LED (color temperature : 12000 K) photobioreactor system was used. The $CO_2$ fixation speed and rate were increased. Although the total production of chlorophyll content undergoes a proportional increase in the biomass, the net content per dry cell weight (DCW) showed the higher production with a blue LED (color temperature : 7500 K) light than that of any other wavelengths. The carbon dioxide loss was marked as 0.15% of the inlet gas (5% $CO_2/Air$, v/v) at the maximum biomass culture condition.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.595-606
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• 2020

To find out the a Study on experiential consumption and development of the customized cosmetics on female university students in their 20s, this study conducted sampling using probability sampling from cosmetics major students in S City from September 1 to October 30, 2020. In this study, a study model was designed for a total of 30 people and studied as an Experience-Consume Experimentation. First, the result of the pre-purchase survey revealed that skincare cosmetics had the highest percentage for being selected by 30 people for "the preferred cosmetic type per the perception regarding customized cosmetics." Second, the result of the pre-purchase survey revealed that 11 people answered skincare cosmetics, 1 person answered shade cosmetics, and 2 people answered fragrance products (perfume, diffusers, etc.) for "the experience type for customized cosmetics." Third, the result of the post-purchase survey revealed that 29 people are willing to recommend the products, while 1 person is not. For the appropriateness of the price, 23 people answered yes; 7 people answered no. for the characteristics of the experience, 24 people (80%) answered that they selected ingredients according to their skin type; 9 people answered that the price is cheap considering they received 1:1 consultation; 18 people answered that they made a choice per their preferences (skin type) rather than per brands; 3 people answered that their self-esteem is stronger as if they received personal care. Therefore, customized cosmetics are expected to increase the attractiveness and purchase rate of female students in their twenties given that 'Human Touch,' genetic analysis, and 'hyper-customization technology,' which requires new development of customized cosmetics experience consumption for female college students in their 20s.

• Journal of Industrial Convergence
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• v.20 no.3
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• pp.33-40
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• 2022

Recently, IoT-linked services have been used in various environments, and IoT and artificial intelligence technologies are being fused. However, since technologies that process IoT data stably are not fully supported, research is needed for this. In this paper, we propose a processing technique that can optimize IoT data after generating embedded vectors based on machine learning for IoT data. In the proposed technique, for processing efficiency, embedded vectorization is performed based on QR such as index of IoT data, collection location (binary values of X and Y axis coordinates), group index, type, and type. In addition, data generated by various IoT devices are integrated and managed so that load balancing can be performed in the IoT data collection process to asymmetrically link IoT data. The proposed technique processes IoT data to be orthogonalized based on hash so that IoT data can be asymmetrically grouped. In addition, interference between IoT data may be minimized because it is periodically generated and grouped according to IoT data types and characteristics. Future research plans to compare and evaluate proposed techniques in various environments that provide IoT services.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.29-35
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• 2022

This paper proposes a fuel cell education framework installed on a Metaverse environment, which is to reduce the burden of education costs and improve the effect of education or learning. This Meta-Fuel cell platform utilizes the Unity 3D Web and enables not only theoretical education but also hands-on training. The platform was designed and developed to accommodate a variety of unit education contents, such as ppt documents, videos, etc. The platform, therdore, integrates ppt and video demonstrations for theoretical education, as well as software content "STACK-Up" for hands-on training. Theoretical education section provides specialized liberal arts knowledge on hydrogen, including renewable energy, hydrogen economy, and fuel cells. The software "STACK-Up" provides a hands-on practice on assembling the stack parts. Stack is the very core component of fuel cells. The Meta-Fuelcell platform improves the limitations of face-to-face education. It provides educators with the opportunities of non-face-to-face education without restrictions such as educational place, time, and occupancy. On the other hand, learners can choose educational themes, order, etc. It provides educators and learners with interesting experiences to be active in the metaverse space. This platform is being applied experimentally to a education project which is to develop advanced manpower in the fuel cell industry. Its improvement is in progress.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.79-89
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• 2022

With the popularity and the advanced graphics hardware technology of mobile devices, various mobile applications that help children with physical activities have been studied. This paper presents SandUp, a mobile application that guides the play of building sand castles using artificial intelligence and augmented reality(AR) technology. In the process of building the sandcastle, children can interactively explore the target virtual sandcastle through the smartphone display using AR technology. In addition, to help children complete the sandcastle, SandUp informs the sand shape and task required step by step and provides visual and auditory feedback while recognizing progress in real-time using the phone's camera and deep learning classification. We prototyped our SandUp app using Flutter and TensorFlow Lite. To evaluate the usability and effectiveness of the proposed SandUp, we conducted a questionnaire survey on 50 adults and a user study on 20 children aged 4~7 years. The survey results showed that SandUp effectively helps build the sandcastle with proper interactive guidance. Based on the results from the user study on children and feedback from their parents, we also derived usability issues that can be further improved and suggested future research directions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.4
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• pp.501-510
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• 2023

The importance of using construction data is increasing in accordance with the recent trend in the smart construction. However, construction project and maintenance information is distributed on the web, and the existing BIM(Building Information Modeling) information exchange and linking method using IFC(Industry Foundation Classes) cannot support connection with BIM data and web resources. This study aims to establish the BIM-based port facility data integration system using linked data(LD) technology in order to integrate BIM and heterogeneous data in the port maintenance domain. To this end, the port BIM-based ifcOWL and port facility maintenance ontology were designed, and LD was built for the BIM and maintenance information of Busan New Port 2-1 Pier3, a BIM pilot project. In addition, service prototypes such as search, statistics and SPARQL(SPARQL Protocol and RDF Query Language) endpoint functions were implemented using the issued LD. The LD-based information utilization system is expected to improve the reusability of information by converting the existing closed information system into an open system and BIM and maintenance data as a web resource in a standard format.

• Composites Research
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• v.37 no.3
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• pp.219-225
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• 2024

It is essential to develop a light-weight, high-performance structure for the deployable reflector antenna, which is the payload of a reconnaissance satellite, considering launch and orbital operation performance. Among them, the composite main reflector is a key component that constitutes a deployable reflector antenna. In particular, the development of a high-performance main reflector is required to acquire high-quality satellite images after agile attitude control maneuvers during satellite missions. To develop main reflector, the initial design of the main reflector was confirmed considering the structural performance according to the laminate stacking design and material properties of the composite main reflector that constitutes the deployable reflector antenna. Based on the initial design, four types of composite main reflectors were manufactured with the variable for manufacturing process. As variables for manufacturing process, the curing process of the composite structure, the application of adhesive film between the carbon fiber composite sheet and the honeycomb core, and the venting path inside the sandwich composite were selected. After manufacture main reflector, weight measurement, non-destructive testing(NDT), surface error measurement, and modal test were performed on the four types of main reflectors produced. By selecting a manufacturing process that does not apply adhesive film and includes venting path, for a composite main reflector with light weight and structural performance, we developed and verified a main reflector that can be applied to the SAR(Synthetic Aperture Rader) satellite.