• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.252-260
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• 2022

In Korea, low-quality kaolin has significantly greater reserves and superior economic efficiency than high-purity kaolin. However, the utilization is low because it does not match the demand conditions of the market, and it is difficult to find a suitable source of demand. The purpose of this study is to derive the possibility and optimal calcination temperature of domestic low-quality kaolin that can be used as a raw material for limestone plastic clay cement (LC³). Isothermal calorimetry, X-ray diffraction analysis, Thermogravimetric Analysis, and compressive strength tests were conducted to evaluate hydrate generation and mechanical properties of LC³ paste according to calcination temperatures (600 ℃, 700 ℃, 800 ℃, 900 ℃). As a result, although 50 % of the clinker was replaced, the domestic low-quality kaolin clay produced calboaluminate hydrate and C(A)SH from the 3rd day of hydration, showing almost equal or higher strength to OPC, and there was a big difference in strength depending on the firing temperature.

• Journal of Internet Computing and Services
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• v.24 no.1
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• pp.71-86
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• 2023

The purpose of this exploratory study is to compare the differences in public perceptual characteristics of Korean and Chinese societies regarding the metaverse using big data analysis. Due to the environmental impact of the COVID-19 pandemic, technological progress, and the expansion of new consumer bases such as generation Z and Alpha, the world's interest in the metaverse is drawing attention, and related academic studies have been also in full swing from 2021. In particular, Korea and China have emerged as major leading countries in the metaverse industry. It is a timely research question to discover the difference in social awareness using big data accumulated in both countries at a time when the amount of mentions on the metaverse has skyrocketed. The analysis technique identifies the importance of key words by analyzing word frequency, N-gram, and TF-IDF of clean data through text mining analysis, and analyzes the density and centrality of semantic networks to determine the strength of connection between words and their semantic relevance. Python 3.9 Anaconda data science platform 3 and Textom 6 versions were used, and UCINET 6.759 analysis and visualization were performed for semantic network analysis and structural CONCOR analysis. As a result, four blocks, each of which are similar word groups, were driven. These blocks represent different perspectives that reflect the types of social perceptions of the metaverse in both countries. Studies on the metaverse are increasing, but studies on comparative research approaches between countries from a cross-cultural aspect have not yet been conducted. At this point, as a preceding study, this study will be able to provide theoretical grounds and meaningful insights to future studies.

• Journal of Radiation Protection and Research
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• v.33 no.4
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• pp.151-160
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• 2008

In Korean nuclear power plants (NPPs), two thermoluminescent dosimeters (TLD) were provided to workers who work in an inhomogeneous radiation field; one on the chest and the other on the head. In this way, the effective dose for radiation workers at NPPs was determined by the high deep dose between two radiation dose from these TLDs. This represented a conservative method of evaluating the degree of exposure to radiation. In this study, to prevent the overestimation of the effective dose, field application experiments were implemented using two-dosimeter algorithms developed by several international institutes for the selection of an optimal algorithm. The algorithms used by the Canadian Ontario Power Generation (OPG) and American ANSI HPS N13.41, NCRP (55/50), NCRP (70/30), EPRI (NRC), Lakslumanan, and Kim (Texas A&M University) were extensively analyzed as two-dosimeter algorithms. In particular, three additional TLDs were provided to radiation workers who wore them on the head, chest, and back during maintenance periods, and the measured value were analyzed. The results found no significant differences among the calculated effective doses, apart from Lakshmanan's algorithm. Thus, this paper recommends the NCRP(55/50) algorithm as an optimal two-dosimeter algorithm in consideration of the solid technical background of NCRP and the convenience of radiation works. In addition, it was determined that a two-dosimeter is provided to a single task which is expected to produce a dose rate of more than 1 mSv/hr, a difference of dose rates depending on specific parts of the body of more than 30%, and an exposure dose of more than 2 mSv.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.103-113
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• 2017

In the current study, retarding type and standard type admixture design of concrete have been proposed to control the generation of hydration heat for foundation members that use high strengths concrete. Finite element analysis also has been conducted to understand the rational placing heights of concrete. In addition, real-size structures have experimented and their results were compared to the analytical results to evaluate the reducing effect of thermal stress. For a large $6.5m{\times}6.5m{\times}3.5m$ member with retarding and standard type horizontal partition placement of concrete showed the manageable possibility of temperature difference within 25-degree Celcius between the middle and surface portion while the maximum temperature was 77-degree Celcius. Also, temperature cracking index from the finite element analysis appeared to be 1.49 that predicts no formation of cracking due to the effects of temperature. Finally, it appeared that horizontal partition placement of retarding and standard type concrete has the significant effect of reducing the thermal stress that generated by the hydration heat in the high strengths mass concrete.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.105-112
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• 2000

The conventional model did not take momentum conservation into consideration when the electron absorbs and emits the photons. II-ray provides momentum conservations on any directions of the entering photons, and also the electrons have radial momentum conservations and fully elastic bouncing between two atoms, in the new atom model. Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, fur examples sexual motion, tidal motion, day and night etc. Because the radius of hydrogen atom's electron orbit is the order of 10$^{-11}$ m and the radia of the nucleons in the nucleus are the order of 10$^{-l4}$m and then the converging $\pi$-gamma rays to the nucleus have so great circular momentum, the electron can not have a circular motion. We can say without doubt that any elementary mass particle can have only linear motion, because of the $\pi$-rays' hindrances, near the nucleus. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The h v is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. Any magnet absorbs n-rays to S pole and sends out the $\pi$-rays from N pole. Proton are constructed with the closed n-rays quantum-mechanically. The crystallizing n-bonding makes two $\pi$-far infrared rays of one wave length between two protons if two $\pi$-rays are supplied to each proton. It is easily done for a $\pi$-ray to be absorbed to a proton if there is a parallel magnetic flow to the blood flow because a $\pi$-ray advances axially under a magnetic field and a proton looks like a sphere. A axially advancing disk-like $\pi$-ray can meet more easily the coming spheres than from the other directions. The blood crystals stimulate the autonomous nerves on the blood vessels during the flow by their mechanical sliding collisions. SM n-ray meridian therapy and SMACN $\pi$-ray meridian therapy show the stimulation of blood flow and also combinational experiment between SM $\pi$-ray meridian therapy and n-ray psycho-physics acupuncture shows more clearly that magnet is forcing to make $\pi$-rays absorbed to the nucleons.s.ons.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.162-177
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• 2020

The perception of traffic environment based on various sensors in autonomous driving system has a direct relationship with driving safety. Recently, as the perception model based on deep neural network is used due to the development of machine learning/in-depth neural network technology, a the perception model training and high quality of a training dataset are required. However, there are several realistic difficulties to collect data on all situations that may occur in self-driving. The performance of the perception model may be deteriorated due to the difference between the overseas and domestic traffic environments, and data on bad weather where the sensors can not operate normally can not guarantee the qualitative part. Therefore, it is necessary to build a virtual road environment in the simulator rather than the actual road to collect the traning data. In this paper, a training dataset collection process is suggested by diversifying the weather, illumination, sensor position, type and counts of vehicles in the simulator environment that simulates the domestic road situation according to the domestic situation. In order to achieve better performance, the authors changed the domain of image to be closer to due diligence and diversified. And the performance evaluation was conducted on the test data collected in the actual road environment, and the performance was similar to that of the model learned only by the actual environmental data.

• Journal of Korean Home Economics Education Association
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• v.30 no.3
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• pp.195-213
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• 2018

The purpose of this study is to verify the effect by developing and applying a new program for improvement of creative problem solving ability and collaborative ability. Development of a sewing practice program was performed through the ADDIE model. The subjects of the study were 1^st grade middle school students and the research plan of the study was pretest-posttest control group design. The study method was performed by mixing the quantitative and qualitative analysis methods. Results of this study are as follows. First, the students in the experimental group showed higher creative problem solving ability than the students in the control group, but the difference was not significant at the 5% significance level. Qualitative analysis results indicated that creative problem solving ability is closely related to learning experiences involving the 'generation of diverse ideas', 'rebirth of creative ideas', 'self-directed learning plan', 'active problem solving', 'immediate feedback'. Second, the students in the experimental group showed a significantly higher level of collaborative ability than the students in the control group. This demonstrated that the program developed in this study had an effect on fostering the collaborative ability of middle school students. It was found that collaborative ability is closely related to learning experiences involving 'forming a positive atmosphere', 'continuous interaction', and 'working together'.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.83-92
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• 2023

The purpose of this research is to develop a creative education program that utilizes AI education program based on big data for general education high schools, and to investigate its effectiveness. In order to achieve the purpose of the research, we developed a creative education program using artificial intelligence based on big data for first-year general high school students, and carried out on-site classes at schools and a validation process by experts. In order to measure the creative problem-solving ability and class satisfaction of high school students, a creative problem-solving ability test was conducted before and after the program application, and a class satisfaction test was conducted after the program. The results of this study are as follows. First, AI education program based on big data were statistically effective to improve the creative problem solving ability according to independent sample t test about 'problem discovery and analysis', 'idea generation', 'execution plan', 'conviction and communication', and 'innovation tendency' except 'execution', 'the difference between pre- and post-scores of male student and female student' on first year high school students. Secondly, in satisfaction conducted after classes of AI education program based on big data, the average of 'Satisfaction', 'Interest', 'Participation', 'Persistence' were 3.56 to 3.92, and the overall average was 3.78. Therefore, it was investigated that there was a lesson effect of the AI education program based on big data developed in this research.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.681-688
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• 2022

In this study, the process of drone photography, automatic volume calculation, total floor area conversion, and waste calculation was constructed as a QGIS plug-in to predict the demolition waste (DW) generated in an aged area where drawing information or building information is uncertain. Through a case study, the high consistency between the automatically calculated volume using the drone and the BIM volume based on the field measurement was confirmed. Field application was carried out for the planned demolition work site, and the consistency between the drone-based volume and the actual measurement-BIM-based volume was reconfirmed. The waste generation unit was applied and the amount of DW was calculated by setting the floor height and building type, and the entire process was completed within 6 hours. Although the difference between building information and building objects through drones occurred according to the setting of temporary structures, loads, and floor heights, it was found that the actual amount of DW was generated more than the initial estimate. It is expected that measures to improve the accuracy of volume and floor area conversion will be required through case studies in the future.

• 한국노년학
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• v.40 no.1
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• pp.73-89
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• 2020

This study validates an abridged version of the age integration scale by Chung et al. (2015), which constitutes sub-dimensions of age flexibility and age heterogeneity-from Riley et al. (1994)-and observes disparities in the perception of age integration among different socio-cultural characteristics. This study analyzed 1,433 people in the "Age Integration and Generation Integration Survey" data, with the support of the Social Science Competency Enhancement Project (SSK) (supported by the Korea Research Foundation). This paper analyzed the data using exploratory factor analysis, confirmatory factor analysis, multiple-group factor analysis, and a compare means test. The results are as follows. First, the scale was abridged to 13 items from 28, of which eight items concern age heterogeneity and five concern age flexibility. Second, the multi-group analysis did not show a significant difference among younger, middle, and older age groups, therefore allowing the scale to be used among all age groups. Third, when sociocultural characteristics were observed, younger adults showed differences in their levels of age integration, age heterogeneity, and age flexibility regarding their residential area. Middle-aged adults showed dif f erences in their levels of age integration, age heterogeneity, and age flexibility regarding their residential area and social status. Older adults showed differences in their level of age integration regarding their residential area, education level, and social status. They also showed differences in the level of age flexibility regarding their residential area and social status and differences in the level of age heterogeneity regarding their residential area and education. Based on the results of the study, political and practical measures to promote perception on age integration in the future were suggested.