• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.13-21
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• 2019

Prussian blue analogues(PBAs) are comprised of cyano-bridged transition metal ions. The wide and unique open-framework structures of the PBAs enable reversible intercalation and deintercalation of various ions such as $Na^+$, $K^+$, $Mg^{2+}$, $Zn^{2+}$, etc. In addition, since PBAs are synthesized through coprecipitation reaction in aqueous solution at room temperature, they are produced economically and environmentally friendly. However, the formation of crystals proceeds rapidly, and defects such as vacancy and crystal water tend to be present in the crystals, thereby affecting key battery performance. Therefore, significant efforts to inhibit defects in PBAs have been made. In the case of vacancy, the reaction rate was controlled at the synthesis stage to reduce the formation of vacancy, and the crystal water was removed by heat treatment under vacuum. In addition, by adding transition metals that do not react within the structure of PBA, the structural instability during the electrochemical reaction was largely alleviated.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.648-653
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• 2018

Analysis of a specific wavelength band of a video signal is an old research field. However, studies on the analysis of signals having the characteristics of a specific wavelength band or the generation of samples have been conducted actively in recent years. In this paper, we analyze the signal of digital halftoned image. The interpretation of halftoning in terms of signals was first made by Ulichney. We have come to the view that the signal characteristics between pixels used for half toning are good for blue noise. Lau has developed a halftoning method that uses green-noise characteristics by using output-dependent feedback as an error diffusion method. Jho has developed a method for producing halftoned images using a reaction diffusion model. In this paper, we analyze reaction diffusion halftoning in terms of signal to show green noise and compare it with existing green noise half tone.

• Smart Media Journal
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• v.8 no.1
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• pp.59-66
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• 2019

The importance of data is increasing at a high rate as data is massively generated and taken into account in various policy supports and contents. However, because of their speed of growth, it is difficult to find the data that is needed. Both the methodological elements that summarize the data and the technical elements of the visualization that help to see at a glance are important. This paper summarizes data visualization methods to improve the currently used design - oriented infographics and propose data - centric infographics. In addition, we will present examples of data analysis and infographics production using Tableau Public. The Gwangju metropolitan city bus user data was used for infographics production, and the results show that the total number of passengers using the stopping point is similar to that of the general passengers, while it is different from the numbers of transit passengers and teen riding-and-transit passengers. Data-centric infographics visualization, unlike existing infographics that is pronounced only as a visual role, is expected to be used as a tool for scientific research as well as efficiently delivering data.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.434-440
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• 2021

This study aimed to understand the effects on the improvement of hair texture by producing a hair texture improvement agent with milk thistle oil, and then applying it to the damaged hair. Each sample before and after application was measured. To understand the effects on the improvement of hair texture, the tensile strength, absorbance with the use of methylene blue, and gloss were measured. In the results of measuring the tensile strength to understand the effects on the improvement of hair texture, In the results of analyzing the absorbance with the use of methylene blue, the value after application was decreased than the value before application. In the results of measuring the gloss, none of the samples showed huge differences. In the results of this study, the milk thistle oil showed the effects on the texture improvement of damaged hair.

• Journal of Internet Computing and Services
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• v.21 no.6
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• pp.71-79
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• 2020

In this paper, we propose a theft prevention technology based on beacon and smart device for smart stroller. The smart stroller has two Bluetooth devices. One is for data transmission and the other is for distance measurement as beacon. Thus, smart device uses a Bluetooth for strength level setting, manual locking and data transmission of smart stroller. Furthermore, smart device can do automatic locking of smart stroller using Bluetooth beacon when the stroller go further away from smart device. At this time, we apply a distance measurement algorithm and theft prevention algorithm with improved beacon distance measurement technique. To show usefulness of the proposed technology, we make a smart stroller and developed a smart device application. We did two distance measurement experiments and a theft prevention experiment with the proposed technology and the result shows 91.3% accuracy for theft prevention. Therefore, the proposed technology would be more usefulness technology for smart stroller.

• Journal of IKEEE
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• v.24 no.4
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• pp.1188-1191
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• 2020

In this paper, automotive safety and convenience service is proposed based on bluetooth and smart watch. The proposed service performs accident detection, kidnapping detection, kid-left-alone-in-car detection, parking location recording, and smart key function. Conventional smartphone services often fails to precisely recognize accident and kidnapping situations since smartphone is located on the dashboard or in the bag. On the contrary, smartwatch recognizes accident and kidnapping situations more precisely since it is always worn on the wrist with hearbeat monitoring. The proposed service recognise various situations around drives and passengers using acceleration sensor, GPS sensor, heartbeat sensor and bluetooth link status. It also performs accident notice, sound recording, and other necessary actions. It also performs door opening, door closing, hazard light flickering, and other necessary actions using OBD-II connection to the vehicle.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.384-394
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• 2022

This study aimed to examine how COVID-19 affected life and health of welfare recipients by comparing groups associated with sex, living with children, and household type and suggest directions for welfare policy and services. Researchers collected a random sample of 500 recipients from 𐩒𐩒gu, Seoul who are registered in Haengbok E-eum, the social security information system and conducted a survey on overall life domains and physical and mental health. For data analysis, t-test, Anova and chi-square test were used. The results showed that factors of sex, living with children, and household type made significant differences in difficulties of employment status, child care, leisure and cultural activities and overall social activities. In terms of health status, mental health status and life satisfaction have been decreased after COVID-19. There were statistical differences in COVID blue and thinking about death among different groups. Based on these findings, this study suggested directions for welfare services for the future New Normal society.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.614-622
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• 2022

This study attempted to investigate the effect of manufacturing a formulation with lavender extract and applying it to damaged hair. The experimental material was prepared by adding 0 g, 3 g 6 g, and 9 g of lavender extract to the perm base agent. The prepared formulation was applied to four damaged hair samples and compared and analyzed. As a measurement method for the effect on damaged hair, tensile strength, absorbance using methylene blue, and gloss were measured. Statistical analysis was conducted for the reliability of the research results. The tensile strength measurement results showed that the tensile strength of the sample applied with a formulation containing 6 g and 9 g at 8 levels increased, affecting damaged hair. As a result of absorbance analysis using methylene blue, it was found that the absorbance of all samples applied by adding extracts decreased, affecting damaged hair. The gloss measurement results showed that the addition of 9 g affected the damaged hair. In conclusion, it can be seen that lavender extract affects damaged hair, so it is considered to have an effect of improving Damage hair.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.56-65
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• 2022

This paper aims at estimating self-cleaning performance of mortar coated with photocatalytic suspension under various conditions. Experimental variables included the concentration (1.5 % and 3.0 %) of photocatalytic suspension for coating mortar specimen, the presence of hydrophilic agent in photocatalytic suspension, and applying the primer on the surface of mortar. The color change of methylene blue solution increased and accordingly self-cleaning performance increased as photocatalytic concentration increased. The presence of hydrophilic agent in photocatalytic suspension slightly decreased the self-cleaning performance compared to the conventional photocatalytic suspension. Test results also showed that mortar specimen including primer and specimen not including primer did not show significantly different self-cleaning performance. In addition, cracks on the surface of mortar specimens decreased as the photocatalytic concentration increased. Therefore, increase in cracks on the surface of mortar at different photocatalytic concentration might adversely affect the self-cleaning performance of mortar specimens.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.63-68
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• 2023

In this paper, we introduce a system that tracks and shares the position of objects based on tags. After receiving the location information of objects through the tag location tracking app, the location of the tag is shared as a group, and the shared users also check the location of objects in real time. Our system offer a differentiated function that allows multiple users to manage and supervise the location of objects, compared to legacy systems. The GPS module and Bluetooth are connected to the Arduino board to obtain the location information of the tag and check it through the Android app. We used Android Studio to create app, and the tag brings up the location of the object. The location of the tag is stored in the phpMyadmin DB and the latitude/longitude is received to the Android app and displayed on the map of the app. The proposed system will be useful for loss prevention and managing public goods.