• The Journal of the Korea Contents Association
• /
• v.21 no.3
• /
• pp.282-300
• /
• 2021

The purpose of this study was to explore what social media posts tell us about family life during the COVID-19 pandemic by examining the keywords and topics underlying posts on blogs and online forums. Our criteria for web crawling were (a) blog and forum posts on Naver and Daum, the top portal sites in Korea, (b) posts between February 23 and April 19, 2020, the period of the first heightened social distancing orders, and (c) inclusion of "COVID" and "family" or "COVID" and "home." We analyzed 351,734 posts using TF-IDF values and topic modeling based on latent Dirichlet allocation. We identified and named 22 topics including COVID-19 prevention, family infection, family health, dietary life and changes, religious life, stuck at home, postponed school year, family events, travel and vacations, concerns about family and friends, anxiety and stress, disaster and damage, COVID-19 warning text messages, family support policies, Shin-cheon-ji and Daegu. The results show that COVID-19 impacted various domains of family life including health, food, housing, religion, child care, education, rituals, and leisure as well as relationships and emotions.

• Journal of Korean Academy of Rural Health Nursing
• /
• v.17 no.1
• /
• pp.23-33
• /
• 2022

Purpose: This study was conducted to identify the effects of an integrated health improvement program for the elderly based on primary health care posts during the COVID-19 pandemic. Methods: A single group pretest-posttest design (n=16) was employed to evaluate an integrated health improvement program that took place twice a week for 11 weeks. The program was conducted in a small group of no more than 10 people in compliance with the guidelines to prevent COVID-19 infection. The program consisted of various contents such as making letters using blocks, health education, and talking about one's memories. The data were analyzed using the Wilcoxon signed rank test. Results: Following the program, social support (Z=-3.50, p<.001) and quality of life of the elderly (Z=-3.74, p<.001) were significantly improved among depression, social support and quality of life. Conclusion: The integrated health improvement program based on primary health care posts, considered in this study, was useful to improve the social support and quality of life of the elderly in the community, and needs to be applied to a larger number of elderly people throughout the community.

• IEIE Transactions on Smart Processing and Computing
• /
• v.5 no.3
• /
• pp.185-192
• /
• 2016

Today, the Internet has penetrated almost all the ins and outs of social life, has changed work, communications, social influence and the lifestyle of humankind. However, it is still short of flexibility, transparency etc., due to network address translator overuse, masschanges, uncomfortable protocols, and so on. Hence, more research is necessary into future telecommunications networks based on contemporary networks accompanied by new requisitions and new designs that are compatible with today's and tomorrow's demands. This paper researches a new vision of the telecommunication network of the future, its effects on human life and society, and the targets to achieve a new generation network (NwGN). In the paper, we also propose orientation towards an NwGN from the current networks, especially with Vietnam's telecommunications networks.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2016.07a
• /
• pp.233-234
• /
• 2016

본 프로젝트는 편안하고 안전하게 세상과 소통하고 관심사를 공유할 수 있는 커뮤니티 사이트이다. 게시글에 수명을 설정하여 자동으로 글이 삭제되는 기능을 통해 사용자의 보안성을 향상시키며, 기본적으로 닉네임을 사용하여 안전한 익명성을 보장한다. 즉, 자동으로 게시글이 삭제되는 커뮤니티 웹 사이트로 사용자들의 일상, 관심사, 정보 공유 등을 게시글을 통해 공유하고 소통할 수 있고, 커뮤니티 활동에 따라 마일리지를 누적하여 게시글의 기본 수명을 연장 할 수도 있다.

• Journal of Power Electronics
• /
• v.16 no.1
• /
• pp.217-226
• /
• 2016

A new method is proposed based on a hidden Markov model (HMM) to estimate and analyze battery states of health. Battery system health states are defined according to the relationship between internal resistance and lifetime of cells. The source data (terminal voltages and currents) can be obtained from vehicular battery models. A characteristic value extraction method is proposed for HMM. A recognition framework and testing datasets are built to test the estimation rates of different states. Test results show that the estimation rates achieved based on this method are above 90% under single conditions. The method achieves the same results under hybrid conditions. We can also use the HMMs that correspond to hybrid conditions to estimate the states under a single condition. Therefore, this method can achieve the purpose of the study in estimating battery life states. Only voltage and current are used in this method, thereby establishing its simplicity compared with other methods. The batteries can also be tested online, and the method can be used for online prediction.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.1
• /
• pp.7-15
• /
• 2008

Currently existing high-accuracy and high-speed die sets used in reciprocal press create scratches at the surface of guide posts, steel balls, and bushes due to vertical movement of balls with point-contacts between inner surface of bushes and guide posts. Consequently, accuracy of the die set and the life span of the metal mold are reduced. However, those scratches could reduce the pre-load of the steel ball. This research designed and developed a groove-type die set which improves life span of the die set by eliminating point-contacts of steel balls with guide posts. The guide post consisted of a steel-ball retainer, a steel-ball retainer stopper, a guide bush, a guide pin, a snap ring, and a spring. The steel-ball retainer has 72 holes with 8 columns of 9 holes in each column. The inner surface of the guide bush was grinded(surface roughness: $Ra\;\\;0.2{\mu}m$, accuracy: $0\;{\sim}\;-0.002mm$) after NC turning and heat treatment. Also, a line of small intermediate pocket was processed inside of the guide bush for lubrication and elimination of foreign materials. Guide grooves of steel balls were processed using a wire EDM(Electrical Discharge Machining) after heat treatment. With such a design of the guide post stated above, loads against steel balls could be dispersed greatly by the line contacts through the guide groove between the guide post and the guide bush, and the life span of the guide post could be expanded semi-permanently.

• Journal of Information Technology Services
• /
• v.21 no.2
• /
• pp.43-59
• /
• 2022

This study investigates an association among Facebook users' upward comparison (e.g., envy), social support (e.g., favorable comments and like), and life satisfaction, putting their self-esteem as a mediating variable. For this analysis, 1,332 female and male Facebook users in Seoul and other four cities in South Korea were surveyed. Structural equation modeling including confirmative factor analysis were employed as quantitative analysis methods. Results show that Facebook users' upward comparison with other users and social support significantly impact their satisfaction mediated by their self-esteem. Specifically, when users feel envious of other users, this emotion lowers their self-esteem, and subsequently, the self-esteem reduces their satisfaction. On the other hand, sufficient social support for users positively affects their self-esteem, which leads to the increase of their satisfaction. The present study is differentiated from previous studies in that it focuses on Facebook users' emotional changes in the process of sharing massive amounts of posts and finds a stepwise relationship among their feelings, including self-esteem as a mediating variable. Additionally, this study is the first to verify a situation when Facebook users' envy of other users' posts affects the decline in their satisfaction through the mediation of their self-esteem.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.7
• /
• pp.2286-2304
• /
• 2022

Blockchain is a distributed ledger that combines technologies such as cryptography, consensus mechanism, peer-to-peer transmission, and time stamping. The rapid development of blockchain has attracted attention from all walks of life, but storage scalability issues have hindered the application of blockchain. In this paper, a scalable blockchain storage model based on Distributed Hash Table (DHT) and the InterPlanetary File System (IPFS) was proposed. This paper introduces the current research status of the scalable blockchain storage model, as well as the basic principles of DHT and the InterPlanetary File System. The model construction and workflow are explained in detail. At the same time, the DHT network construction mechanism, block heat identification mechanism, new node initialization mechanism, and block data read and write mechanism in the model are described in detail. Experimental results show that this model can reduce the storage burden of nodes, and at the same time, the blockchain network can accommodate more local blocks under the same block height.

• Journal of Korean Public Health Nursing
• /
• v.29 no.3
• /
• pp.565-581
• /
• 2015

Purpose: This study was conducted to confirm the factors affecting recipients' quality of life by two types of hypertension management, one was telemedicine provided by community health posts(CHPs) in a rural area, the other was traditional hypertension management by comparing patients' health related lifestyles, self-efficacy and health related quality of life. Methods: The study was conducted from February 1, 2015 through April 25, 2015 on 193 hypertension patients in 6 CHPs consisting of 98 patients in 2 CHPs running telemedicine and 95 patients in 4 CHPs running traditional hypertension management services. The data were analyzed and assessed with frequency, percentage, chi-square test and multiple regression. Results: Self-efficacy and health related quality of life were high for the subjects managed by traditional hypertension management services. Self-efficacy, age, hobby, balanced meals, more than 7~8 hours sleep and regular exercise, which affected the quality of life for recipients were explanatory in 45.9%(F=22.368, p<.001). Conclusion: When any services utilizing telemedicine are provided in the future, consideration of emotional aspects including self-efficacy and quality of life is recommended.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.3
• /
• pp.177-183
• /
• 2009

Characteristics analysis and species identification of post were carried out in four old traditional wooden frame houses in Cheongdo-gun. The diameter and height of post, and distance between posts are related with each other. It was considered that the traditional wooden frame houses were constructed according to the diameter and height of post as a basic dimension in distance between posts. Of the wood member samples obtained in the site, softwoods in three old houses and hardwoods in one old house were separated through light microscopy. The hardwoods were found to be Castanea crenata. and softwoods were all identified as Pinus densiflora.