Robotic Manipulation System Design and Control for Non-Contact Remote Diagnosis in Otolaryngology: Digital Twin Approach

The COVID-19 pandemic has emphasized the need for non-contact medical robots to alleviate the heavy workload and emotional stress experienced by healthcare professionals while preventing infection. In response, we propose a non-contact robotic diagnostic system for otolaryngology clinics, utilizing a digital twin model for initial design optimization. The system employs a master-slave robot architecture, with the slave robot comprising a flexible endoscope manipulation robot and a parallel robot arm for controlling additional medical instruments. The novel 4 degrees of freedom (DOF) control mechanism enables the single robotic arm to handle the endoscope, facilitating the process compared to the traditional two-handed approach. Phantom experiments were conducted to evaluate the effectiveness of the proposed flexible endoscope manipulation system in terms of diagnosis completion time, NASA task load index (NASA-TLX), and subjective risk score. The results demonstrate the system's usability and its potential to alternate conventional diagnosis. © 2013 IEEE.

Signal Preprocessing Technique With Noise-Tolerant for RF-Based UAV Signal Classification

Since the beginning of the COVID-19 pandemic, the demand for unmanned aerial vehicles (UAVs) has surged owing to an increasing requirement of remote, noncontact, and technologically advanced interactions. However, with the increased demand for drones across a wide range of fields, their malicious use has also increased. Therefore, an anti-UAV system is required to detect unauthorized drone use. In this study, we propose a radio frequency (RF) based solution that uses 15 drone controller signals. The proposed method can solve the problems associated with the RF based detection method, which has poor classification accuracy when the distance between the controller and antenna increases or the signal-to-noise ratio (SNR) decreases owing to the presence of a large amount of noise. For the experiment, we changed the SNR of the controller signal by adding white Gaussian noise to SNRs of -15 to 15 dB at 5 dB intervals. A power-based spectrogram image with an applied threshold value was used for convolution neural network training. The proposed model achieved 98% accuracy at an SNR of -15 dB and 99.17% accuracy in the classification of 105 classes with 15 drone controllers within 7 SNR regions. From these results, it was confirmed that the proposed method is both noise-tolerant and scalable.

An outbreak of carbapenem-resistant Acinetobacter baumannii in an isolation ward for COVID-19 and successful outbreak control with infection control measures

Background. The superinfection of multidrug-resistant bacteria is an important complication in critically ill COVID-19 patients. An outbreak of carbapenemresistant Acinetobacter baumannii (CRAB) occurred in an isolation ward for COVID-19. We performed an outbreak investigation, and successfully controlled the outbreak with the enhanced environmental cleaning and additional gowning and gloving. Methods. This study analyzed all COVID-19 patients with CRAB in any specimen, who admitted to an isolation ward for COVID-19 of a tertiary hospital in South Korea from October to November 2021. Results. During the outbreak period, a total of 23 patients with COVID-19 and CRAB were identified (Figure 1). Index case was 85-year old female patient who was referred from a long-term care facility. The mean age of cases was 72.9 and 14 (60.9%) patients were male. In most patients (91.3%), CRAB were identified in sputum culture, two were identified in blood culture at initial, and four patients were identified in sputum and blood culture at the same time. Most of the patients were applying high flow nasal cannula (26.1%) or mechanical ventilation (60.9%)(Table1). As shown in figure2, CRAB outbreak occurred mainly in the wards around the index case, and in particular, environmental culture was carried out in the area marked with a rectangle. CRAB was cultured on the floor, air inlet, air outlet, and window frame of the ward except for wards 3305 and 3319. Phenotypic antimicrobial resistance patterns of CRAB isolates from patients and environment were identical, and additional whole genome sequencing analyses are ongoing to find the clonality of isolates. We applied the infection control measures with the enhanced environmental cleaning using sodium hypochlorite(NaClO) 1000ppm and phenolic compounds more than twice a day, enhanced hand hygiene, and additional gowning and gloving over personal protective equipment (PPE) mandatory for COVID-19 on 29th October. No additional CRAB cases occurred since 2nd November 2021 for two weeks. Conclusion. Even when PPEs and precautions for COVID-19 are applied to isolation wards for COVID-19, it is helpful for preventing transmission of multidrug-resistant bacteria to apply additional contact precautions and environmental cleaning.

Clinical accuracy and utility of plasma microbial cell free DNA NGS for the diagnosis of invasive aspergillosis in patients with hematologic malignancy and COVID-19

Background. Invasive aspergillosis (IA) is a great threat to the severely immunocompromised and patients with coronavirus disease (COVID-19). However, diagnosis of IA is often difficult due to need for invasive biopsy and low sensitivity of other diagnostic tests. Next-generation sequencing (NGS) of plasma cell free DNA (cfDNA) can be a novel non-invasive diagnostic modality. We evaluated the clinical accuracy and utility of microbial cfDNA NGS for the diagnosis of IA in patients with hematologic malignancy (HM) and COVID-19. Methods. A single-center prospective study of plasma microbial cfDNA NGS was conducted in a tertiary-care hospital in South Korea. We enrolled adult patients with HM and COVID-19, who suspected IA and performed conventional diagnostic tests for IA. The results of NGS were compared with the diagnosis of IA through conventional methods. IA cases were diagnosed according to EORTC/MSG definitions in patients with HM, and modified AspICU criteria in patients with COVID-19. (Figure 1). Figure 1. Flow chart for the participant selection method used in this study Results. Between March 2021 and January 2022, a total of 33 participants (22 [64.7%] male, median age 66.0 [50.5, 72.0]) were enrolled;19 participants with HM and 15 with COVID-19 were analyzed (Figure1 and Table1). In participants with HM, aspergillus cfDNA was detected in 100% of both proven (1/1) and probable (12/12) IA cases, and 33.3% of both possible (1/3) and no IA (1/3) cases. In participants with COVID-19, 46.2% of probable IA (6/13) showed positive aspergillus cfDNA. Detection rate of aspergillus cfDNA was significantly higher in proven/probable IA cases in participants with HM compared to participants with COVID-19. (100% vs 46.2%, p=0.005) (Figure 2). As shown in Table 2, among proven/probable IA cases, participants with positive aspergillus cfDNA showed significantly higher rate of having uncontrolled hematologic disease, receiving stem cell transplantation and recent chemotherapy. In three participants with HM, non-aspergillus strains confirmed by cfDNA NGS were in accordance with pathogens identified through conventional culture methods. Conclusion. Detection of aspergillus cfDNA showed high concordance in the results of conventional diagnostic methods in proven/probable IA of patients with HM and could be a helpful non-invasive approach to IA diagnosis in those populations.

Risk factors for COVID-19 associated pulmonary aspergillosis (CAPA) in severe COVID-19 and impact of airborne fungal contamination within negative pressure isolation room

Background. COVID-19 increase the risk of invasive pulmonary aspergillosis. However, the risk factors and fungal origin of COVID-19 associated pulmonary aspergillosis (CAPA) is not fully defined yet. We aim to identify the risk factors for CAPA in severe COVID-19 and evaluate association between fungal contamination within the air of negative pressure rooms and diagnosis of CAPAs. Methods. We performed a retrospective case-control study to identify risk factors for CAPA with 420 severe COVID-19 patients from March 2020 to January 2022 who admitted to a tertiary care hospital in South Korea. CAPA was defined with modified AspICU criteria. Control, matched by admission date and severity of COVID-19 at admission, was selected for each case. Air sampling and fungal culture was done on Jan 2022 with a microbial air sampler (MAS-100NT) at 11 spaces in the COVID-19 designated isolation ward including 9 negative pressure isolation rooms (IRs). A cross-sectional comparison between rooms with and without airborne fungal contamination was performed. Results. A total of 420 COVID-19 patients were hospitalized during the study period, and 51 patients were diagnosed with CAPA (prevalence 12.14%, incidence 6.26 per 1000 patient.day). Multivariate analysis showed that older age (odds ratio [OR] 1.051, 95% confidence intervals [CI] 1.006-1.009, p=0.025), mechanical ventilator use (OR 2.692, 95% CI 1.049-6.911, p=0.04), and lymphopenia (OR 4.353, 95% CI 1.727-10.975, p=0.02) were independent risk factors for CAPA. (Table 1, 2) Aspergillus spp. was identified within the air from 7 out of 11 spaces including 6 IRs and 1 doctors' room. (Figure 1). All 6 IRs with positive aspergillus culture were being occupied by patients at least 8 days. Among 6 patients, 3 had already been diagnosed with CAPA whereas the other 3 were not diagnosed with CAPA through the observation period. Among 4 patients in isolation rooms without airborne aspergillus contamination, one patient had been diagnosed as CAPA before air sampling. (Table 3). Conclusion. Association between CAPA and airborne aspergillus contamination within the negative pressure room could not be demonstrated in this study. Rather than environmental factors, patient factors such as older age, ventilator care, and lymphopenia were found to be associated with CAPA diagnosis.

Risk factor and clinical characteristics of pneumothorax and pneumomediastinum in COVID-19: a matched case-control study

Background. During the novel coronavirus SARS-CoV-2 pandemic, a considerable number of pneumothorax and pneumomediastinum associated with COVID-19 have been reported, and the incidence was higher in critically ill patients. Despite using a protective ventilation strategy, barotrauma still occurs in COVID-19 patients with invasive mechanical ventilation. This study aims to identify the risk factors and clinical characteristics of pneumothorax and pneumomediastinum in COVID-19 by a matched case-control study. Methods. This retrospective study enrolled adult patients diagnosed with a COVID-19, admitted to a critical care unit in South Korea from 2020 March 1st to 2022 January 31st. COVID-19 patients with pneumothorax and pneumomediastinum were compared, in a 1 to 2 ratio, to a control group of COVID-19 patients without pneumothorax and pneumomediastinum, matched on age, gender, and worst National Institute of Allergy and Infectious Diseases ordinal scale (NIAID-OS). Conditional logistic regression analysis was performed to assess the risk factors for pneumothorax and pneumomediastinum in COVID-19. Results. A total of 427 patients with COVID-19 were admitted during the study period. Of these patients, 24 patients were diagnosed as pneumothorax or pneumomediastinum. When comparing the characteristics of both groups, body mass index (BMI) was significantly lower in the case group (22.8 kg/m2 and 24.7 kg/m2;P = 0.048). BMI was statistically significant risk factor for barotrauma in univariate conditional logistic regression analysis (Odds ratio (OR), 0.85;Confidence interval (CI), 0.72-0.996;P = 0.044) but not in multivariate analysis. For the patients with invasive mechanical ventilation, the period from symptom onset to intubation was longer in the case-patients (13 and 9.5 days;P = 0.032). Univariate conditional logistic regression analysis showed the statistical significance of the period from symptom onset to intubation (OR, 1.14;CI, 1.006-1.293;P = 0.041). Conclusion. In this case-control study with age, gender, severity matching, lower BMI was associated with the pneumothorax in COVID-19, and delayed application of invasive mechanical ventilation might contribute to this complication.

Clinical significance of antineutrophil cytoplasmic antibody positivity in patients infected with SARS-CoV-2

Background. The Coronavirus Disease 2019 (COVID-19) is well-known for its broad spectrum of immune-related phenotypes similar to those seen in autoimmune or inflammatory diseases. Furthermore, evidence has gradually accumulated that COVID-19 may induce systemic inflammatory manifestations such as multisystem inflammatory syndrome, haemophagocytic syndromes, and systemic vasculitis. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small vessel vasculitis characterised by necrotising vasculitis. So far, there have been several case reports regarding AAV occurrence after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which have indicated a triggering potential of SARS-CoV-2 infection for AAV occurrence. This study investigated the rate of ANCA positivity and its clinical significance in COVID-19 patients. Methods. This study included 178 patients infected with SARS-CoV-2 who were enrolled in a cohort of a single center. Myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA from the stored blood sera were measured using the immunoassay kits. Mortality, mechanical ventilator care, and severe infection were assessed as poor outcomes. Severe infection was defined as a medical condition that required a high-flow nasal cannula and/or mechanical ventilator care. The 2022 American College of Rheumatology and the European Alliance of Associations for Rheumatology classification criteria for the three subtypes of AAV were applied only to patients who had MPO-ANCA or PR3-ANCA among the study subjects Results. The detection rate of ANCA positivity was 18.5%: MPO-ANCA and PR3-ANCA were found in 22 (12.4%) and 14 (7.9%) patients. Patients with ANCA positivity exhibited a lower cumulative survival rate than those without, but the difference was not statistically significant (P = 0.057). However, neither MPO-ANCA nor PR3-ANCA affected the three poor outcomes. According to the new criteria, 12 (6.7%) and 21 (11.8%) patients were classified as having granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) Neither ANCA positivity nor ANCA subtype (MPO-ANCA and PR3-ANCA) positivity had a significant influence on poor outcomes of SARS-CoV-2. ANCA: antineutrophil cytoplasmic antibody;MPO: myeloperoxidase;PR3: proteinase 3;SARS-CoV-2: severe acute respiratory syndrome coronavirus 2. Conclusion. SARS-CoV-2 infection may increase the rate of ANCA positivity, which may not affect poor outcomes but contribute to the classification of GPA and MPA despite uncertain clinical significance.

Examining Participant’s Perception of SPICE Factors of Metaverse MICE and Its Impact on Participant’s Loyalty and Behavioral Intentions

The COVID-19 pandemic has made most MICE (an acronym that stands for Meeting, Incentive travel, Convention and Exhibition) events postponed or canceled but some are held as online and virtual, or as hybrid events combining online and offline format. In recent years, evolved from the physical MICE events, metaverse-based MICE events are spot-lighted as the participants can indirectly participates in the virtual world called metaverse through avatars, the virtual self. As various metaverse contents are developed based on advanced technology, the MZ (millennials and Generation Z) generation, who proficiently handle digital platforms, accepts the virtual world as a part of reality, and enjoys new experiences (Hwang, Media Issue Trend 45:6–15, [3]). The purpose of this study is to investigate which factors of the metaverse-based MICE events affect the participants’ loyalty and intention to attend the MICE events and provide empirical data for establishing an effective metaverse-based MICE marketing strategy. To do that this study adopted SPICE(Seamlessness, Presence, Interoperability, Concurrence, Economy) model of metaverse suggested by Kim and Shin (S.K. Kim, B.H. Shin, Metaverse new opportunity. Vegabooks (2021)). A total of valid responses collected from MICE industry stakeholders were investigated. The findings of this study identified that among five dimensions of SPICE model, Seamlessness, Presence, and Economy factors have statistically significant influence on participants’ loyalty of the event while only Presence and Economy factors have significant influence on intention to attend the event. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Common Adverse Events Following COVID-19 Vaccination in Patients with Type 2 Diabetes

In the COVID-19 pandemic, vaccines have emerged as the most effective tool to protect people from COVID-19. However, there is a limited study of adverse events (AEs) for COVID-19 vaccines among people with type 2 diabetes. The purpose of this study is to report the common adverse events following the COVID-19 vaccines, mRNA-1273, BNT162b2, and JNJ-78436735 in diabetic patients. We collected data for common adverse events to the COVID-19 vaccines using Vaccine Adverse Event Reporting System (VAERS). To identify the people with and without diabetes, we used the Natural language processing algorithms. After a 1:3 propensity score matching, we used 6,829 people with type 2 diabetes and 20,487 healthy control groups. Multiple logistic regression analysis was performed to obtain the odds ratio for 25 common AEs in order of high frequency. The most common AEs were pain (17.9%), headache (16.6%), pyrexia (13.4%), chills (12.4%), fatigue (12.0%), dizziness (11.0%). In particular, AEs of the dysmenorrhea in women were rare (0.14%), but a 15-fold higher frequency was observed in patients with diabetes (0.45% versus 0.03%) than in those with controls. The risk of all common AEs following both mRNA vaccines was significantly lower (OR = 0.87, 95% CI = 0.77–0.97, P = 0.015) than that after one viral vector vaccine, as well as the risk among males (OR = 0.56, 95% CI = 0.53–0.59, P < 0.001) was lower than among females. In conclusion, the risk of common adverse events among people with type 2 diabetes was low after both mRNA vaccines and in males. These findings might have implications for safe vaccine use. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Comprehensive assessment of vertical variations in urban atmospheric CO2 concentrations by using tall tower measurement and an atmospheric transport model

In this study, we performed a comprehensive assessment of the vertical CO2 concentration in the urban atmosphere using measurements at two different heights (113 m and 420 m) in Seoul, South Korea. The difference in CO2 concentration between the two altitudes (△CO2 = CO2 at 113 m minus CO2 at 420 m) showed a significant diurnal variation, with the highest at 07:00 (19.9 ppm) and the lowest at 16:00 (3.9 ppm). When the planetary boundary layer (PBL) rose above the two sites (daytime), the CO2 concentrations at the two altitudes were highly correlated (r = 0.87) with low △CO2. In contrast, when the PBL was located between the two sites (night time), the correlation coefficient of the CO2 concentration between the two altitudes decreased by 0.55 with a high △CO2. To explain the cause of this variation in △CO2 according to PBL, we performed Weather Research and Forecasting-stochastic time-inverted Lagrangian transport (WRF-STILT) simulations. Simulations showed that CO2 measurements at two different heights were influenced by the same nearby urban areas during the daytime. However, the site above the PBL only measured the CO2 of air transported from the outside downtown area during the night time. Consequently, the observed night time △CO2 is explained by the difference in air mass between the two measurements owing to PBL variations. The night time △CO2 further implicates the local attribution of observed CO2 below the PBL by removing the effect from the remote area. Because of this unique night time characteristic of △CO2, we evaluated the changes in CO2 concentration in Seoul during the COVID-19 period. Compared to the pre-COVID-19 period, △CO2 clearly decreased from 26.5 ppm to 6.2 ppm with the implementation of social distancing, thus confirming the decreasing local influence of CO2 concentrations. Our findings highlight the potential of atmospheric CO2 monitoring at high altitudes as an observation-based method to assess the effectiveness of local carbon management. © 2022 Elsevier B.V.

A Study on Methods to Promote Social Interaction among Participants in the Online Co-creation Process: Focusing on the Front-end Process

Background This study focused on online social interactions as non-face-to-face interactions increase due to the COVID-19 pandemic today. This study aims to identify factors that affect the smooth interaction between participants, and the outputs in online co-creation, to propose ways of using co-creation tools. Methods Based on the conversations of participants in the online co-creation empirical study, the frequency of social interaction and facilitating factors were derived. Then, a t-test was performed to compare the ideas of the groups and to confirm the difference. Finally, the effects of the facilitating factors were verified by comparing the results of the empirical study and the literature search. Results First, the most frequent ‘personal experience mention’ factor in ‘human’ is based on daily conversations between participants. Second, the ‘facilitator’s answer induction’ factor, which is the most frequent in ‘facilitator’, intentionally leads to an answer, increasing interaction. Third, the ‘shared post-it’ factor, which is the most frequent in ‘technology and material’, effectively helps online collaboration. Fourth, the ‘pre-participant experience gathering’ factor, which is the most frequent in ‘other’, increases opinion feedback by expressing ideas visually. Conclusions The ‘Silence’ domain and ‘the participant experience gathering’ factors analyzed in this study could compensate for the problem of low feasibility of ideas developed online. In addition, where online collaboration research is increasing, it is necessary to conduct a follow-up study on the participation of multi-stakeholders in online co-creation in the future based on the results of this study. Copyright: This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0/), which permits unrestricted educational and noncommercial use, provided the original work is properly cited.

Short-term reduction of regional enhancement of atmospheric CO2 in China during the first COVID-19 pandemic period

Recent studies have reported a 9% decrease in global carbon emissions during the COVID-19 lockdown period;however, its impact on the variation of atmospheric CO2 level remains under question. Using atmospheric CO2 observed at Anmyeondo station (AMY) in South Korea, downstream of China, this study examines whether the decrease in China's emissions due to COVID-19 can be detected from the enhancement of CO2 mole fraction (Delta CO2) relative to the background value. The Weather Research and Forecasting-Stochastic Time-Inverted Lagrangian Transport model was applied to determine when the observed mole fractions at AMY were affected by air parcels from China. Atmospheric observations at AMY showed up to a -20% (-1.92 ppm) decrease in Delta CO2 between February and March 2020 compared to the same period in 2018 and 2019, particularly with a -34% (-3.61 ppm) decrease in March. Delta CO, which was analyzed to explore the short-term effect of emission reductions, had a decrease of -43% (-80.66 ppb) during the lockdown in China. Particularly in East China, where emissions are more concentrated than in Northeast China, Delta CO2 and Delta CO decreased by -44% and -65%, respectively. The Delta CO/Delta CO2 ratio (24.8 ppb ppm(-1)), which is the indicator of emission characteristics, did not show a significant difference before and after the COVID-19 lockdown period (alpha = 0.05), suggesting that this decrease in Delta CO2 and Delta CO was associated with emission reductions rather than changes in emission sources or combustion efficiency in China. Reduced carbon emissions due to limited human activity resulted in a decrease in the short-term regional enhancement to the observed atmospheric CO2.

Digital technology initiatives in response to covid-19 challenges in the Galapagos Islands

The global health crisis caused by COVID-19 has severely affected several countries in Latin America. Ecuador has been dealing with concerns in their national health services as well as the economic crisis due to the oil price crash earlier in the year. The Galapagos Islands have also been affected by the pandemic due to a reduction in tourism caused by travel restrictions. Tourism is the main source of income for the Islands. Schools have also been affected as the regular school year in Ecuador was initially delayed and later switched to online sessions. Due to the current health hiatus and considering the challenges with internet access, quality of education, and tourism, a number of initiatives are considered here to promote Digital Literacy Education for the youth as well as digital solutions to provide a safer environment for tourists attractions in the Galapagos Islands. An overview of the different projects, experiences, and future work will be presented. © 2021 IEEE.

Social Perception Network Analysis of Educational Communities before and After the Covid-19 Based on Big Data

The purpose of this study is to understand the meaning by utilizing and analyzing big data on the educational community before and after the era of Covid-19, and to suggest the research direction of the future educational community. The keyword ‘Education + Community’ was used to compare big data before February 19, 2020 and after February 19, 2020, when confirmed cases with Covid-19 began to be reported in Republic of Korea. Semantic network analysis was performed from the collected data to the final data that had undergone a refinement process. The big data used in this study consisted of data before February 19, 5,280 data (1,866 KB) and 1314 data (849 KB) after February 19, searched with the keyword ‘educational community’. The analyzed data is a total of 6,594 cases (2715 KB). This study is meaningful in comparing the relationship between keywords related to the educational community in big data before and after the outbreak of Covid-19.Based on the results of this study, practical welfare alternatives and policy alternatives for the future educational community were suggested. © 2021

Cold War Discourse and Geopolitical Flashpoints in Post-Covid-19 Northeast Asia

This paper examines the possible ramifications of the COVID-19 pandemic as they relate to changing American strategic posture and geopolitical dynamics in Northeast Asia. Since the spread of the pandemic, the overall security situation in Northeast Asia appears to be worsening, contrary to public expectations. Disputes over the origin of the COVID-19 pandemic between Beijing and Washington have aggravated the Sino-American relationship, already shifting from the existing “cold peace” between the two into a Cold War. The authors explore the new and rapidly evolving Cold War discourse in the United States and traces its geopolitical implications across Northeast Asia. The first section examines emerging patterns of new Cold War discourse and practice in the United States. The second discusses four major geopolitical flashpoints in the region: the dynamics of military modernization and strategic arms races between China and the United States, Taiwan Strait relations, the South China Sea, and the Korean Peninsula. Finally, the paper makes suggestions to mitigate rising geopolitical tensions in Northeast Asia. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the Nagasaki University.

A Study on Factors Affecting the Intention to Use Library Information System

The new virus COVID-19 outbreak in Wuhan, China on Dec. 08, 2019 has had a huge impact on all sectors of society including economy, politics, and science sector, around the world. As a result, the government is continuing its contactless lifestyle by implementing life prevention guidelines which prevent the spread of COVID-19 by minimizing human-to-human contact. Several public user services are also being converted to non-contact way, changing the overall environment of our society. The Library Information System, one of the user services, provides various services through online and offline, including lending and reading books, non-books lending and reading, and operating cultural spaces. However, due to the influence of COVID-19, online user services are required to be expanded, making it important for the Library Information System to improve stability and reliability. This study defined the user service of the Library Information System and examined the variables that are needed for the construction of next generation Library Information System through a group of experts. Based on these selected factors, the research contributes to the construction of the next generation Library Information System with the correlation results of the empirical analysis. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

System Resilience Concept against the Disaster and Resilience Characteristics of Seven Countries for the COVID-19 Disaster

In general, resiliency of the power system can be defined as "the ability of the power system to quickly return to its original state from external shocks, such as natural disasters characterized by great influence and low probability of occurrence." Data is needed to study resiliency of the power system. However, even though the probability of an accident such as the Chernobyl nuclear accident and the Fukushima nuclear accident is extremely low, it is difficult to establish a database of actual accidents that once occurred accidents can bring a crisis to the survival of mankind. System resiliency, therefore, is very hot issue in recent. This paper develops new function and models in order to identify characteristics of the resiliency for COVID-19 confirmer data for seven countries. © 2021 Korean Institute of Electrical Engineers. All rights reserved.

Analysis on Applicability of Air Purifiers in Schools to Prevent the Spread of Airborne Infection of SARS-CoV-2

The social and economic losses caused by viruses such as SARS-CoV, MERS-CoV, and SARS-CoV-2 has been serious. In this study, the size of airborne droplet nuclei particles and the number of virions generated by speaking or coughing were analyzed. Particle collection efficiencies of E11 and H13 grade air filters used in commercial air purifiers were evaluated for different particle sizes and the possibility of removing the airborne droplet nuclei particles by air purifiers was studied. In addition, the reduction of SARS-CoV-2 virion concentration and dose by using air purifiers was theoretically investigated for elementary school classrooms. When an infected student continuously emits virions with a rate of 6.0x10(5) virions/h in a 165 m(3)-sized classroom, the virion concentration and dose was estimated to be reduced by more than 60% by using an air purifier of clean air delivery rate (CADR) 780 m(3)/hr and by more than 70% by using two air purifiers (that is, CADR 1560 m(3)/h) compared to when not in use of the air purifier. However, to prevent the spread of infection by the air stream generated by the air purifier, it is necessary to operate an instruction for using the air purifier such as facing the air outlet toward the ceiling and installing at least 50 cm away from occupants.

Lessons from covid-19 and seoul: Effects of reduced human activity from social distancing on urban co2 concentration and air quality

Social restriction in cities to curb infection rates of COVID-19 has become an opportunity to investigate the relationship between humans and the urban atmosphere. We evaluate the impact of the decline in human activities as a result of social distancing on the urban CO2 concentrations and air quality in Seoul during February and March of 2020 compared to 2019. Due to the reduction in human activity in 2020, local measurements of CO and NO2 show a decrease in background concentration (up to –11.9% and –41.7%, respectively) and urban enhancement (up to –16.7% and –38.1%, respectively) compared to the previous year. In contrast, the background concentration of CO2 increases by 3.9% in 2020. Ratios of CO:CO2 and NO2:CO2 also show a decrease in 2020 compared to the previous year, signaling an improvement in the urban air quality of Seoul. Moreover, the insignificant change in wind speed and wind direction during the months of February and March 2020 compared to 2019 implies that CO2, CO, and NO2 concentrations have not been influenced by meteorological conditions, but mainly by changes in emissions from decreased human activity. Despite the rise in background CO2 concentration, urban contributions of CO2 show a decline of –12.6%, indicating that cities with high emissions have the potential to reduce urban CO2 enhancements and air pollutant concentrations, and ultimately impact the global atmosphere. © The Author(s).