• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.7
• /
• pp.724-739
• /
• 2023

Located in the sea area between South Korea, North Korea, and China, the Yellow Sea plays an important role from a geopolitical perspective, and recently, as the use of marine space in the Yellow Sea is expanding, its social and economic values have been increasing further. In addition, owing to rapid climate changes, the need for joint response and cooperation between Korea and China is increasing in various fields, including changes in the marine environment and marine ecosystem and generation and movement of air pollutants. Accordingly, in this study, core topics were derived from research papers with the Yellow Sea as a keyword, and research trends to date were explored through author network analysis. As a specific research method, research papers related to the Yellow Sea published between 1984 and 2021 were extracted from the Web of Science database and were classified into four periods to derive core topics using topic modeling, a type of text mining. Furthermore, the influences of major research communities, researchers, and research institutes in the appropriate fields were identified through analyzing the author network, and their implications were presented. The analysis results indicated that the core topics of research papers on the Yellow Sea had changed over time, and differences existed in the influence (centrality) of key researchers. Finally, based on the results of this study, this study aims to identify research trends related to the Yellow Sea, major researchers, and research institutes and contribute to research cooperation between Korea and China regarding the Yellow Sea in the future.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.6
• /
• pp.385-391
• /
• 2023

As the use of electric vehicles has increased to minimize carbon emissions, the analyzing the state and performance of lithium-ion batteries that is instrumental in electric vehicles have been important. Comprehensive analysis using not only the voltage, current and temperature of the battery pack, which can affect the condition and performance of the battery, but also the driving data and charging pattern data of the electric vehicle is required. Therefore, a thorough analysis is imperative, utilizing electric vehicle operation data, charging pattern data, as well as battery pack voltage, current, and temperature data, which collectively influence the condition and performance of the battery. Therefore, collection and preprocessing of battery data collected from electric vehicles, collection and preprocessing of data on driver driving habits in addition to simple battery data, detailed design and modification of artificial intelligence algorithm based on the analyzed influencing factors, and A battery analysis and evaluation model was designed. In this paper, we gathered operational data and battery data from real-time electric buses. These data sets were then utilized to train a Random Forest algorithm. Furthermore, a comprehensive assessment of battery status, operation, and charging patterns was conducted using the explainable Artificial Intelligence (XAI) algorithm. The study identified crucial influencing factors on battery status, including rapid acceleration, rapid deceleration, sudden stops in driving patterns, the number of drives per day in the charging and discharging pattern, daily accumulated Depth of Discharge (DOD), cell voltage differences during discharge, maximum cell temperature, and minimum cell temperature. These factors were confirmed to significantly impact the battery condition. Based on the identified influencing factors, a battery analysis and evaluation model was designed and assessed using the Random Forest algorithm. The results contribute to the understanding of battery health and lay the foundation for effective battery management in electric vehicles.

• Korean Chemical Engineering Research
• /
• v.62 no.1
• /
• pp.70-79
• /
• 2024

Raman analyzer is an analytical technique that utilizes the "Raman effect", which occurs when light is scattered by the inherent vibrations of molecules. It is used for molecular identification and composition analysis. In the natural gas industry, it is widely used in bunkering and tank lorry fields in addition to LNG export and import terminals. In this study, a LNG-specific Raman analyzer was installed and operated under actual field conditions to analyze the composition and principal properties (calorific value, reference density, etc.) of LNG. The measured LNG composition and calorific value were compared with those obtained by conventional gas chromatograph that are currently in operation and validated. The test results showed that the Raman analyzer provided rapid and stable measurements of LNG composition and calorific value. When comparing the calorific value, which serves as the basis for LNG transactions, with the results from conventional gas chromatograph, the Raman analyzer met the acceptable error criteria. Furthermore, the measurement results obtained in this study satisfied the accuracy criteria of relevant international standards (ASTM D7940-14) and demonstrated similar outcomes compared to large-scale international demonstration cases.

• Journal of the Korea Safety Management & Science
• /
• v.25 no.4
• /
• pp.45-56
• /
• 2023

This study attempted to provide implications by analyzing the impact of business Owner's safety commitment on industrial accidents and examining the mediating role of management supervisors' safety leadership and worker participation. Analysis was conducted on 2,067 manufacturing sites with 20 to 50 employees in the 10th Occupational Safety and Health Survey data. SPSS waw used to secure the reliability of the measurement variable. Hypothesis vertification was carried out after securing the suitability and validity of the structural model using AMOS. The direct impact of three latent variables on industrial accidents was confirmed: the business owner's safety commitment, the management supervisor's safety leadership, and the worker participation. The employer's safety will and the management supervisor's safety leadership do not directly affect industial accidents, but it has been verified that worker participation has a diret impact on industrial accident reduction. In addition, it has been confirmed that the safety leadership and worker participation of the management. Supervior have a complete mediating effect on the reduction of industrial accidents by mediating with the safety leadership of the management supervior and the participation of the workers. This study analyzed the impact on industrial accidents by dividing the stakeholders constituting the workplace into three classes: business owners, superviors, and workers, but the results suggest that employers and all workers inside the workplace may be organically linked to achieving the goal of reducing industrial accidents. Therefore, in order to establish an autonomous safety management system for safety and health at workerplaces, efforts are needed to reduce industrial accidents in their respective location by forming an organic community among internal stakeholders.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.12 no.2
• /
• pp.196-205
• /
• 2024

In this study, sample collection and quantification analysis of Tire and Road Wear Particles (TRWP) from the road surface were conducted to predict the amount of TRWP generated on the road surface moving by environmental compartment depending on rainfall intensity. Samples were collected from TRWP remaining on the road surface two days after the 3 days average rainfall (0-60 mm/day) occurred and the road surface was completely dry. Only TRWP were separated from the collected samples through size and density separation, and the difference in the content of TRWP remaining on the road surface after rainfall was based on the value of 60.2 g o f TRWP o n a day witho ut rain (0 mm/day). By calculating, it was co nfirmed that 0-49.4 g o f TRWP can mo ve to the environmental compartment depending on the intensity of rainfall. In addition, it was confirmed that when the rainfall intensity was 60 mm/day, the amount of TRWP moving to each environmental section was 3.75 times higher compared to 5 mm/day, and using the results of previous research, the total amount of TRWP that can be transported to the environmental compartment by rainfall from the domestic road environment annually is 9,592 tons, and 288 tons of this can be affected by marine microplastics. However, this study has limitations in terms of limited space and predicted results, but it would like to mention the need to improve the domestic road environment and sewage treatment system to reduce TRWP. In the future, we plan to conduct sample collection and concentration analysis studies of TRWP in real environmental compartments to verify the results of this study.

• Korean Journal of Radiology
• /
• v.20 no.4
• /
• pp.671-682
• /
• 2019

Objective: To investigate whether computed tomography (CT) and fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) may be applied to distinguish thymic epithelial tumors (TETs) from benign cysts in the anterior mediastinum. Materials and Methods: We included 262 consecutive patients with pathologically proven TETs and benign cysts 5 cm or smaller who underwent preoperative CT scans. In addition to conventional morphological and ancillary CT findings, the relationship between the lesion and the adjacent mediastinal pleura was evaluated qualitatively and quantitatively. Mean lesion attenuation was measured on CT images. The maximum standardized uptake value (SUVmax) was obtained with FDG-PET scans in 40 patients. CT predictors for TETs were identified with multivariate logistic regression analysis. For validation, we assessed the diagnostic accuracy and inter-observer agreement between four radiologists in a size-matched set of 24 cysts and 24 TETs using a receiver operating characteristic curve before and after being informed of the study findings. Results: The multivariate analysis showed that post-contrast attenuation of 60 Hounsfield unit or higher (odds ratio [OR], 12.734; 95% confidence interval [CI], 2.506-64.705; p = 0.002) and the presence of protrusion from the mediastinal pleura (OR, 9.855; 95% CI, 1.749-55.535; p = 0.009) were the strongest CT predictors for TETs. SUVmax was significantly higher in TETs than in cysts (5.3 ± 2.4 vs. 1.1 ± 0.3; p < 0.001). After being informed of the study findings, the readers' area under the curve improved from 0.872-0.955 to 0.949-0.999 (p = 0.066-0.149). Inter-observer kappa values for protrusion were 0.630-0.941. Conclusion: Post-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.5
• /
• pp.1109-1118
• /
• 2024

Probiotics, specifically Lacticaseibacillus rhamnosus, have garnered attention for their potential health benefits. This study focuses on evaluating the probiotic properties of candidate probiotics L. rhamnosus IDCC 3201 (3201) using the Caenorhabditis elegans surrogate animal model, a well-established in vivo system for studying host-bacteria interactions. The adhesive ability to the host's gastrointestinal tract is a crucial criterion for selecting potential probiotic bacteria. Our findings demonstrated that 3201 exhibits significantly higher adhesive capabilities compared with Escherichia coli OP50 (OP50), a standard laboratory food source for C. elegans and is comparable with the widely recognized probiotic L. rhamnosus GG (LGG). In lifespan assay, 3201 significantly increased the longevity of C. elegans compared with OP50. In addition, preconditioning with 3201 enhanced C. elegans immune response against four different foodborne pathogenic bacteria. To uncover the molecular basis of these effects, transcriptome analysis elucidated that 3201 modulates specific gene expression related to the innate immune response in C. elegans. C-type lectin-related genes and lysozyme-related genes, crucial components of the immune system, showed significant upregulation after feeding 3201 compared with OP50. These results suggested that preconditioning with 3201 may enhance the immune response against pathogens. Metabolome analysis revealed increased levels of fumaric acid and succinic acid, metabolites of the citric acid cycle, in C. elegans fed with 3201 compared with OP50. Furthermore, there was an increase in the levels of lactic acid, a well-known antimicrobial compound. This rise in lactic acid levels may have contributed to the robust defense mechanisms against pathogens. In conclusion, this study demonstrated the probiotic properties of the candidate probiotic L. rhamnosus IDCC 3201 by using multi-omics analysis.

• Journal of the Korean Electrochemical Society
• /
• v.27 no.3
• /
• pp.97-104
• /
• 2024

The electrodes of commercialized lithium secondary batteries are manufactured through a wet coating process, and the drying process (DC) is a very important factor as to electrode production speed and process cost. In this study, silicon anodes were manufactured under high-temperature (180 ℃) and low-temperature (50 ℃) DC to investigate the quality and the electrochemical performance of Si-electrodes according to DC. High-temperature DC can quickly evaporate the solvent in the Si-electrode slurry, improving the electrode production rate. However, this also causes the electrode composite to peel off from the current collector. As a result, the Si-electrode's adhesion weakened, and the electrode coating's quality deteriorated. In addition, the Si-electrode manufactured under high-temperature was found to have a thicker composite material than the Si-electrode manufactured under low-temperature. Si-electrodes manufactured under high-temperature had higher sheet resistance and lower electrical conductivity than those manufactured under low-temperature. Consequently, the Si-electrode manufactured under low-temperature showed 152.5% superior cycle performance compared to the Si-electrode manufactured under high-temperature. (Discharge capacities of Si-electrodes manufactured under high-temperature and low-temperature DC were 844 and 1287 mAh g^-1, respectively, after 300 cycles). Establishing the DC of Si-electrodes can easily provide new perspectives to improve the quality and stability of Si-electrodes.

• Clinical and Experimental Pediatrics
• /
• v.51 no.4
• /
• pp.343-350
• /
• 2008

Asthma and allergic diseases are one of the most common disorders in children. Due to its increased prevalence, as well as the increased morbidity and mortality from these diseases, asthma and allergic diseases have come to be recognized as a major worldwide public health issue. In addition, socioeconomic burden of asthma and allergic diseases has increased in Korea also. The International Study of Asthma and Allergies in Childhood (ISAAC) investigated the worldwide prevalence of asthma and other allergic diseases using simple standardized methods because of the comparison of asthma and allergic diseases between the countries. In Korea, several epidemiologic studies have been conducted to determine the prevalence of asthma in children. Although these studies showed increased prevalence of asthma among Korean children (from 3.4% in 1964 to 10.1% in 1989), these findings were based on data from small numbers of subjects. The first Nationwide Study of Asthma and Allergies in Korean Children, which utilized the Korean version of ISAAC written and video questionnaire, was conducted in 1995 and the second Nationwide Study of Asthma and Allergies in Korean Children was conducted in 2000, directed by the Korean Academy of Pediatric Allergy and Respiratory Diseases. We report here the prevalence of asthma and other allergic diseases in Korean children and adolescents, and show the changes that occurred over this 5 year period. We also describe the risk factors for development of these diseases in Korean children. We developed Korean versions of the ISAAC written (WQ) and video (AVQ) questionnaires for allergic diseases. In 1995, the enrolled population consisted of 25,117 children selected from 34 elementary school and 14,946 children selected from 34 middle school across the nation, the response rate was 94.8%. In 2000, 27,831 children selected from 34 elementary school and 15,214 children selected from 34 middle school, and the response rate was 96.4%. From these studies, we can confirm that increase of the prevalences of asthma, allergic rhinitis, and atopic dermatitis in Korea, except the prevalence of food allergy. Especially, the video questionnaire showed increases in the lifetime and 12 month prevalence rates of wheeze at rest, exercise-induced wheeze, nocturnal wheeze, nocturnal cough, and severe wheeze over this period of time in middle school children. In addition, the increase of prevalences of symptoms, diagnosis and treatment of atopic dermatitis was noted significantly. Risk factor analysis showed that body mass index (BMI), passive smoking and living with a dog or cat were associated with higher risk of wheeze. Also the occurrence of fever during infancy and the frequent use of antibiotics were associated with the risk of wheeze. In conclusion, during the 5 year period from 1995 to 2000, the prevalences of asthma, allergic rhinitis, and atopic dermatitis has increased in Korean children. BMI, passive smoking, living with a dog or cat, the fever episodes in infancy, and the frequent use of antibiotics in infancy are important risk factors to development of asthma and atopic dermatitis. In the near future, the birth cohort study will be needed to investigate the causes of this increase and the natural course of allergic diseases, then we develop the methods to control asthma and allergic diseases.

• Clinical and Experimental Pediatrics
• /
• v.52 no.3
• /
• pp.324-329
• /
• 2009

Purpose : Acute interstitial pneumonia (AIP) is a rare disease, but its prognosis is fatal because of lack of efficient treatment modality. Recently, it has been reported that there was epidemic AIP in Korea. This study aims to investigate the past and current status of AIP in Korea. Methods : We performed a nationwide survey and a prospective study. From August 6 to 15, 2008, a questionnaire survey was conducted to identify the prevalence, local distribution, and response to current treatments. The questionnaire was answered by pediatrician working in 23 referral centers in Korea. In addition, 5 referral centers in Seoul performed a preliminary prospective observational study by obtaining clinical data and specimens from appropriate patients. The Korea Centers for Disease Control and Prevention analyzed the samples for possible pathogens. Results : The survey showed 78 AIP cases had occurred and 36 patients had died. Lung biopsy was performed only on 20 patients. In 2008, 9 AIP cases developed. In a prospective study, 9 (M:F=5:4) patients developed AIP in spring and 7 (78%) died, with the mean rate of death occurring 46 days after diagnosis. Human corona virus 229E, cytomegalovirus, influenza A virus, influenza B virus, and parainfluenza virus were isolated from the respiratory specimens. Conclusion : This study showed nationwide prevalence of AIP in Korea. In addition, because of the high mortality rate and rapid progress, pediatricians need to be aware of the disease. Further studies and a nationwide network are required for reducing the morbidity and mortality rates related to AIP.