• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.1-9
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• 2022

Objectives: The purpose of this study is to evaluate exposure characteristics of lead using data from the domestic occupational exposure literature. Methods: Occupational airborne exposure data on lead reported in the domestic literature from 1981 to 2018 were collected and re-analyzed. The exposure levels in the data were expressed as an estimated arithmetic mean and a weighted arithmetic mean (WAM) of the number of samples. Lead exposure characteristics were analyzed by industry, process, and year. Results: From a total of 14 documents, 8,305 airborne lead measurements for 17 industries were identified, and the WAM concentration in eight industries exceeded the occupational exposure limit of 50 ㎍/m³. Three industries (battery manufacturing, lead smelting, and litharge manufacturing) accounted for 95% of the total data, and exposure trends could be confirmed over 10 years. Exposure levels continue to decrease in all three industries. Conclusions: Considering the distribution outlook of lead and lead compounds, the main management targets are lead storage battery manufacturing and secondary smelting for lead regeneration.

• Journal of Practical Engineering Education
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• v.13 no.3
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• pp.533-544
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• 2021

The purpose of this study is to investigate the structural relationship among psychological contract violation, job burnout, and turnover intention of MZ generation workers in small and medium enterprises. The sample collected through online and offline was 144 units of millennial generation and 140 units of Z generation. The results of analysis using structural equations showed that psychological contract violation had a positive (+) effects on turnover intention and job burnout, and job burnout also had a positive (+) effect on turnover intention. In the relationship between psychological contract violation and turnover intention, job burnout had a partial mediating effect.

• Human Ecology Research
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• v.59 no.2
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• pp.199-213
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• 2021

The purpose of the study was to apply latent transition analysis to the work-family balance of working mothers with a child in elementary school by focusing on the effect of antecedents on both work-family balance typology and the transition between typologies. Data from 400 working mothers who participated in the eighth and eleventh waves of the Panel Study on Korean Children were used. The results can be summarized as follows. First, the latent profile analysis of working mothers whose children were in the first grade classified the work-family balance types as 'contradictory' or 'beneficial' and of working mothers whose children were in the fourth grade as 'conflictual', 'contradictory', 'high beneficial', 'low beneficial' or 'beneficial'. Second, working mothers whose work-family balance was 'contradictory' or 'beneficial' when their children were in the first grade mostly had, respectively, a 'low beneficial' or a 'high beneficial' balance when their children were in the fourth grade. Third, the probability of being classified into each type differed according to subjective happiness and marital conflict in the first grade, and marital conflict and social support in the fourth grade. Moreover, marital conflict and social support were significant in the transition between the types of work-family balance. The study showed that the types of work-family balance differed for each time point for individual working mothers. The study also highlighted the importance of parenting-related personal, family and social factors in determining the work-family balance type and transition between types.

• The Journal of Korean Medicine
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• v.42 no.2
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• pp.1-20
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• 2021

Objectives: The purpose of this study was to confirm the relavance between the dependent variables and the treatment effects of nonsurgical spinal decompression(NSD). Methods: 105 patients suffering from disc herniation and treated with NSD were investigated and analyzed. Results: The intention of retreatment showed a tendency to be higher in having occupation, western treatment only before NSD(WTB) and non-western treatment(WTN) group. As the number of NSD increased, satisfaction score and the Numeric Rating Scale(NRS) difference increased and the NRS after NSD decreased. On the other hand, as western treatment after NSD increased, satisfaction score and the NRS difference decreased and the NRS after NSD increased. The odds ratio of having intention of retreatment was lower in western treatment only after NSD(WTA) group than WTN group. The NRS difference showed a high tendency in the age group of 20s, 60s, and 70s and older. The NRS difference of group with NSD more than 10 times was higher than that of the group with less than 10 times. Satisfaction score of WTN and WTB group was higher than that of WTA group. Adjusted NRS after NSD was the lowest in non-western treatment group and the highest in WTA group. Adjusted NRS after NSD was the lowest in the group with NSD over 21 times, and the NRS after NSD increased as the number of NSD decreased. Conclusion: This study included patients with cervical or lumbar disc herniation and showed that occupation, the number of NSD, western treatment and age statistically affected the treatment effect.

• Journal of Broadcast Engineering
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• v.26 no.6
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• pp.738-747
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• 2021

Today, with the improvement of deep learning technology, computer vision areas such as image classification, object detection, object segmentation, and object tracking have shown remarkable improvements. Various applications such as intelligent surveillance, robots, Internet of Things, and autonomous vehicles in combination with deep learning technology are being applied to actual industries. Accordingly, the requirement of an efficient compression method for video data is necessary for machine consumption as well as for human consumption. In this paper, we propose an object-based compression of thermal infrared images for machine vision. The input image is divided into object and background parts based on the object detection results to achieve efficient image compression and high neural network performance. The separated images are encoded in different compression ratios. The experimental result shows that the proposed method has superior compression efficiency with a maximum BD-rate value of -19.83% to the whole image compression done with VVC.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.109-115
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• 2019

Objective : Herbal medicinal mixture (JMB) are consisted of Caryophylli Flos, Aucklandiae Radix, and Angelicae Dahuricae Radix. Each of these herbal medicines has studied on anti-aging effect in vitro. So this study was conducted to investigate efficacy and potency of JMB extract on dermal anti-aging and whitening. Methods : The JMB was extracted at room temperature by 80% ethanol. Collagenase and elastase inhibition activity in JMB ethanol extract were determined at 10, 50, 100, 500, 1000 mg/ml concentrations by colorimetric method. The toxic range of JMB ethanol extract was evaluated using MTT assay. Also, The inhibitory effect of JMB ethanol extract on tyrosinase activity and melanin contents in mouse melanoma cell line (B16F10 cell) was identified at 50, 100, 200 ㎍/㎖ levels by spectrometric assay. In each analysis, EGCG (epigallocatechin gallate) and Kojic acid were used as positive controls, respectively. Results : The elastase and collagenase inhibitory activity of JMB ethanol extract increased dose dependently. Also, The MTT assay showed that JMB, up to 400 ㎍/㎖ concentration, exhibited no toxic effect to the B16F10 cell. And following the JMB ethanol extract treat, cellular melanin contents and tyrosinase activity were dose-dependently decreased compared to those of control. Conclusion : These results suggest that JMB ethanol extract has effects to inhibitory activity on dermal wrinkle enzyme and melanogenesis. Therefore, JMB has applicable benefits for development of materials or products to have whitening and anti-aging functions on skin.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.139-146
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• 2019

Objective : Recently, hair has become one of the important aspects of beauty. So, there are many studies about prevention and treatment of alopecia. Finasteride and minoxidil have been known to drug for alopecia treatment. However, these agents have side effects such as irritation, pruritus, and erythema when they were used for a long time. So, we assessed hair growth effect on herbal mixture (RAA) include in Rehmanniae Radix Preparata, Achyranthis Radix, and Acanthopanacis Cortex. Methods : 6 weeks aged C57BL/6 mice were divided three treatment groups. : CON group (vehicle solution), MNXD group (positive control, 3% minoxidil), RAA group (15% RAA solution). And we applied 200 ㎕ of three groups to shaved dorsal skin every day. Hair growth effects of treatment were determined through phototrichogram by folliscope and hair follicle morphometry by H&E staining. And we assessed hair growth-related gene (VEGF, IGF-1, TGF-β1) expressions by western blot and 5-α reductase II analysis of dermal (skin) or internal organ (prostate gland). Results : Hair density and hair follicle size in MNXD or RAA group was enhanced compared to those of CON group, respectively. Also, the protein expression levels in dermal of VEGF, IGF-1 increased but TGF-β1 decreased in RAA and MNXD group, compared to CON group, respectively. 5-α reductase II levels of tissues in MNXD or RAA group significantly decreased compared to those of CON group, respectively. Conclusion : These results suggest that RAA has the promoting effect on hair growth.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.6
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• pp.25-33
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• 2022

In this study, a monitoring method using high-resolution images acquired by unmanned aerial vehicles and deep learning algorithms was proposed for the management of the Sinduri coastal sand dunes. Class classification was done using U-net, a semantic division method. The classification target classified 3 types of sand dune vegetation into 4 classes, and the model was trained and tested with a total of 320 training images and 48 test images. Ignored label was applied to improve the performance of the model, and then evaluated by applying two loss functions, CE Loss and BCE Loss. As a result of the evaluation, when CE Loss was applied, the value of mIoU for each class was the highest, but it can be judged that the performance of BCE Loss is better considering the time efficiency consumed in learning. It is meaningful as a pilot application of unmanned aerial vehicles and deep learning as a method to monitor and manage sand dune vegetation. The possibility of using the deep learning image analysis technology to monitor sand dune vegetation has been confirmed, and it is expected that the proposed method can be used not only in sand dune vegetation but also in various fields such as forests and grasslands.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.9
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• pp.627-638
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• 2022

This paper discusses the utilization of fault-tolerant technology in the industry by analyzing the status of drone failures in the unmanned vehicle industry survey conducted in 2020. Based on the survey results of the domestic unmanned vehicle industry, we identify subsystems with high fault rates and high severity when faults occur. In addition, fault simulations of the identified subsystems are conducted to analyze the effect of the fault on the vehicles. After that, the fault diagnosis and fault compensation methods studied so far are reviewed, and research cases of the methods are examined. Moreover, the ways to apply it to actual fault cases in the unmanned vehicle industry are debated. Furthermore, based on the previous discussion, the fault-tolerant system is presented, and the consideration when designing the fault-tolerant system in the industry are studied.

• The Journal of Pediatrics of Korean Medicine
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• v.36 no.3
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• pp.49-62
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• 2022

Objectives This study aimed to provide evidence for the use of Korean medicine in underweight patients by analyzing the medical records of underweight children and adolescents. Methods Children and adolescents who visited Korean pediatrics at Kyung Hee University Hospital from June 1, 2019 to May 31, 2022, who had an age-specific weight percentile which was less than 5 and diagnosed with E639.005 or R628.001 were selected for the study. A retrospective chart review was conducted by examining the medical records of subjects who received Korean medical treatment. The treatment effect was analyzed in all subjects and subgroups by comparing changes in height, weight, and body mass index (BMI) percentiles before and after Korean medicine treatment. Results A total of 55 underweight subjects were included in the study. General characteristics such as distribution by sex, age, number of visits, and weight percentile, and clinical characteristics such as diagnosis, past history, family history, drug history, current or past symptoms, and symptom differentiation were collected. The composition of herbal medicines and the contents of other Korean medical treatments were analyzed. In the case of treatment effect, the weight and BMI percentile of all subjects increased significantly. Conclusions This study was conducted to suggest Korean medicine as a method of proper weight management in children and adolescents. In the future, follow-up studies with a large number of subjects and controlled variables, such as the period of taking herbal medicine, are needed.