• Journal of Biomedical Engineering Research
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• v.38 no.2
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• pp.74-81
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• 2017

The purpose of this study was to investigate the EMG characteristics of driver's upper extremity and driving performance for manipulating brake and accelerator pedal by using left and right hand control devices during simulated driving. The people with disabilities in the lower limb have problems in operation of the motor vehicle because of functional loss for manipulating brake and accelerator pedal. Therefore, if hand control device is used for adaptive driving controls in people with lower limb impairments, the disabled people can improve their quality of life by driving a motor vehicle. Six subjects were participated in this study to evaluate driving performance and muscle activities for operating brake and accelerator pedal by using two different hand controls (steering column mounted hand control and floor mounted hand control) in driving simulator. We measured EMG activities of six muscles (posterior deltoid, middle deltoid, triceps, biceps, flexor carpi radialis, and extensor carpi radialis) during pushing and pulling movement with different hand controls for acceleration and braking. STISim Drive 3 software was used for the performance test of different hand control devices in straight lane course for time to reach target speed and brake reaction time. While pulling the hand control lever toward the driver, normalized EMG activities of middle deltoid, triceps and flexor carpi radialis in subjects with disabilities were significantly increased (p < 0.05) compared to the normal subjects. It was also found that muscle responses of posterior deltoid were significantly increased (p < 0.05) when using the right hand control than left hand control. While pushing the hand control lever forward away from the driver, normalized EMG activities of posterior deltoid, middle deltoid and extensor carpi radialis in subjects with disability were significantly increased (p < 0.05) compared to the normal subjects. It was shown that muscle responses of middle deltoid, biceps and extensor carpi radialis were significantly increased when using the right hand control than left hand control. Brake reaction time and time to reach target speed in subjects with disability was increased by 12% and 11.3% on average compared to normal subjects. The subjects with physical disabilities showed a tendency to relatively slow acceleration at the straight lane course.

• Journal of Families and Better Life
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• v.23 no.1 s.73
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• pp.85-98
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• 2005

The purpose of this study is to make it clear that the influence the adults' work-family conflicts affect the family life satisfaction and the work life satisfaction of theirs, according to the personal backgrounds (sex, age, monthly income and whether the person works S days a week or not). The target group of this study is the selected 754 adults who are married with children that are in the employ of the various companies in Seoul and Incheon. The picked data are analyzed to factor analysis, frequencies, means, One-way ANOVA and multiple regression analysis etc..using Spss 11.5 version statistical program. Following is the result of the study: First, the level of work-family conflicts have been shown to be different as the result of verification by sex, age, monthly income and the type of duty(whether working 5days a week or not) out of the personal variables. The study shows that the level of work-family conflicts is different by the subordinate variables of work-family conflicts as the results of male and female comparison. And the older the age, the higher the level of family conflicts.'rho study shows that The level of the places of work conflicts is the highest in the 30s. The smaller monthly income, the higher the level of work-family conflicts. The study shows that the level of family conflicts is high in working 6days a week and the level of work conflicts is high in working 5days a week. Second, such factors for conflicts at home as family support, family expectations and financial difficulties affect the level of satisfaction at work, while such personal backgrounds as monthly pay, kinds of work and age level also play a role. At the same time, satisfaction in family life is influenced by such factors for conflicts at the places of work as support, involvement, expectations and work-overload at the places of work, with such personal backgrounds as monthly pay, age and sex compounding the impact. On the point how much conflicts at work and home affect the satisfaction at home, work and leisure, the study shows that family life does not have noticeable influence in the level of satisfaction at the places of work, whereas situations at the place of work have significant impact on the level of satisfaction in family lives. In other words, the lesser conflicts the work situations cause to family lives, the greater the level of satisfaction at work, home and at leisure.

• Health Policy and Management
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• v.34 no.2
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• pp.141-155
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• 2024

Background: This study aimed to identified the relationship between the risk of obstructive sleep apnea, subjective health, and health-related quality of life among the middle-aged and elderly population in Korea. Methods: Adults aged 40 or older were extracted from the total 22,559 respondents to the 2019-2020 Korea National Health and Nutrition Examination Survey VIII, and secondary analysis was conducted on a total of 6,659 middle-aged and elderly people with no missing values. Logistic regression analysis and multiple regression analysis were conducted to examine the relationship between obstructive sleep apnea risk factors and subjective health as well as quality of life. Results: The subjective health status decline in the high-risk group compared to the non-risk group for obstructive sleep apnea was statistically significantly higher, with an odds ratio of 1.84 (p<0.001). The health-related quality of life was also statistically significantly lower by 0.02 points (β, -0.02; p<0.001). As a result of subgroup analysis on specific variables, the association between the risk of obstructive sleep apnea and subjective health and health-related quality of life was statistically significant depending on gender, sleep time, presence of depression, household income, and number of household members. Based on the obstructive sleep apnea risk group, women had a higher correlation with low subjective health and lower health-related quality of life scores than men. Sleeping time of more than 8 hours or less than 6 hours was more associated with low subjective health and lower health-related quality of life score than sleeping time of 6-8 hours. Patients with depression were more likely to have low subjective health than those without depression. The lower the household income level and the smaller the number of household members, the higher the association with low subjective health and the lower the health-related quality of life score. Conclusion: It is essential to recognize that the risk of obstructive sleep apnea not only directly affects sleep disorders but also impacts individuals' subjective health and quality of life. Consequently, social support and education should be provided to raise awareness of this issue. Particularly, programs for preventing and managing obstructive sleep apnea should target vulnerable groups such as women, individuals in single-person households, low household income, and those with depression, aiming to improve their subjective health and quality of life.

• Smart Structures and Systems
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• v.20 no.3
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• pp.385-396
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• 2017

The recent advancements in sensing technologies allow us to record measurements from target structures at multiple locations and with relatively high spatial resolution. Such measurements can be used to develop data-driven methodologies for condition assessment, control, and health monitoring of target structures. One of the state-of-the-art technologies, Fiber Optic Strain Sensors (FOSS), is developed at NASA Armstrong Flight Research Center, and is based on Fiber Bragg Grating (FBG) sensors. These strain sensors are accurate, lightweight, and can provide almost continuous strain-field measurements along the length of the fiber. The strain measurements can then be used for real-time shape-sensing and operational load-estimation of complex structural systems. While several works have demonstrated the successful implementation of FOSS on large-scale real-life aerospace structures (i.e., airplane wings), there is paucity of studies in the literature that have investigated the potential of extending the application of FOSS into civil structures (e.g., tall buildings, bridges, etc.). This work assesses the feasibility of using FOSS to predict operational loads (e.g., wind loads) on chain-like structures. A thorough investigation is performed using analytical, computational, and experimental models of a 4-story steel building test specimen, developed at the University of Southern California. This study provides guidelines on the implementation of the FOSS technology on building-like structures, addresses the associated technical challenges, and suggests potential modifications to a load-estimation algorithm, to achieve a robust methodology for predicting operational loads using strain-field measurements.

• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.316-326
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• 2008

The Earth's temperature has risen $0.76^{\circ}C$ (degree) during last 100 years which Implies a sudden rise, compare with the 4oC (degrees) rise through out the past 20,000 years. If the volume of GHG (Greenhouse Gas) emission continues at the current level, the average temperature of the Earth will rise by $1^{\circ}C$ (degree) by 2030 with the further implication that the temperature of Earth will rise by $2{\sim}5^{\circ}C$ (degrees) every 100 years. Therefore, as we are aware that the temperature of the glacial epoch was $8{\sim}9^{\circ}C$ (degrees) lower than the present time, we can easily predict that the above temperature rises can be potentially disastrous for human life. Every country in the world recognizes theseriousness of the current climate change and adopted a convention on climate change in June 1992 in Rio. The COP1 was held in March 1995 in Berlin and the COP3 in Dec. 1997 in Kyotowhere the target (2008-2012) was determined and the advanced nations' reduction target (5.2%, average)was also agreed at this conference. Korea participated in the GHG reduction plan which required the world's nations to ratify the Kyoto Protocol. Ratification of the Kyotoprotocol and the followup requirement to introduce an international emissions trading scheme will require severe reductions in GHGs and considerable economic consequences. USA are still refusing to fully ratify the treaty as the emission reductions could severely damage the economies of these countries. In order to estimate the exact $CO_2$ emission, this study statistically analyzed $CO_2$ emission of each country based on the following variables : level of economic power and scientific development, the industrial system, productivity and energy efficiency.

• Genomics & Informatics
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• v.18 no.4
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• pp.43.1-43.13
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• 2020

The coronavirus disease 2019 is a contagious disease and had caused havoc throughout the world by creating widespread mortality and morbidity. The unavailability of vaccines and proper antiviral drugs encourages the researchers to identify potential antiviral drugs to be used against the virus. The presence of RNA binding domain in the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be a potential drug target, which serves multiple critical functions during the viral life cycle, especially the viral replication. Since vaccine development might take some time, the identification of a drug compound targeting viral replication might offer a solution for treatment. The study analyzed the phylogenetic relationship of N protein sequence divergence with other 49 coronavirus species and also identified the conserved regions according to protein families through conserved domain search. Good structural binding affinities of a few natural and/or synthetic phytocompounds or drugs against N protein were determined using the molecular docking approaches. The analyzed compounds presented the higher numbers of hydrogen bonds of selected chemicals supporting the drug-ability of these compounds. Among them, the established antiviral drug glycyrrhizic acid and the phytochemical theaflavin can be considered as possible drug compounds against target N protein of SARS-CoV-2 as they showed lower binding affinities. The findings of this study might lead to the development of a drug for the SARS-CoV-2 mediated disease and offer solution to treatment of SARS-CoV-2 infection.

• Computers and Concrete
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• v.31 no.5
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• pp.457-468
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• 2023

Buildings, bridges, and dams are examples of civil infrastructure that play an important role in public life. These structures are prone to structural variations over time as a result of external forces that might disrupt the operation of the structures, cause structural integrity issues, and raise safety concerns for the occupants. Therefore, monitoring the state of a structure, also known as structural health monitoring (SHM), is essential. Owing to the emergence of the fourth industrial revolution, next-generation sensors, such as wireless sensors, UAVs, and video cameras, have recently been utilized to improve the quality and efficiency of building forensics. This study presents a method that uses a target-based system to estimate the dynamic displacement and its corresponding dynamic properties of structures using UAV-based video. A laboratory experiment was performed to verify the tracking technique using a shaking table to excite an SDOF specimen and comparing the results between a laser distance sensor, accelerometer, and fixed camera. Then a field test was conducted to validate the proposed framework. One target marker is placed on the specimen, and another marker is attached to the ground, which serves as a stationary reference to account for the undesired UAV movement. The results from the UAV and stationary camera displayed a root mean square (RMS) error of 2.02% for the displacement, and after post-processing the displacement data using an OMA method, the identified natural frequency and damping ratio showed significant accuracy and similarities. The findings illustrate the capabilities and reliabilities of the methodology using UAV to evaluate the dynamic properties of structures.

• Journal of fish pathology
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• v.37 no.1
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• pp.1-8
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• 2024

The advantages of replicon vectors of RNA viruses include a high ability to stimulate innate immunity and exponential amplification of target mRNA leading to high expression of foreign antigens. The present study aimed to construct a DNA-layered nervous necrosis virus (NNV) replicon vector system in which the capsid protein gene was replaced with a foreign antigen gene and to compare the efficiency of foreign antigen expression between the conventional DNA vaccine vector and the present replicon vector. We presented the first report of a nodavirus DNA replicon-based foreign antigen expression system. Instead of a two-vector system, we devised a one-vector system containing both an NNV RNA-dependent RNA polymerase cassette and a foreign antigen-expressing cassette. This single-vector approach circumvents the issue of low foreign protein expression associated with the low co-transfection efficiency of a two-vector system. Cells transfected with a vector harboring hammerhead ribozyme-fused RNA1 and RNA2 (with the capsid gene ORF replaced with VHSV glycoprotein ORF) exhibited significantly higher transcription of the VHSV glycoprotein gene compared to cells transfected with either a vector without hammerhead ribozyme or a conventional DNA vaccine vector expressing the VHSV glycoprotein. Furthermore, the transcription level of the VHSV glycoprotein in cells transfected with a vector harboring hammerhead ribozyme-fused RNA1 and RNA2 showed a significant increase over time. These results suggest that NNV genome-based DNA replicon vectors have the potential to induce stronger and longer expression of target antigens compared to conventional DNA vaccine vectors.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.40-45
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• 2006

The baculovirus-insect Drosophila melanogaster S2 cell system combines advantages of conventional baculovirus system and non-lytic S2 cell system because baculoviruses can infect non-permissive cells such as mammalian and Drosophila S2 cells but cannot replicate themselves inside the cells. In the present work, we investigated effects of infection conditions on production of green fluorescent protein (GFP) as a target protein using this baculovirus-S2 cell system. Even though higher MOI and longer baculovirus contact time showed better GFP expression yield during the shorter period, overall protein yield could be lower during the longer period due to the relatively higher cell detachment and lysis (lower cell viability). In addition, maintaining high MOI will be not practical for large-scale cell culture. Therefore, instead of maintaining high MOI, we found that high initial cell number and concentrated (10X) baculovirus volume can confer comparable protein expression even under the moderate MOI condition. Also, we found that the post-infection time that is connected to state of cells after infection was an important factor for production yield.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.2
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• pp.200-208
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• 2024

The occurrence a fire on a training ship with a large number of people on board can lead to severe casualties. Hence the Seafarers' Act and Safety Life At Sea(SOLAS) emphasizes the importance of the abandon ship drill. Therefore, in this study, the training ship of Mokpo National Maritime University, Segero, which has a large number of people on board, was selected as the target ship and the likelihood and severity of fire accidents on each deck were predicted through the preliminary hazard analysis(PHA) qualitative risk assessment. Additionally, assuming a fire in a high-risk area, a simulation of evacuation time and population density was performed to quantitatively predict the risk. The the total evacuation time was predicted to be the longest at 501s in the meal time scenario, in which the population distribution was concentrated in one area. Depending on the scenario, some decks had relatively high population densities of over 1.4pers/m², preventing stagnation in the number of evacuees. The results of this study are expected to be used as basic data to develop training scenarios for training ships by quantifying evacuation time and population density according to various evacuation scenarios, and the research can be expanded in the future through comparison of mathematical models and experimental values.