• Journal of Trauma and Injury
• /
• v.36 no.4
• /
• pp.343-353
• /
• 2023

Purpose: The COVID-19 pandemic led to significant changes in the lifestyle patterns of children and affected the patterns of pediatric injuries. This study analyzed the changing patterns of pediatric injury overall and by age groups, based on the datasets before and during the COVID-19 pandemic. Methods: This study is based on the data of patients who presented with injuries at 23 hospital emergency departments participating in the Emergency Department-based Injury In-depth Surveillance (EDIIS) conducted by the Korea Disease Control and Prevention Agency. The surveillance data was categorized by injury mechanism, location, activity, and severity. We analyzed the injury patterns of pediatric patients aged 0 to 15 years. Subgroup analysis was conducted by age group in children aged 7 to 15 years, 1 to 6 years, and <1 year. Results: When comparing the COVID-19 pandemic period to the pre-COVID-19 period, the total number of pediatric patients with injuries decreased by 38.7%, while the proportions of in-home injuries (57.9% vs. 67.9%), and minor injuries (38.9% vs. 39.7%) increased. In the 7 to 15 years group, bicycle riding injuries (50.9% vs. 65.6%) and personal mobility device injuries (2.4% vs. 4.6%) increased. The 1 to 6 years group also showed an increase in bicycle accident injuries (15.8% vs. 22.4%). In the <1 year group, injuries from falls increased (44.5% vs. 49.9%). Self-harm injuries in the 7 to 15 years group also increased (1.6% vs. 2.8%). Conclusions: During the COVID-19 pandemic period, the overall number of pediatric injuries decreased, while injuries occurring at home and during indoor activities increased. Traffic accidents involving bicycles and personal mobility devices and self-harm injuries increased in the 7 to 15 years group. In the <1 year group, the incidence of falls increased. Medical and societal preparedness is needed so that we might anticipate these changes in the patterns of pediatric injuries during future infectious disease pandemics.

• Journal of Advanced Navigation Technology
• /
• v.28 no.1
• /
• pp.102-108
• /
• 2024

In the initial stages of urban air mobility (UAM) operations, compliance with existing visual flight rules and instrument flight regulations for conventional human-crewed aircraft is crucial. Additionally, voice communication between the on board pilot and relevant UAM stakeholders, including vertiports, is essential. Consequently, very high frequency (VHF) aviation voice communication must be consistently provided throughout all phases of UAM operations. This paper presents the results of the VHF communication coverage analysis for the initial UAM demonstration areas, encompassing the Hangang River and Incheon Ara-Canal corridors, as well as potential vertiport candidate locations. By considering the influence of terrain and buildings through the utilization of a digital surface model (DSM), communication quality prediction results are obtained for the analysis areas. The three-dimensional coverage analysis results indicate that stable coverage can be achieved within altitude corridors ranging from 300 m to 600 m. However, there are shaded areas in the low-altitude vertiport regions due to the impact of high-rise buildings. Therefore, additional research to ensure stable coverage around vertiports in the lower altitude areas is required.

• Journal of Biomedical Engineering Research
• /
• v.38 no.4
• /
• pp.143-152
• /
• 2017

The main purpose of this research was to examine the EMG characteristics of driver's upper limb and driving performance for operating accelerator and brake pedal by using four types of left hand control devices(Push/Pull, Push/Right angle, Push/Rock, Push/Twist) during simulated driving. The persons with disabilities in the lower extremity have problems in operation of the vehicle because of functional impairments for controlling accelerator and brake pedal. Therefore, if hand control device is used for adaptive driving controls in persons with lower extremity loss, the disabled people could improve their quality of mobility life by driving a car. Twenty subjects were involved in this research to assess driving performance and EMG activities for operating accelerator and brake pedal by using four types of left hand controls in driving simulator. We measured EMG responses of six muscles(posterior deltoid, middle deltoid, biceps, triceps, extensor carpi radialis, and flexor carpi radialis) during pulling and pushing movement with four types of left hand controls for acceleration and braking. STISim Drive 3 program was used for evaluation test of four types of left hand control devices in straight lane course for time to reach target speed and brake reaction time. While operating the four types of left hand controls for acceleration, EMG activities of posterior deltoid in normal subjects were significantly increased(p < 0.05) compared to the disabled subjects. It was also found that EMG responses of triceps and posterior deltoid were significantly increased(p < 0.05) when using the Push/Right angle type than Push/Pull type. While operating the four types of left hand controls for braking, EMG activities of flexor carpi radialis and triceps in subjects with disability were significantly increased(p < 0.05) compared to the normal subjects. It was shown that muscle responses of posterior deltoid, middle deltoid and triceps were significantly increased when using the Push/Right angle type than Push/Rock type. Time to reach target speed and brake reaction time in subjects with disability was increased by 2.5% and 4.6% on average compared to normal subjects. The person with disabilities showed a tendency to relatively slow performance in acceleration at the straight lane course.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.419-427
• /
• 2020

This study was undertaken to address the difficulties and inconveniences of an electric wheelchair. We focused on improving usability of initially completed products by augmenting the prototypes designed in the previous study. For evaluation of usability, 10 elderly women aged over 65 years, capable of movements and physical activities in daily life, were enrolled as subjects. The experimental method included a subjective satisfaction questionnaire evaluation of the elderly women using the target product, and the observation evaluation was achieved using video recording data, etc. Usability evaluation revealed that the elevating sector requires improvement of intuition through separation of the elevating control panel and the driving control panel. Improvements in the driving sector include corrections of the front wheel mechanism or driving control algorithm, UI, and sudden stop system. Transferring section assessment revealed a necessity to secure structures and add structures that support power. We believe that based on the inconveniences and improvements presented in the usability evaluation, appending the existing prototype with complementary products will improve the quality of life of elderly women with limited mobility.

• Journal of the Ergonomics Society of Korea
• /
• v.35 no.1
• /
• pp.11-27
• /
• 2016

Objective: The purpose of this study was to develop and evaluate high technology adaptive driving controls, such as mini steering wheel-lever system and joystick system, for the people with physical disabilities in the driving simulator. Background: The drivers with severe physical disabilities have problems in operation of the motor vehicle because of reduced muscle strength and limited range of motion. Therefore, if the remote control system with driver-by-wire technology is used for adaptive driving controls for people with physical limitations, the disabled people can improve their quality of life by driving a motor vehicle. Method: We developed the remotely controlled driving simulator with drive-by-wire technology, e.g., mini steering wheel-lever system and joystick system, in order to evaluate driving performance in a safe environment for people with severe physical disabilities. STISim Drive 3 software was used for driving test and the customized Labview program was used in order to control the servomotors and the adaptive driving devices. Thirty subjects participated in the study to evaluate driving performance associated with three different driving controls: conventional driving control, mini steering wheel-lever controls and joystick controls. We analyzed the driving performance in three different courses: straight lane course for acceleration and braking performance, a curved course for steering performance, and intersections for coupled performance. Results: The mini steering wheel-lever system and joystick system developed in this study showed no significant statistical difference (p>0.05) compared to the conventional driving system in the acceleration performance (specified speed travel time, average speed when passing on the right), steering performance (lane departure at the slow curved road, high-speed curved road and the intersection), and braking performance (brake reaction time). However, conventional driving system showed significant statistical difference (p<0.05) compared to the mini steering wheel-lever system or joystick system in the heading angle of the vehicle at the completion point of intersection and the passing speed of the vehicle at left turning. Characteristics of the subjects were found to give a significant effect (p<0.05) on the driving performance, except for the braking reaction time (p>0.05). The subjects with physical disabilities showed a tendency of relatively slow acceleration (p<0.05) at the straight lane course and intersection. The steering performance and braking performance were confirmed that there was no statistically significant difference (p>0.05) according to the characteristics of the subjects. Conclusion: The driving performance with mini steering wheel-lever system and joystick control system showed no significant statistical difference compared to conventional system in the driving simulator. Application: This study can be used to design primary controls with driver-by-wire technology for adaptive vehicle and to improve their community mobility for people with severe physical disabilities.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.335-335
• /
• 2014

Over the past several years, transparent conducting oxides have been extensively studied in order to replace indium tin oxide (ITO). Here we report on fluorine doped zinc tin oxide (FZTO) films deposited on glass substrates by radio-frequency (RF) magnetron sputtering using a 30 wt% ZnO with 70 wt% SnO2 ceramic targets. The F-doping was carried out by introducing a mixed gas of pure Ar, CF4, and O2 forming gas into the sputtering chamber while sputtering ZTO target. Annealing temperature affects the structural, electrical and optical properties of FZTO thin films. All the as-deposited FZTO films grown at room temperature are found to be amorphous because of the immiscibility of SnO2 and ZnO. Even after the as-deposited FZTO films were annealed from $300{\sim}500^{\circ}C$, there were no significant changes. However, when the sample is annealed temperature up to $600^{\circ}C$, two distinct diffraction peaks appear in XRD spectra at $2{\Theta}=34.0^{\circ}$ and $52.02^{\circ}$, respectively, which correspond to the (101) and (211) planes of rutile phase SnO2. FZTO thin film annealed at $600^{\circ}C$ resulted in decrease of resistivity $5.47{\times}10^{-3}{\Omega}cm$, carrier concentration ~1019 cm-3, mobility~20 cm2 V-1s-1 and increase of optical band gap from 3.41 to 3.60 eV with increasing the annealing temperatures and well explained by Burstein-Moss effect. Change of work function with the annealing temperature was obtained by ultraviolet photoemission spectroscopy. The increase of annealing temperature leads to increase of work function from ${\phi}=3.80eV$ (as-deposited FZTO) to ${\phi}=4.10eV$ ($600^{\circ}C$ annealed FZTO) which are quite smaller than 4.62 eV for Al-ZnO and 4.74 eV for SnO2. Through X-ray photoelectron spectroscopy, incorporation of F atoms was found at around the binding energy of 684.28 eV in the as-deposited and annealed FZTO up to 400oC, but can't be observed in the annealed FZTO at 500oC. This result indicates that F atoms in FZTO films are loosely bound or probably located in the interstitial sites instead of substitutional sites and thus easily diffused into the vacuum from the films by thermal annealing. The optical transmittance of FZTO films was higher than 80% in all specimens and 2-3% higher than ZTO films. FZTO is a possible potential transparent conducting oxide (TCO) alternative for application in optoelectronics.

• Journal of Biomedical Engineering Research
• /
• v.24 no.5
• /
• pp.427-434
• /
• 2003

In this paper, we present a speech-based Environmental Control System(ECS) and its application. In the concrete, an ECS using the speech recognition and an portable wheelchair lift control system with the speech synthesis are developed through the simulation and the embodiment. The developed system apply to quadriplegic man and we evaluate the result of physical effect and of mental effect. Speech recognition system is constructed by real time modules using HMM model. For the clinical application of the device, we investigate the result applied to 54-years old quadriplegic man during a week through the questionnaires of Beck Depression Inventory and of Activity Pattern Indicator. Also the motor drive control system of potable wheelchair lift is implemented and the mechanical durability is tested by structural analysis. Speech recognition rate results in over 95% through the experiment. The result of the questionnaires shows higher satisfaction and lower nursing loads. In addition, the depression tendency of the subject were decreased. The potable wheelchair lift shows good fatigue life-cycle as the material supporting the upper wheelchair and shows the centroid mobility of safety. In this paper we present an example of ECS which consists of real-time speech recognition system and potable wheelchair lift. Also the experiments shows needs of the ECS for korean environments. This study will be the base of a commercial use.

• Journal of Preventive Medicine and Public Health
• /
• v.16 no.1
• /
• pp.25-30
• /
• 1983

This research is to examine the detoxication effect of methionine on cadmium intoxication For this purpose, this paper provides an analysis of the data on the groups of mice (ICR), one group of mice treated with 40 ppm of cadmium only. and other groups of mice combined-treated with cadmium and 0.1%, 0.25%, 0.5% and 1% methionine. After breeding for 40 days, the data on the growth of mice, changes in activation of alkaline phosphatase in blood, and the cadmium content in the liver and kidney, are analysed. The results were as follows: 1) The growth-rate of mice, in the cadmium only injected group, was declined by 9% in comparison with the control group after 40 days. But the two groups of cadmium with 0.5% and 1% methionine showed the rise of 9% ana 14% respectively above the growth-rate of the control group. The results from the groups of cadmium with 0.1% and 0.25%, methionine were similar to that from the cadmium only injected group. 3) Changes in activation of alkaline phosphatase in blood decreased to 86.45% in the cadmium only injected group behind the 100% activation of the control group. The groups of cadmium with 0.1% and 0.25% methionine showed no difference with the former group. But the groups of cadmium with 0.5% and 1% methionine recovered to the 93.14% and 96.08% of activation respectively. 3) The mean content of cadmium in the liver was $0.028{\pm}0.001{\mu}g/g$ in the control group. The cadmium only injected group showed the mean cadmium content of $2.80{\pm}0.62{\mu}g/g$ in the liver, which was similar to $2.82{\pm}1.03{\mu}g/g$ in the group of cadmium with 0.1% methionine, and $2.56{\pm}0.77{\mu}g/g$ in the group of cadmium with 0.25% methionine. But the groups of cadmium with 0.5% and 1% methionine showed the reduction of cadmium contents in the liver to $1.84{\pm}0.56{\mu}g/g$ and $1.74{\pm}0.35{\mu}g/g$ respectively. In the kidney, the groups of cadmium with 0.1%, 0.25% and 0.5% methionine shelved the similar cadmium content to the group treated with cadmium only. But the group of cadmium with 1% methionine showed a small increase to $4.13{\pm}1.00{\mu}g/g$ in comparison with the group treated with cadmium only. This analysis proves that the mobility and diffusion of cadmium in tile tissues advance faster ill the group treated with cadmium and methionine than in the group treated with cadmium only.

• Science of Emotion and Sensibility
• /
• v.25 no.1
• /
• pp.3-20
• /
• 2022

Recently, prior to the commercialization of urban air mobility (UAM), the importance of R&D for air transportation-related industries in urban areas has significantly increased. To create a UAM environment, research is being conducted on personal air vehicles (PAVs). They are key means of air transportation, but research on the physical factors influencing their passengers is relatively insufficient. In particular, because the PAV is expected to be used as a living space for the passengers, research on the effects of the physical elements generated in the PAV on the human body is essential to design an interior space that supports the in-vehicle activities of the passengers. Therefore, the purpose of this study is to derive the constraint factors that affect the human body due to the air navigation characteristics of the PAV and to understand the impact of these constraint factors on the bodies of the passengers performing in-vehicle activities. The results of this study indicate that when the PAV was operated at less than 4,000 ft, which is the operating standard, the constraint factors were noise, vibration, and motion sickness caused by low-frequency motion. These constraint factors affect in-vehicle activity; thus, the in-vehicle activities that can be performed in a PAV were derived using autonomous cars, airplanes, and PAV concept cases. Furthermore, considering the impact of the constraint factors and their levels on the human body, recommended constraint factor criteria to support in-vehicle activities were established. To reduce the level of impact of the constraint factors on the human body and to support in-vehicle activity, the seat's shape and built-in functions of the seat (vibration reduction function, temperature control, LED lighting, etc.) and external noise reduction using a directional speaker for each individual seat were recommended. Moreover, it was suggested that interior materials for noise and vibration reduction should be used in the design of the interior space. The contributions of this study are the determination of the constraint factors affecting the in-vehicle PAV activity and the confirmation of the level of impact of the factors on the human body; in the future, these findings can be used as basic data for suitable PAV interior design.

• Journal of Korean Academy of Nursing
• /
• v.23 no.2
• /
• pp.207-223
• /
• 1993

Inpatients are mostly occupied in bed with restricted activity, nearly all patient populations are at risk for the occurrence of skeletal muscle atrophy due to decreased level of activity. Restriction of mobility is far greater in pediatric patients compared with adult patients since almost all the activities of daily living is performed by parents or caregivers. It could be assumed that pediatric patients are more vulnerable to skeletal muscle atrophy than adult patients, however, there have been no attempts to reduce the atrophy of developing muscle. Therefore it is important to determine the effect of exercise in developing muscle during decreased activity. The purpose of this study was to determine the effect of periodic weight support during hindlimb suspension on the mass and cross-sectional area of Type I and II fibers in developing soleus(Type I ) muscle. To examine the effectiveness of periodic weight support activity in maintaining mass and fiber size. the hindlimb of young female Wistar rats was suspended(HS) and half of these rats walked on a treadmill for 45min / day(15min every 4h) at 5m / min at a 15 grade(HS-WS). After 7days of hindlimb suspension, soleus wet weight was 28. 57% smaller and relative soleus weight was 28. 21% smaller in comparison with con-trol rats (p〈0.05) Soleus wet weight and relative soleus weight increased by 67.72% and 71.43% each with periodic weight support activity during hindlimb suspension (p〈0.01, p〈0.005), moreover soleus wet weight and relative soleus weight of the HS -WS rats were greater than those of the control group. No change was observed in fiber type percentage of the developing soleus muscle after 1 week of hindlimb suspension plus weight support activity. Type I and II fiber cross-sectional areas of the developing soleus muscle were 50.45% and 43.39% lower in the HS group than in the control group (p〈0.0001), type I and II fiber cross-sectional areas of the developing soleus were 24.49% and 29.93% greater in the HS - WS group than in the HS rats (p〈0.0001), whereas Type I and II fiber cross-sectional areas of HS - WS group were less than those of the control group, The results suggest that periodic weight support activity can ameliorate developing soleus muscle atrophy induced by hindlimb suspension, even in type II fibers that would not have been expected to be recruited by this type of neuromuscular demand. Clinical experimental study is needed to deter-mine the effect of periodic weight bearing exercise on developing atrophied leg muscle based on these results.