• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.708-715
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• 2014

In this paper, we suggest a method of realtime confidence interval estimation to detect abnormal states of sensor data. For realtime confidence interval estimation, the mean square errors of the exponential smoothing method and moving average method, two of the time series analysis method, where compared, and the moving average method with less errors was applied. When the sensor data passes the bounds of the confidence interval estimation, the administrator is notified through alarming. As the suggested method is for realtime anomaly detection in a ship, an Android terminal was adopted for better communication between the wireless sensor network and users. For safe navigation, an administrator can make decisions promptly and accurately upon emergency situation in a ship by referring to the anomaly detection information through realtime confidence interval estimation.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.314-320
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• 2024

Objectives: This study aimed to identify the prevalence of falls in community-dwelling older adults and to identify associated factors using the 2019 Community Health Survey. Methods: The original data was from the 2019 Community Health Survey, and the study sample comprised 1,642 older adults aged 65 years and older in Jeju province. Data collection was conducted from August 16 to November 20, 2019, through an interview done by a trained investigator. Respondents were queried about demographic characteristics, riding bicycles, hospital treatment due to an accident or poisoning in the previous year, fall experiences in the past year, fear of falling, self-management status, and pain and discomfort. Multivariate logistic regression analysis was used to evaluate for associations between potential risk factors and falls. Results: The prevalence of falls in this community-dwelling older adults was 13.1%. Falls were associated with riding bicycles (odds ratio = 4.7; 95% confidence interval: 2.26-9.81), fear of falling (odds ratio = 0.3; 95% confidence interval: 0.24-0.49), hospital treatment due to an accident or poisoning in the previous year (odds ratio = 7.8; 95% confidence interval: 5.02-12.19), self-management status (odds ratio = 0.6; 95% confidence interval: 0.34-0.89), and pain and discomfort (odds ratio = 0.6; 95% confidence interval: 0.40-0.87). Conclusions: We found that the prevalence of approximately about 13% of older adults living in a community has experienced falls. Based on the results of the study, we provided primary data to develop the care management intervention program to prevent falls and avoid risk factors that cause falls in community-dwelling older adults.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.229-235
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• 2008

Lack of honey bee toxicity data for most pesticide products used for strawberry restricts to predict the adverse effects to foraging honey bee after treatment of pesticide in plastic house. This study was conducted to evaluate the actual risk of worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test and toxicity of residues on foliage test with 21 pesticide products. The mortality of honeybee sprayed with 6 pesticides including dichlofluanid WP showed significantly different from control at recommended application rate in acute contact toxicity test at 24 hours after treatment. Fenpropathrin EC and milbemectin EC treatment groups showed more than 25% mortalities at recommended application rate in acute oral toxicity test. In toxicity of residues on foliage test, only fenpropathrin EC treatment group showed more than 25% mortalities at 10 days after treatment at recommended application rate. It was concluded that the most toxic route to exposure for honey bee is direct contact exposure to sprayed pesticides. Safety interval for honey bee was established by concerning the results of these tests.

• Safety and Health at Work
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• v.7 no.3
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• pp.231-236
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• 2016

Background: To analyze the effects of the factors associated with different types of injury (superficial wounds, dislocations and sprains, bone fractures, concussion and internal injuries, burns scalding and freezing) caused by occupational accidents in automotive repair workshops. Methods: Study of a sample consisting of 89,954 industry accidents reported from 2003 to 2008. Odds ratios were calculated with a 95% confidence interval. Results: Belonging to a small company is a risk factor for suffering three of the five types of injury studied. Women are less likely to suffer burns and superficial wounds, and more likely to suffer dislocations or sprains. Foreign workers are more likely to suffer concussion and internal injuries. Conclusion: Health and safety strategies and accident prevention measures should be individualized and adapted to the type of worker most likely to be injured in each type of accident. Occupational health and safety training courses designed according to worker profile, and improving the participation of the workers in small firms creating regional or roving safety representatives would improve working conditions.

• Journal of Mechanical Science and Technology
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• v.20 no.9
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• pp.1418-1427
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• 2006

Windshield wipers play a key role in assuring the driver's safety during precipitation. The traditional wiper systems, however, requires driver's constant attention in adjusting the wiper speed and the intermittent wiper interval because the amount of precipitation on the windshield constantly varies according to time and vehicle's speed. Because the manual adjustment of the wiper distracts driver's attention, which may be a direct cause of traffic accidents, many companies have developed automatic wiper systems using some optical sensors with various levels of success. This paper presents the development of vision-based smart windshield wiper system that can automatically adjust its speed and intermittent interval according to the amount of water drops on the windshield. The system employs various image processing algorithms to detect water drops and fuzzy logic to determine the speed and the interval of the wiper.

• Journal of the Korean Institute of Rural Architecture
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• v.20 no.1
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• pp.45-52
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• 2018

The purpose of this study is to investigate safety and dangerous awareness of environment on walking trails. For this purpose, questionnaire survey are carried out by people who had experience using walking trails during 2016. It is evaluated that environments of walking trails located inside big cities are inferior than ones located in small and medium-sized cities and countryside in air pollution, bed smell, water pollution, noise, and waste. Needs about management and number installed public restroom are high for hygienic environment of walking trails. With waste treatment, users of 2.4 percentage are showed improper behavior that they left their rubbish at the place out of view but others bring their trash. Accident likelihood is highly appreciated and possibility of physical accident like slipping is showed at the highest. The reasons of accident on walking trails are responded with carelessness of walkers and improper of installation or management of safety facility at the most. For safety environment of walking trails, needs of installation of safety fences and notices of dangerous area are requested. In order to separate prevention from paths of walking trails, signposts are needed at visual clearness, maintenance, installation with proper interval and location, and correct contents. Respondents of 2.4 percentage have experiences of accident on walking trails and physical accident like slipping is occurred at the most.

• New & Renewable Energy
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• v.16 no.4
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• pp.49-64
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• 2020

Photovoltaic and Thermal collector (PV/T) systems are renewable energy devices that can produce electricity and heat energy simultaneously using solar panels and heat exchangers. Since PV/T systems are exposed to the outdoors, their reliability is affected by various environmental factors. This paper presents a reliability test for a PV/T system and evaluates the test results. The reliability assessment entails performance, environment, safety, and life tests. The factor that had the greatest influence on the life of the system was the hydraulic pressure applied to the heat exchanger. A test was conducted by repeatedly applying pressure to the PV/T system, and a reliability analysis was conducted based on the test results. As a result, the shape parameter (β) value of 5.6658 and the B10life 308,577 cycles at the lower 95% confidence interval were obtained.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1694-1699
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• 2003

A windshield wiper system plays a key part in assuring the driver's safety during the rainfall. However, because the quantity of rain and snow vary irregularly according to time and the velocity of the automobile, a driver changes wiper speed and interval from time to time to secure enough visual field in the traditional windshield wiper system. Because a manual operation of windshield wiper distracts driver's sensitivity and causes inadvertent driving, this is becoming a direct cause of traffic accidents. Therefore, this paper presents the basic architecture of a vision-based smart windshield wiper system and a rain sensing algorithm that regulates speed and interval of the windshield wiper automatically according to the quantity of rain or snow. This paper also introduces a fuzzy wiper control algorithm based on human's expertise, and evaluates the performance of the suggested algorithm in an experimental simulator.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.10-10
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• 2018

• Journal of Biosystems Engineering
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• v.21 no.2
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• pp.155-166
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• 1996

A direct injection sprayer was designed using the concepts of injection mixing and total flow control, flowrate-based system compensating for the variation of forwarding speed. A metered rate, proportionally to the actual diluent flow rate, of a tracer chemical was injected directly into the diluent stream. The injection of chemical may improve the precision and safety of chemical application process. The control system was evaluated for the variables of the control interval, tolerances and sensitivities of flow regulation valve and injection pump. Performance of the system was assessed as that the response time of flow rate, response time of injection rate, absolute steady state error, and the coefficient of variance(C.V.) of concentration were 8.5 and -0.53 seconds, 0.067 lpm(0.8%) and 3.15%, respectively, at optimal parameters of control interval of 1.0 sec, fast sensitivity of flow regulation valve, medium sensitivity of injection pump and medium tolerance of flow rate. Performance of the system can be improved by increasing the sensitivity of flow regulating valve and employing a high resolution velocimeter, such as Doppler radar.