• Journal of Biomedical Engineering Research
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• v.30 no.5
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• pp.381-392
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• 2009

Due to the aging effect, older people have relatively weaker muscular performance, less range of motion in the joint articulation, and the lower sense of equilibrium than younger people. These factors attribute to their slow and clumsy ingress/egress motion. In order to analyze ingress/egress motion strategy of the elderly, healthy thirty 65 or more years old volunteers were recruited. The health condition of the each volunteer was verified by the medical checkup and also their physical capabilities were quantified by six fitness tests. Through the video analysis, older driver's ingress/egress motion strategies were classified and statistically investigated. For a comparison purpose, another thirty young volunteers also participated in the same test protocol and their ingress/egress motion strategies were also included in the statistical analysis.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.40-46
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• 2010

DC link electrolytic capacitors are widely used in various PWM power converter system, such as adjustable speed driver(ASD) or DC/DC converter. Electrolytic capacitors, which is the most of the time affected by aging effect, plays a very important role for the power electronics system quality and reliability. This objective of this paper is to propose a improvement method to detect the rise of equivalent series resistor(ESR) in order to realize the online failure prediction of electrolytic capacitor for DC link of PWM power converter. The ESR detection scheme is based on the determination of the electrolytic capacitor AC losses calculated from voltage/current measurement using AC coupling. Therefore, the preposed online failure prediction method has the merits of easy ESR computation and circuit simplicity compare with BPF method. Simulation results show the veridity of the proposed on-line ESR estimation method.

• Journal of the Korean Society of Safety
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• v.32 no.6
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• pp.22-28
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• 2017

According to the National Fire Data System (NFDS), more than 5,000 vehicle fires have occurred every year for the last 10 years. Vehicle fires are primarily caused by mechanical (breaking system and engine), electrical (wiring and battery), and chemical (oil and fuel gas leakage) problems. The electrical factor has increased with the installation of driver convenience equipment. For example, today, the black box is widely used to provide video data recording of motor vehicle accidents. The black box consists of a front camera, rear camera, and wires. The black box wires are directly connected to the junction box or fuse box from the start battery that operates to provide normal on power supplying for engine stop. It is extremely dangerous when the wires short circuit due to insulation aging, mechanical and electrical stress, etc. In this study, the black box wiring fire risk have been analyzed and investigated when the steady state and abnormal operations, and under the following conditions: wiring arrangements with a high temperature condition, insulation aging, poor contact, and short circuits. The results showed that black box wiring short circuits had a higher fire risk than the other fire hazard elements. To prevent fire hazards caused by black box wiring, the black boxes must be installed by qualified service personnel. Do not modify the wiring, remove the fuse and secure the wiring using cable ties or insulation tape.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.94-102
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• 2012

Recently entered into an aging socity as the number of elderly drivers is increasing. Traffic accidents of elderly drivers are caused by driver inattentions such as poor vehicle control due to aging, visual information retrieval problems caused by presbyopia, and objects identifying problems caused by low contrast sensitivity. In this paper, detection method of ROIs on the road is proposed. The proposed method creates the saliency map to detect the candidate ROIs from the input image. And, the input image is segmented to obtain the ROIs boundary. Finally, selective visual attention regions are detected according to the presence or absence of a segmented region with saliency pixels. Experimental results from a variety of outdoor environmental conditions, the proposed method presented a fast object detection and a high detection rate.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.235-242
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• 2008

Due to the lack of judgement in an information processing on road sign, older drivers usually are having a hard time driving than young group. Furthermore, according to increasing in aging population, older drivers in Korea have been growing much faster. That means research for older drivers' characteristics and the number of guide name for road sign should be needed. In accordance with suggestions, this study was carried out the number of guide names for road sign with a variety of ages from the twenties to the seventies. For the sake of this study, statistical verification was conducted to confirm a change of speed, a reading time and a misreading rate with Driving Simulator and Electrooculogram tool. As the results of study, change of speed in the age range has shown that the higher the proportion of age, the lower the rate of velocity. Also reading time in the age range with regression analysis found that the higher the proportion of age, the higher the rate of reading time by 0.106sec. Finally, a binary logistic model was used to find the main factors. As the results, 4 number of guide names for road sign have been the best of them for older driver. The result of this study verified the importance of ideal guide numbers on road sign for older driver and proved itself to be an effective method to determine the road safety for the road signs.

• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.141-150
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• 2017

A rapid increase in traffic accidents involving senior vehicle occupants has been an issue in Korea because of the aging of the population occurring at one of the fastest rates in the world; unfortunately, few studies beyond several looking at the effect of senior occupants on the level of accident injury severity can be found in the literature. A Multinomial logit model was estimated with Newton-Raphson algorithm to perform bias-reducing penalized likelihood optimization. Model covariates integral to developing the model were included, but the main focus was on the interaction of seating position and injury to senior vehicle occupants. It was found that the likelihood of an accident resulting in a fatality increased: 2.2 times for the driver seat, 2.7 times for the front passenger seat, and even 6.7 times for the rear seat. A mandatory seatbelt law to be extended to the rear seat needs to pass the assembly as soon as possible, and government, industry, and safety groups should be encouraged to join forces to strongly carry out targeted campaigns for the wearing of seatbelts in all vehicle seats to enhance the safety of senior occupants as well as other occupants who are vulnerable to road traffic accidents.

• Journal of the Korea Safety Management & Science
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• v.20 no.3
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• pp.21-26
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• 2018

This paper describes result of a study on safety against a fire of charging cable for mobile phone for vehicle. Combustion on the USB cable in the car was happened while driving. Gas coming from the burning USB cable could be a reason which can make a secondary car accident since the driver also can be embarrassed while driving. In order to prevent a secondary car accident connected on the road, to research a reason why USB cable can emit gas and be burned in charging. We did simulation test with abnormal fault condition for the electronic component on the board in the USB cable. So we get the result from abnormal fault condition simulation test, for instance, shorted test for output terminal of 8 pin switch, shorted test for chip resistor after thermal aging in the condition $25^{\circ}C$, 93 % RH during 48 hours. To analysis the result of all test, Combustion on the USB cable was not the 8 pin but other electrical component such as a chip resistor. Therefore we guess that the reason for USB cable combustion in charging in a car was not 8 pin and a LED but another defective component.

• Biomolecules & Therapeutics
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• v.30 no.5
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• pp.391-398
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• 2022

Polyploidization is a process by which cells are induced to possess more than two sets of chromosomes. Although polyploidization is not frequent in mammals, it is closely associated with development and differentiation of specific tissues and organs. The liver is one of the mammalian organs that displays ploidy dynamics in physiological homeostasis during its development. The ratio of polyploid hepatocytes increases significantly in response to hepatic injury from aging, viral infection, iron overload, surgical resection, or metabolic overload, such as that from non-alcoholic fatty liver diseases (NAFLDs). One of the unique features of NAFLD is the marked heterogeneity of hepatocyte nuclear size, which is strongly associated with an adverse liver-related outcome, such as hepatocellular carcinoma, liver transplantation, and liver-related death. Thus, hepatic polyploidization has been suggested as a potential driver in the progression of NAFLDs that are involved in the control of the multiple pathogenicity of the diseases. However, the importance of polyploidy in diverse pathophysiological contexts remains elusive. Recently, several studies reported successful improvement of symptoms of NAFLDs by reducing pathological polyploidy or by controlling cell cycle progression in animal models, suggesting that better understanding the mechanisms of pathological hepatic polyploidy may provide insights into the treatment of hepatic disorders.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.560-567
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• 2019

South Korea, which has entered an aged society, is about to enter a super-aged society in 2025. With the increase of an aging population, traffic accidents by aged drivers have been settled as a social problem. Now, when Korea is facing a super-aged society to come, a study was conducted to prevent traffic accidents that occur while the elderly people are driving through a disaster prevention design. For theoretical research, this study examined the concept and necessity of disaster prevention design, the present condition of an aged society, aged drivers' physical and cognitive characteristics, and the policies related to the forms of traffic lights the elderly people see. In addition, to propose the design, this study investigated and analyzed the traffic safety forms and colors of the International Standards Organization and proposed the first and second forms of the design of traffic lights for the gradual improvement of the traffic lights based on that. The first improved design form is a plan for displaying a triangle, an arrow with a large area, and a quadrangle in the lens of the head of the existing traffic lights, and the second improved design form is a plan for introducing a new traffic light head and forming the traffic light with a bigger triangle, an arrow with a large area and a quadrangular lens. Since it has a visually clearer form than the present traffic lights, it is expected that aged drivers who have physical and cognitive characteristics due to aging can secure better visibility and conspicuity and that they can make better reflex responses than they can now, also in the change of driving environment (rain and heavy snowstorm, etc.). In addition, it is expected that this study would be a preceding study to prepare standard guidelines on traffic safety signs other than traffic lights to be prepared for the super-aged society.

• Journal of Korean Society of Transportation
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• v.30 no.4
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• pp.61-70
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• 2012

This research explores different non-work trip characteristics between the elderly group (65+) and the working age group (20-64) using heteroscadastic ordered logit model. The analysis is based on travel survey data of Seoul Metropolitan area in 2006. The results show that age induces heteroscadasticity and the model provides a better fit than ordered logit model. The factors increasing the number of non-work trip of the elderly were driver's license and household income. Conversely, the number of non-work trips decreased in those groups that were male, with a job, in aging, and with the number of preschool children. The factors having opposite effects (increased the number of non-work trips in the working age groups and decreased in the elderly group) between the elderly group and working age group were age and job.