• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.191-201
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• 1997

Accurate positioning of a throttle valve is required to implement the traction control system(TCS) which improves acceleration performance in slippery roads. In this research, position control system is developed for the main throttle actuator(MTA) system which uses one throttle actuation for small volume and DC servo motor for fast response. In order to drive DC motor, PWM signal generator and PWM amplifier were built and interfaced to the motor and controller. Digital PID control law is used as basic control algorithm. In order to prevent overshoot and improve accuracy, velocity profiles are generated and implemented whenever the targer throttle angle is given from the TCS controller. Thanks to velocity profiles, the control performance was very good and only one set of PID gains was used to cover the entire operating range. Also, the resolution of position is about 0.4$^{\circ}C$, which is better than that of stepping motor also used as throttle actuator in some products. The response time of the developed system is also fast enough to implement the engine control based TCS algorithm.

• Journal of Fashion Business
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• v.16 no.1
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• pp.41-51
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• 2012

Polyester is mainly used as a bedding filler material. PLA fiber as an eco-friendly material for substituting polyester has a low melting temperature and therefore a hardening process is impossible. This study is to develop the oil for feather touch that can treat at the melting temperature of PLA. The slippery and soft aminosilicone emulsion, and the bulky epoxysilicone emulsion were used. They had proper viscosity and particle size for flexibility and elasticity. When using methoxy aminosilane [$H_2NSi(OCH_3)_3$] as an aminosilane and [$Zn(OCOCH_3)_2$] as a catalyst, the hardening reaction was fast and effective. Feather touch process were treated by 2 steps. At first step, aminosilicone emulsion, epoxysilicone emulsion and methylaminosilane were mixed and homogenized, and at second step, 5% blened solution of the first step, Zn catalyst 1%, distilled water 94% were treated at PLA fiber. After treatment the static friction coefficient and dynamic friction coefficient were reduced to 23.5-60.8% and 30.0-61.3% respectively, and the laundry and sun light fastnesses have not shown any decrease.

• Safety and Health at Work
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• v.9 no.2
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• pp.180-183
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• 2018

Background: This research investigates the degrees of slipperiness felt by the participants who walk on contaminants applied to a floor surface to decide degrees of slipperiness for various contaminants. Methods: For the experiment, 30 participants walked on a floor to which six contaminants were applied. All participants took the analytic hierarchy process (AHP)-based slipperiness questionnaire survey for the six kinds of contaminants, and the results were compared with the coefficient of friction. Results: The results of slip risk from the AHP indicate that grease is the most slippery of the six contaminants, followed by diesel engine oil, hydraulic oil, cooking oil, water-soluble cutting oil, and water in a decreasing order of slipperiness. When the results of slip risk from the AHP are compared with the static coefficient of friction for each contaminant, the order of slip risk follows the same trend. Although the results of slip risk from the AHP coincide with the static coefficient of friction, further study would be needed to investigate this relationship. Conclusion: This study will contribute as reference material for future research on preventing industrial accidents that result in falls from high places due to slipping.

• Journal of the Korean housing association
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• v.18 no.2
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• pp.1-9
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• 2007

This survey on the housing consumers in the Daegu region aims to understand their needs for differentiating design items, which are now regarded to be essential factors to take the lead in the apartment housing market. The survey questionnaires on the differentiating items in six categories, were filled by 135 apartment households in Deagu, and the answers on each item were analyzed according to their home size and age. For the general apartment plan, the strongest need was found in the energy saving design; and larger windows for a fine view are significantly favored by the older households. For the unit design, more households were interested in the design items related to the kitchen or subsidiary-kitchens. For the storage space design, enough space for ampler storage was desired the most. For the interior design, prevailing needs for the use of environment-friendly furnishing materials and the non-slippery flooring of bathroom were found. For facilities and up-to-date system design, most of households displayed their interests in noise-proof doors. For the environment design of the complex, the need for a walk passage was highest in general.

• Korean Journal of Bronchoesophagology
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• v.7 no.1
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• pp.14-18
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• 2001

Background and Objectives： Vegetable Foreign bodies (VFB) in the bronchial tree may be complicated by fragmentation, slippage and impaction during the removal with forceps. This study is to evaluate the safety and efficacy for the technique of removing VFB from the bronchial tree in infants and early childhood using Fogarty balloon catheter. Materials and methods : The subjects consisted of 18 infants and early childhood (7-22 months old) with VFB in the bronchial tree from January 1991 through October 1998. The authors first attempted removal of VFB with forceps and if that failed, removed VFB with Fogarty arterial embolectomy catheter under the ventilating bronchoscopy and general anesthesia. Results: We removed 6 VFB with forceps. could not remove anymore, and so removed 12 VFB with Fogarty catheter. In 8 VFB of less than 24 hours, we could remove 6 VFB with forceps and 2 VFB which could not be removed with forceps were removed with Fogarty catheter. In 10 VFB of more than 24 hours, we could not remove with forceps and removed with Fogarty catheter. Conclusions : VFB in the bronchial tree of infants and early childhood can usually be removed with forceps. But we think that Fogarty balloon catheter technique is a easy, safe method for the removal of bronchial VFB of more than 24 hours, fragmentation, impaction, lower bronchus and too round or slippery to remove with forceps in infants and early childhood.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.106-109
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• 2005

The awareness of ecological friendliness has been emerging in the recent years, and the application to housing is quite notable. The purpose of this study was to examine multi-family housing that has recently developed with the idea of ecological friendliness, and to investigate the residents' attitudes toward and their preferences for the features. The research utilized in-depth interviews and site visits, and seven residents in the studied housing developments participated in the study. The analytical tool used in the interview was reviewed by a panel of professionals and included five aspects of ecologically friendliness: residential comfort, energy saving, open housing, storage, and safety and security. The respondents pointed out that south-facing housing in relation to residential comfort was most favorable. With regard to energy-saving, water-saving features and dehydrator of food waste were most needed features. As for open housing-related features, flexibility in spatial configuration was necessary, and efficient storage was regarded as important. Also, the respondents mentioned the preference for flooring preventing slippery in bathroom for the safety of family member.

• Safety and Health at Work
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• v.9 no.1
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• pp.17-24
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• 2018

Background: Increasing the slip resistance of floor surfaces would be desirable, but there is a lack of evidence on whether traction properties are linearly correlated with the topographic features of the floor surfaces or what scales of surface roughness are required to effectively control the slipperiness of floors. Objective: This study expands on earlier findings on the effects of floor surface finishes against slip resistance performance and determines the operative ranges of floor surface roughness for optimal slip resistance controls under different risk levels of walking environments. Methods: Dynamic friction tests were conducted among three shoes and nine floor specimens under wet and oily environments and compared with a soapy environment. Results: The test results showed the significant effects of floor surface roughness on slip resistance performance against all the lubricated environments. Compared with the floor-type effect, the shoe-type effect on slip resistance performance was insignificant against the highly polluted environments. The study outcomes also indicated that the oily environment required rougher surface finishes than the wet and soapy ones in their lower boundary ranges of floor surface roughness. Conclusion: The results of this study with previous findings confirm that floor surface finishes require different levels of surface coarseness for different types of environmental conditions to effectively manage slippery walking environments. Collected data on operative ranges of floor surface roughness seem to be a valuable tool to develop practical design information and standards for floor surface finishes to efficiently prevent pedestrian fall incidents.

• Korean Journal of Metals and Materials
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• v.50 no.8
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• pp.591-597
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• 2012

This paper presents regularly micro-textured glass surfaces ensuring the superhydrophobic properties in the Cassie-Baxter regime. The proposed surfaces were fabricated simply and efficiently by filling the glass material into a silicon micro-mold with periodic micro-cavities based on a thermal-reflow process, resulting in a successful demonstration of the textured glass surface with periodically-arrayed micro-pillar structures. The static and dynamic wetting properties of the micro-textured glass surfaces were characterized by measuring the static contact angle (SCA) and contact angle hysteresis (CAH), respectively. In addition, the surface wettability was estimated theoretically based on Wenzel and Cassie-Baxter wetting theories, and compared with the experimental ones. Through the experimental and theoretical observations, it was clearly confirmed that the proposed micro-textured glass surfaces showed the slippery superhydrophobic behaviors in the Cassie-Baxter wetting mode.

• The Journal of Korea Robotics Society
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• v.17 no.2
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• pp.238-244
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• 2022

Maintenance works of offshore wind turbines could take a longer time, which causes the reduction of their energy production efficiency, than those of onshore wind turbines owing to severe offshore environment. Subsequently, preventive maintenance measures are required to increase the production efficiency. Thus, we proposed a wheel-based Underwater Pole Climbing Robot (UPCR) platform, which was aimed at the periodic inspection and maintenance of the substructures of the offshore wind turbines, with three advantages: high speed, good mobility and low power consumption. In the proposed platform, a self-locking system using a gripper module was adopted for preventing slippery problem and a dual configuration was chosen for moving on a branched structure. As a result, the proposed robot was able to continuously climb, preserve it's position at the pole without consuming energy, and move from the pole to the other branched pole. The results of this research show that the UPCR has basic moving capabilities required for the underwater work for the substructures of the offshore wind turbines.

• ETRI Journal
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• v.44 no.4
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• pp.641-653
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• 2022

In the process of autonomous vehicle motion planning and to create comfort for vehicle occupants, factors that must be considered are the vehicle's safety features and the road's slipperiness and smoothness. In this paper, we build a mathematical model based on the combination of a genetic algorithm and a neural network to offer lane-change solutions of autonomous vehicles, focusing on human vehicle control skills. Traditional moving planning methods often use vehicle kinematic and dynamic constraints when creating lane-change trajectories for autonomous vehicles. When comparing this generated trajectory with a man-generated moving trajectory, however, there is in fact a significant difference. Therefore, to draw the optimal factors from the actual driver's lane-change operations, the solution in this paper builds the training data set for the moving planning process with lane change operation by humans with optimal elements. The simulation results are performed in a MATLAB simulation environment to demonstrate that the proposed solution operates effectively with optimal points such as operator maneuvers and improved comfort for passengers as well as creating a smooth and slippery lane-change trajectory.