• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2345-2347
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• 2000

ABS(Antilock Brake System) prevents the wheels from "locking" and improve "handling" during braking. Currently, safety and environmental issues are a major concern in the automotive industry. ABS has become the vital brake system. ABS is composed of sensors for wheel speed, a pressure modulator for controlling the brake pressures in the wheel brake cylinders, and an electronic control unit(ECU) which evaluates the signals from the wheel speed sensors and converts these to commands to control the pressure of modulator. In this paper, ECU developed for commercial vehicles is described. Detection of wheel slip, control algorithms of ABS, and diagnosis method of ECU are presented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.181-194
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• 2013

Landslides are known as gravitational mass movements that can carry the flow materials ranging in size from clay to boulders. The various types of landslides are differentiated by rate and depositional features. Indeed, flow characteristics are observed from very slow-moving landslides (e.g., mud slide and mud flow) to very fast-moving landslides (e.g., debris avalanches and debris flows). From a geomechanical point of view, shear-rate-dependent shear strength should be examined in landslides. This paper presents the design of advanced ring-shear apparatus to measure the undrained shear strength of debris flow materials in Korea. As updated from conventional ring-shear apparatus, this apparatus can evaluate the shear strength under different conditions of saturation, drainage and consolidation. We also briefly discussed on the ring shear apparatus for enforcing sealing and rotation control. For the materials with sands and gravels, an undrained ring-shear test was carried out simulating the undrained loading process that takes place in the pre-existing slip surface. We have observed typical evolution of shear strength that found in the literature. This paper presents the research background and expected results from the ring-shear apparatus. At high shear speed, a temporary liquefaction and grain-crushing occurred in the sliding zone may take an important role in the long-runout landslide motion. Strength in rheology can be also determined in post-failure dynamics using ring-shear apparatus and be utilized in debris flow mobility.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1349-1354
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• 2013

Sealing structure to prevent flowing hot gas into the driving device, located between the driving shaft and the liner of On-Off valve for controlling the hot gas flow path was studied. Wear occurs due to the constant movement of the driving shaft controlled by actuator on graphite as the sealing material. In this paper, the dynamic wear behavior in high temperature of graphite(HK-6) to be used as sealing material was evaluated. Reciprocating wear test was carried out for the graphite(HK-6) to the relative motion between shaft materials(W-25Re). The results of friction coefficient and specific wear rate according to contact load, sliding speed at room temperature and $485^{\circ}C$ considering the actual operating environment were evaluated. Through the SEM analysis of the worn surface, third body as lubricant films were observed and lubricant effect of third body was considered.

• Journal of Korean Home Economics Education Association
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• v.21 no.3
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• pp.1-28
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• 2009

The purpose of this research was to provide the information needed for improving the elderly housing education and the elderly housing contents of Technology and Home Economics textbook. Thus, the elderly housing contents of current Technology and Home Economics textbook were categorized. Then, a total of 233 teachers were surveyed to examine their importance perception on the elderly housing contents. Elderly housing contents were grouped into S categories, each of which was named 'safety and safety management', 'room plan for the elderly', 'shrinking stage in family life cycle and dependency stage in housing life cycle','a house for 3-generation extended family', and 'universal design'. Teachers' importance perception was generally high for 'safety and safety management' and especially for 'safety and safety management' of bathroom(protection against slippery floor, safety bar, the appropriate position and height of shower, bathtub, and wash stand) ; the basic guidelines of 'room plan for the elderly'(emergency call, closely located bathroom, flat and non-slippery floor) ; the general guidelines during shrinking stage in family life cycle and dependency stage in housing life cycle'(protection equipments against safety accident, emergency call, flat and non-slippery floor) ; independent life among 3-generation extended family members(bathroom for the elderly, space plan for independent life among extended family members) ; the basic design guidelines of universal design(safety bar in bathroom, flat floor) and the guidelines of universal design which were especially helpful for wheelchair users(enough empty space in front of door and in corridor, wide door and corridor). Recommendations for the elderly housing education and the elderly housing contents of Technology and Home Economics textbook were that 'emergency call','safety bar in bathroom' and 'flat and non-slippery floor' were the most basic guidelines for elderly housing; that 'enough empty space in front of door and in corridor', 'wide door and corridor', 'low and wide steps', 'ramp for wheelchair users' and 'D-type or lever-type door handle' were most recommendable guidelines for universal design; that 'need for elderly housing', 'types of elderly housing', 'alternatives and choices of dependency stage in housing life cycle' and 'house plans for shrinking stage in family life cycle' were required guidelines for increasing elderly-only family.

• Journal of Nutrition and Health
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• v.50 no.4
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• pp.402-414
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• 2017

Purpose: The purpose of the study was to evaluate the status of safety accidents and importance-performance analysis (IPA) between regular and non-regular employees in industry foodservices. Methods: The participants were regular employees (n = 119) and non-regular employees (n = 163) in industry foodservices in the Jeonbuk area. Demographic characteristics, status of safety accidents, safety education, and importance and performance status were assessed using a self-administered questionnaire. Results: Approximately 66.4% of regular employees and 53.4% of non-regular employees experienced safety accidents (p < 0.05). Types of safety accidents of regular and non-regular employees were mostly burns, and causes were mostly from their own negligence. Approximately 98.3% of regular employees and 95.1% of non-regular employees experienced safety education. Approximately 88.9% of regular employees and 96.8% of non-regular employees received safety education from dietitians. Approximately 41.9% of regular employees and 50.0% of non-regular employees had difficulty applying the contents of safety education due to lack of time during work. As a result of IPA, regular and non-regular employees were aware of the importance of the following and performed them well: 'Clean the floor of the work place', 'Arrange in the work area', 'Wear safety shoes', 'Check for heater cord', and 'Safety cooking when using oil'. On the other hand, they were not aware of the importance of the following and performed them insufficiently: 'Check for the MSDS', 'Aware of chemical signs', 'Wear protection gloves etc.', 'Do stretching exercise', and 'Using ancillary tools'. Conclusion: Therefore, it is necessary to improve the consciousness of dietitians for effective application of safety education contents, development of contents, especially MSDS, and related things.