• Journal of the Ergonomics Society of Korea
• /
• v.31 no.1
• /
• pp.177-183
• /
• 2012

Objectives: The objectives of this study are to discuss the importance of job stress and to introduce a model of job stress at the shipbuilding industry considering the characteristics of the shipbuilding works. Background: Shipbuilding works consist of grinding, painting, interior works, welding, and assembling and using heavy equipment in narrow space or work at outside or at high and dangerous places. The working environments aggravate the stress to the workers. Methods: Studies of job stress in industries including shipbuilding industries were reviewed and the characteristics of jobs of shipbuilding were analyzed to find causes of job stress. Results: A model was constructed based upon these findings and reviews. Conclusions: Job stress of shipbuilding workers are very high and thus job and working conditions need to be improved to attenuate the level of job stress of shipbuilding workers. Applications: This model can be used to identify the highly stressed workers and sources of stress.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.113-113
• /
• 2003

Four main factors, cling force, wicking force, water retention and water transport, affecting the clinginess of the sportswear fabric have been identified and measured by combining a new equipment and a statistical analysis. A classification model based on those factors has been developed in order to evaluate and standardize fabric wear comforts during heavy physical acting. Ten sportswear fabrics assumed different in their wear characteristics have been employed to investigate the relationship between the measurements and actual performance. It has been shown that the subjective evaluation ratings were well agreed with the measurement.

• IE interfaces
• /
• v.23 no.3
• /
• pp.213-220
• /
• 2010

As the market becomes increasingly globalized and competition among companies increases in severity, various specialized organizations are participating across the process plant lifecycle, including the stages of design, construction, operation and maintenance, and dismantlement, in order to ensure efficiency and elevate competitiveness. In this regard, it is an important technical issue to develop services or information systems for sharing process plant data among participating organizations. ISO 15926 is an international standard for integration of lifecycle data for process plants including oil and gas facilities. ISO 15926 Part 7, a part of the ISO 15926 standard, specifies an implementation method called a facade that uses Web Services and ontology technologies for constructing plant data repositories and related services, with the aim of sharing lifecycle data of process plants. This paper discusses the ISO 15926-based prototype facade implemented for storing equipment data of nuclear power plants and servicing the data to interested organizations.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.2
• /
• pp.142-147
• /
• 2009

Conventional HP(high pressure) sodium or Metal-halide lamps have a life span of around one year requiring at least annual replacement and maintenance. High Power LED lights require no regular maintenance further increasing savings on replacement bulbs, access equipment and labour costs. New installations benefit from a substantial reduction in the cost of expensive heavy duty cable required for sodium lighting. Especially, LED light can achieve variable color temperature, high functional performance in the field of street light. There are two main method to achieve variable color temperature function of the street light. one method is using RGB multi-chip LED, the other is using Orange-White LED method. In this paper, it was compare RGB Multi-chip LED with white-orange LED for there characteristics performance.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.5
• /
• pp.646-652
• /
• 2013

PRA(Position Reporting Accuracy) for EO/IR(Electro-Optic/Infrared) airborne camera is an important factor in geo-pointing accuracy. Generally, rate table is used to measure PRA of gimbal actuated camera like EO/IR. However, it is not always possible to fix an EUT(Equipment for Under Test) to rate table due to capacity limit of the table on the size and weight of the object(EUT). Our EO/IR is too big and heavy to emplace on it. Therefore, we propose a new verification method of PRA for airborne camera and assess the validity of our proposition. In this method we use collimator, angle measuring instrument, 6 dof motion simulator, optical surface plate, leveling laser, inclinometer and poster(for alignment).

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.5
• /
• pp.538-544
• /
• 2012

In this paper, design optimization of C-frame of a precision drilling and autorivet machine has been performed. The machine, Autoriveter has been developed by Korea Aerospace Industry (KAI), For current autoriveter, it is hard to achieve high efficiency because of heavy weight of the machine. In this paper, we suggest new structure of the current C-frame, a part of autoriveter, by optimization. The result of the study can give much profit for mass-production of the machine.

• Structural Monitoring and Maintenance
• /
• v.7 no.1
• /
• pp.43-58
• /
• 2020

Pile foundations of existing bridges lie in soil and water environment for long term and endure relatively heavy vertical loads, thus prone to damages, especially after stricken by external forces, such as earthquake, collision, soil heap load and etc., and the piles may be injured to certain degrees as well. There is a relatively complete technical system for quality inspection of new bridge pile foundations without structures on the top. However, there is no mature technical standard in the engineering community for the non-destructive testing technology specific to the existing bridge pile foundations. The quality of bridge pile foundations has always been a major problem that plagues bridge maintenance. On the basis of many years' experiences in test engineering and theoretical studies, this study developed a new type of detection technology and equipment for the existing bridge piles.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.10b
• /
• pp.90-93
• /
• 2003

Forging machinery traditionally gives an impression of heavy, greasy, noisy and approximate equipment. Recent demands from markets, especially automobile, have made machine designers to reconsider their concept. It is also noted that more advanced technologies in other industries, such as electronics and IT, have become accessible. Naturally these technologies were first applied in highly sophisticated fields for additional performance or features with extra expense. Drastic cost reduction in last decade changes this picture. They provide not only performance and functions but also a chance in reducing costs. Powerful servomotors, accurate sensors and fast processor satisfy performance, precision and machine control requirement. Control by wires replaces traditional mechanical linkage. Additional features such as factory automation will come almost free.

• Journal of Institute of Control, Robotics and Systems
• /
• v.11 no.11
• /
• pp.936-942
• /
• 2005

Recently the exoskeletal power assistive equipment which is a kind of wearable robot has been widely developed to help the human body motion. For the elderly people and patients, however, some limits exist due to the weight and volume of the equipments. As a feasible solution, a tendon-driven exoskeletal power assistive device fur the lower body, and caster walker are proposed in this research. Since the caster walker carries the heavy items, the weight and volume of the wearable exoskeleton are minimized. The key control is used to generate the joint torque required to assist motions such as sitting, standing and walking. Experiments were performed for several motions and the EMG sensors were used to measure the magnitude of assistance. When the motion of sitting down and standing up was compared with and without wearing the proposed device, the $25\%$ assistance was acquired.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.2071-2075
• /
• 2005

Hydraulic excavators have been popular devices in construction field because of its multi-workings and economic efficiency. The mathematical models of excavators have many nonlinearities because of nonlinear opening characteristics and dead zone of main control valve, oil temperature variation, etc. The objective of this paper is to develop a simulator for hydraulic excavator using AMESim. Components and whole circuit are expressed graphically. Parameters and nonlinear characteristics are inputted in text style. The simulator can be used to forecast excavator behavior when new components, new mechanical attachments, hydraulic circuit changes, and new control algorithm are applied. The simulator could be a kind of development platform for various new excavators.