• Journal of Drive and Control
• /
• v.17 no.4
• /
• pp.15-22
• /
• 2020

With the need for efficient maintenance technology to reduce maintenance costs for steel bridges, repainting robots are being developed to automate the work in narrow and poor bridge spaces. The repainting robot is equipped with a blasting module to remove paint layers and contaminants. This study developed a prototype monitoring module to be mounted on the repainting robot. The monitoring module analyzes the condition of the painting surface through a camera installed in the front, guides the direction of movement of the robot, and provides the operator with a video to check the working status after blasting through a camera installed in the back. Various image visibility enhancement technologies were applied to the monitoring module to overcome worksite challenges where incomplete lighting and dust occurs.

• Journal of the Korea Society for Simulation
• /
• v.18 no.3
• /
• pp.147-154
• /
• 2009

In this study we investigate the problem of reducing color change cost at painting operations in an automobile assembly plant. Changing control logic at conveyor junction points prior to the top coat line has been proposed and analyzed using the discrete event simulation model we developed using AutoMod. We also discussed the project which initiated this research as well as the details of painting operations. Simulation analysis showed that the grouping ratio increases from 1.8 to 2.5 if the proposed control logic change is applied to the plant. Contrary to other approaches such as using dedicated equipment for resequencing, our approach has the merit of less investment cost, no need for additional space consumption. We finally note that the grouping ratio can be further increased if our algorithms is implemented as well as CRS (Color Rescheduling Storage) is installed.

• 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 SAREK Conference
• /
• 2009.06a
• /
• pp.248-253
• /
• 2009

For the energy's effective utilization, the mixed humidifier has been developed and popularized by combining the cooling dehumidifier with the desiccant humidifier properly. This has contributed in many ways to the industry. Hybrid Desiccant Dehumidifier that would be shown in this study could be indispensible in site due to the reduced equipment, with more than 50% reduction in energy.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2001.11a
• /
• pp.130-135
• /
• 2001

In this study, I have researched into the causes of defects in apartment house, The results of this study are listed below. (1) Water leakages which result from land sinking and cracks, results of misuse of back filling method, are the main reason of defects in civil engineering work and architectural work. (2) Inexperience and unwillingness are the main reason of defects in plaster work. (3) In windows work and painting work, the main reasons are lacks of precision construction and efflorescence resulting from outdoor air, respectively. (4) Defects in waterproofing work and electric work result from fault construction by low unit Costs. (5) Equipment work requires uses of standardized construction materials and management, and landscape architecture work requires minimizing human mistakes, for instance, degin carelessness. For the reasons stated above, the causes of defects in apartment house are insufficient construction labors, inferior construction materials, urgent construction process time, and conscientiousless industrialists who only seek after a profit margin.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.2
• /
• pp.85-91
• /
• 2011

Many protection methods such as surface coating, electric protection, or other methods have been applied to the numerous steel structures widely used in continental and marine areas to control their corrosion, which is done from an economic point of view. Most of these steel structures are primarily protected by coating methods. However, some steel piles under seawater are protected by the electric protection method, that is, either using an impressed current or a sacrificial anode method. Furthermore, environmental contamination may cause a severely corrosive environment, which, in turn, causes the accelerated corrosion of steel structures. Subsequently, coated steel structures could deteriorate more rapidly than the designed lifetime because of the acid rain caused by air pollution, etc. Therefore, a coating of marine paint exposed to seawater, that is, underwater hardening painting, is increasingly required to be fast drying as well as highly corrosion resistant. In this study, five types of underwater hardening paints were prepared with different resin series and additives. Their corrosion and water resistances were investigated using electrochemical methods such as corrosion potential, polarization curves, impedance and cyclic voltammogram measurements, etc. Even though it is generally accepted that the corrosion resistance of bare steel tends to increase with a shift of the corrosion potential in the noble direction, the corrosion resistance of a sample with a coating exhibited a relatively better tendency when it had a lower corrosion potential in this study. The corrosion current density was also decreased with a decrease in the diffusion limiting current density, which may mean that there is some relationship between corrosion and water resistance. The S sample of the ceramic resin series showed the relatively best corrosion and water resistance among those of samples, while the worst corrosion and water resistance were observed for the R sample of the epoxy resin series. The corrosion and water resistance of those samples tended to deteriorate with an increase in the immersion days, and their corrosion and water resistances were considered to be apparently improved by the types of resin and additives.

• Archives of design research
• /
• v.13 no.4
• /
• pp.233-242
• /
• 2000

The traditional image of hydraulic excavator started to change in two ways since 1990. First, post-heavy equipment's visual image was new waves to traditional image of heavy, strong, and wild. They are the negative aspect that excavators have. Another movement of getting rid of its negative image can be found in late-heavy equipment, which was intended to adapt traditional and positive, but off negative images. In 1990s, the design trend is moving from warm/hard to warm/soft, and KOBELCO can be exceptional example that went even further, gone up to cool-soft image. KOBELCO specially aimed 'post- excavator image' strategy, which has been successful. Image of cabin as a human space changed little bit further than outside image. Each company tried to differentiate the design of cabin focusing on its safety. Following paragraphs show specific trend of image change in form, colour, texture, and the composition. Major visual image change in form tries to follow the image of cars and home appliances which are showing the movement from tough and hard image to soft one. Structural change on local image shows the movement from angular edge to edgeless and the movement of cabin's pillar C placed to back of the equipment with gentle inclination. All of these movements are the result of effort to improve traditional excavator's negative image, that top structure is assembled separately, to positive ones. Today's tendency about its color becomes important to apply two different colour styles. Each style has brightness and tone comparison. As an enormous power convey system, it was in common that its brightness comparison was useful because of the alarm of its damage possibility. However, as its colour control and its design have been emphasized gradually, the tone comparison takes a part in an important role, too. As an example, there is an occasion that these comparisons are compromised simultaneously. In the respect of its image creation, its texture treatments make the tendency of being the same as passenger cars. It is caused from its development of the manufacture techniques of from the fabrication method in small business to the press method in big firm. Further, it is also because of its improvement of painting & coating skills. It may prohibit the reflection effect from solar rays. In the point of view of its visual images, it is recognized the prominent tendency that its composition has been gradually decreased. Lots of windows and the frames tends dark-colour as a whole. It is more preferred to have one colour image, but except KOBELCO and HITACHI. As well, there is another high-tendency to improve its standard treatments, especially for its corner and texture treatments.

• Clean Technology
• /
• v.9 no.4
• /
• pp.163-168
• /
• 2003

Basic concepts and procedures for designing air turbine and atomizing disk, which require core technologies, of rotary atomizer were established. Experimental data agreed well with the computational fluid dynamics analysis results. The rotary atomizer RPM was varied remarkably for various air turbine and atomizing disk types. Experimentally, the atomizer with $20^{\circ}$, slope-contraction and 2 nozzle air turbine has shown the most desirable performance.

• Proceedings of the Korean Professional Engineer Association Conference
• /
• 1984.03a
• /
• pp.52-60
• /
• 1984

As far as we handle industrial products, the painting process is prerequisite; and the preparatory treatment of materials is, therefore, indispensable to the above process. However, it is a matter for regret that people are liable to overlook the importance the treatment of materials at the preparatory stage, giving themselves up to the surface of finished goods. The preparatory treatment of materials is like backstage personnel (operations) in dramatic performance; the performance cannot be successful without the support of backstage operations in surface treatment. The various methods which are being applied widely as preparatory treatment are as follow: (1) the method by using hand tools such as grinders, etc. (2) the method with blasting (3) the method with chemical coating (4) the method by getting rid of fatty substance with organic solvent The methods No. 1 and No. 2 are in use mainly for larger structures, and those No. 3 and No. 4, either singly or combined, are applied for mass-produced, smaller items (acid cleaning is applied for getting rid of rust, as the case may be). The method No. 3 is used mainly as anti-rust by forming zinc phosphate film on the surface of steel plate or enhancing the bonding power of paints by taking advantage of irregular surfaces of films. Recently are no the market steel plates treated directly with film-coating by omitting the process No. 3. Furthermore, those goods painted include not only nonferrous goods but plastics and elastomer. The present discourse describes the cleaning process by using the steam of organic acid, picked up from among No. 4, and its equipment applied.

• Journal of Drive and Control
• /
• v.12 no.3
• /
• pp.1-10
• /
• 2015

In this paper, the authors propose a method to easily recognize and reproduce the robot motion made by an operator. This method is targets for applications similar to painting and welding, and it is based on a process of that identifies a family of plants, by control design and by conducting an experimental evaluation. In this study, the models and controllers for all joints of 3DOF robot system are obtained individually. And a robust control system for motion control of the individual joints is designed based on $H_{\infty}$ control framework. An experimental comparison is made between the proposed control method and existing PID control method. And the results indicate that the proposed designing method is more efficient and useful than conventional method.