• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.1466-1472
• /
• 2010

In order to construct extremely large scale of sea dike like Saemanguem dike, extremely large amount of mass of rock are needed. In this case, it is general methods to estimate required amount of rock mass based on characteristics of consolidation settlement and bearing capacity of seabed, because it is impossible to estimate exact amount of rock material based on varied seabed condition.. Even in this general methods, it is very few case to manage rock mass amount by estimation of actual input rock mass but the main point is focused on the final section formation considering of designed section and reserve embankment, so excessive or underestimating result of rock mass would be occurred surely. This general methods is not resonable in the points of economic and stable. In this study, optimum construction management method of rubble mound in the 3rd section construction of Saemanguem sea dike is suggested based on comparing required rock mass estimating from consolidation settlement theory with actual input rock mass. It is found out that the optimum input quantity of rock mass is about $1,900{\sim}2,000m^3$/day.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.21 no.47
• /
• pp.267-275
• /
• 1998

As social and economic environments rapidly change, all enterprises are struggling for the 21C. K company, a motor company, is building a new production system by one way of paradigm shift to get the competitive power in the market. This system includes concepts of the thinking shift from maker's view to consumers' view when it makes cars. Simultaneously, K company has been applying another new method 'Interchanges of Different Section of Industry' to make more competitive vendors since 1996. The old method, used until 1995, had worked well and gained lots of effects during the reform activities. But after the technical supervisors from K company had left almost everything went back to the starting point in the vendor company. The major causes of this phenomenon are that there were no ‘structure’ to maintain the reforming activities. We have confirmed that ‘Interchanges of Different Section of Industry’ is a good way to let this ‘structure’ exist continuously. After we compared and analyzed merits or demerits of this system through the experience of applying it to a vendor C, we have suggested more progressive method by strengthening the merits and removing the demerits.

• Proceedings of the KIEE Conference
• /
• 2005.07e
• /
• pp.55-57
• /
• 2005

Along with the development of the industrial society, as the transportation of water which is the indirect capital of society and petroleum, gas, etc used as energy sources is rapidly increased. the underground material is being expanded. Like this, the pipes laid under the ground not only bring the corrosion to the land circumstances to reduce the life of the pipes, but also raise the social problem of leakage accidents and the economic loss by Pin Hole. By reason of this, for the purpose of protecting the corrosion of the underground material, we are constructing and operating the electrolytic protection facilities. In case of a region of which specific resistance is high, however, we are not keeping proper protection potential(that is -850mV) to get protection effects. In this study, for the water pipes that under-voltage phenomena occur in the protection potential, we made a spot survey on the under-voltage section and normal-voltage section, compared, analyzed each of the contents and examined the under-voltage causes of the protection potential.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.73-76
• /
• 2000

A novel, continuous bioreactor system combining a bubble column (absorption section) and a two-phase bioreactor (degradation section) has been designed to treat a gas stream containing benzene. The bubble column contained hexadecane as an absorbent for benzene, and was systemically chosen considering physical, biological, environmental, operational and economic factors. This solvent has infinite solubility for benzene and very low volatility. After absorbing benzene in the bubble column, the hexadecane served as the organic phase of the two-phase partitioning bioreactor, transferring benzene into the aqueous phase where it was degraded by Alcaligenes xylosoxidans Y234. The hexadecane was then continuously recirculated back to the absorber section for the removal of additional benzene. All mass transfer and biodegradation characteristics in this system were investigated prior to operation of the integrated unit, and these included: the mass transfer rate of benzene in the absorption column, the mass transfer rate of benzene from the organic phase into the aqueous phase in the two-phase bioreactor, the stripping rate of benzene out of the two-phase bioreactor, etc. All of these parameters were incorporated into model equations, which were used to investigate the effects of operating conditions on the performance of the system. Several experiments were conducted to show the feasibility of this system. This process is believed to be very practical for the treatment of high concentrations of gaseous pollutants.

• Journal of Ocean Engineering and Technology
• /
• v.17 no.6
• /
• pp.23-31
• /
• 2003

As there are so many uncertainties associated with using the determinism analysis method in the design of rubble mound breakwater, it is impossible for a designed construction to provide ultimate stability. First of all, due to the uncertainty of Load and Resistance, a safety level concerning the destruction mode of construction must be given. Then, the optimization design should be processed. After all, we can say that it is a more reasonable design method than the design used by the stability rate. In this study, an established design process is accomplished using Hudson's equation and an economic analysis with the breakwater's section is also conducted. Hudson's equation is compared to Van der Meer's equation. These results are utilized to drop a damage rate, increase the stability of construction, and determine the optimization section of the breakwater.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.05a
• /
• pp.5-8
• /
• 1999

The present work is concerned with three-dimensional finite element analysis of the hollow section extrusion process using a porthole die. For economic computation, mismatching refinement, an efficient domain decomposition method with different mesh density for each subdomain, is implemented. The proposed method improves the computational efficiency significantly, especially fur the three-dimensional analysis of extrusion problems. As a numerical example, extrusion of the underframe part of a railroad vehicle are analyzed. For three-dimensional mesh generation of a complicated shape with hexahedral elements, a modified grid-based approach with the surface element layer is utilized. The analysis results are then successfully reflected on the industrial porthole die design.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1293-1299
• /
• 2010

Daegu urban railroad line 3 is introduced with straddle-type monorail system within the country at the first time. This system is long line with 24km in total length which has not the results of construction in Korea. The rail beam of monorail bridge to be constructed/ installed in the city is adopted on the basis of the PSC rail beam. It is required to apply the steel rail beam at rapid/ curved line parts or location to be required the long span bridge as passing river and intersection. The composition of span bridge is various and the height of bridge is change with each section and exist the different curve radius due to all section is passes in the city. The rail beam shall be considered the ground conditions and then consider the construction methods. It is analyzed to construction period of PSC rail beam to be linked with period of infrastructure construction and construction of steel rail beam, structure construction of station etc. It is compared to crane construction methods and launching girder as alternative construction methods and propose to upper construction methods which is superior in economic and construction.

• Proceedings of the KSEEG Conference
• /
• 2002.04a
• /
• pp.163-166
• /
• 2002

Initial velocity model close to real velocity structure of the subsurface governs the quality of image of prestack depth migration. Geophysicists employ velocity estimation tools such as velocity analysis (curvature method, coherency inversion), tomography and waveform inversion. We present a reflection tomography that parameterizes the subsurface into the movable blocks. By interpreting the depth-migrated section or stacked section, we can design an initial constant velocity model having only impedance boundaries. We use shooting-raytracing method that allows us to calculate the Jacobian-matrix efficiently.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.6
• /
• pp.28-35
• /
• 1997

Occupant injuries are always possible in a rollover accident, one of the major accidents in a bus. Thus the structure of body frame should have sufficient strength to protect passengers under accidental loads,. ECE(Economic Commission for Europe) regulation No.66 prescribes that residual space shall be preserved in the passenger compartment during and after the structure has been subjected to the prescribed rollover test. Rollover test on a bus section was completed according to the regulation. The coordinates of body section before and after rollover were measured, and it was checked that the structure still complied with the requirements of residual space. Direct measurement on a bus is difficult because of its large size. Thus photogrammetry by photographing and 3 dimensional digital modeling was introduced, and the coordinates of each point were measured through this method.

• Journal of Powder Materials
• /
• v.2 no.1
• /
• pp.19-28
• /
• 1995

Powder forging is a combined technology of powder metallurgy and precision hot forging. Recently, the technology is developing rapidly because of its economic merits, especially in automotive part manufacturing. In the present study, the finite element technique was developed to predict density variation during P/M forging and the technique was applied to analysis of forging of a P/M connecting rod. Although deformation mode of the connecting rod was quite complex, several sections were selected and analyzed under an assumption of asymmetric or plane strain deformation. It was found that some modifications were necessary on the cross section of the beam portion. Therefore, the cross section was modified repeatedly until a satisfactory result of the analysis was obtained. On the other hand, no modifications were necessary in the ring and the pin portions. It is anticipated that the developed technique can be used to optimize preform design and manufacturing processes in P/M forging, which are highly critical to produce successful products in practice.