• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.923-931
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• 1999

In this paper, a modeling and a robust time-delay control for the reclaimer are investigated. Supplying the same amount of a raw material throughout the reclamation process from the raw yard to a sinter plant is important to keep the quality of the molten steel uniform in blast furnaces. As the actual parameter values of the reclaimer are not available, the boom rotational dynamics are modeled as a second order differential equation with unknown coefficients. The unknown parameters in the nominal model are estimated using a recursive estimation method. Another important factor in the control design of the reclaimer is the large time-delay in output measurement. Assuming a multiplicative uncertainty, that accounts for both the unstructured uncertainty neglected in the modeling and the structured uncertainty contained in the parameter estimation, a robust Smith predictor is designed. A robust stability criterion for the multiplicative uncertainty is also derived. Following the work of Goodwin et al. [4], a quantifying procedure of the multiplicative uncertainty bound, through experiments , is described. Experimental and simulation results are provided.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.09a
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• pp.61-69
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• 2000

It is not easy to find a good soil condition due to the shortage of suitable land for construction work. The earth structure and buildings can be constructed over the soft soil. The soft soil must be treated either using the reinforcement element or dewatering. Most of land reclamation projects are being implemented along the south coast or west coast of the Korean Peninsula. The soils in these areas are covered with the soft marine clay, so soil and site improvement is the most important things to do. Pile foundation at the bottom of embankment can be constructed either in the soft ground or in the soil contaminated area. The purpose of this research is to develop "geogrid-reinforced piled embankment method" to prevent the differential settlement and increase the bearing capacity of soil. In this study, the effectiveness of the geogrid-reinforcement was studied by varying the space between piles and reinforcement conditions. Also, the geotechnical engineering properties of the embankment material and foundation soil were determined through the laboratory tests as well as the field tests. As a result, the site that the pile-spacing S = 3b with geogrid reinforcement is the most effective to reduce the differential settlement and increase load bearing capacity.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.4
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• pp.411-420
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• 1999

Coastal development and reclamation work make environment of shore destroy, such as rapid change of land use and destruction of wet-land and ocean ecosystem. Therefore new technique to detect change have been needed. This study designed new change detection method and applied to study area. The change detection image and quantitative change area by each classes are calculated. Also, this study can use the basic idea-determination data for coastal development and city plan as the sense of sight by changed images that changed from any land-cover to any land-cover between two dates.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.113-118
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• 2007

Now a performance process of Demolition works is 'Before-Removal & After-Classification' method in Korea. This method is short of demolition time, but construction wastes contained substances lower recycling rate of construction, raise expenses of reclamation & treatment. Then the government has decided upon a positive 'Before-Classification & After-Removal' method, and substantially raise a recycling rate of construction wastes. Therefore, this study makes an investigation into state of internal and external demolition field through evaluating technological level, we make a proposal of dismantling method from there. Also, we put dismantling to the test in an apartment by proposed work process. As the result, it made a term of works increased for removing interior material. To solve this problem, we need to develop tools and methods of construction that can remove efficiently. From now on, we continuously need to study a breakdown system of dismantling, analysis of dismantling process and general system by inspecting entire demolition process. And we have to study details for making a specific thesis of method of removing interior material which was based on developing a suitable partial demolition machine and dismantling works.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.179-183
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• 2006

As there are many human activities in the coastal regions, various facilities and coastal engineering structures for protecting beach have been built. Dredging work, reclamation and harbor construction have caused the topography of sea floor to change rapidly. So sedimentation in the vicinity of the groins has get dull and the serious aspects sometimes turn up. Analyzing the surface sediments with transport vector model is one of the good methods to understand the sedimentation in the vicinity of the groins. I analyzed the transport vector of the surface sediments in the vicinity of the groins at the region where serious beach erosion happens near Pohang harbor.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.33-44
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• 2005

The 'Silt Pond' is 180 hectares in size and contained ultra soft slurry-like soil varying between 3 to 20 meters in thickness. Soil improvement work in the Silt Pond commenced by installing vertical drains in the mid of 1996, following completion of sand spreading up to +4.0m CD. Prior to soil improvement work in the main area of Silt Pond, experimental tests including laboratory tests with a large diameter consolidation cell and pilot tests were carried out to investigate the deformation behavior of an extremely soft soil. Due to its high compressibility, large strain usually occurred in the initial stage of deformation does not comply with Terzaghi's one dimensional consolidation theory. Taking into consideration experimental test results, the soil improvement works were carried out in main area of Silt Pond containing ultra soft soil. This paper presents the case study on improvement of ultra-soft soil.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.627-635
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• 2016

Recently, several construction projects have been built to create residential area, industrial complex and agricultural land on reclaimed on- and offshore regions. Estimating the quantity of filling materials during reclamation is the most curcial factor of the total construction cost of reclamation project. However, the estimation of loss ratio, defined as the ratio of loss amount to overall dumped amount, mostly depends on the empirical methods and formulae based on the material characteristics due to the lack of sufficient literature about the loss ratio according to hydraulic conditions. In this studies the loss ratio of materials considering flow conditions and material characteristics were examined through hydraulic experiments. A series of hydraulic experiments was conducted using five different hydraulic conditions and two types of materials such as sand and anthracite in a horizontal rectangular flume ($13.0m{\times}5.0m{\times}0.10m$), in which a round type revetment was installed. It is found that the loss ratio generally tends to increase with increasing the particle Froude number regardless of the types of materials. Also, when the flow velocity(u) becomes higher than the critical flow velocity ($u_c$), the loss ratios of sand and anthracite are dramtically increased up to 7.4% and 24.4%, respectively. As a future work, more specific mean velocities will be considered to figure out the loss ratio and more accurate estimation of amount of filling materials will be possible to present with confidence.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.1
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• pp.54-65
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• 2012

While fishery has been continuously suffering from deteriorating economic feasibility, the amount of the deposited marine litter has been increasing due to an increased number of marine leisure tourists which are caused by an improved quality of life and five-day work week. In addition, the fishery area has been reduced by the reclamation projects and it is being destroyed by marine pollution with a variety of contaminants coming from land and sea. To protect and improve fisheries in these poor conditions, Korean governments have implemented the submerged marine litter collection projects. However, previous research results on the marine environment and resources indicate that it requires a lot of time investment to achieve tangible results of such improvement. The 300 billion won marine environment and resource investigation project has been executed since July 2004 by Korean governments, which demands strategic approaches to obtain more effective and satisfactory results before the project expires in 2013. Ocean environment research institutes and governments need to cooperate each other to gain efficient and reasonable achievement by identifying and linking related projects. This study suggests that the marine environment and resources investigation projects should run parallel with the submerged marine litter collection projects on mutually agreed research items in the identical area of the ocean to obtain cost-effective improvement of marine environment and fishery conditions.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.1-20
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• 2004

This study focuses on the hydrochemical characteristics in goundwater affected by reclamation at 2000 Sydney Olympic Games site, Sydney, Australia. The Olympic Games site can be divided into three areas, i.e. reclaimed areas; landfill areas and non-infilled areas. In the current work, 'reclaimed areas' were previously estuarine, and were filled with waste materials and are now above present high tide level, whereas 'landfill areas' are areas where deposition of waste materials occurred above sea level. No deposition of waste took place in 'non-infilled areas'. This study was also evaluated by three different types such as deep boreholes, shallow boreholes and standpipes. The hydrochemishy of groundwaters in reclaimed and non-in-filled areas is characterized by Mg- and Ca-enrichment, whereas groundwaters in landfill areas are elevated in K and NO₃. Na, K and Mg are the dominant cations in groundwater from reclaimed areas and Na and K are the dominant cations in groundwater in landfill areas. Na and Mg are the dominant cations in groundwater in deep boreholes, whereas Na and K are the dominant cations in groundwater in shallow boreholes and standpipes. There is no distinct trend in heavy metals with electrical conductivity in the groundwater between the re-claimed, landfill and non-infilled areas. Fe and Mn in landfill areas with respect to reclaimed areas and non-infilled areas show a distinct increase in concentration with declining pH. Mean electrical conductivity values in the deep and shallow boreholes are higher than that of standpipes, but the minimum and maximum value of electrical conductivity in groundwater in standpipes shows remarkably different value, probably due to perched pond. There is no correlation between Cu, Pb, Zn, Cr concentrations in groundwater with pH, from deep boreholes, shallow boreholes and standpipes, except for Fe and Mn, which demonstrate increasing concentrations with declining pH. The results revealed a close association between elevated concentrations in groundwater and the presence of fill materials at the site. Trace metals teachability from re-claimed soils adjacent to estuary plays a significant role in determining their potential environmental risk to surrounding environment.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.97-104
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• 2006

Recently the first stage qf construction for Busan new port emerged over the sea surface at the north container terminal site. With this, there are lot of discussions and debates on increasing the water depth at the approaching channel and mooring basin from the existing 15m to 18m by dredging work in order to be able to serve 12,000TEU containership, and at the same time, correction to the reclamation plan of hinterland at the part of Undong Bay qf the new port site. Since the attack of typhoon 'Maemi' in 2003, it is expected that the design wave parameters for coastal and harbor structures in this area would be somewhat changed and so the extreme wave condition at each terminal and tranquility of berthing area does, and therefore, it is necessary to analyze the tranquility at each berth Hence in this study, we constructed a wave model for these conditions and performed simulation together with the circulation model simulation, compared with the field data collected The result showed the increase of the harbor response throughout the basin but not severe condition However, a certain location needs to be prepared for the rough sea condition when a severe typhoon hit the site.