• Journal of Ecology and Environment
• /
• v.37 no.3
• /
• pp.113-122
• /
• 2014

The purpose of this study is to compare soil $CO_2$ efflux between burned and unburned sites dominated by Pinus densiflora forest in the Samcheok area where a big forest fire broke out along the east coast in 2000 and to measure soil $CO_2$ efflux and environmental factors between March 2011 and February 2012. Soil $CO_2$ efflux was measured with LI-6400 once a month; the soil temperature at 10 cm depth, air temperature, and soil moisture contents were measured in continuum. Soil $CO_2$ efflux showed the maximum value in August 2011 as 417.8 mg $CO_2m^{-2}h^{-1}$ (at burned site) and 1175.1 mg $CO_2m^{-2}h^{-1}$ (at unburned site), while it showed the minimum value as 41.4 mg $CO_2m^{-2}h^{-1}$ (at burned site) in December 2011 and 42.7 mg $CO_2m^{-2}h^{-1}$ (at unburned site) in February 2012. The result showed the high correlation between soil $CO_2$ efflux and the seasonal changes in temperature. More specifically, soil temperature showed higher correlation with soil $CO_2$ efflux in the burned site ($R^2$ = 0.932, P < 0.001) and the unburned site ($R^2$ = 0.942, P < 0.001) than the air temperature in the burned site ($R^2$ = 0.668, P < 0.01) and the unburned site ($R^2$ = 0.729, P < 0.001). $Q_{10}$ values showed higher sensitivity in the unburned site (4.572) than in the burned site (2.408). The total soil $CO_2$ efflux was obtained with the exponential function between soil $CO_2$ efflux and soil temperature during the research period, and it showed 2.5 times higher in the unburned site (35.59 t $CO_2ha^{-2}yr^{-1}$, 1 t = $10^3$ kg) than in the burned site (14.69 t $CO_2ha^{-2}yr^{-1}$).

• Nuclear Engineering and Technology
• /
• v.51 no.4
• /
• pp.1098-1108
• /
• 2019

Korea's first commercial nuclear power plant at Kori site was permanently shut down in 2017 and is currently in transition stage. Preparatory activities for decommissioning such as historical site assessment, characterization, and dismantling design are being actively carried out for successful D&D (Dismantling and Decontamination) at Kori site. The ultimate goal of decommissioning will be to ensure the safety of workers and residents that may arise during the decommissioning of nuclear facilities and, thereby finally returning the site to its original status in accordance with the release criteria. Upon completion of decommissioning, the resident's safety at a site released will be assessed from the evaluation of dose caused by radionuclides expected to be present or detected at the site. Although the U.S. commercial nuclear power plants with decommissioning experience use different site release criteria, most of them are 0.25 mSv/y. In Korea, both the unrestricted and restricted release criteria have been set to 0.1 mSv/y by the Nuclear Safety and Security Commission. However, since the dose is difficult to measure, measurable concentration guideline levels for residual radionuclides that result in dose equivalent to the site release criteria should be derived. For this derivation, site reuse scenario, selection of potential radionuclides, and systematic methodology should be developed in planning stage of Kori site decommissioning. In this paper, for calculation of a preliminary site-specific Derived Concentration Guideline Levels (DCGLs) for the Nuclear Power Plant site, a novel approach has been developed which can fully reflect practical reuse plans of the Kori site by taking into account multiple site reuse scenarios sequentially, thereby striking a remarkable distinction with conventional approaches which considers only a single site scenario.

• Journal of Construction Engineering and Project Management
• /
• v.4 no.1
• /
• pp.45-50
• /
• 2014

Productivity analysis is the most important and significant method for evaluating management and engineering performance during whole project stage. However, it is very difficult in developing qualitative index to construction industry comparing to other industries. Therefore, analytical hierarchy process (AHP) is one of the methods for overcoming these limitations by checking consistency index using duality comparison. In this study, it is scraped up an application plan and selection for innovative tools by analyzing survey results on tool users and site managers with respect to using Modified-AHP performance measurement method.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.739-742
• /
• 2004

The term 'Grid' refers to systems and applications that integrate and manage resources and services distributed across multiple control domains. Resource sharing is, necessarily, highly controlled, with resource providers and consumers defining clearly and carefully just what is shared, who is allowed to share, and the conditions under which sharing occurs. In this paper, we design and implement a grid access control system, called PGAM. This system works on heterogeneous resources, can be applied to the additional service development and its service, provides template account management mechanism, and tries to ensure site autonomy. This system is implemented to increase portability and to be tit tll any kind of economic model.

• 기술발표회
• /
• s.2006
• /
• pp.311-319
• /
• 2006

Artesian Pressure exists in Hwa Jeon Project Site of Nakdong Delta Area. Maxium value of the pressure ranges between 06 tonf/m2 and 1 3 tonf/m2 in the design site. This paper presents a design case study considering the Artesian Pressure to calculate the consolidation settlement of the deep marine clay.

• Ocean Systems Engineering
• /
• v.9 no.1
• /
• pp.43-77
• /
• 2019

A local-analytic-based Navier-Stokes solver has been employed in conjunction with a compound ocean structure motion analysis program for time-domain simulation of passing ship effects induced by multiple post-Panamax class ships in the exact condition of a real waterway. The exact seabed bathymetry was reproduced to the utmost precision attainable using the NOAA geophysical database for Virginia Beach, NOAA nautical charts for Hampton Roads and Norfolk harbor, and echo sounding data for the navigation channel and waterfront facilities. A parametric study consists of 112 simulation cases with various combinations of ship lanes, ship speeds, ship heading (inbound or outbound), channel depths, drift angles, and passing ship coupling (in head-on or overtaking encounters) were carried out for two waterfront facilities at NAVSTA Norfolk and Craney Island Fuel Terminal. The present paper provides detailed parametric study results at both locations to investigate the site-specific passing ship effects on the motion responses of ships moored at nearby piers.

• Journal of Environmental Science International
• /
• v.17 no.4
• /
• pp.397-403
• /
• 2008

The purpose of this study is to investigate weighted compaction density according to a leading density in truck, a compaction density of solid waste and composition ratios of solid waste fur calculation of a capacity of the landfill sites. The experiments for calculations of in-place density at landfill site have been conducted in S landfill site at B City. The size of vessel for measuring the compaction density was $1m^3(1m{\times}1m{\times}1m)$. The experiment tests have been carried out methods (1 time for bulldozer and 4 times for compactor) that do contain all of specification at the landfill site. Average of the loading density at the landfill site was $0.264\;ton/m^3$ ($0.113{\sim}0.487\;ton/m^3$). When the loading density for each compositions was compared, the composition of the highest average loading density ($0.474\;ton/m^3$) was miscellaneous wastes. The composition of the lowest average loading density ($0.120 ton/m^3$) was general solid waste. The reported results indicated that the compaction density at the landfill site was $0.538\;ton/m^3$, which was calculated with weighted incoming ratios of compositions. The ranges of the density for each composition were from $0.021\;ton/m^3$ to $0.221\;ton/m^3$. When the compaction density for each composition was compared, the composition with the highest average compaction density ($0.221\;ton/m^3$) was miscellaneous wastes. The composition with the lowest average compaction density ($0.021\;ton/m^3$) was general solid wastes.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.10
• /
• pp.1043-1051
• /
• 2005

In this stduy, adsorption and transport characteristics of Fe in the soil were investigated using convection-dispersion local equilibrium sorption model and two-site non-equilibrium sorption model. In batch experiments with different Fe concentration, characteristics of Fe adsorption was investigated using Freundlich and linear isotherm. Column experiments with different flow rate, organic matter content md Fe concentration were also carried out. We measured Fe concentrations in injection-liquid and in effluent, and then applied them to CXTFIT program. As a result of column experiments, some parameters(D, R, ${\beta}$, ${\omega}$) used in two-site non-equilibrium adsorption model were obtained. Characteristics of Fe transport were analyzed using the parameters(D, R, ${\beta}$, ${\omega}$) obtained from the CXTFIT program, Consequently, characteristics of Fe transport in the soil were predicted through two-site non-equilibrium adsorption model.

• Journal of the Korean Society of Radiology
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2017

The U.S. NRC establishes a radiological criteria with regard to restricted or unrestricted use of nuclear plant site after decommissioning in NUREG-1757. According to this, a nuclear plant site can be released in a restricted way or unrestricted way only if a licensee demonstrates that the dose criteria is fulfilled after the site decontamination and remediation. In order to prove compliance with the radiological criteria of site release, LTP(License Termination Plan) must include the site release criteria, site characterization, final survey plan with major radionuclides and DCGL(Derived Concentration Guideline Levels), etc. Based on the decommissioning case of Rancho Seco nuclear power plant in the United States, this paper analyzed a method of setting the DCGL that can be applied to Kori NPP Unit 1 which will be permanently disabled in 2017.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.5
• /
• pp.43-52
• /
• 2018

Generally, research on construction cost has been done mostly regarding its direct cost, thus model regarding indirect cost lacks attention. This research seeks to introduce a model to predict on-site overhead cost for apartment construction projects, which constitutes a big portion in Korean construction industry. We devised an equation of 9th degree via curve-fitting, using multiple on-site actual expense data, which can be used to calculate per-progress rate, per-day on-site overhead cost. We further show prospective usage of the model by applying it on construction projects sizing about 30 billion won. Regarding the fact that previous studies could not recognize pattern changes of a total on-site overhead cost, this model is worthy of its conveniency and thoroughness, as well as providing reasonal ground for its derivation in predicting on-site overhead cost of apartment construction projects.