• Journal of Korea Society of Industrial Information Systems
• /
• v.23 no.2
• /
• pp.19-28
• /
• 2018

In this paper, we studied on the sampling of ocean meteorological data to analyze signature of naval ships. The newest ocean meteorological data, that was quality controled by the Korea Meteorological Administration(KMA), was collected. Outliers were removed from the data by setting the usable range of data. After that, the data size was reduced through the random sampling method, taking geopolitical significance and effective area of buoy, for probabilistic analysis. Moreover, the sample sizes were set at 100, 200, and 400 by considering the population size and a 95% confidence level. The final sample was obtained using the two-dimensional stratified sampling method based on highly correlated water temperature and air temperature. The sum of the squared errors and the confidence interval was calculated to compare the result of sampling. As a result, this study proposed reasonable sample size for infra­red signature analysis of naval ships.

• Journal of Wetlands Research
• /
• v.15 no.1
• /
• pp.59-69
• /
• 2013

The numerical simulations were performed to analyze the advection-diffusion processes of dredging-induced turbidity plume using RMA2 and RMA4 models in Bunam reservoir, Seosan, Chungnam. Field survey was also performed to measure the turbidity using the multi water quality monitoring system (YSI6600EDS). In the field survey, the vertical and horizontal distributions of the turbidity were measured during the dredging operation in Bunam reservoir. RMA2 model was used to simulate the velocity distributions in both the whole domain and the 2nd part of Bunam reservoir. RMA4 model was also used to simulate the concentration distribution in only the 2nd part of Bunam reservoir, where the dredging work were conducted. The comparison of the simulation results with the field data for the advection-diffusion of the turbidity plume using the concentration ratio concepts shows that the numerical model can be applied to analyze the environmental impact of dredging works.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.7 no.1
• /
• pp.44-49
• /
• 2019

The purpose of this study is to analyze the fundamental characteristics of concrete with the change of reject ash(Reject ash=Rj) in the mixed aggregate where single grain aggregate of different grain size and aggregate of opposite grain size are mixed together, to analyze the possibility of a mixed aggregate system that premixes at an aggregate manufacturing plant and delivers it as one aggregate. As a result of the experimental study, it was found that the grain size regulation is satisfied if the mixed aggregate(CSb+SS) is substituted for about 5% of Rj. In the case of the fluidity slump, slump flow and air volume, it was found that they decrease as the substitution ratio of Rj increases, while the compressive strength increases as the substitution ratio of Rj increases. Therefore, it is analyzed that it would contribute greatly to an improvement of quality such as improvement of compressive strength if adequate fluidity and air quantity are secured by the water reducing agent and AE agent while premixing the Rj, which is disposed of by landfill, with about 5% of the mixed aggregate.

• Journal of Korea Society of Industrial Information Systems
• /
• v.15 no.1
• /
• pp.109-114
• /
• 2010

In this paper, we developed the web content of statistical analysis using statistical package and Active Server Page (ASP). A statistical package is very difficult to learn and use for non-statisticians, however, non-statisticians want to do analyze the data without learning statistical packages such as SAS, S-plus, and R. Therefore, we developed the web based statistical analysis contents using S-plus which is the popular statistical package and ASP. In real application, we developed the web content for various statistical analyses such as exploratory data analysis, analysis of variance, and time series on the web using water quality data. The developed statistical analysis web content is very useful for non-statisticians such as public service person and researcher. Consequently, combining a web based contents with a statistical package, the users can access the site quickly and analyze data easily.

• Korean Journal of Environmental Biology
• /
• v.28 no.4
• /
• pp.202-211
• /
• 2010

The variations of physico-chemical factors and the species compositions of phytoplanktons were investigated to analyze the marine ecosystem at the depths during summer in the coast of Dokdo (stations DOK 1-3). The mean values of conductivity (48.9 mS $cm^{-1}$), salinity (32.9 psu) and total suspended solids (57.9 mg $L^{-1}$) were the highest in DOK 1. The biomass (Chl-a) of phytoplanktons was the highest in the surface of DOK 1 (2.61 ${\mu}gL^{-1}$). By the means of physicochemical factors (salinity, turbidity, Chl-a, TN, TP and Si), the water estimated in the coast of Dokdo was more eutrophicated than that in 2008. The phytoplanktons were a total of 42 species in Dokdo, which were composed of 33 species (78.6%) for Bacillariophyceae and 9 species (21.4%) for Dinophyceae. The standing crops of phytoplanktons were the highest ($18{\times}10^3$ cells $L^{-1}$) in the surface of DOK 2 and in the surface of DOK 3, while they were the lowest ($2{\times}10^3$ cells $L^{-1}$) at depth of 40 m of DOK1 and at depth of 30 m of DOK 3. The dominant species of phytoplanktons were Chaetoceros castracanei ($6{\times}10^3$ cells $L^{-1}$) in the surface, Rhizosolenia alata f. gracillima ($3{\times}10^3$ cells $L^{-1}$) at depth of 20 m and Protocentrum compressum ($4{\times}10^3$ cells $L^{-1}$) at the depth of 30 m of DOK 1. At the surface of DOK 2, the dominant species was Bacillaria paxillifer ($6{\times}10^3$ cells $L^{-1}$), while it was Hemiaulus indicus ($12{\times}10^3$ cells $L^{-1}$) at the surface of DOK 3. The DOK 1, which is affected by upwelling, whirlpool and circulation due to the East Korean Warm Current, was the most eutrophicated water body among three stations. The monitoring of marine ecosystem in the coast of Dokdo should be continued to propose the alternatives for water quality and species conservation and to purify the eutrophicated water body due to artificial pollutants as well as natural effectors by the global warming, the climatic change, etc.

• Journal of Korean Society on Water Environment
• /
• v.23 no.4
• /
• pp.518-526
• /
• 2007

There have been serious soil erosion and water pollution problems caused by highland agriculture practices at Doam-dam watershed. Especially agricultural activities, chemical and organic fertilizer and pesticide applications, soil reconditioning to maintain soil fertility are known as primary causes of soil erosion and water qaulity degradation in the receiving water bodies. Among these, soil reconditioning can accelerate soil erosion rates. To develop soil erosion prevention practices, it is necessary to estimate the soil erosion from the watershed. Thus, the Universal Soil Loss Equation (USLE) model has been developed and utilized to assess soil erosion. However, the USLE model cannot be used at watershed scale because it does not consider sediment delivery ratio (SDR) for watershed application. For this reason, the Sediment Assessment Tool for Effective Erosion Control (SA TEEC) was developed to assess the sediment yield at any point in the watershed. The USLE-based SA TEEC system can estimate the SDR using area-based SDR and slope-based SDR module. In this study, the SATEEC system was used to estimate soil erosion and sediment yield at the Doam-dam watershed using the soil properties from reconditioned agricultural fields. Based on the soil sampling and analysis, the US LE K factor was calculated and used in the SA TEEC system to analyze the possible errors of previous USLE application studies using soil properties from the digital soil map, and compared with that using soil properties obtained in this study. The estimated soil erosion at the Doam-dam watershed without using soil properties obtained in the soil sampling and analysis is 1,791,400 ton/year (123 ton/ha/year), while the soil erosion amount is 2,429,900 ton/year (166.8 ton/ha/year) with the use of soil properties from the soil sampling and analysis. There is 35 % increase in estimated soil erosion and sediment yield with the use of soil properties from soil reconditioned agricultural fields. Since significant amount of soil erosion are known to be occurring from the agricultural fields, the soil erosion and sediment yield from only agricultural fields was assessed. The soil erosion rate is 45.9 ton/ha/year without considering soil properties from soil reconditioned agricultural fields, while 105.3 ton/ha/year after considering soil properties obtained in this study, increased in 129%. This study shows that it is very important to use correct soil properties to assess soil erosion and sediment yield simulation. It is recommended that further studies are needed to develop environment friendly soil reconditioning method should be developed and implemented to decrease the speed of soil erosion rates and water quality degradation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.34 no.1
• /
• pp.46-53
• /
• 2002

This study was carried out to analyze the effects of preservation temperature and relative humidity to the physical properties of corrugated fiberboard boxes for fruit and vegetable packaging. The preservation temperature did not affect severely to physical properties of corrugated fiber-board. Relative humidity was a major cause of corrugated fiberboard box quality deterioration. The burst and compressive strengths of experimental boxes measured with Mullen high pressure tester and tong crush tester were decreased gradually as relative humidity increased from 55% to 75%. But, the strength properties slightly decreased relative humidity at 75% or higher. This tendency was the greater for single wall (SW) corrugated fiberboard box than that for double wall (DW). It is suggested that development of the water-resistant corrugated fiberboard and box be needed that can be used under the condition of low temperature and high moisture content, which are being employed in the cold chain system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2007.12a
• /
• pp.129-130
• /
• 2007

A great variety of models including marine ecology model, water quality model, marine fluid model have been used in the marine research. The results of marine model is presented as a numerical value that is difficult for researcher to understand. In this paper, we developed a method for conversing and presenting results of marine models to visual form to improve the visualization of modelling results that is difficult to analyze and applied the method in actual practice.

• Journal of Korean Society of Rural Planning
• /
• v.20 no.1
• /
• pp.27-36
• /
• 2014

The purposes of this study are to identify assessment items to evaluate riverfront for amenity and recreation and to analyze the relative importance of the items using Analytic Hierarchy Process(AHP). Total 15 items of 5 categories were identified through literature review and panel discussion. Based on the AHP analysis results, a weighted value was set for each of the layers in the hierachy. 'Ecological Characteristics' (0.333) was rated with the highest weighted value. followed by 'Landscape Characteristics'(0.190) and 'Physical Characteristics'(0.166). Among the assessment items, 'Water Quality' (0.152) and 'River Naturality'(0.118) had higher weighted values. With the set of assessment items field assessments were carried out for Gyung-An Stream of Gyeonggi-Do to exam its applicability. Total 6 segments and 31 reaches out of the 22.5 km long river were evaluated and the mean scores of the five categories were converted into a percentile score for comparison. Overall, the segments which had higher scores were located close to neighborhood areas and had better connections with other historical and cultural amenities. Also, existing facilities was an important factor and needs to be considered for waterfront development.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.535-538
• /
• 2004

Recently, people have been more interested in the quality of the apartment house, and the new trend has come out, which we use the rooftop of big buildings, people take a propound interest in materials and methods of the rooftop waterproofing. So far, many methods have been developed for convenience of maintenance and use. However, we don't have enough methods and materials to handle many problems and causes. We need the method which is not influenced by movement and cracks of substrate.. Therefore, what we are going to do is to check and analyze the present waterproofing methods of the rooftop and then suggest the new way.