• Journal of Korean Society for Geospatial Information Science
• /
• v.8 no.1 s.15
• /
• pp.51-63
• /
• 2000

Dynamic traffic assignment(DTA) has been a topic of substantial research during the past decade. While DTA is gradually maturing, many aspects of DTA still need improvement, especially regarding its formulation and solution algerian Recently, with its promise for In(Intelligent Transportation System) and GIS(Geographic Information System) applications, DTA have received increasing attention. This potential also implies higher requirement for DTA modeling, especially regarding its solution efficiency for real-time implementation. But DTA have many mathematical difficulties in searching process due to the complexity of spatial and temporal variables. Although many solution algorithms have been studied, conventional methods cannot iud the solution in case that objective function or constraints is not convex. In this paper, the genetic algorithm to find the solution of DTA is applied and the Merchant-Nemhauser model is used as DTA model because it has a nonconvex constraint set. To handle the nonconvex constraint set the GENOCOP III system which is a kind of the genetic algorithm is used in this study. Results for the sample network have been compared with the results of conventional method.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.3
• /
• pp.231-239
• /
• 2006

In this study, we evaluated the efficiency of using sulfur-$CaCO_3$ complex pellet in the sulfur oxidizing autotrophic denitrification process for synthetic wastewater with high $CaCO_3$ concentration. The sulfur-$CaCO_3$ complex pellet was packed in reactor(R4). Influent ${NO_3}^--N$ loading rate was from 200 to $1,000g/m^3{\cdot}day$. During the operation, average denitrification efficiency of R4 was above 95%. Particularly, the denitrififation rate at $1,000g/m^3{\cdot}day$ loading was 98.96% for R4. High ${NO_3}^--N$ removal efficiency was determined in R4 compared with other reactors. Through $Ca^{2+}$ and alkalinity analyses, we calculated the supplied alkalinity from the packed $CaCO_3$ in the reactor. Sulfur-$CaCO_3$ complex pellet more effectively supplied alkalinity through the dissociation of $CaCO_3$ as compared with other media. Based on these results, sulfur-$CaCO_3$ complex pellet increased the pH buffering capacity while also providing the carbon source to the denitrifying bacteria. Denitrification efficiency of R4 was also higher than other reactors. ESEM pictures of sulfur-$CaCO_3$ complex pellet show higher porosity than that of the granular sulfur. Hence, more denitrifying bacteria attached on the sulfur-$CaCO_3$ complex pellet than on granular sulfur. It can be concluded that the sulfur-$CaCO_3$ complex pellet is a more suitable media for a sulfur oxidizing autotrophic denitrification process as it provides high denitrification efficiency.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.10 no.1
• /
• pp.29-43
• /
• 2007

For effective management of water quality on the southern coast of korea, a three-dimensional eco-hydrodynamic model is used to predict water quality in summer and to estimate the reduction rate in pollutant loads that would be required to restore water quality. Under the current environmental conditions, in particular, pollutant loadings to the study area were very high, chemical oxygen demand (COD) exceeded seawater quality criteria to comply with current legislation, and water quality was in a eutrophic condition. Therefore, we estimated reduction rates of current pollutant loads by modeling. The model reproduced reasonably the flow field and water quality of the study area. If the terrestrial COD, inorganic nitrogen and phosphorus loads were reduced by 90%, the water quality criteria of Region A were still not satisfied. However, when the nutrient loads from polluted sediment and land were each reduced by 70% simultaneously, COD and $Chl-{\alpha}$ were restored. When we reduced the input COD and nutrient loads from the Nakdong River by 80%, $Chl-{\alpha}$ and COD of Region B decreased below $10\;{\mu}g\;1^{-1}$ and $2\;mg\;1^{-1}$, respectively. The water quality criteria of Region C were satisfied when we reduced the terrestrial COD and nutrient loads by 70%. Total allowable loadings of COD and inorganic nutrients in each region were determined by multiplying the reduction rates by current pollutant loads. Estimated high reduction rates, although difficult to achieve at the present time under the prevailing environmental conditions, suggest that water pollution is very severe in this study area, and pollutant loads must be reduced within total allowable loads by continuous and long-term management. To achieve the reduction in pollutant loads, sustainable countermeasures are necessary, including the expansion of sewage and wastewater facilities, polluted sediment control and limited land use.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.5
• /
• pp.285-292
• /
• 2008

To investigate the effect of tillage methods on the silage barely growth and the soil environment in paddy field, liquid pig manure(LPM) was applied after harvesting rice at Jisan series soil for 2 years. Five plots, a LPM applied rate as N%; 0, 100, 150, 200(basal dressing) and 100(basal dressing)+50(additional fertilizer) were divided by tillage methods; non-tillage, non-tillage+rice straw and rotary tillage method. Emission amounts of $NH_3$ gas highly decreased in the rotary tillage and the non-tillage+rice straw plot compared to non-tillage plot. The contents of soil organic matter and exchangeable cation were increased in the applied LPM plot. $NH_4-N$ and $NO_3-N$ contents in soil were the highest in the non-tillage+rice straw plot and followed by the rotary tillage and highly decreased along with the growth of plant. Run-off rate of mineral components were higher in order of the rotary tillage plot£æthe non-tillage plot£æthe non-tillage+rice straw plot and then leached to $SO_4$, $NO_3-N$, K plentifully. The yield of silage barley in dry weight was higher in order of the non-tillage+rice straw plot>the rotary tillage plot>the non-tillage plot. To estimate the feed value of silage barley, crude protein, acid detergent fiber(ADF) and neutral detergent fiber(NDF) contents were analyzed. Crude protein and ADF contents were the highest at rotary tillage N150% plot as 9.7 and 29.4%, respectively. NDF contents was the highest at non-tillage+rice straw N150% plot as 56.7%. In conclusion, we recommend not to incinerate rice straw and to apply LPM at non-tillage status in cultivating the silage barley. This may prevent water pollution and increase barley yields.

• Food Science and Preservation
• /
• v.22 no.1
• /
• pp.36-43
• /
• 2015

The edible crab is among the rich resources that can be used as materials for food products, but living crabs and crabs marinated in soy sauce are the only widely utilized materials for food products. For seafood development, research is needed to promote the use of crabs in various products. In this study, the quality changes of fried rice prepared with crab meat, crab emulsion sauce and crab cooker effluent were investigated. The pH and acidity values did not show any significant difference at $-20^{\circ}C$. The acidity of the fried rice continuously increased during storage at 4 and $25^{\circ}C$. The VBN and TBA values of the fried rice stored at 4 and $25^{\circ}C$ were significantly higher than those of the fried rice stored at $-20^{\circ}C$ during the storage period. The viable cell count of the fried rice stored at $-20^{\circ}C$ changed little during the storage period while that of the fried rice stored at 4 and $25^{\circ}C$ rapidly increased over 2 weeks. For the fried rice stored at $-20^{\circ}C$, the overall quality did not show significant differences during the storage period. In conclusion, the best storage temperature for both quality and safety was found to be $-20^{\circ}C$. At such storage temperature, the quality of the stored instant rice using crab meat did not change, and through research the expanding possibilities of using crab materials were confirmed.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.21 no.3
• /
• pp.115-122
• /
• 2001

The purpose of this study was to suggest the possibility of utilizing the wildflower pasture as the livestock herbage sources as well as promoting the public interests. Not only dry matter (DM) yield and soil properties of pastures were observed, but also chemical composition of herbages was analyzed. The experimental design includes four treatments: Conventional pasture(COP, forage 6 species), Bottomgrass pasture(BOP, turf grass 6 species), Native wildflower pasture(NWP, turf grass 6 species + native wildflower 11 species) and Introduced wildflower pasture(IWP, turf grass 6 species + introduced wildflower 9 species). The field trials were carried out on the experimental pasture plots at Chungnam National University throughout from 1997 to 2000. The results obtained are as follows : 1. As wildflower pasture was composed of turf grasses and wildflowers, the yearly mean of DM yield in the wildflower pastures (NWP 6,688kg/ha and IWP 7,240kg/ha) was lower than that of COP(8,592kg/ha) or BOP(7,264kg/ha)(p<0.05). This result indicated that the forage productivity of wildflower pasture for livestock is low. 2. The nutritive quality of herbages from wildflower pasture tended to be slightly low compared to that of COP and BOP. On the other hand, compared with IWP, the content of CP, NDF and lignin of herbages from NWP were lower than those from IWP, while IVDMD was higher(p<0.05). 3. The pH and the content of exchangeable Ca in NWP and IWP soils were tended to be low compared to those of COP in changes of soil properties after 3-years experimental trials, while the contents of organic matter, nitrogen, available phosphate, Mg and K were slightly improved. In conclusion, even though DM yield seem to be lower in wildflower pasture than those of COP, and the nutritive quality of herbages from wildflower pasture tended to be slightly low compared to that of COP and BOP. but, possibility of utilizing herbages from wildflower pasture for livestock was to some extent expected. In addition. compared to COP, wildflower pastures improved the property of soil. Thus, although wildflower pasture was not enough for livestock as a herbage, wildflower pasture has enough possibility for promoting the public interest.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.6
• /
• pp.1572-1578
• /
• 2007

The specified wastes consist of waste acid, waste alkali, waste oil, waste organic solvent, waste resin, dust, sludge, infectious waste, and others. Among these specified wastes, a great portion is liquid phase wastes. The purpose of this study is to develop the high temperature and high pressure (HTHP) treatment system for decomposition of the liquid phase specified waste (LPSW). For this, we analyzed the physical and chemical properties of the LPSW such as density, proximate analysis, ultimate analysis, heating values, and designed 0.3 ton/day HTHP treatment system. The LPSW tested in this experiment were prepared by adding TCE(trichloroethylene) and toluene to liquid phase waste which was brought into the commercial waste treatment company. The average density of waste oil (25 samples), waste resin (5 samples), and waste solvent (12 samples) was 0.99 g/mL, 0.91 g/mL, and 0.93 g/mL, respectively. And the average lower heating value of waste oil, waste resin, and waste solvent was 8,294 kcal/kg, 5,809 kcal/kg, and 7,462 kcal/kg, respectively. The DRE (Destruction & Removal Efficiency) of TCE and toluene were 99.95% and 99.73% at atmospheric pressure conditions and that were 99.99% and 99.82% at pressurized conditions, respectively. These results showed that TCE/toluene mixtures were properly decomposed over about 99.73% of DRE by the HTHP treatment system and pressurized conditions were more effective to destroy those pollutants than atmospheric pressure conditions. Also these systems could be directly applied to industries which try to treat the liquid phase specified waste within the regulation limit.

• Microbiology and Biotechnology Letters
• /
• v.38 no.2
• /
• pp.177-182
• /
• 2010

The goal of this study was to characterize the quality and physiological functionality of some traditional rice wines in Chungnam province, Korea. Non-sterilized and commercial sterilized traditional rice wines from five traditional rice wine factories of Chungnam province were collected and investigated for nutritional components, noxious compounds and physiological functionality. Ethanol content ranged from 16.1~18.3% and pH ranged from 3.27~4.76, and they also contained 0.15% to 0.55% of total acid. All traditional rice wines contained 10.15~139.9 mg% of amino nitrogen and 2.5~25.7% of total sugar. Among organic acids, lactic acid was contained 7.4~29.6 mg%, and succinic acid and propionic acid was also contained 0.2~2.7 mg% and 0.7~8.3 mg%, respectively. Antihypertensive angiotensin I-converting enzyme inhibitory activity were showed 37.0~86.0% in all rice wines, however, fibrinolytic activity, antioxidant activity, SOD-like activity and acetylcholinesterase inhibitory activity were low or not detected.

• Journal of Dairy Science and Biotechnology
• /
• v.32 no.2
• /
• pp.131-139
• /
• 2014

The aim of this study was to manufacture Cutting-Gouda cheese and to investigate the change in physicochemical properties of Cutting-Gouda cheese made with Lactobacillus rhamnosus_p1. Lactic acid bacteria were isolated from Gouda cheese ripened for more than 1 year. They were identified as 2 strains of L. rhamnosus, Lactobacillus casei, Lactobacillus curvatus, and Staphylococcus saprophyticus by 16S rDNA sequencing and named L. rhamnosus_p1, L. casei_p2, L. curvatus_p3, L. rhamnosus_p4 and S. saprophyticus_p5. The proteolytic activities of isolated strains against casein were measured using prepared skim milk agar plates. L. rhamnosus_p1 showed the highest proteolytic activity. Cutting-Gouda cheese was made with L. rhamnosus_p1, and its physicochemical properties (moisture, protein, fat, ash and free amino acid content) were measured during ripening periods. Because of the modified atmosphere packaging ($N_2{^-}$), there was no change in moisture, protein, fat, and ash in the experimental group. The total amount of free amino acids in the control and experimental group gradually increased during ripening periods. The sensory evaluation showed that the experimental group was preferable to the control group. This result suggests that L. rhamnosus_p1 has potential to be developed as a new starter for Gouda cheese.

• Korean Journal of Environmental Biology
• /
• v.32 no.1
• /
• pp.58-67
• /
• 2014

The outdoor mass cultivation is not possible for microalgae in Korea all year round, due to cold winter season. It is not easy to maintain proper level of productivity of microalgae even in winter. To prevent a drastic decrease of temperature in a greenhouse, two layers were covered additionally, inside the original plastic layer of the greenhouse. The middle layer was made up of plastic and the inner layer, of non-woven fabric. Acrylic transparent bioreactors were constructed to get more sunlight, not only from the upper side but also from the lateral and bottom directions. In winter at freezing temperatures, six different culture conditions were compared in the triply covered, insulated greenhouse. Wastewater after anaerobic digestion was used for the cultivation of microalgae to minimize the production cost. Water temperature in the bioreactors remained above $10^{\circ}C$ on average, even without any external heating system, proving that the triple-layered greenhouse is effective in keeping heat. Algal biomass reached to 0.37g $L^{-1}$ with the highest temperature, in the experimental group of light-reflection board at the bottom, with nitrogen and phosphorus removal rate of 92% and 99%, respectively. When fatty acid composition was analyzed using gas-chromatography, linoleate (C18 : 3n3) occupied the highest proportion up to 61%, in the all experiment groups. Chemical oxygen demand (COD), however, did not decrease during the cultivation, but rather increased. Although the algal biomass productivity was not comparable to warm seasons, it was possible to maintain water temperature for algae cultivation even in the coldest season, at the minimum cost.