• Journal of Intelligence and Information Systems
• /
• v.7 no.1
• /
• pp.81-95
• /
• 2001

Plant construction projects usually take much higher uncertainty and risks than the projects from other domains. This implies the importance of plant construction project management should be more emphasized than the other domain. Especially, the overall successes of the projects often depend on the performance of process planning and scheduling performed at the initial stage of the project. However, most plant construction projects suffer great difficulties in establishing proper process planning and scheduling timely because of unstructureness and dynamicity of environment of the project itself In this paper, we propose a knowledge-based process planning and scheduling approach in a plant construction domain to cope this problem. First, we modulize process planning knowledge and present the knowledge representation scheme. Second, we propose an inferencing mechanism to build a process planning for plant construction based on the represented process planning knowledge. Since our approach automate the initial process planning, which was usually done by manual way, it can improve the correctness and also completeness of the process plan and schedule by reducing the time to plan and allowing simulations on the various situation. We also design and implement this our approach as a real working system, and it is successfully applied to real plant construction cases from a leading construction company in Korea. Based on this success, we expect our approach can be easily applied to the projects of other areas, while contributing to enhancement in productivity and quality of project management.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.6
• /
• pp.279-290
• /
• 2013

In digital forensics log files have been stored as a form of large data for the purpose of tracing users' past behaviors. It is difficult for investigators to manually analysis the large log data without clues. In this paper, we propose a text mining technique for extracting intrusion logs from a large log set to recommend reliable evidences to investigators. In the training stage, the proposed method extracts intrusion association words from a training log set by using Apriori algorithm after preprocessing and the probability of intrusion for association words are computed by combining support and confidence. Robinson's method of computing confidences for filtering spam mails is applied to extracting intrusion logs in the proposed method. As the results, the association word knowledge base is constructed by including the weights of the probability of intrusion for association words to improve the accuracy. In the test stage, the probability of intrusion logs and the probability of normal logs in a test log set are computed by Fisher's inverse chi-square classification algorithm based on the association word knowledge base respectively and intrusion logs are extracted from combining the results. Then, the intrusion logs are recommended to investigators. The proposed method uses a training method of clearly analyzing the meaning of data from an unstructured large log data. As the results, it complements the problem of reduction in accuracy caused by data ambiguity. In addition, the proposed method recommends intrusion logs by using Fisher's inverse chi-square classification algorithm. So, it reduces the rate of false positive(FP) and decreases in laborious effort to extract evidences manually.

• Korean Journal of Remote Sensing
• /
• v.28 no.1
• /
• pp.1-9
• /
• 2012

The diurnal variation in pollen vertical distributions in the atmosphere was observed by a surface-based lidar remote sensing technique. Aerosol extinction coefficient and depolarization ratio at 532 nm were obtained from lidar measurements in spring ($4^{th}$ May - $2^{nd}$ June) 2009 at Gwangju Institute of Science & Technology (GIST) located in Gwangju, Korea ($35.15^{\circ}E$, $126.53^{\circ}N$). Unusual variations of depolarization ratio were observed for six days from $4^{th}$ to $9^{th}$ May. Depolarization ratios varied from 0.08 to 0.14 were detected at the low altitude in the morning. The altitude with those high depolarization ratios was increased up to 1.5 - 2.0 km at the time interval between 12:00 and 14:00 LT and then decreased. The temporal variations in high values of depolarization ratios from lidar measurements show good agreement in patterns with the sampled pollen concentrations measured using the Burkard trap sampler. This study demonstrates that the pollen distribution data obtained by lidar measurements can be a useful tool for investigating spatial and temporal characteristic of pollen particles.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.4
• /
• pp.357-363
• /
• 1992

A series of studies were conducted to find out the effects of chemical composition in brown rice on the occurance of chalky grain in paddy soil which had been applied compost, lime and silicate fertilizer every year for 38 years. Effects of nitrogen fertilizer on occurance of chalky grain were greater in order of ammonium sulfate>urea>no fertilizer. The occurance of chalky grain was decreased by lime and silicate fertilizer application, but compost application markedly increased occurance of cralky grain due to increment of nitrogen uptakes. Rice quality tend to lower by increasing nitrogen uptakes whereas Mg/K and $Mg/K{\cdot}N$ ratio were reverse. It is considered that the occurance of chalky grain are closely associated with uptakes of nitrogen, magnesium and potassium.

• Korean Journal of Soil Science and Fertilizer
• /
• v.30 no.4
• /
• pp.309-313
• /
• 1997

Field experiments were conducted on Jeonbug series (Fine silty, mesic family of Aeric Fluventic Haplaquepts), to study the effect of split application of N fertilizer in combination with rice straw on N use efficiency of dry-soil-direct seeded paddy rice. Treatments involved conventional application of N (in three splits; 40% at planting, 30% at five leaf stage and at heading stage) without rice straw, all basal application of N with straw application (5000 kg/ha), N application in two splits (70% at planting and 30% at heading stage) with rice straw application and N application in three splits (40% at planting, 30% at five leaf stage, 30% at heading stage) with application of rice straw. There was Zero N plot too for the estimation of N use efficiency. Seeding was done on dry soil and the filed was flooded 32 days after seeding. The fertilizer application rates were 160, 70, and 80 kg/ha of N, $P_2O_5$ and $K_2O$, respectively. The experiment was conducted for two years, in the same filed. The apparent use efficiency of fertilizer N by rice tended to be higher under the application of rice straw when N was applied in three splits. This, however, did not increase the yield of rice significantly. Even under the application of rice straw, the apparent N use efficiency was lower when N fertilizer was applied in one dose at the planting and in two splits. The lower N use efficiency in these cases, did not yield of rice significantly. The periodical analysis of mineral N in the soil suggested that higher mineral N in the soil at the early stages was responsible for the lower apparent N use efficiency.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.6
• /
• pp.943-948
• /
• 2012

This study was conducted to estimate the effect of nitrogen reduction by applying ryegrass and to determine the relationship between yield and nitrate concentration of soil solution for cucumber cultivation in plastic film house. Nitrogen levels with recovery of ryegrass ($42.3Mg\;ha^{-1}$) was 0, 50, 75, 100 % of 199 kg N $ha^{-1}$ as N recommendation by determining soil EC value. Yield and nitrate concentration in soil solution was investigated during cucumber cultivation. Yields of N treatments applied ryegrass showed 64.3, 70.9, 70.3, and $76.5Mg\;ha^{-1}$, respectively, it could reduce about 25-50% of nitrogen application compared to yield ($68Mg\;ha^{-1}$) of NPK plot applied 199 kg N $ha^{-1}$. Nitrate concentration in soil solution was average 26.0, 30.1, 41.4, $58.5mg\;L^{-1}$ during cucumber cultivation and was related between yield and average nitrate concentration of soil solution following as; $Y=49.3+0.63X+0.0034X^2$ ($R^2=0.778^{**}$). However, it needs to conduct extra-experiment due to high variation of nitrate concentration during cultivation periods.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.2
• /
• pp.119-123
• /
• 2010

This experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts) in 2007 to 2008 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Three kinds of green manure crops (hairy vetch, barley, rye) incorporated in soil for rice cultivation. 6.3 kg N $10a^{-1}$, and3.2 kg $P_2O_5$ $10a^{-1}$ were applied to rye and barley plot before rice transplanting. Chemical fertilizers had not been applied to hairy vetch plot. Glomalin concentration, soil bulk density, and porosity were measured in soil from different green manure crops incorporation after rice harvesting in paddy. Soil bulk density and porosity after rice harvesting improved at surface soil of hairy vetch incorporation plot. Degree of water stable aggregates increased all green manure incorporation plots. Glomalin concentrations significantly increased at hairy vetch incorporation treatment. In barley plot, the concentration of glomalin increased at 10-20 soil depth. There were no differences relationship between soil carbon, and glomalin concentration, but relationship between soil aggregate stability, and glomalin concentration significantly positive under green manure crop-rice cropping system. Rice yield decreased at hairy vetch incorporation plot because of field lodging. We suggested that hairy vetch incorporation should be considered about application amount, and water management using rice cultivation because of soil properties changes.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.2
• /
• pp.180-184
• /
• 2005

This study was peformed to assess environmental effect through rice culture with sewage irrigation using Iksan stream water from 2002 to 2003. Contents of $NH_4-N$ in irrigation water keep up one day at the tillering stage and panicle formation stage were decreased 40% and 52% respectively, but that of continued 4 days was decreased $88%{\sim}98%$. The $NH_4-N\;and\;NO_3-N$ in run off by reduction 50% fertilization were more decreased 17% and 44% respectively, than those of conventional fertilization level. Amount of K and $NO_3-N$ loss in infiltration water were more decreased 18% and 4% respectively, those of than conventional fertilization level. The Cu and Pb contents in soil of after experiment were slightly increased but other heavy metals were not accumulated. The rice yield by reduction 50% fertilization level was not significant compare with conventional fertilization level but head rice rate was increased.

• Korean Journal of Environmental Agriculture
• /
• v.17 no.3
• /
• pp.227-233
• /
• 1998

To mitigate the methane emission from rice paddy fields, effects of nitrogen fertilizers source and cultural patterns were evaluated on silty loam soils. And a pot experiment was carried out to find out the effects of nitrogen fertilizers on soil pH, Eh, sulfate concentration of soil water in flooded soil. In transplanting cultivation, the total methane emission depending on fertilizers was $32.9gm^{-2}$ for urea ; $30.3gm^{-2}$ for ammonium sulfate ; $26.4gm^{-2}$ for coated urea. Methane emitted in direct seeding on dry soil was $24.7gm^{-2}$ for urea ; $16.7gm^{-2}$ for ammonium sulfate : and $22.8gm^{-2}$ for coated urea. Thus, the methane emission rate of direct seeding on dry soil was 29.7% lower than transplanting. According to the nitrogen fertilizers, the methane emission rate by ammonium sulfate and coated urea were reduced 18.4 and 15.9% in comparison with urea, respectively. In pot experiments, pH in flooded soils depending on nitrogen fertilizers dereased in order of urea > coated $urea{\fallingdotseq}no$ fertilizer > ammonium sulfate and the order was coincided with that of total $CH_4$ emission from flooded soil. Soil Eh was highest in ammonium sulfate application followed by coated urea, no fertilizer, urea. And sulfate concentrations of soil water were in order of ammonium sulfate > coated urea > urea > no fertilizer.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.25 no.2
• /
• pp.137-142
• /
• 2005

This study was conducted to evaluate the effects of cutting frequency and level of fertilizer application on the botanical composition and forage yield of alpine pasture. Field experiment was established at 600 m (a.s.1) altitude with two cutting frequency schedules (two and three times annually) and two levels of fertilizer application (lower level of fertilizer, 200-200-200 kg / ha and standard level of fertilizer, 280-200-240 kg / ha; N, $P_2O_5$ and $K_2O$, respectively). Higher grass to clover ratio was observed in two cutting frequencies. The clover ratio was highest as $16\%$ in thee cutting frequencies with lower level of fertilizer application End the ratio of weed was low in all treatments ($3.7 {\~} 6.7\%$). No significant difference was observed in forage dry matter (DM) yield among treatments, however forage DM yield in three cutting frequencies tended to be greater in standard level of fertilizer application compared to lower level of fertilizer application. The forage quality was greater in three cutting frequencies, but not changed with different levels of fertilizer application. This result indicates that three cutting frequency and standard level of fertilizer application system are considered to be proper management methods at alpine grassland of 600 m altitude considering the botanical composition, forage DM yield md forage quality.