• Hwankyungkyoyuk
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• v.21 no.2
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• pp.11-24
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• 2008

This research verifies the effect on environmental attitude and knowledge accomplishment by t-test as producing and running programs regarding global warming which is raised as a representative environmental issue subject to 6th grade-elementary students. For this, environmental education programs about global warming for elementary students are developed and applied 15 times by reconstituting classes based on the contents regarding global warming from the text books revised as of 7th course of study. The result is as below. First, some part of contents from social study and science of 6th grade elementary curriculum of 7th course of study was able to be reconstituted to 15 education programs. Secondly, the programs about global warming improved students' environmental attitude Application of the programs about global warming showed significant difference(p<.05) on building environmental attitude as it proved those are effective on both area of recognition level and practice level. The method used on the test had .866's Cronbach alpha modulus value therefore, it obtained reliability. Thirdly, the programs regarding global warming improved students' knowledge accomplishment. As a result of test for knowledge accomplishment which was executed with same method for attitude test, the application of the programs about global warming showed significant difference(p<.05) on improving students' knowledge accomplishment on the global warming therefore, it resulted that the application of the program is effective on knowledge acquirement.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.69-73
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• 2000

To investigate proper method of nitrogen application, six levels of nitrogen fertilizer and five different split applications were tested in Liriope platyphylla. Leaf length and content of total nitrogen in plant increased with the increase of nitrogen application level from zero to 360kg per ha. Number and weight of tuber increased with the increase of nitrogen level and tuber production reached to highest level of 4.44M/T per ha with the level of 220kg nitrogen. And then, tuber production decreased with the addition of extra nitrogen fertilizer to level of 360kg per ha. In the research of proper nitrogen split application, tuber yield (3.52M/T per ha) was increased by 18% at the combination of 40% basal application and three times of top dressing, than that of 100% basal application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.81-88
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• 1983

This experiment was conducted to study about influenced inorganic element contents of flag leaf and chaff with different nitrogen and silicate application in Jinan (sea level 303m). The recommended rate of fertilizer application above N 15kg/10a was poor for dry production increment in cold in July elevation and was demanded increment of silicate. In the elevation of cold in July high rates of nitrogen application produced more incomplete grain and a reduced cold tolerance. These effects were due to over-content of soluble nitrogen within flag leaf and disturbance of uptaking potassium and silicate. On the other hand, the application of silicate could increase yield by promoting resistance to cold- damage. The application of increasing level of nitrogen resulted in increasing the contents of total nitrogen and phosphate in both sterile and fertile glumes. The contents of potassium and calcium were the highest at the level of nitrogen 10 - 15kg/10a, but magnessium was rather high at low nitrogen levels. It is interesting that at any level of nitrogen, over 6% higher silicate contents were noted in the fertile chaff than in the sterile chaff. Application of increasing level of silicate fertilizer decreased total nitrogen contents, but increased the contents of phosphate, potassium. and silicate in the chaff. Increasing rate of silicate content by increasing silicate addition was remarkably higher in the fertile chaff than in the sterile chaff.

• Applied Biological Chemistry
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• v.30 no.1
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• pp.9-16
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• 1987

This experiment was conducted to increase the available constituents contents of Angelica gigas Nakai and to decide the application amounts of nitrogen, phosphorus and potassium fertilizer. The effects of the amounts of their application and absorption on the contents of decursin and sugar in Angelicae gigantis Redix were studied. The decursin contents of root was decreased with increasing the application amount of nitrogen more than 10kg/10a, and increased along with the increasing application level until 20kg/10a and 15kg/10a of phosphorus and potassium, respectively. The decursin yield per 10a was increased with increasing application level until 10kg/10a, 10kg/10a and 10kg/10a of nitrogen, phosphorus and potassium, respectively. The decursin yield per l0a was decreased with increasing application level more than 20kg/10a of nitrogen. The total sugar yield per 10a was increased with increasing the application level until 15kg/10a, 10kg/10a of nitrogen and potassium respectively. But the effect of phosphorus application on the total sugar yield was not observed. The significant negative correlation was obtained between the decursin contents and the nitrogen contents of root$(r=-0.437^{\ast})$, and the significant positive correlation between the decursin contents and the contents of phosphorus$(r=0.587^{{\ast}{\ast}})$ or potassium$(r=0.467^{\ast})$ in root. But the significant correlations between the decursin contents and the their contents of shoots were not observed. It is recommended for decursin production to apply 10kg/10a, 15kg/10a and 10kg/10a of nitrogen, phosphorus and potassium, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.70-75
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• 2010

In Korea, standard N application level was amended from 110 to 90kg per ha for high quality rice production in 2005. So far, N application method, however, has not been considered for yield and quality based on changed standard N application level. Therefore, this experiment was conducted to find out more efficient N application method for improving rice quality or labor saving under the amended standard N application level with several varieties at three site (Suwon, Iksan, and Milyang) for two years from 2005 to 2006. Top dressing of N at 15 days before heading compared to the standard (25 days before heading) showed improved rice qualities such as 1000 grain weight and head rice ratio without changing rice yield and protein content of brown rice. In addition, there were no significant differences in yield and quality between different N split application of 70-0-30% and 50-30-20%, indicating that the former would be useful for labor saving without yield decrease and quality deterioration.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.226-231
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• 1994

This experiment was conducted to evaluate the effect of coated urea complex fertilizer(CUC) on the growth and quality of rice in high-ridged dry seeding and infant -seedling machine transplanting on clay loam and sandy loam in Milyang, Korea, 1993. The CUC level applicated was 100 %, 80 %, 60% and 40% to standard application amount of fertilizer. Results obtained were as follows : 1. The nitrogen releasing rate in dry seeding was 83% for sandy loam, 81% in clay loam for 3.5 months after initial releasing, and in infant-seedling was 89% in both soil types for 4 months. 2. The degree of rice leaf color was the highest at the heading stage, and was high with increasing CUC application level regardless of cultural methods, especially was higher at harvesting stage in the 100% level of CUC to standard application amount of fertilizer than conventional fertilizer. 3. The perfect rice grain ratio was higher in infant-seedling than in dry seeding, but lowered with increasing CUC application level regardless of cultural methods. The green kerneled rice ratio among imperfect rice grain was high in dry seeding, and the notched belly rice kernel ratio was high in infant-than infant-seedling of the both soil types, and increased with increasing CUC application level. 4. Hon-value in rice grain was higher at the treatment of CUC application than conventional fertilizer in dry seeding. However, it was contrary result in infant seedling, and was low tendency with decreasing CUC application. On the other hand, the protein in rice grain was also same tendency of Hon-value. Cel-consistency related to eating quality was longer with increasing CUC application level regardless of cultural methods. However, there was no clear tendency at clay loam. 5. No significant difference between rice yield and CUC application in the range of 60% to 100% at both soil types in dry seeding was observed. These results appeared in clay loam under infant seedling except sandy loam. Accordingly, it was thought that 60% level of CUC to standard application amount of fertilizer could be applicated for growth and quality of rice.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.1
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• pp.117-130
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• 1989

In this study, an implicit one-dimensional model, DWRM(Dynamic Wave Routing Model) was developed by using the four-point weighted difference method. By applying the developed model to the Keum River, the parameters were calibrated and the model applicability was tested through the comparison between observed and computed water levels. In addition, the effects of the construction of an estuary dam to the flood wave were estimated as a result of the model application. The results of the study can be summarized as follows; 1. The roughness coefficients were evaluated by comparison between observed and computed water level at Jindu, Gyuam and Ganggyeung station in 1985. The Root Mean Squares for water level differences between observed and computed values were 0.10, 0.11, 0. 29m and the differences of peak flood levels were 0.07, 0.02, 0. 07m at each station. Since the evaluated roughness coefficients were within the range of 0.029-0.041 showing the realistic value for the general condition of rivers, it can be concluded that the calibration has been completed. 2. By the application of model using the calibrated roughness coefficients, the R. M. S. for water level differences were 0.16, 0.24, 0. 24m and the differences of peak flood level were 0.17, 0.13,0.08 m at each station. The arrival time of peak flood at each station and the stage-discharge relationship at Gongju station agreed well with the observed values. Therefore, it was concluded that the model could be applied to the Keum River. 3. The model was applied under conditions before and after the construction of the estuary dam. The 50-year frequency flood which had 7, 800m$^3$/sec of peak flood was used as the upstream condition, and the spring tide and the neap tide were used as the downstream condition. As the results of the application, no change of the peak flood level was showed in the upper reaches of 19.2km upstream from the estuary dam. For areas near 9.6km upstream from the estuary dam, the change of the peak flood level under the condition before and after the construction was 0. 2m. However considering the assumptions for the boundary conditions of downstream, the change of peak flood level would be decreased.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1997.03a
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• pp.163-181
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• 1997

This dissertation provides a theroetic study on the network security in general , the firewall in particular . In fact, the firewall has been recognized as a very promising option to obtain the security in the real world network environment . The dissertation provides a thorough theoretic investigation on the various problems raised in the computer network, and also explores a methodology of the security against IP spoofing. Moreover, it investigates a systematic procedure to make analysis plans of the firewall configuration. Based on the above investigation and analysis , this dissertation provides two approaches to network security, which address a number of issues both at the network and at application level. At the network level. a new methdo is proposed which uses packet filtering based on the analysis of the counter plot about the screen router. On the other hand at the application level, a novel method is exlored which employs security software , Firewall-1, on Bastion host. To demonstrate the feasibility and the effectiveness of the proposed methodologes, a prototype implementation is made. The experiment result shows that the screen router employing the proposesed anti-IP spoofing method at the network level is effective enough for the system to remain secure without being invaded by any illegarl packets entering from external hackers. Meanwhile , at the application level. the proposed software approach employing Firewall -1 is proved to be robust enough to provent hackings from the outer point to point protocol connection. Theoretically, it is not possible to provide complete secuirty to the network system, because the network security involove a number of issues raised from low level network equipments form high level network protocol. The result in this dissertation provides a very promising solution to network security due to its high efficiency of the implementation and superb protectiveness from a variety of hacking.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.560-576
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• 2018

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.63-68
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• 2006

This experiment was carried out to investigate the availability of swine slurry on mixed grassland pasture. Three types of fertilizer was used, chemical fertilization($N-P_2O_5-K_2O=210-150-180kg/ha$), no fertilization and swine slurry was further subdivide into three groups (100%, 150%, 200%) as compared to the level of N used in the chemical fertilizer. The results showed that dry mater yield of forage was increased with increasing application level of swine slurry. Production of dry matter of swine slurry 200% was similar to that of chemical fertilizer, but percentage of legume in mixed pasture was lower in chemical fertilization. Percentage of legume was increased with increasing application level of swine slurry. Level of $NO_3-N$ in filtered water was very low in all groups applied with swine slurry. Based on this results the optimum level of swine slurry application is 200% of the normal standard of N fertilizer used in grassland pasture.