• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.295-306
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• 1994

The object of this experiment was to suggest the suitable cutting frequency and cutting height for orchardgrass (0G)-red clover(RC) mixtures under the intensive system of short-term pasture utilization. The fields trials were conducted over 3-year period(1991-1993) to evaluate dry matter yield, botanical composition, chemical composition and CP, DDM yield on the cutting frequency (30, 40 and 50 days) and cutting height(5, 7 and 9cm) With decreasing the cutting frequency, the DM yield of OG in the OG-RC mixtures was significantly increased(P

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.17-26
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• 1996

This experiment was carried out to investigate the effects of endophyte staWendophyte-free and -infect) and cutting frequency(3, 4, 5 and 6 timeslyear) on the forage quality of tall fescue(Festuca crnrtzdit~crcerr Schreb.) at the Experimental Field of Grassland and Forage Crops Division. National Livestock Research Institute, Suweon, from 1993 to 1994. 'Ihe results obtained are summarized as follows: CP content of tall fexue was increased with endophyte-free and cutting frequency for two varieties. Crude protein yield(CPY) of tall fescue in 1993 was increased with endophyte-free and cutting frequency for two varieties(P<0.05). In 1994, however. CPY of endophyte-free tall fescue was slightly lower than that of endophyte-infected tall fescue and the higher CPY was observed when tall fescue was harvested 6 times per year. NDF content of tall fescue was not different between endophyte-infected and -free. NDF was decreased with cutting frequency for two varieties in 1993, however. it was not influenced by the endophyte and cutting frequency in 1994. ADF content of tall fescue was not different between endophyte-infected and -free. and it was decreased with cutting frequency for two varieties. IVDMD was not influenced by endophyte, however, it was increased with cutting frequency for two varieties. Based on the results of this experiment, it is suggested that a slight increase in forage quality could be obtained from endophyte-free tall fescue and the quality was increased with frequent cutting.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.33-42
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• 1996

In this study, the adequate cutting frequency and level of cattle slurry nitrogen application were investigated for the production of Reed canarygrass. Higher relative dry matter yields were recorded in 2nd cut in 3 cutting frequency, 3rd cut in 4 cutting frequency and 4th cut in 5 cutting frequency respectively. With no fertilization, mean dry matter yields per year were 6.4~7.5 tons/ha and the highest yield appeared in 3 cutting frequency. The increased application of cattle slurry nitrogen resulted in the increased dry matter yield. Significantly higher dry matter yields than that of no fertilization were recorded in fertilization of 180 kg cattle slurry-N per year in 3 cutting frequency, 120 kg in 4 cutting frequency and 300 kg in 5 cutting frequency respectively. Efficiency of dry matter production with cattle slurry nitrogen application (kg DM/kg N) was higher in 120 kg N, 30 kg N and 90 kg N/ha/cut in 3, 4 and 5 cutting frequency respectively. In each cutting frequency, the higher efficiency of dry matter production appeared in 1st cut in 3 cutting frequency, and 2nd cut in 4 and 5 cutting frequency respectively. Economic slurry N level (kg/ha) was 462.7~525.3 kg/ha in 3 cutting frequency, and 353.1~423.2 kg/ha and 380.1~424.4 kg/ha in 4 and 5 cutting frequency respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.2
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• pp.123-134
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• 1997

The effects of cutting 6equency and nitrogen fertilization on feed values of reed canarygrass were investigated in uncultivated rice paddy and the attemp was made to estimate the economical and efficient levels of nitrogen fertilization for the increased production of nutrients in reed canarygrass. The results are summarized as follows; 1. Crude protein(CP) content was higher at 1st cut of all treatments(12.5% in 3 cutting 6equency; 19, 7% in 4 cutting frequency; 22.5% in 5 cutting kquency). However, Total Digestible Nutrients(TDN) and Relative Feed Value(RFV) in 3 and 4 cutting 6equencies were higher at 3rd cut(63.5%, 126.8) and 4th cut(65.7%, 146.4) respectively in which the contents of Neutral Detergent Fiber(NDF) and Acid Detergent Fiber(ADF) were lowest. In 5 cutting frequency, 1st cut showed the highest TDN and RFV as 70.5% and 232.4 respectively. 2. The level of nitrogen fertilization affected CP content of reed canarygrass. Nitrogen fertilization of 120kgl halcut showed high CP contents of 11.4, 14.7 and 16.5% in 3, 4 and 5 cutting eequency respectively. In 3 and 4 cutting frequency, TDN and RFV were highest with nitrogen fertilization of 90kg/ha/cut where NDF and ADF were lowest, however those in 5 cutting frequency were highest with nitrogen fertilization of 30kg/ha/cut. 3. The yields of CP varied according to the number of cutting frequency and those were 0.45~0.65 in 3 cutting hquency, 0.35~0.50 in 4 cutting frequency, and 0.19~0.67tond/ha in 5 cutting 6equency respectively and TDN was 2.09~3.60, 1.64~2.77 and 0.73~2.96tons/ha respectively. 4. The ratios between the yields of CP and TDN were 5.48, 4.60 and 4.34 in 3, 4 and 5 cutting 6equency respectively and it indicates lower ratio in result of higher number of cutting 6equency. 5. Higher nitrogen fertilization increased the yields of CP and TDN. The yields of CP were higher in 5 cutting frequency as 1.55~2.62tons/ha than of 3(1.20~1.91tons/ha) and 4 cutting frequency(1.35-2.23tons/ha). The yields of TDN were 6.31~9.93, 5.99~9.99 and 7.16~10.57tons/ha in 3, 4 and 5 cutting frequency respectively. 6. The levels of nitrogen fertilization for high production efficiency of crude protein(kg CPYkg N) was estimated as 113.4~302.5kg/ha and it resulted in 1.44~2.09ton/ha of CP yields. The levels of nitrogen fertilization for high production efficiency of dry matter was 199.2-361.3kgha in which nitrogen were fertilized below 400kg/ha and it resulted in 1.64~2.17ton/ha of CP yields. 7. The levels of nitrogen fertilization for high production efficiency of total digestible nutrients(kg TDNYkg N) were 149.9~294.1kg/ha in 3 and 4 cutting kequency and it resulted in 8.66~8.89ton/ha of TDN yileds. With the levels of nitrogen fertilization for high production efficiency of dry matter of 199.2~361.3kg/ha, TDN yields were high as 8.77~9.94ton/ha.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.55-60
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• 2000

This experiment was carried out to determine the effect of cutting frequency(3rd and 5th cut) and level of nitrogen fertilization(l50 + liquid manure, 300 and 450kgha) on growth characteristics, dry matter yield and nutritive vaule of reed canarygrass(Pha1aris arundinacea L.), at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon. Plant height of 3rd cutting(79.2cm) was significantly higher than that of 5th cutting(58.0cm). And dry mattter yield of cutting frequency was observed in 3rd cutting(16,902kgPna) and 5th cutting(l7,833kg/ha) As the nitrogen fertilization was increased, DM yield was significantly increased(p<0.05). When the nitrogen fertilization was applied at the level 150 + liquid manure, 300 and 450kg, dry matter yields were 16,5 12, 17,123 and 18,368kg/ha, respectively. The contents of neutral detergent fiber(NDF), acid detergent fiber(ADF) and in vitro dry matter digestibility(1VDMD) were similar among cutting frequency. However, slightly higher NDF, ADF and IVDMD contents were found in 5th cutting, but there was not affected by nitrigen fertilization. Based on the results of this experiment, it were indicated that to 5th cutting and 450kg nitrogen fertilization could be obtained from the increase of dry matter yield and nutritive value (Key words : Cutting frequency, Nitrogen fertilization, Dry matter yield, Nutritive Value, Reed canarygrass)

• Journal of Welding and Joining
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• v.14 no.5
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• pp.59-68
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• 1996

This study was aimed to characterize the laser cutting process for the cold rolled stainless steel sheet. The principal process parameters of the cutting process were applied to both the continuous wave form and the pulsed wave form for the laser output mode. The laser-oxygen cutting process and the laser-nitrogen cutting process were also considered to characterize the quality and efficiency of the cutting process. The laser-oxygen cutting process revealed the better productivity than the laser-nitrogen cutting process, since the laser energy and the exothermic oxidation energy exerted on the laser-oxygen cutting process simultaneously during the entire cutting process. However, the straightness of the cutting section, which was considered as the most important factors, was inferior to that of the laser-nitrogen cutting process due to the formation of chromum oxide on the cutting surface. Frequency and duration of the pulsed wave form act as the main factors for the better quality, When the frequency increased from 100 Hz to 200 Hz and the duty increased from 20% to 40%, the quality factors such as the height of dross and the surface roughness were improved remarkably. The increase in the frequency from 200 Hz to 300 Hz, on the other hand, revealed the less effective in the cutting quality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.257-263
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• 1994

The experiment was canied out to investigate the effects of cutting frequencies (3, 4 and 5 cuts per year) in relation to fertilization of mineral nitrogen on crude protein yield and the contents of crude protein and acid detergent fibre in orchardgms(Dacty1is glomerata L.). Tne results are as follows : 1. The content of crude protein increased according to the increase in cutting frequency and showed the highest in the 1st cut in all treatments. At 4 and 5 cutting frequencies per year, the content of crude protein increased in a large extent according to the increased fertilization of mineral nitrogen. However at 3 cutting frequency, the content of cmde protein appeared higher for no application of mineral nitrogen than for the treatments with fertilization. 2. 'Ihe content of acid detergent fibre(ADF) was considerably reduced at 4 and 5 cutting frequencies and in all treatments, the lowest were recorded in the 1st cut or in the last cut. At 3, 4 and 5 cutting frequencies, the highest ADF were shown in the 2nd cut, 3rd cut and 3rd cut respectively. However, the general trend was that the content of ADF was greatly reduced according to increased level of mineral nitrogen fertilization. 3. The yeild of cmde protein was the highest at 5 cutting frequency(l.2 ton DMIha) and it indicated that the yield of cmde protein increased in accordance to the increase in fertilization of mineral nitrogen and cutting frequency. 4. In all treatments, positive correlation(p<0.001) between the yeilds of crude protein and annual dry matter yield appeared. Negative correIation(p

• Design & Manufacturing
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• v.16 no.3
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• pp.39-43
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• 2022

In this study, we designed an vibration cutting tool that can achieve improvements such as low cutting force, interrupted chip evacuation and better surface quality of cutting performance to obtain high-quality surface roughness and improvement of tool wear, which is an issue in the machining of high-hardness mold steel. Among the resonance frequency modes of the vibration cutting tool, the bending mode was used to maximize the driving amplitude of the vibration tool tip, and the resonance frequency was confirmed through the finite element method. After measuring the actual resonant frequency of the designed tool using an optical fiber sensor, the cutting force and machining surface of vibration cutting and conventional cutting were compared and analyzed in the turning process of high hardness mold steel (STAVAX). As a result of the experiment, the cutting force was reduced by about 20 % compared to the conventional cutting process, and the surface roughness was also improved by about 60 %. This study suggested that the tool wear and surface quality of high-hardness steel can be improved through the vibration cutting method in the machining of high hardness mold steel.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.76-85
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• 1993

Based on the cutting force model, three-dimensional optimal design model was developed and optimal designed tool which is minimized cutting force is developed by computer simulation technique. In this model the objective function which is minimized resultant cutting force was used and the variables are radial rake angle, axial rake angle, lead angle of the tool. The cutting forces using conventional and optimal tools by simulation, are compared and analyzed in time and frequency domains. In time domain the cutting force of optimal tool in feed direction was more reduced and less fluctuated than that of conventional tool. Cutting forces of optimal tool in X-and Z-directions are shown a little increased than those of conventional tool. In frequency domain amplitude of insert frequency components of optimal tool in feed direction was more reduced than that of convent- ional tool. The amplitudes of insert frequency components of optimal tool in X-and Z-direction are a little increased than those of conventional tool. As the reduction of amplitude and fluctuations of the cutting force, Optimal tool is considered that tool life and surface roughness would be improved, and stable cutting would be expected.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.3
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• pp.129-134
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• 1989

This experiment was conducted to evaluate the effect of cutting frequency and nitrogen fertilization on th change of vegetation and the yield of dry matter on the different mixture combination of permanent pasture. 1. DM yield was increased as the increasing Arrhenatherum elntius but was decreased as the increasing Tkisetum fkavescens. 2. DM yield was unaffectdd by the different mixture combination of permanent pasture eventually. 3. In case of cutting frequency, 2-cutting showed higher DM yield than that of 3-cutting, and N-fertilization level showed significant increase in DM yield as the increasing N-level, especially 2-cutting block of N-3 showed the highest yield and 3-cutting block of N-l showed the lowest yield. 4. Mixture combination, N-level and cutting frequency did not show significant changes in DM yield of permanent pasture eventually.