• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.140-145
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• 2011

In order to establish the application method of slurry composting & biofilteration liquid fertilizer (SCB LF) in rice cultivation, experiments were studied on split application method of it and effects of it on soil chemical properties and rice yields. Land leveling by rotary tillage within 2 days after application of SCB LF, $NH_4$-N concentration in soil was maintained uniformly in all paddy field. Initial concentrations of $NH_4$-N and $NO_3$-N in soil were high at standard fertilization and 100% application of SCB LF as basal fertilization, however, after tillering stage they maintained similar concentrations in all experimental plots. $NO_3$-N content in infiltration water was slightly lower at 70% application of SCB LF as basal fertilization and 30% application of SCB LF as fertilization at panicle initiation stage than at standard fertilization. Yields of rice by split application of SCB LF were lower at 100% application of SCB LF as basal fertilization, however, those of the other application of SCB LF were similar with that of standard fertilization. In case of rice quality, perfect kernel rates were high and protein contents were lower at non-application and 100% application of SCB LF. Rice quality of 70% application of SCB LF as basal fertilization and 30% application of SCB LF as fertilization at panicle initiation stage were similar with that of standard fertilization.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1053-1063
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• 2011

Social network analysis is the social statistical analysis of any social structure involving a stream of mutual information between observations. In this study we used the results of passes between players in a soccer game. The analysis contents are as follows. (1) Players with important or leading roles are identified. (2) Players are assessed by pass frequency and the success rate of passes. The purpose of this study is for use as basic data for future team strategy, and achieves this by evaluating the role of each individual player within a team. In this study, social network analysis without separating positions is conducted, and is also performed for defensive and attacking positions respectively. The results of this study are as follows: First, when complete team data were available, the players performing leadership roles were Jung-woo Kim, Sung-yeung Ki and Chung-young Lee, whereas Jeong-su Lee acted as a sub-leader. In case of data for defensive positions Jeong-su Lee was a leading player, and in terms of attacking positions, all of the players excelled in the game and could be evaluated as playing lead roles.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.460-464
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• 2007

This study was carried out to elucidate the proper split application method of nitrogen fertilizer for early dry seeding culture of rice in Honam plain area from 1997 to 1998 in Korea. Dongjinbyeo was selected as rice variety for this experiment. The rate of $160kg\;ha^{-1}$ of nitrogen was split as 40-30-30% of total nitrogen at three different application time combination ; T1) basal-5th leaf-panicle formation(PF) stage, T2) 3rd leaf-5th leaf-PF, and T3) 3rd leaf-7th leaf-PF. The content of $NH_4-N$ in soil at 5th leaf stage was higher in top dressing plots(T2, T3) compared with basal application(T1), at 7th leaf stage it was most in top dressed at 3rd leaf and 5th leaf stage, but there was no difference at heading stage. Amount of nitrogen uptake and nitrogen use efficiency was higher in the order of T3, T2 and T1(basal application). Spikelet number per unit area was more in the order of T3, T2 and T1, but rate of ripened grain and 1,000 grain weight were not significantly different among three nitrogen split application methods. Milled rice yields were higher in top dressed plots compared with basal nitrogen application plots. From the results of this experiment, reasonable nitrogen split application method for early dry seeding culture of rice could be 40-30-30% of total nitrogen at 3rd leaf, 7th leaf and panicle formation stage.

• Journal of the Korean Geosynthetics Society
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• v.18 no.1
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• pp.25-37
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• 2019

This study confirms reinforcing effect of geosynthetics in the use of soil at higher water contents as a compaction material on compaction tests, field compaction tests, and numerical analysis. To verify a confined effect, a large mold(area ratio of rammer / mold = 0.19) larger than D compaction mold(area ratio of rammer / mold = 0.33) was performed for compaction. It showed that in the D compaction test, dry density were 0.5~0.6% increases and in the compaction test using the large mold, it were 2.4~3.7% increases at high water contents. It shows that when the area of compacted area is large enough, a confined effect could be arising from the reinforcement of geosynthetics even at high water contents. As a result of analyzing of compaction effects according to 'depth(z/B) from compacted surface' in the field, when not reinforced, the compaction state deteriorated due to the over-compaction and the compaction did not work well. However, when reinforcement of geosynthetics, restraint effect by geosynthetics occurs, it is confirmed that the compaction energy is effectively transferred to the compaction layer and the dry density is increased. Also, through the conceptual model of the behavior of geosynthetic and soil layer, the mechanism in the ground due to reinforcement of geosynthetics is presented and it is verified through finite element analysis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.04a
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• pp.160-161
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• 2005

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.625-633
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• 2017

Fielding Independent Pitching (FIP) is a statistic that measure pitcher performance by eliminating plate appearance outcomes that involve defensive play. FIP uses pitcher dependent outcomes such that walks, strikeouts, hit by pitches, and home runs allowed. The FIP equation derived from linear weights uses three coefficients 13, 3, -2 for evaluating Major League Baseball pitchers. However, these coefficients derived from run value of major league baseball are not suitable to Korea Baseball Organization pitchers due to baseball circumstances. In this study, new FIP called kFIP for Korea Baseball Organization pitchers are provided. We recalculate coefficients and get 14, 3, -1 for evaluating Korean Baseball pitchers. As a result, kFIP is statistically significantly better than FIP at predicting pitcher ERA in KBO League.

• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.23-31
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• 2002

This study shows that tensile strength in moist sand clearly exists due to moisture and it is possible to simply and accurately measure the tensile strength of sands at low moisture contents. These measurements were made through the use of a newly developed direct tension apparatus and technique which are able to produce highly accurate results. The magnitudes of the tensile strengths of these moist and relatively clean sands are not equal to zero, as is widely assumed. Tensile strength increases with increasing moisture content and this trend is more noticeable at increasing relative densities. The influence of tensile strength in geotechnical problems was also examined by considering a simple rigid circular footing in sandy soil. It clearly shows that a small amount of tensile strength can significantly enhance the stability of a geotechnical system.

• Journal of The Geomorphological Association of Korea
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• v.24 no.2
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• pp.15-25
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• 2017

Subi basin is located at the crestline of Taebaek mountains. This paper aims to elucidate the geomorphic development of Subi basin through the analysis of river terraces built in Wangpi-cheon and Banbyeon-cheon. Wangpi-cheon flows northeastward from Subi basin, and Banbyeon-cheon flows southward at the west of Subi basin. Absolute age of terrace is measured by means of OSL methodology, long profile of Wangpi-cheon is made up with 10m interval contour line, and the elevation above river bed of high terraces is measured at the end part of terrace. The results are as follow: Firstly, high river terraces of Subi basin, Wangpi-cheon and Banbyeon-cheon are formed about 40 kyr(MIS 3) being interstadial stage of last glacial period. Secondly, the elevation above river bed of high terraces of Wangpi-cheon and Banbyeon-cheon tends to increase toward upstream. It means that the uplift of Taebaek Mountains influences considerably the formation of their terraces. Thirdly, the elevation above river bed of high terraces at the reach from Seomchon to Suha-ri of Wangpi-cheon tends to decrease toward upstream. This section is captured from Banbyeon-cheon flowing in the opposite direction. River piracy has occurred from the time of formation of Suha-ri high terrace to the time of formation of Hantee wind gap. Finally, for fluvial system of Wangpi-cheon to establish dynamic equilibrium, topographic axis will move toward Banbyeon-cheon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.13-23
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• 2009

To intensively analyze and examine the changes in palatability of cooked rice and structural properties of rice grains influenced by increased nitrogen topdressing during the panicle formation and ripening stage, a series of experiments were carried out using three japonica rice cultivars with contrasting rice quality characteristics. The protein content of brown rice increased maximally up to $35{\sim}47%$ of that in standard N6 plot with the increase in nitrogen topdressing fertilizer during 20 days before heading to 10 days after flowering. The high-yielding rice cultivars showing poor palatability of cooked rice revealed larger increase in protein content of rice grains by increased nitrogen topdressing. Under the same nitrogen level of 15 kg per 10a with nitrogen topdressing at 3 kg/10a, high-yielding rice cultivars, Yumehikari and Reihou showed the significant increase in protein content of brown rice when topdressing was applied at 10 days after flowering as compared with when it was applied at 30 days after transplanting. Although the variation in amylose content of milled rice as affected by nitrogen topdressing level was relatively small, it decreased within 1% with the opposite tendency against increased protein content of brown rice by increased nitrogen topdressing. The total score of sensory evaluation was higher in the order of Hinohikari < Yumehikari < Reihou in panel test. It decreased significantly by increased amounts of nitrogen topdressing during 20 days before heading to 10 days after flowering when nitrogen level was higher than 12 kg/10a. The more poor palatable rice cultivar in panel test revealed the larger decreasing in total score of sensory evaluation by higher nitrogen topdressing rates. All sensory evaluation components were largely affected by the change in protein content of brown rice rather than amylose content of milled rice. The influence of protein content to palatability of cooked rice was larger in poor-palatable rice than in high-palatable rice. The protein content decreased drastically from outer layer to inner layer of rice grains, while the amylose content increased on the contrary. The high-palatable rice exhibited higher distribution of protein content on bran layer but lower distribution of protein content on the layer of polished rice as compared with the poor-palatable rice. Especially, the high-palatable rice showed also significantly lower distribution of amylose content on the outer layer of polished rice as compared with the poor-palatable rice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.3_4
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• pp.79-91
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• 1971

A boat seine has been used as a major fishing gear for catching anchovy (Engraulis japonica) in the southern coastal waters of Korea since 1920s. The original seine was operated by two rowing boats as the haul seine. The rowing boats were, in recent, replaced by powered boats. The net size was enlarged by more than three times the original nit as they began to by operated in the deeper waters of approximately sixty meters. However, there are many problems in the efficiency of the fishing gear to be improved. The authors studied on the hydrodynamic resistance and performance of the boat seine net of the 1/10 scale model in tow. The results are summaried as follows. 1. The hydrodynamic resistance converted from model experiment into the full scale is: $$R_1=30,000\;v^{1.2}\;(0.2{\leqq}v{\leqq}1.0)$$ $$R_2=16,000\;v^2\;(0.2{\leqq}v{\leqq}0.6)$$ where $R_1$ and $R_2$ denote the resistance of whole gear and of bag net in kg respectively, and v the speed of flow in m/sec. 2. In the extension wing, approximately seventy percent of the length of the ground rope from the towing end to the inside-wing slopes down from sea level toward the sea bottom, while the thirty percent of the inside of it remains parallel with th: 5:a level. The performance is regarded to b: inefficient for driving fish shoal into the inside-wing, especially for the shoal diving suddenly. 3. At the towing speed higher than 0.2 m/sec, the trailing edge of the inside-wing is blown backward beyond the seaming line connecting the inside-wing and the mouth of the bag net. It is regarded as an unreasonable performance to drive the fish shoal smoothly into the bag net. 4. At the towing speed higher than 0.2 m/sec, the posterior end of the lower bosom is lifted up above the level of the ground rope of the inside-wing. It is considered that the fish shoal diving suddenly can escape through the discrepancy between the lower bosom and the sea bottom, even if the ground rope of the inside-wing sweeps the sea bottom. 5. The angle of inclination of the upper bosom is estimated as $35\~40^{\circ}$. It seems that the inclination is too steep to drive smoothly the fish shoal diving toward the sea bottom into the bag net. 6. In structure, circumference of the posterior section of the bag net is wider by 1.3 times that of the anterior section. Actually in towing at a speed higher than 0.2m/sec, however, the circumference of the posterior section becomes smaller than that of the anterior section. It is recommended to be designed in a long cylindrical form.