• Applied Biological Chemistry
• /
• v.24 no.4
• /
• pp.230-237
• /
• 1981

For the investigation of efficient use of fertilizer nitrogen NPK simple trials were carried out using newly bred Tongil line(japonica indica hybrid selection) and the leading local varieties with sulfur coated area in fields for two years. The yield of Tongil line was higher than that of leading local varieties by 16% in the cool year and 23% is warm year with high solar radiation from NPK simple trials including SCU and 2-split application which were carried in 130 fields at 32 locations. Warm year increased yield by 9% in Tongil but only 3% in the local than the cool year did. Optimum nitrogen level was higher in Tongil by 3.8㎏ in the cool year and 5.5㎏ in warm year than for the local. Yearly variation of optimum nitrogen in the carne variety was greater than varietal variation in the same Year. Two-split application resulted in 1 to 2% of inconsistent yield variation. Sulfur coated urea increased yield by average 2 to 4% even at 20% reduced rate of nitrogen. It was remarkably effective in same $(27{\sim}39%)$, virgin (20%) and unmatured (10%) soils.

• Korean Journal of Soil Science and Fertilizer
• /
• v.8 no.4
• /
• pp.177-181
• /
• 1975

The pot experiment was conducted primarily to clarify the relationship between lime application and they amount of potassium for the basal and top dressings on paddy rice. (Orizae sativa L. cultivar; variety Jinheung) The soils mixed with lime and without lime were separately filled in to 0.2827 a. open-bottom concretepots. The soil with lime was treated with slaked lime, at two weeks before transplanting to correct soil pH. around 7.0. The total amount of potassium 12 kilograms per 10a was applied by two or three split doses during transplanting, 19 days after transplanting and primodial stages. The results of experiment obtained are summarized as follows: 1. The application of potash in the rate of 4kg per 10a or less for basal dressing and the remaining amount of potash for top dressing at 19 days after transplanting and primodial stage or one top dressing, at primodial stage have increased the yield of paddy with increased number of panicles per hill, milliequivalent ratio of $K^-/Ca^{++}+Mg^{++}$ in leaves in the later stage of growth, number of ripened grains per panicle, and rate of grain maturity. 2. On the other hand, the greater the amount of potassium given for the basal dressing (over 4kilograms per 10a), the smaller number of tillers and panicles were resulted. And the tendency was considered chiefly due to high salt concentration at the early stage of rice growth.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1714-1719
• /
• 2003

Antilock Brake System (ABS) is indispensable safety equipment for vehicles today. In order to develop new ABS ECU suitable for pneumatic brake system of a bus, a Hardware In-the-Loop Simulation (HILS) System was developed. In this HILS, the pneumatic brake system of a bus and antilock brake component were used as hardware. For the computer simulation, the 14-Degree of Freedom (DOF) bus dynamic model was constructed using the Matlab/Simulink software package. This model was compiled and downloaded in the simulation board, where the Power PC processor was used for real-time simulation. Additional commercial package, the ControlDesk was used to monitor the dynamic simulation results and physical signal values. This paper will focus on the procedure and results of evaluating the ECU in the HILS simulation. Two representative cases, wet basalt road and $split-{\mu}$ road, were used to simulate real road conditions. At each simulated road, the vehicle was driven and stopped under the help of the developed ECU. In each simulation, the dynamical behavior of the vehicle was monitored. After enough tests in the laboratory using HILS, the parameter-tuned ECU was equipped in a real bus, which was driven and stopped in the real test field in Korea. And finally, the experiment results of ABS equipped vehicle's dynamic behavior both in HILS test and in test fields were compared.

• Korean Journal of Environmental Biology
• /
• v.32 no.4
• /
• pp.327-334
• /
• 2014

Emission reduction of $CH_4$ (methane gas) from rice paddy soil is a very important measure for climate change mitigation in agricultural sector. In this study, we investigated the changes in crop yield and $CH_4$ emissions in response to application of biochar and fertilizers. The experimental site is located in Hwasung, Kyunggido and experimental design is the split-plot method with three replicates. Treatments included rice straw (RS) and biochar (BC) amendments nested with the conventional NPK fertilizer (NPK) and slow release fertilizer (SRF). Control was also prepared with the soil with the conventional NPK fertilization with no amendment. Measurement of $CH_4$ emission was conducted during the growing season of 2014 using a dynamic chamber method. The results showed that application of rice straw increased daily $CH_4$ emission rate by 15%, while application of biochar reduced daily $CH_4$ emission rate by 38%. When we combined biochar application with slow release fertilizer, $CH_4$ emission was reduced by 45%. Further, the crop yield was also increased in all treatments compared with the control except for the treatment of rice straw application with slow release fertilizer. Overall results imply that biochar amendment to agricultural soil can be an effective strategy to decrease annual $CH_4$ emission with no reduction in crop yield.

• Proceedings of the KIEE Conference
• /
• 2003.07d
• /
• pp.2025-2027
• /
• 2003

미끄럼방지 제동장치는 차량의 급제동 시 바퀴의 장김을 방지하여, 바퀴의 슬립을 최적으로 유지 시킴으로써 제동거리를 단축시키고, 운전자가 차량 조향성을 유지할 수 있게 만드는 차량 안정장치이다. 이 장치는 비행기의 착륙거리를 줄이기 위해 개발된 이래로, 철도 및 차량 등에도 널리 적용되고 있으며, 국내에서도 이미 승용차를 위주로 양산되고 있는 추세이다. 이러한 미끄럼방지 제동 장치는 공압 브레이크 장치를 사용하는 대형차량 분야에서는 아직 국내에서 적용된 사례가 없었으나, 지난 3 년간의 연구개발의 성과로 대형 버스에 적용 가능한 미끄럼방지 제동장치의 전자제어기가 개발 완료되었으며, 국제 규격을 바탕으로 국내 현실에 적합한 미끄럼방지 제동장치 장착 대형차량의 시험 규격을 정하여 이 규격에 의거 제동시험을 실시하고 개발 제어기의 성능을 평가하였다. 각 제동 시험은 $\mu$-Jump 제동시험 및 Split-$\mu$ 제동시험 등의 직진 주행 중 급제동시험, 급제동 중 차선변경 시험, 장애물 회피 제동시험 등을 포괄하며 국제적인 규격을 기준으로 정한 독자 규격을 만족하였다. 본 논문에서는 공압 브레이크를 장착한 대형차량의 미끄럼방지 제동장치의 제동성능평가 시험방법을 소개하고, 이 방법에 의해 성능평가 시스템 및 측정 시스템을 구성하여, 개발 전자제어기의 우수성을 확인하였으며, 그 측정결과의 일부를 제시하였다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.1
• /
• pp.25-29
• /
• 2012

Agriculture activities account for 58% of total anthropogenic emissions of nitrous oxide ($N_2O$) with global warming potential of 298 times as compared to carbon dioxide ($CO_2$) on molecule to molecule basis. Quantifying $N_2O$ from managed soil is essential to develop national inventories of greenhouse gas (GHG) emissions. The objective of the study was to compare $N_2O$ emission from livestock compost applied arable land with that for fertilizer treatment. The study was conducted for two years by cultivating Chinese cabbage (Brassica campestris L.) in Chuncheon, Gangwon-do. Accumulated $N_2O$ emission during cultivation of Chinese cabbage after applying livestock compost was slightly greater than that for chemical fertilizer. Slightly greater $N_2O$ emission factor for livestock compost was observed than that for chemical fertilizer possibly due to lump application of livestock compost before crop cultivation compared with split application of chemical fertilizers and enhanced denitrification activity through increased carbon availability by organic matter in livestock compost.

• 전기의세계
• /
• v.17 no.3
• /
• pp.29-38
• /
• 1968

The development of the frequency converter using semiconductor enables to easily control the speed of A.C. motors. It is now technically possible and economically feasible to provide them with power at variable frequency, using silicon-controlled-rectifier (or thyristor) inverters. In such a case, if an induction motor is to be operated efficiently over a wide speed range, it must be supplied from a variable-frequency source whose frequency is adjustable over a range similar to that required for the motor speed. It is desired to observe how several characteristics are changed such as primary current, torque-speed, etc. Although the characteristics could be obtained by means of the conventional method, it requires very complicated calculation. It is assumed that the charateristics above are easily investigated by means of current diagram method from variable circuit constants relating to the motor which is designed in rated frequency. In this paper, the results of the study on the current-diagram method and its application are described as follows; (1) In order to discuss the construction of current diagram, the equation of the stator current with adjustable frequency was derived for applying the Current Diagram Method. (2) The radius, the center of the current circle and current vector locus at any desired frequency could be easily determined with the aid of both above mentioned equation and the standard current diagram at reference frequency. (3) This method could be applicable to the various types of Induction Motors, and this paper has dealt with its application to the capacitor, split-phase and 2-phase types of motors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.427-428
• /
• 2008

We have studied design and application about an self generation equipment for underground power transmission cable. The split CT(Current Transformer), which has the applicable underground power transmission cable, was manufactured through electromagnetic simulation of magnetic core. And manufactured the AC-DC converter that supplied stable DC power for PLC modem when current of power line has more than 150A. An self generation equipment using the CT and AC-DC converter get into operation the PLC modem consistently. As a result, the underground power transmission cable was showed the application possibility through the stable communication and network characteristics.

• Journal of the Korean Geosynthetics Society
• /
• v.7 no.3
• /
• pp.1-7
• /
• 2008

The geotextile tube shall be sewen with geotextile longitudinally in the shape of hose and it shall be filled hydraulically through filling ports at the proper intervals to construct structure. Geotextile container shall be sewen after spreading of geotextile on the split barge and sealed shut after the filling soil, and then moved and positioned at the required position. And the geotextile container passes through the bottom of barge by opening split barge and drops to the seabed to form structure. This structure for the ${\bigcirc}{\bigcirc}$ project, UAE and we would propose that geotextile containment for core material of power plant breakwater to be constructed for lower bunds with containers up to -4.0m and do upper parts with the structures of tube up to 0.0m. For the application of proposed geotextile containment, review on stability of breakwaters and design consideration were adopted. The evaluation on stability of geotextile containment was classified by 3 items, internal design consideration for material selection, reviews on stability for individual and global structure. In this research, the geothermal analysis was performed to estimate the geothermal behavior of central breakwater. Central breakwater is located boundary of intake and outfall channel, it is mean that the central breakwater is thermal boundary of intake low temperature sea water and outfall high temperature sea water. Therefore, it is required to be designed a low permeability to ensure no mix of intake and outfall waters.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.233-236
• /
• 2000

The acoustical response of fish depends on size and physical structure na, most important, on the presence or absence of a swimbladder. Acoustic scattering models for swimbladdered fish represent a fish by an ideal pressure-release surface having the size and shape as the swimbladder. Target strength experiments of red seabream (Chrysophrys major) have been conducted using 38 (split-beam), 120 (split-beam) and 200kHz (dual-beam) frequencies. At each start of each experiment, the live fish are placed in the cage at the surface, then the cage is lowed to about $4{\cal}m$ depth where it remains during the measurements. To test the acoustic models, predictions of target strength based on swimbladder morphometries of 10 red seabream offish total length from $103{\cal}mm{\;}to{\;}349{\cal}mm$ ($3 <$TL/\lambda$ < 45)are compared with conventional target strength measurements on the same, shock-frozen immediately after caged experiments. X-ray was projected along dorsal aspect to know the morphological construction of swimbladder. and fish body. At high frequencies, Helmholtz-kirchhoff(HK) approximation would greatly enhance swimbladdered fish modeling. Sound scattering model [HK-ray approximation model] for comparison to experimental target strength data was used to model backscatter measurements from individual fish. The scattering data can be used in the inverse method along with multiple frequency sonar systems to investigate the adequacy of classification and identification of fish