• 한국철도학회논문집
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• 제9권6호
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• pp.766-771
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• 2006

Railway stations are important facilities for transport of passengers and freights. The location of station have an effect on the efficiency of railway transport and operation. In this study, an inspection of the primary factors for station spacing in urban railway has been performed and a review for the propriety of the present states and further improvement has been carried. It may be helpful for proper decisions on the route planning in urban railway. Primary factors for station spacing are 1)train capacity, 2)competitiveness with other transportation, 3)accessibility and 4)construction cost, which is out of consideration in the inspection. From the result of this study, the proper station spacing is about 600m for the accessibility, more over 1.03km for the train capacity and more over 1.4km for the competitiveness with other transportation.

• 한국약용작물학회지
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• 제5권1호
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• pp.67-71
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• 1997

시호(柴胡) 성력화(省力化) 재배기술(栽培技術) 개발(開發)의 일환(一環)으로 기계파종시(機械播種時) 재식밀도(栽植密度) 차이(差異)가 생육과6 수량에 미치는 영향을 검토(檢討)코자 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 인력파종기(人力播種機)를 이용(利用)한 파종(播種) 소요시간(所票時間)은 손파종(播種)에 비하여 조간(條間) 20 및 30cm 처리(處理) 모두 96%의 파종노력을 절감(節減)할 수 있었다. 2. 재식밀도(栽植密度)에 따른 입모수(立毛數)는 조간(條間) 및 주간(株間)이 좁아질수록 많아졌으며, 경장(莖長) 및 마디 수는 차이가 없었다. 3. 주간거리(株間距離)가 좁아질수록 경태(莖太), 분기수(分枝數), 지상부종(地上部重), 규근경(圭根莖), 생체중(生體重) 및 건근중(乾根重)등이 감소(減少)되는 경향(傾向)이었다. 4. 근수량(根收量)은 조간(條間) 20cm 처리(處理)가 30cm보다 증가(增加)되었으며, 주간거리(株間距離)에 따라서는 조간(條間) 20 및 30cm 처리(處理) 모두 밀식(密植)일수록 증가(增加)되어 적정(適定) 재식밀도(栽植密度)는 조간(條間) 20cm에 조파(條播) 또는 주간(株間) 5cm로 나타났다. 5. 재식밀도(栽植密度)를 다르게 할 경우 입모수(立毛數)와 근수량(根收量)과는 정상관(正相關)을 보여 유의성(有意性)이 인정(認定) 되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1989년도 춘계 학술대회지
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• pp.54-55
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• 1989

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.605-608
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• 1993

Breakdown characteristics of a small rod-to-rod microairgap has been studied for obtain an optimum breakdown voltage and an airgap spacing to be used as an emission control means by the electrical arc-burning unburnt carbon particulates exhausted from a power station burner. It is found that the breakdown voltage at the rod-to-rod airgap spacing in the rang of $1{\sim}100{\mu}m$ decreased with decrease in the rod-to-rod airgap spacing. And there were no minimum breakdown voltage on a $V_b$-Pd characteristics which is known as the minimum voltage in Paschen's law in air atmosphere. Breakdown voltages of the airgap at the constant airgap spacing were $V_{b-dc}>V_{b-ac}>V_{b-pulse}$, and it was lowest for the pulse voltage applied. As a result, it is found that a pulse power was one of effective power compared with dc or ac to be used as such an unburnt carbon particulate emission control means and the airgap spacing became to several tens ${\mu}m$, then the breakdown voltages were down to several handreds voltages.

• 한국작물학회지
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• 제7권1호
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• pp.133-137
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• 1969

This experiment was conducted to determine the optimum row width and plant spacing within row under the tropical environment for a leading soybean variety Palmetto and it was carried out at Eakmat Experiment Station in Vietnam. The experiments were arranged in a split plot design with four replications and the test was repeated twice in two years. Variations for seed yield due to the distance between rows were significant at 1 per cent level in 1967 test(dry season growing) and at 5 per cent level in 1968 test. Significant differences for plant height, lodging, maturity, number of branches per plant, and number of pods per plant due to the row width were not found in both tests, while significant differences in difference spacing within row was found in all traits studied. Interaction between width of row and spacing within row for seed yield and plant height were found at five percent level in 1967 test. These results indicate that close planting may increase in seed yield and plant height in both seasons, and decrease in loadging. From these studies, one could be understood that the plant population, particularly in dry season, plays decisive roles on seed yield in soybean culture, and the maximum plant height and minimum value of lodging index were also observed in closest spacing plots. The highest soybean yield in late planting would be expected by a combinations of 30 cm(between rows)${\times}$5cm(between hills) plot, while 40cm ${\times}$ 5cm planting method would be suggested for rainy season growing. Highest seed yield was obtained at closet spacing in both dry and rainy season, and these results led to drilling method in seeding where about 20 seeds per meter of row could be recommended. Besides the seed yield, the close planting may produce some advantages, such as increase plant height and decrease lodging, weeds and erosion of surface soil.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권10호
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• pp.4759-4780
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• 2017

Full Dimension multiple input multiple output (FD-MIMO) architecture employs a planar array design at the Base Station (BS) to provide high order multi-user MIMO (MU-MIMO) via simultaneous data transmission to large number of users. With FD-MIMO, the BS can also adjust the beam direction in both elevation and azimuth direction to concentrate the energy on the user of interests while minimizing the interference leakage to co-scheduled users in the same cell or users in the neighboring cells. In a typical highly populated macrocell environment, modelling the elevation angular characteristics of three-dimensional (3D) channel is critical to understanding the performance limits of the FD-MIMO system. In this paper, we study the throughput performance of FD-MIMO system with varying elevation angular spread and inter-element spacing using a 3D spatial channel model. Our results show that for a typical urban scenario, horizontal beamforming with correlated antenna spacing achieves optimal performance but by restricting the spread of elevation angles of departure, elevation beamforming achieves high array gain with wide inter-element spacing. We also realize significant gains due to spatial array processing via modelling the elevation domain and varying the inter-element spacing for both the transmitter and receiver.

• 전기학회논문지
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• 제61권9호
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• pp.1374-1379
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• 2012

Urban rail transit tends to global grounding system in order to control ground potential rise and potential differences between electric equipments. In addition, global grounding system can discharge the large capacity surge current to the ground safely. Since some railway electric equipments are installed all section of line, the global grounding system connected with the connecting grounding wire is more effectively. However, if the fault occurred in the connecting grounding wire area, some dangerous voltage is generated. So, the installation of additional grounding rod will be required. In this study, the global grounding system is simulated using CDEGS program to analyze the divergence spacing of additional ground rod depending on dangerous electric potential characteristics. Grounding net of the each station is modelled in depending on the size of the platform, and the spacing of the connecting grounding rod are compared 50m, 100m, 250m and 400m. Simulation results considering of earth resistivity and underground condition of the connecting grounding wire, spacing of the connecting grounding rod is that less than 250m to spacing of the ground rod was appropriately confirmed.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1989년도 하계 학술대회지
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• pp.32-33
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• 1989

• 대한교통학회:학술대회논문집
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• 대한교통학회 1996년도 제3회 한-중 국제학술회의
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• pp.95-128
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• 1996

Dipped track profiles between rail transit stations can significantly reduce propulsive energy, braking energy and travel times. This work quantifies their potential benefits for circumstances reflected in various values for dips, speed and acceleration limits, station spacings, and available power. A deterministic simulation model has been developed to precisely estimate train motions and performance using basic equations for kinematics, resistance, power and braking. For a dip of 1% of station spacing, in which gradients never exceed 4%, our results show savings (compared with level tracks) exceeding 9% for propulsive energy, 15% for braking energy and 5% for travel time between stations.

• 한국작물학회지
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• 제51권spc1호
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• pp.193-197
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• 2006

고구마 소형 간식용 생산을 위한 적정 재배기술 확립을 위하여 고구마 삽식기, 재식거리 및 수확시기를 달리하여 소비자의 선호도에 부응한 간식용으로 적합한 소형 고구마 생산을 향상시키고자 시험을 수행하였던 결과를 요약하면 다음과 같다. 1. 소형간식용 고구마생산을 위한 적정 삽식시기는 4월 중순(피복재배)에 삽식거리는 $75cm{\times}15{\sim}20cm$, 6월 중 순(무피복재배) 삽식시 $75cm{\times}15cm$가 적합하였다. 2. 고구마 상저수량은 삽식후 수확일수가 길어질수록 증수되었으나, 삽식후 100일 수확이 80일이나 120일 수확보다 소형 간식용으로 적합한 고구마 괴근 비율이 높았다. 3. 삽식시기 및 삽식거리에 따라 상저수량이 차이가 인정되었으며, 4월 15일 조기 비닐피복재배에서 처리간에 변이폭이 적어 안정적이었다. 4. 보통기(5월) 비닐무피복재배보다 조기(4월) 비닐피복 재배가 농가소득이 $32{\sim}61%$ 증가되어 유리하였다.