• Title/Summary/Keyword: FOC

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Establishment of the Chickpea Wilt Pathogen Fusarium oxysporum f. sp. ciceris in the Soil through Seed Transmission

  • Pande S.;Rao, J. Narayana;Sharma M.
    • The Plant Pathology Journal
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    • v.23 no.1
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    • pp.3-6
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    • 2007
  • Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris(FOC) is the most destructive disease in India. It is seed-borne as well as soil-borne pathogen. The role of seed-borne FOC in introducing and establishing wilt in FOC free soils is unknown. Using seeds of FOC infected chickpea cultivar K 850, we provided an evidence of establishing wilt disease in the FOC free soils within three crop cycles or seasons. In the first cycle, typical wilt symptoms were observed in 24 pots in 41 days after sowing. These 24 pots were used for second and third cycles without changing the soil. These 24 pots were sown with seeds collected from healthy plants of a susceptible cultivar JG 62, one seed per pot and development of wilt symptom was recorded. Wilt symptoms appeared in all the pots 26 days after sowing in second cycle and in 16 days after sowing in third cycle. On selective medium, all of the wilted plants yielded FOC in all the three cycles indicating that the mortality was due to wilt. FOC propagules on selective medium were 172, 1197, and 2280 $g^{-1}$ soil at the end of the first, second, and third cycles, respectively. These studies indicated that Fusarium wilt of chickpea is seed-borne and seeds harvested from wilted plants when mixed with healthy seeds can carry the wilt fungus to new areas and can establish the disease in the soil to economic threshold levels within three seasons.

Estimation of ship operational efficiency from AIS data using big data technology

  • Kim, Seong-Hoon;Roh, Myung-Il;Oh, Min-Jae;Park, Sung-Woo;Kim, In-Il
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.440-454
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    • 2020
  • To prevent pollution from ships, the Energy Efficiency Design Index (EEDI) is a mandatory guideline for all new ships. The Ship Energy Efficiency Management Plan (SEEMP) has also been applied by MARPOL to all existing ships. SEEMP provides the Energy Efficiency Operational Indicator (EEOI) for monitoring the operational efficiency of a ship. By monitoring the EEOI, the shipowner or operator can establish strategic plans, such as routing, hull cleaning, decommissioning, new building, etc. The key parameter in calculating EEOI is Fuel Oil Consumption (FOC). It can be measured on board while a ship is operating. This means that only the shipowner or operator can calculate the EEOI of their own ships. If the EEOI can be calculated without the actual FOC, however, then the other stakeholders, such as the shipbuilding company and Class, or others who don't have the measured FOC, can check how efficiently their ships are operating compared to other ships. In this study, we propose a method to estimate the EEOI without requiring the actual FOC. The Automatic Identification System (AIS) data, ship static data, and environment data that can be publicly obtained are used to calculate the EEOI. Since the public data are of large capacity, big data technologies, specifically Hadoop and Spark, are used. We verify the proposed method using actual data, and the result shows that the proposed method can estimate EEOI from public data without actual FOC.

Rhizosphere Inhibition of Cucumber Fusarium Wilt by Different Surfactinexcreting Strains of Bacillus subtilis

  • Jia, Ke;Gao, Yu-Han;Huang, Xiao-Qin;Guo, Rong-Jun;Li, Shi-Dong
    • The Plant Pathology Journal
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    • v.31 no.2
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    • pp.140-151
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    • 2015
  • Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of $0.96log_{10}ng/g$ to $2.39log_{10}ng/g$ was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of $2.91log_{10}ng/g$ to $3.36log_{10}ng/g$ at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field.

Direct Power Control of a DFIG in Wind Turbines to Improve Dynamic Responses

  • Jou, Sung-Tak;Lee, Sol-Bin;Park, Yong-Bae;Lee, Kyo-Beum
    • Journal of Power Electronics
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    • v.9 no.5
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    • pp.781-790
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    • 2009
  • This paper presents an implementation of a direct active and reactive power control for a doubly fed induction generator (DFIG), which is applied to a wind generation system as an alternative to the classical field-oriented control (FOC). The FOC has a complex control structure that consists of a current controller, a power controller and frame transformations. The performance of the FOC depends highly on parameter variations of the rotor and stator resistances and the inductances. The proposed direct power control (DPC) method produces a fast and robust power response without the need of complex structure and algorithms. One drawback, however, is its high power ripple during a steady state. In this paper, active and reactive power controllers and space-vector modulation (SVM) are combined to replace hysteresis controllers used in the original DPC drive, resulting in a fixed switching frequency of the power converter. Simulation results with the FOC and DPC for a 3kW DFIG are given and discussed, and the experimental results of a test involving identical machines are presented to illustrate the feasibility of the proposed control strategy.

Multinational Management in Shipping : Flag of Convenience (해운의 다국적 경영 : 편의치적)

  • Kim, Eun-Joo;Pak, Myong-Sop;Han, Nak-Hyun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.24
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    • pp.51-72
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    • 2004
  • Over the past fifty years, the share of the World's shipping fleet operating under open registry has grown from 4 % to almost half of the total tonnage. While there has been strong opposition based on the costs of maritime disasters and opposition both from the traditional maritime nations, which have suffered erosion of their fleets, and from labour unions, which point to worker exploitation, the shipping companies have found the greater operational and financial flexibility which accompanies open registry to be a considerable attraction The paper consists of seven sections. Section 1 explains the background and of the study. Section 2 reviews the characteristics and definition of FOC. Section 3 is to identify ship register categories and their competitive conditions. Section 4 tackles the emerging forces of globalisation-the advent of FOC. Section 5 deals with legal maritime framework. Section 6 tackles the current structure and characteristics of FOC vessels. Some concluding comments follow in the last section.

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The Time Course Effects of Conjugated Linoleic Acids on Body Weight, Adipose Depots and Lipid Profiles in the Male ICR Mice Fed Different Fat Sources

  • Hwang, Yun-Hee;Kang, Keum-Jee
    • Nutritional Sciences
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    • v.8 no.4
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    • pp.205-211
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    • 2005
  • This study examined the time course effects of conjugated linoleic acid (CLA) on the body weight, adipose depots and lipid profiles of ICR male mice using two different sources of fats in the diet Ninety eight mice weighing 25 to 30 g were divided into four groups: beef tallow (BT) and fish oil (FO), beef tallow with CLA supplementation (BTC), and fish oil with CLA supplementation (FOC) group. Eight to nine mice in each group were fed with the experimental diets for 1, 2 or 4 weeks, respectively. All mice were fed experimental diets containing $12\%$ of total dietary fat (w/w) with or without $0.5\%$ CLA (w/w). CLA supplementation did not affect the body weight The weight of epididymal and visceral fats were significantly lower in BTC compared to those in BT groups during the periods examined (p<0.05), whereas they were significantly lower in FOC than those in FO only at 4 weeks (p<0.05). The levels of triglycerides in the plasma were significantly decreased in the BTC group than in BT group throughout the experimental periods (p<0.05). But, FOC was only effective at 4 weeks as compared to FO. The levels of total cholesterol and HDL-C were significantly increased in the BTC than in BT during the entire period (p<0.05), whereas there were no difference between FO and FOC on the levelsof total cholesterol and HDL-C. The levels of free fatty acids (FFA) were significantly decreased in BTC than in BT at 1 and 4weeks and in FOC only at 4 weeks as compared to FO (p<0.05). Taken these results together, CLA was more effective in the beef tallow diet in lowering the epididymal and visceral fat weights and triglyceride level rather than fish oil diet with CLA. Furthermore, the effect became clearer at 4 weeks than at one week of the experiment.

Sorption and desoption behaviors of PAHs in soil and sediments

  • Wang, Qiliang;Shin, Sik;Song, Dong-Ik
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.04a
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    • pp.277-284
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    • 2004
  • Batch experiments were conducted to investigate the sorption and desorption behaviors of PAHs (naphthalene, phenanthrene and pyrene) in soils. Three different soils montmorillonite KSF (foc =0.14%), masato (foc =0.08%), and diatomite (foc =0.007%) were investigated. The results of sorption-desorption experiment indicate that the sorption affinity of PAHs was in the order of montmorillonite > masato > diatomite. The Freundlich model was well fitted to the sorption and desorption data. Sorption affinity increased as loc increased. Desorption of PAHs from soils was biphasic composed of reversible and irreversible compartments. Desorption-resistance of phenanthrene in soils was also determined. The biphasic desorption model was used to explain desorption-resistance of phenanthrene in soils. The linear term represents reversible sorption fraction and Langmuinian-type term represents desorption-resistant fraction.

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Active Flutter Control of an Aircraft Wing Using Controller Order Reduction (제어기축차기법을 이용한 항공기 날개의 플러터제어)

  • 고영무;황재혁;김종선;백승호
    • Journal of KSNVE
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    • v.5 no.4
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    • pp.525-536
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    • 1995
  • In this study, an ROC(Reduced Order Controller) is designed to increase the flutter velocity of an aircraft wing, and the effect of ROC on the flight performance is also analyzed. The aircraft wing used in the paper is modelled as a 3 DOF two-dimensional rigid body. In the disign of controller, LQG and BACR(Balanced Augmented Controller Reduction) strategy is used as control algorithm and controller reduction method respectively. Simulation has been conducted to evaluate the effectiveness of ROC on the active flutter control, compared to FOC(Full Order Controller). It has been found that ROC using BACR is much effective than FOC in the sense of computation effort, without sacrificing the active flutter control performance.

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A Study on Detent Force Reduction of PMLSM Using FOC (FOC를 이용한 PMLSM의 디텐트력 저감에 관한 연구)

  • Jin, Sang-Min;Zhu, Yu-Wu;Cho, Yun-Hyun
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.974-975
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    • 2008
  • 영구자석 선형 동기 전동기(PMLSM)의 detent force는 입력전류가 가해지지 않은 상태에서의 영구자석과 철심간의 상호 작용에 의하여 발생된다. 이는 고정자에 관한 이동자의 위치 함수로서 표현 가능하다. 본 논문에서는 이동자의 위치에 따른 detent force를 측정하고, 이를 바탕으로 PMLSM 추력 리플의 원인이 되는 detent force를 저감하기 위한 보상법이 추가된 Field Oriented Control(FOC)을 제안하였다. 또한, 동일한 상황에서의 시뮬레이션 및 실험을 통해 제안된 제어법의 유효성을 입증하였다.

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Comparative Study of Field-Oriented Control in Different Coordinate Systems for DTP-PMSM

  • Zhang, Ping;Zhang, Wei;Shen, Xiaofeng
    • Journal of international Conference on Electrical Machines and Systems
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    • v.2 no.3
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    • pp.330-335
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    • 2013
  • This paper performs two kinds of Field-Oriented Control (FOC) for dual three phase permanent magnet synchronous motor (DTP-PMSM).The first is based on vector space decomposition to study the effect of current harmonics on electromechanical energy conversion. And the second presents the coupling relations between two sets of windings using two d-q transformation. And then this paper has deeply studied the differences between these two strategies, the different effect on the control of harmonic current and the reason for these differences. MATLAB-based Simulation studies of a 3KW DTP-PMSM are carried out to verify the analysis of differences between the two FOC strategies.