• Title/Summary/Keyword: unstable plant

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Major Characteristics of Hordeum bulbosum and Haploid Production of Cultivated Barley by Pollinating with H. bulbosum L. (야생보리(Hordeum bulbosum)의 주요 특성 및 이를 이용한 보리 반수체육성)

  • 정동희;민경수;천종은
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.6
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    • pp.531-536
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    • 1993
  • Bulbosum method, which haploids are developed by pollinating with H. bulbosum have been productive to be recommended as an effective method for the production of genetically stable normal barley hybrids. The purpose of this study is to investigate several characters of H. bulbosum, seed set and embryo development rate pollinated with H. bulbosum in order to establish a method for improvement of embryo development and to find conditions favoring plant development from the embryos cultured in vitro. Three lines of H. bulbosum used as pollinators: GBC(2${\times}$), Spenish diploid(2${\times}$) and var. Jaaska (4${\times}$) were morphologically similar, having characteristically narrow leaves, narrow and long culms, long spikes and anthesis duration in comparison with H. vulgare. H. bulbosum, var. Jaaska(4${\times}$) on being pollinated to barley cultivars, increased embryo formation by 8% and plant development in vitro by three times compared to the other diploid lines. the plants developed were not normal barley hybrids but had some H. bulbosum chromosomes uneliminated, indicating that the line was unstable as a pollinator to induce barley haploids.

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A Comparative Study on a Supplier Credit and a Buyer Credit in International Transactions of Capital Goods - Focusing on Industrial Plant Exports, Shipbuilding Exports, and Overseas Constructions -

  • Kim, Sang-Man
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.48
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    • pp.127-155
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    • 2010
  • The international transactions of capital goods such as industrial plant exports, overseas constructions, and shipbuilding exports, are so huge that tremendous amount of funds are required, and that most of the loans are long-term credits of over five years. In the export of huge capital goods, financing is more crucial than technology itself. Some of the importing countries are developing ones that are politically and economically unstable. Therefore the financing mechanism for these transactions is conclusive in winning these projects. Global financial market instability caused by US sub-prime mortgage financial crisis expanded all over the world, and the international transactions have been decreased due to global credit crisis. This indicates how much influential the financing market is in international transactions. The financing schemes are classified into supplier credit and buyer credit by who provides the financing. A supplier credit is a credit extended by an exporter(seller) to an importer(buyer) as part of an export contract. Cover for this transaction may be extended by an export credit agency('ECA') to the exporter. In a sales contract a seller shall provide fund required to manufacture goods, and in a construction contract a contractor shall provide fund required to complete a construction. A buyer credit is an arrangement in which an exporter enters into a contract with an importer, which is financed by means of a loan agreement A Comparative Study on a Supplier Credit and a Buyer Credit in International Transactions of Capital Goods 155 where the borrower is the importer. In a sales contract a buyer shall provide fund required to manufacture and procure the goods, and in a construction contract an owner shall provide fund required to complete a construction. Therefore an exporter is paid on progressive payment method. A supplier credit and a buyer credit have their own advantages and disadvantages in the respect of the parties respectively. These two financing methods are selectively used considering financing conditions such as funding cost, importer's and/or exporter's financial conditions, importing country's political risk.

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Summer Marine Algal Floras and Community Structures in Taean Peninsula, Korea (태안반도 하계 해조상 및 군집구조)

  • Yoo, Hyun-Il;Lee, Ji-Hee;Lee, Ki-Hun;Baek, Sang-Hum;Heo, Young-Beam;Noh, Hyoung-Soo;Choi, Han-Gil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.4
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    • pp.210-219
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    • 2007
  • The benthic marine algal flora and community structure were examined at five sites of the Taean Peninsula, Korea, during July-August 2005. Ninety-six algal species were Identified, including 14 green, 21 brown, and 60 red algae, and 1 marine plant. The common species that occurred at the five sites were Sargassum thunbergii, Gelidium divaricatum, Caulacanthus okamurae, Gracilavia vermiculophylla, and Neorhodomela aculeata. Sthunbergii was the dominant species in terms of coverage and biomass at ail of the study sites. The average biomass varied from $23.72g/m^2$ in dry weight at Chaeseokpo to $66.43g/m^2$ at Padori. The species could be divided into six functional groups in terms of morphological characteristics: 41 coarsely branched forms, 25 filamentous forms, 16 sheet forms, 7 thick leathery forms, including the marine plant Phyllospadix iwatensis, 4 crustose forms, and 3 Jointed calcareous forms. The seaweed communities at the five study sites were unstable and the environmental conditions were bad or very bad. Among the five study sites, the ecological evaluation index (EEI) and diversity index (H') were maximal at Padori at 2.29 and 1.98, respectively. By contrast, the dominance index (DI) was minimal at Padori (0.55) and maximal at Baramarae (0.96). Therefore, we conclude that the rocky shore at Padori has the best environment among the five study sites, although the species richness and biomass of seaweeds have declined continuously over the last 10 years.

A Simulation Method of PID Tuning with Process Modeling in Operating Nuclear Power Plants (가동원전에서 공정모델링을 통한 PID 튜닝 시뮬레이션 방법)

  • Min, Moon-Gi;Jung, Chang-Gyu;Lee, Kwang-Hyun;Lee, Jae-Ki;Kim, Hee-Je
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.4
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    • pp.290-294
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    • 2014
  • PID(Proportional, Integral, Derivative) controller is the most popular process controllers in nuclear power plants. The optimized parameter setting of the process controller contributes to the stable operation and the efficiency of the operating nuclear power plants. PID parameter setting is tuned when new process control systems are installed or current process control systems are changed. When the nuclear plant is shut down, a lot of PID tuning methods such as the Trial and Error method, Ultimate Oscillation method operation, Ziegler-Nichols method, frequency method are used to tune the PID values. But inadequate PID parameter setting can be the cause of the unstable process of the operating nuclear power plant. Therefore the results of PID parameter setting should be simulated, optimized and finally verified. This paper introduces the simulation method of PID tuning to optimize the PID parameter setting and confirms them of the actual PID controller in the operating nuclear power plants. The simulation method provides the accurate process modeling and optimized PID parameter setting of the multi-loop control process in particular.

Identification and Characterization of SOD Isoenzymes in Acanthopanax koreanum Plants (섬오갈피나무에서 SOD Isoenzyme의 식별 및 특성규명)

  • 오순자;박영철;김응식;고석찬
    • Korean Journal of Plant Resources
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    • v.12 no.3
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    • pp.234-239
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    • 1999
  • The isoenzyme patterns and activities of superoxide dismutase(SOD) were investigated from leaves of Araliaceae plants. Of the eight isoenzymes, two isoenzymes(SOD 4 and SOD 6) were prevalent to leaves of Araliaceae plants. The patterns of these two isoenzymes were most various in the leaves of Acanthopanax senticosus for. inermis, while their activity was highest in the leaves of A. koreanum. These two isoenzymes were respectively identified as Fe-SOD and CuZn-SOD, based on selective inhibition with KCN or$H_2O_2$. The SOD isoenzyme patterns did not differed among stem barks, root barks and leaves of A. koreanum. However, the activities of Fe-SOD and CuZn-SOD were higher in the root bark and in leaves, respectively. Both of Fe-SOD and CuZn-SOD were stable for 1 hr at 30-4$0^{\circ}C$, while unstable above 5$0^{\circ}C$.

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Trend of Fire Outbreaks in Ghana and Ways to Prevent These Incidents

  • Addai, Emmanuel K.;Tulashie, Samuel K.;Annan, Joe-Steve;Yeboah, Isaac
    • Safety and Health at Work
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    • v.7 no.4
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    • pp.284-292
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    • 2016
  • Background: In Ghana, fire incidents have become a regular occurrence, with thousands of lives and millions of dollars lost every year. Hardly a day passes without news of a fire outbreak in some part of Ghana, causing fear and panic among the people. This generates much discussion centering on rumors relating to politics, sabotage, misfortune, religious differences, etc. This article seeks to discuss the trend of fire incidents occurring in Ghana from 2000 to 2013 and the different ways to prevent these incidents. Methods: The pattern of fire incidence in Ghana as a whole as well as in each region is discussed. The study took into consideration the causes, mechanisms, as well as preventive measures against the fire menace. Data were obtained from the head office of Ghana's national fire service. Results: It was noticed that in general the rate of fire incidence increased each year. This increase was attributed to several factors: rate of population growth and industrialization, unstable electricity, urbanization, negligence, illegal electrical connection, etc. The cause of fire was categorized into domestic, industrial, vehicular, institutional, electrical, commercial, bush, and others. Among these causes, domestic fire accounted for 41% of the total number of fire incidents in the country. Conclusion: Finally, this study presents several recommendations to help prevent and mitigate fire incidents in Ghana.

Design of Double Digital Controller to Improve Performance for the Silent Discharging Ozonizer (무성방전 오조나이저의 성능개선을 위한 2중 디지털 제어기의 설계)

  • Park, Jee-Ho;Kim, Dong-Wan;Woo, Sung-Hoon;Roh, In-Bae;Woo, Jung-In
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.55 no.1
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    • pp.13-20
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    • 2006
  • In this paper, a control method of ozone generator for a tiny deodorizer is proposed, and also a cooling technique is described which is cooling down the flowing air gap into a silent discharger to $2[^{\circ}C]$ to generate ozone of high density and diffusing power. As the digital control system for this method, a double feedback loop is designed which detects the voltage and current of equivalent capacitor of the discharger and compensates for the poor power waveform caused by the noise at high discharging frequency. During the plant modeling of this system, computing time factor is considered as a unique parameter of the power system to improve the respond characteristics with regard to fluctuating load and to replenish the computing time delay of the controller. Through the experiment, sinusoidal input current for discharger can be acquired and all the effectiveness of this accurate control system over unstable ozone discharger are proved.

Enhanced production of hGM-CSF by temperature shifting in transgenic Nicotiana tabacum cell suspension cultures

  • Kim, Yong-Hoon;Lee, Sang-Yoon;Kim, Dong-Il
    • 한국생물공학회:학술대회논문집
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    • 2003.10a
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    • pp.329-333
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    • 2003
  • Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) is a glycoprotein that stimulates the production of granulocytes, macrophages and white blood cells. hGM-CSF secreted by transgenic Nicotiana tabacum suspension cells was unstable in the culture medium and rapidly degraded by extracellular preteases. In order to reduce extracellular pretense activity, culture temperature was lowered. Then, the production of hGM-CSF by transgenic plant suspension cell cultures could be enhanced by reduced degradation of hGM-CSF at low temperature.

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Vibration Control of Condensate Motors in Nuclear Powerplant By Bearing Redesign (베어링 재설계에 의한 원전 COP motor의 진동 제어)

  • Lim, Do-Hyeong;Kim, Won-Hyun;Lee, Jong-Moon;Lee, Soo-Mok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.264-269
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    • 2008
  • This paper presents the summary of control of abnormal vibration found in the COP motors of a nuclear power plant. All six identical units of COP pump-motor assemblies showed unstable vibration pattern of which one or two showed higher vibration enough to exceed the allowable level from the installation stage. Many trials of test, measurement, overhaul and replacement had been repeated to investigate and solve the problem but only to reach unsatisfactory settlement. Recently several times of site tests are made and followed by significant diagnostic actions in which the authors group participated. It was found that the coupled shafting system of motor and pump is in close resonance with the $1^{st}$ shaft rotating speed. Redesign of topside motor bearing clearance is made to increase bearing stiffness and hence to avoid the resonance which consequently led to reduce the troubled vibration to allowable and stable status.

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Development of Multi-Type Soft X-ray Ionizer using Radiation Dose Overlapped Effect (선량 중첩을 이용한 멀티형 연 X-선 정전기 제거장치의 개발)

  • Lee, Su Hwan;Lee, Dong Hoon
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.28-31
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    • 2018
  • In display and semi-conductor manufacturing process, there are numerous unstable factors such as particle concentration, minimal vibration, changes in magnetic field, or electrostatic that becomes an issue to be managed and controlled. In the recent, X-ray ionization is widely used that is neutralized by separating air or gas molecules in the area where the static must be resolved. The mono-type of X-ray ionizer was not capable to be used in $8^{th}$ generation panels manufacturing plant due to its insufficient ionizing coverage since the panel itself is approximately in $2m{\times}3m$. To resolve the current problem, the development of new type called, "Multi-type X-ray ionizer" has resulted in covering enough ionizing space in $8^{th}$ generation panels industry. Comparing mono and multi types with MCNPX code simulation, the multi one indicates more X-ray flux, efficiency, and ionization performance in comparison with either a mono-type or multi-type in array format. In addition, the ionizing efficiency of overlapping area with multi-type showed 30% higher effectiveness rate as to the ordinary mono-type.