• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.10
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• pp.52-58
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• 1997

In this paper, we consider methods of robust stabilization of the interval plant with a PID controller. Suppose that we know apriori a sign of the coefficients of the numerator of the PID controller. Under this condition, it sufficies to make eight polynomials stable for robust stabilization of the interval plant with a minimum phase PID controller. In addition, with a nonminimum phase PID controller, it suffices to make different eight polynomials stable. Especially, with the nonminimum phase PID controller it is shown that stabilization of eight plants is necessary and sufficient for robust stabilization of the interval plants.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.123-128
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• 1998

This paper presents time domain identification of an interval system. We conjectured that Markov parameters (Pulse Responses) from Kharitonov plants would envelope those of the whole interval system. The examination on interrelations between Markov parameters from Kharitonov plants of an interval system and those of the whole interval system determines the validity of the conjecture and is used to give some extremal properties of Markov parameters. The results of this paper are shown in simulations on MBC500 Magnetic Bearing System and a given interval system.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.168-172
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• 1993

As the worst-case analysis for interval plants, a conjecture whether the supremum of the integral of square error(ISE) is attained at the extreme point such as vertices, Kharitonov vertices, CB segment, and edges is suggested. We present a sufficient condition for which the worst performance index occurs at one ofvertices of uncertain parameter space. Numerical examples are also given.

• Journal of People, Plants, and Environment
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• v.23 no.3
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• pp.255-265
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• 2020

Background and objective: The purpose of this study was to provide guidelines for irrigation management by analyzing the effects of soil moisture on the growth characteristics of herbaceous plants in green infrastructure. Methods: In a rain shelter greenhouse, the growth performance of nine species of experimental plants was assessed under different soil moisture contents (20%, 15%, 10%, 5%, and 1%) for about 5 months to analyze plant growth characteristics due to soil humidity. Methods to determine plant growth conditions include surveying growth conditions of the crowns, stems, leaves, flowers and fruits on the aerial part and surveying growth conditions of the roots in the underground part. Results: The results showed that Mukdenia rossii and Astilbe rubra grew well at 15% moisture content with irrigation intervals of 10 and 13 days, respectively. Soil moisture content of 10% with irrigation intervals of 13 and 17 days was appropriate for Sedum kamtschaticum and Pachysandra terminalis. Similarly, Aquilegia japonica and Liriope platyphylla grew well at 15% moisture content with irrigation intervals of 10 and 17 days. However, Ligularia stenocephala grew well-developed stems and roots at 1% soil moisture content and an irrigation interval of 25 days, while the optimum conditions for Lythrum anceps were 5% moisture content and an irrigation interval of 8 days. Conclusion: Although a limited number of experimental plants were used in this study, this study could propose an appropriate irrigation cycle for planting on artificial soil substrates. Based on these results, it is possible to plan suitable planting designs considered irrigation cycles.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.947-951
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• 2015

This study presents proper irrigation interval for the soil condition of green roof system and the smooth growth of the landscaping herbaceous plants available and reveal the need for irrigation in rooftop conditions. Twenty kinds of greenery plants are tested on ground paved wood panels where rain and wind shielder is installed. Before test, irrigation is conducted fully to experimental plants and then soil moisture in pot is measured after every ten minutes. In conclusion, it is suggested that the irrigation has to be carried out every 4~5 days in order to minimize water and heat stress of plants. Also, irrigation management is an essential prerequisite for good condition and the smooth growth of plants and environmental effects in green roof system.

• Research in Plant Disease
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• v.14 no.1
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• pp.37-42
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• 2008

Bacillus subtilis BD0310 isolated from tea leaves was used for the development of a biofungicide against Pestitalotiopsis longiseta causing gray blight of tea plants. After mass culture of the antagonistic bacteria, the biofungicide formulated as a suspension concentrate was evaluated for its control efficacy against the gray blight of tea plant in a greenhouse and a tea plantation, respectively. Spray of the biofungicide 2 days before inoculation of P. longiseta inhibited more efficiently the development of gray blight compared with spray of the biofungicide 2 days after inoculation of the pathogen onto the leaves of tea plants in a greenhouse. In the field investigation under application of the biofungicide in 2005 and 2006, control efficiencies increased according to the number of spray of the biofungicide. Control efficiencies of the biofungicide were 52.4%, 66.7%, 71.4% and 85.7% against gray blight in 4 times spray of the biofungicide alone at 7 days interval, 6 times spray of the biofungicide alone at 7 days interval, 2 times alternate spray of biofungicide and chemical fungicide at 7 days interval and 4 times spray of chemical fungicide alone at 7 days interval, respectively. Therefore, the alternate application of the biofungicide and chemical fungicide at 7 days interval can increase the control efficiency with reduction of the amount of chemical fungicides and the number of spray for the control of gray blight of tea plants in the field.

• Journal of Animal Science and Technology
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• v.57 no.11
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• pp.34.1-34.5
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• 2015

Himalayan dock (Rumex nepalensis) was evaluated for forage value and antinutrients under three, five and seven weeks cutting intervals in the temperate environment. Dry matter (DM) content was measured for each cutting interval. Forage quality parameters such as Crude Protein (CP), Acid Detergent fiber (ADF), Neutral Detergent Fiber (NDF), Calcium (Ca) and Phosphorus (P) were analyzed. Plants with seven weeks cutting interval gave higher DM yield. CP and P content were significantly higher for three weeks cutting intervals. Average CP contents were 31.38 %, 30.73 % and 27.32 % and average P content 0.58 %, 0.52 % and 0.51 % for three, five and seven weeks cutting intervals, respectively. Ca content did not differ significantly between cutting intervals. The average Ca content were 0.91 %, 0.90 % and 90 %, for three, five and seven weeks cutting intervals, respectively. Tannin and mimosine contents were not significantly different between cutting intervals. Average tannin contents were 1.32 %, 1.27 % and 1.26 % and mimosine 0.38 %, 0.30 % and 0.28 % for three, five and seven weeks cutting intervals, respectively. The study concluded that R. nepalensis could be a potential source of protein for livestock. The study also suggests seven weeks harvesting interval to provide plants with high dry matter yield, high forage quality and very low levels of anti-nutrients.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.173-178
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• 1993

In this paper, we present an algorithmic technique for determining a feedback compensator which will stabilize the interval dynamic system, specifically, the robust regulator design for interval plants. The approach taken here is to allow the system parameters to live within prescribed intervals then design a dynamic feedback compensator which guarantees closed-loop system stable. The main contribution of this paper is the idea of introducing a "simplified Kharitonov's result" for low order polynomials to search for suitable compensator parameters in the compensator parameter space to make the uncertain syste robust. We also design the robust regulator which will D-stabilize (have the closed-loop poles in the left sector only) the dynamic interval system while having good performance. The nuerical examples are given to show the substantially improved robustness which results from our approach. approach.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.8
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• pp.64-73
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• 1994

In this paper we present an algorithmic technique for determining a feedback compensator which will stabilize the interval dynamic system specifically the robust regulator design for interval plants. The approach taken here is to allow the system parameters to live within prescribed intervals then design a dynamic feedback compensator which guarantees closed-loop system stable. The main contribution of this paper is the idea of introducting a "simplified Kharitonov`s results" for low order polynomials to search for suitable compensator parameters in the compensator parammeter space to make the uncertain system robust. We also design the robust regulator which will $D_{\phi}$ -stabilize (have the closed-loop poles in the left sector only) the dynamic interval system while having good performance. the numerical examples are given to show the substantially improved robustness which results from our approach.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.231-237
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• 1995

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survival or regrowth yield. Forage rape (Brassica napus L.) was sown by three seeding densities of 5, 15 and 25cm interval among plants on Sep. 1, 1994. Field-grown plants were sampled on the before wintering (Dec. 4) and on the wintering period (Jan. 16) to analyze the nitrogen and non-structural cahohydrate reserves. The rate of winter survival and regrowth yield were also measured in the spring of next year. The dry matter yields from the plots of 5, 15 and 25cm seeding interval were 1,270, 1.01 9 and 1,062 kg/lOa respectively, on the before wintering. The similar pattern wa5 observed in the crude protein yields affected by seeding density. On the before wintering, both of nitrogen and starch contents per plant significantly increased as the seeding density was lowered. Starch content was relatively higher than that of nitrogen in all plots. On the wintering period, the contents of nitrogen reserves were 6.5, 41.2 and 121.7 mglplant, those of starch reserves were 1.0, 5.4 and 185.1 mg/plant, respectively, in the plots of 5, 15 and 25cm seeding interval. Nitrogen reserves on the wintering period increased while starch reserves highly decreased in all plots comparing to the before wintering. 'lhe rates of winter survival were 10.2, 20.6 and 37.1%, and regrowth yields were 76, 96 and 178 kgD.M/ IOa, respectively, in the plots of 5, 15 and 25cm seeding interval. These results cleariy showed that seeding density have a close influence on the level of nitrogen and non-structurd cahohydrate reserves, and that the rate of winter survival and regrowth yield were controlled by reserves level on the wintering period.