• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.718-721
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• 1996

In this work, an effective stiffness generated by internal loading for a planar 3 degrees of freedom RCC mechanism is investigated. For this purpose, the internal kinematic analysis and antagonistic stiffness modeling for this mechanism are performed. It is shown that the antagonistic stiffness could be effectively created at the center of the mechanism in its symmetric configuration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.793-798
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• 1996

In this paper, output compliance effects at RCC point by both redundant joint compliances and antagonistic torques generated by internal preloading between joints of a spherical 3 degree-of-freedom mechanism are investigated. For this purpose, kinematic analysis is briefly described. Then, output compliance models at RCC point, which is generated by redundant joint compliances and by internal preloading between joints are derived. Finally, ranges of output compliance modulation due to these redundant joint compliances and antagonistic torques are examined through simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.317-318
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• 2010

• The Journal of the Acoustical Society of Korea
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• v.10 no.6
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• pp.23-42
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• 1991

본 논문은 시스템 운동학적 자유보다도 많은 수의 input을 사용하여 비선형 구속조건을 갖는 메 카니즘의 정역학적 평형을 유지시키는 경우와 같이 일반 로봇 시스템의 협력 작업시 일어나는 antagonistic stiffness를 연구하였다. 이러한 antagonistic 상황은 coordinations of multiple manipulators, multi-fingered end-efector, walking machine, 그리고 인간의 움직임등을 포함하는 많은 로봇 시스템의 작동시에 일어난다. Antagonism으로 야기되는 stiffness는 이러한 시스템의 특성을 파악하는 좋은 척도 가 될 수 있다. Antagonistic stiffness의 개념은 시스템을 구성하는 강체들의 상대 변위의 함수로 얻어 지기 때문에 바강체들이 변형하는 특성을 나타내는 structural stiffness와는 구별된다. 따라서 이 개념은 여유입력들에 의해 얻어지는 시스템의 effective stiffness로 해석될 수 있고, 일반 로봇 mechanism의 개 경로 안정도의 척도로 이용될 수 있으며 목적에 따라서 stiffness의 제어가 가능한 비선형 spring을 만 드는 데에도 응용이 가능하다. 본 논문에서는 antagonism이 일어나는 몇가지 상황에서의 stiffness 특성 과 개경로 안정성 조건등을 해석적, 기하학적 관점에서 다루었다.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.50-61
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• 1994

Biological control of important fungal diseases such as Phytophthora blight of red pepper, gary mold rot of vegetables, and powdery mildew of many crops was attempted using an antagonistic bacterium, Bacillus sp. AC-1 in greenhouses and fields. The antagonistic bacterium isolated from the rhizosphere soils of healthy red pepper plant was very effective in the inhibition of mycelial growth of plant pathogenic fungi in vitro including Phytophthora capsici, Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea, Valsa mali, Fusarium oxysporum, Pythium ultimum, Alternari mali, Helminthosporium oryzae, and Colletotrichum gloeosporioides. Culture filtrate of antagonistic Bacillus sp. AC-1 applied to pot soils infested with Phytophthora capsici suppressed the disease occurrence better than metalaxyl application did until 37 days after treatment in greenhouse tests. Treatments of the bacterial suspension on red pepper plants also reduced the incidence of Phytophthora blight in greenhouse tests. In farmers' commercial production fields, however, the controlling efficacy of the antagonistic bacteria was variable depending on field locations. Gray mold rot of chinese chives and lettuce caused by Botrytis cinerea was also controlled effectively in field tests by the application of Bacillus sp. AC-1 with control values of 79.7% and 72.8%, respectively. Spraying of the bacterial suspension inhibited development of powdery mildew of many crops such as cucumber, tobacco, melon, and rose effectively in greenhouse and field tests. The control efficacy of the bacterial suspension was almost same as that of Fenarimol used as a chemical standard. Further experiments for developing a commercial product from the antagonistic bacteria and for elucidating antagonistic mechanism against plant pathogenic fungi are in progress.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.75-85
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• 1994

Biocontrol is playing a more and more important role in plant disease management. Evidences show that there are optimum prospects for people to apply biocontrol approach to control plant disease or to study the mechanism of antagonism.“The study of Antagonistic Protein of Bacillus spp.to Xanthomonas oryzae pv. oryzae”has been worked in our laboratory since 1986. One hundred and thirty antagonistics bacteria were screened out, most of them belonged to Bacillus spp., and showed very strong inhibitive effect to various plant pathogens. Nine antagonistic proteins (peptides) were purified (P11-I, P11-II, B8, B826-I, B826-II, A30-I, A30-II, G35). Two antagonistic protein related DNA fragments (B826-I, A30-II) were cloned and sequenced. B826-I DNA fragment composed by 905 bp, and it contained two ORF encoding 95, and 54 amino acids, respectively. By using Rifr and Kamr as the selective markers, we found the bacteria could colonize on rice leaf for at least 40 days. In greenhouse the antagonistic bacteria showed certain degree of control efficiency.

• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.312-316
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• 2004

In oder to select the powerful rhizophere-dorminatable biocontrol agent, we had isolated an indigenous antagonistic bacterium which produced antibiotic and siderophore from a disease suppressive local field soil of Gyungsan, Korea. And we could select the Pseudomosp. 4059 which can strongly antagonize against Fusarium oxysporum and Phytophthora capsici by two kinds of antifungal mechanism that can be caused by the antibiotic of Phenazin, a siderophore and a auxin like subThe selected strain was identified as Pseudomonas fluorescens (biotype A) 4059 by biochemical tests, API $\textregistered$ test, MicroLog TM system and 16S rDNA analysis. The selected antagonistic microorganism, Pseudomosp. 4059 had an antifungal mechanism of antifungal antibiotic and sidrophore. And we were confirmed the antagonistic activity of P fluorescens 4059 with in vitro antifungal test against Phytophthora capsici and in vivo by red-pepper.

• Mycobiology
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• v.36 no.4
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• pp.266-269
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• 2008

Twenty isolates of Bacillus species obtained from livestock manure composts and cotton-waste composts were tested for their antagonistic effects in vitro against three green mold pathogens of mushrooms (Trichoderma harzianum, T. koningii, and T. viridescens). However, there exists a possibility Bacillus species may have antagonistic effects against mushrooms themselves, and thus the same 20 isolates were tested in vitro against three species of mushrooms (Flammulina velutipes, Lentinus edodes, and Pleurotus ostreatus). Of the 20 Bacillus species isolates tested, two inhibited mycelial growth of T. harzianum, seven that of T. koningii, and eight that of T. viridescens. Importantly, the bacterial isolates M27 and RM29 strongly inhibited mycelial growth of all the Trichoderma spp. isolates tested. The isolate M27 was subsequently identified as the most effective in inhibiting mycelial growth of all the Trichoderma species. Interesting results of the effect Bacillus isolates had upon the mushroom species followed. It was found that most Bacillus isolates except 5T33 at least somewhat inhibited mycelial growth of the three mushroom species or some of the mushrooms. Furhermore, the antagonistic effects of the bacterial isolates against the three species of mushrooms varied depending on the mushroom species, suggesting a role for mushroom type in the mechanism of inhibition. The bacterial isolates M27 and RM29 were identified as having the most antagonistic activity, inhibiting mycelial growth of all the Trichoderma spp. as well as mycelial growth of the three species of mushrooms. These results suggest that the bacterial isolates and their antagonistic effects on green mold pathogens should be further studied for their practical use for biological control of green mold in the growing room of the mushrooms.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.846-855
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• 1994

An effective stiffness, analogous to that of a wound spring, can be created by antagonistic redundant actuation of general closed-chain mechanisms. The qualitative and quantitative characteristics of the effective stiffness are investigated through a Four-bar mechanism, and a load distribution method is introduced which simultaneously guarantees the required system motion and the effective stiffness of the Four-bar mechanism. Furthermore, a simulation is performed to understand the inter-relationship among the effective stiffness, the Four-bar geometry, and the actuation effort. Based on this analysis, the Four-bar synthesis problem for effective stiffness generation is discussed.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.217-217
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• 1994

Calcium entry blockers, capable of inhibiting transmembrane influx of extracellular calcium through specific calcium channels, are useful drugs in the treatment of angina pectoris, hypertension, cardiac arrythmia, and various cardiovascular disorders. Compounds having isoquinoline structures have recently been reported to possess calcium antagonistic action. Therefore, in the present study, we have attempted to synthesize some isoquinoline and related compound.; in order to search for potentially effective chemicals acting on cardiovascular system, and evaluated their pharmacological properties focusing on calcium antagonistic actions. Almost all of the compounds so far synthesized, had inhibitory action against phenylephrine or high potassium-induced contraction in vascular smooth muscle with different degrees of potencies depending on their structures, However, some of tetrahydroisoquinoline analogs showed directly inhibit calcium current in isolated rabbit cardiac myocytes examined by patch clamp techniques. The pharmacological properties of these compounds need more intensive investigation as to whether these chemicals may have developed as a new cardiovascular active drugs. Therefore, we are now under investigation of the mechanism of action of these compounds.