• Title/Summary/Keyword: SPOT

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New Fungal diseases of Economic Resource Plants in Korea (III) (유용 자원식물의 진균성 신병해(III))

  • 신현동
    • Korean Journal Plant Pathology
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    • v.11 no.3
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    • pp.197-209
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    • 1995
  • This paper is a third report about the new fungal diseases of economic resource plants in Korea. It contains short descriptions on symptoms, occurrence conditions, pathogen, and some phytopathological notes for each of 10 fungal plant diseases. They are angular leaf spot of Achyranthes japonica by Cercospora achyranthis causing leaf spot and defoliation in the shade of plants, leaf spot of Armoracia lapathifolia by Cercospora armoraciae causing leaf spot to blight from the rainy season to autumn, hypophyllous mold of Dioscorea tokoro by Distocercospora pachyderma causing leaf spot and yellowing, hypophyllous mold of Artemisia spp.by Mycovellosiella ferruginea causing leaf spot and yellowing, angular leaf spot of Aralia elata by Pseudocercospora araliae causing velvety leaf spot and defoliation, hypophyllous mold of Lycium chinense by Pseudocercospora chengtuensis causing velvety leaf spot and defoliation from the rainy season to autumn, angular leaf spot of Diospyros lotus by Pseudocercospora disospyri-morrisianae causing leaf spot and defoliation from summer to autumn, brown leaf spot of Impatiens textori by Pseudocercospora nojimae causing leaf spot to blight from the rainy season, leaf spot of Cephalonoplos segetum by Ramularia cirsii causing leaf spot to blight throughout the growing season, and white mold of Leonurus sibiricus by Ramularia leonuri causing leaf spot to blight mostly in autumn.

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Equivalent Loads for Spot-Weld Distortions (점용접 변형에 대한 등가하중)

  • Chu, Seok-Jae;Lee, Sang-Hyuk
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1499-1504
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    • 2007
  • Spot-welding is widely used to construct passenger car bodies in automotive industry. Occasionally severe spot-weld distortions in sub-assembly make further spot-weld difficult. In this paper, distortions for various spot-weld conditions are measured using coordinate measuring machine. Then, based on finite element solution for unit translation or unit rotation of nugget edge, equivalent loads for spot-weld distortions are determined. They can be used to predict the spot-weld distortion using finite element method.

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Study on the Prediction of Fatigue Life of Multi-Spot Welded Joints (다점용접이음의 피로수명 예측에 관한 연구)

  • Ju, Seok-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.471-478
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    • 2002
  • In real structures, multi-spot welded joints are more frequently used than a single-spot welded joint. Most researches, however, have been focused to a single-spot welded joint until now. In this paper, the fatigue behavior of multi-spot welded joints are investigated using the finite element solutions of the multi-spot welded specimens. The local strain approach is used rather than the stress intensity factor approach to estimate the fatigue life since the former is quite simple and straightforward. It is found that the fatigue behavior of multi-spot welded joints is different from that of single-spot welded joints. The local strain approach is still applicable to multi-spot welded joints.

New Fungal Disease of Economic Resource Plants in Korea (V) (유용 자원식물의 진균성 신병해(V))

  • 신현동
    • Korean Journal Plant Pathology
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    • v.14 no.1
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    • pp.52-61
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    • 1998
  • This paper is the fifth report about the fungal diseases of economic resource plants observed newly in Korea. It contains short descriptions on symptoms, occurrence conditions, pathogens, and some phytopathological notes for each of 10 fungal plant diseases. They are identified as leaf spot of Adenophora triphylla var. japonica by Septoria lengyelii, leaf spot of Calystegia soldanella by S. convolvuli, leaf spot of Campanula punctata by S. campanulae, leaf spot of Codonopsis lanceolata by S. codonopsidis, leaf spot of Geum japonicum by s. gei, black spot of Oenanthe javanica by s. oenanthes, leaf spot of Oenothera odorata by S. oenotherae, angular leaf spot of Rehmannia glutinosa by S. digitalis, brown spot of Rubus crataegifolius by s. rubi, and leaf spot of Viola verecunda by S. violae-palustris, respectively.

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Development of CAD tool for optimal spot weld joints (점용접 위치의 최적화를 위한 CAD Tool 개발)

  • Ryu, Si-Uk;Lee, Jong-Chan;Lee, Tae-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.1
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    • pp.148-159
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    • 1998
  • Spot welding palys a key role in increasing productivity and weight reduction of the final products. This paper proposes a systematic approach on the design of spot weld configuration, dealing with the requried number and location of spot weld joints under the given design parameters, such as the applied loads, lap area, and individual spot weld strength. The optimal design of a spot-welded joint is postulated as a state when the safety factors of all spot weld points (i) are evenly distributed and (ii) reach maximum value. A CAD program is developed to arrange the optimal location of each spot weld based on the derived objective function and constraints. The CAD tool integrates the optimization procedure with Finite Element Analysis (FEA) code through an interface. The interface automatically provides geometrical data and mesh configuration for different spot weld locations to FEA model. It also extracts the transmitted load of each spot weld from the FEA code, and allows the optimization code predict an improved arrangement of spot weld locations. The feasibility of the developed approach is demonstrated by the selected examples.

Grassfire Spot Matching Method for multi-seed matched spot pair (다중 발화점을 이용한 Grassfire 스팟매칭 기법)

  • Ryoo, Yun-Kyoo
    • Journal of the Korea society of information convergence
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    • v.7 no.2
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    • pp.59-65
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    • 2014
  • Grassfire spot matching method is based on similarity comparison of topological patterns for neighbor spots. This is a method where spot matching is performed as if fire spreads all around on grass. Spot matching starts from a seed spot pair confirmed as a matched pair of spots and spot matching spreads to the direction where the best matching result is produced. In this paper, it is a bit complicated way of grassfire method where multi-seed matched spot pair are manually selected and spot matching is performed from each multi-seed matched spot pair. The proposed method shows better performance in detection rate and accuracy than that of the previous method.

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Studies on the flavonoids of the Hibiscus syriacus L. Complex (무궁화 품종내의 flavonoid 성분분포에 관한연구)

  • 유기역
    • Korean Journal of Plant Resources
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    • v.9 no.3
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    • pp.224-229
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    • 1996
  • Floral flavonoids of Hibiscus syriacus L. six complex with 68 formac all in all were examined. Thirteen flavonoids appeared on the two dimensional chromatogtams. Spot 5, however, occupied more than 50% in total flavonoid contents, and other spots were invariably minor pigments in all samples examined. Ten spots among 13 spots showed the characteristics of flavones, having color of purple to dark purple under UV light and yellow under ammonia gas, while spots reagents suggests that 10 purple spots are 4', 5-OH aglycone type. Four spots out of 10 purple spots were possible to be identified: spot 5, saponarin, spot 7, vitexin, spot 9, xylovitexin, and spot 11, rhamnosylvitexin, respectively. It was suggested that spot 13 might be apigenin-7-O-diglycoside.

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Fatigue Strength Evaluation on the IB-Type Spot-welded Lap Joint of 304 Stainless Steel Part 1 : Maximum Principal Stress (304 스테인리스 박강판 IB형 점용접이음재의 피로강도 평가 Part 1 : 최대 주응력에 의한 평가)

  • 손일선;오세빈;배동호
    • Journal of Welding and Joining
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    • v.17 no.6
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    • pp.25-31
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    • 1999
  • Stainless steel sheets are commonly used for vehicles such as the bus and the train. These are mainly fabricated by spot-welding. By the way, its fatigue strength is lower than base metal due to high stress concentration at the nugget. edge of the spot-welding. By the way, its fatigue strength is lower than base metal due to high stress concentration at the nugget edge of the spot-welding point. Especially, it is influenced by welding conditions as well as geometrical factors of spot welded joint. Therefore, it is not too much to say that structural rigidity and strength of spot-welded structures is decided by fatigue strength of spot welded lap joint. Thus, it is necessary to establish a reasonable and systematic long life design criterion for the spot-welded structure. In this study, numerical stress analysis was performed by using 3-dimensional finite element model on IB-type spot-welded lap joint of 304 stainless steel sheet under tension-shear load. Fatigue tests were also conducted on them having various thickness, joint angle, lapped length, and width of the plate. From the results, it was found that fatigue strength of IB-type spot-welded lap joints was influenced by its geometrical factors, however, could be systematically rearranged by maximum principal stress ({TEX}$σ_{1max}${/TEX}) at the nugget edge of the spot-welding point.

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A Design Technique of Homogenous Hot Spot for Object-Oriented Components (객체지향 컴포넌트 개발을 위한 동질 Hot Spot 설계 기법)

  • 박동혁;김수동
    • Proceedings of the Korean Information Science Society Conference
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    • 1999.10a
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    • pp.444-446
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    • 1999
  • 컴포넌트 기반의 개발과 컴포넌트 개발에 대한 관심이 높아지면서 이를 위한 개발 방법론과 개발 도구들의 도입이 확산되고 있다. 또한 컴포넌트의 재사용 범위를 확장시키기 위해 컴포넌트 개발 시 나타나는 Hot Spot 처리를 위한 분석, 설계기법에 대한 관심이 높아지고 있다. 따라서 본 논문에서는 Hot Spot 처리시에 나타나는 의존적인 Hot Spot을 디자인하는 방법을 제시하고 그 방법을 적용하여 의존적인 Hot Spot을 디자인 할 때 발생되는 Hot Spot 간의 결합도 줄이고 디자인 모델의 가독성을 높인다. 본 논문에서는 디자인 모델링을 위한 표기법으로서 객체지향 모델링 기법인 (UML(Unified Modeling Language)를 이용하여 모델링한다.

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A Study on the Calculating Method of the Heat Input Efficiency in Arcspot Welding (아크 스폿 용접의 입열효율 계산 방법에 관한 연구)

  • Jang, Kyoung-Bok;Cho, Sang-Myoung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.7
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    • pp.1065-1070
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    • 2003
  • In arc spot welding process, the arc is not moving and heat input is concentrated in one spot so that the heat input efficiency of arc is higher than that of GMAW. In other words, the heat input efficiency of arc change during weld time because arc start is done in spot and weld metal is filled. Therefore, the heat input model of arc spot welding should be different from that of general GMAW. In present study, the calculating model of heat input efficiency in arc spot welding was suggested by temperature monitoring near spot in arc spot welding of copper plate. The result showed that the heat input efficiency of arc was changed three times during weld time. The accuracy of calculating method of heat input efficiency was verified by heat transfer analysis of arc spot welding process using finite element method.