• Title/Summary/Keyword: Weak parts

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Present Status and Problems of Chemical Seed Treatment of Seedborne Diseases (종자소독의 현황과 문제점)

  • Lee Du Hyung
    • Korean journal of applied entomology
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    • v.22 no.2 s.55
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    • pp.130-137
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    • 1983
  • A wide variety of pathogens are known io be seedborne, carried either as infectious mycelium internally or as contaminants on the seed coat. When seed is infected with a pathogen, the seed nay be rendered nonviable or it may remain viable but produce weak seedling. In some cases, the Infected seedling nay not be severely weakened, but nay serve as a source of primary inoculum within a community of plants. A recent problem nay be the dissemination of seedborne pathogens occurring as a result of the massive movements of seed, as a part of the 'Green revolution' Disease of great danger to agriculture may be introduced with seed from other parts of world. Seed treatment with organic mercury compounds in liquid form had become popular since about 1955. Organic mercury compounds contributed considerably to the increase in production of many crops and vegetables. In 1975, however, the use of organic mercury compound was forbidden because of doubts regarding their residual mammalian toxicity in agricultural products. Benomyl-thiram mixture, thiophanate methyl-;hiram mixture and TCMB have now been registered as seed disinfectants for the use of rice blast, brown spot and Bakanae disease. Oxathiinsthiram mixture has been registered as seed disinfectant for barley and wheat loose smut and leaf stripe of barley. Agricultural techniques have made such rapid progress that the nursery methods changed from the use of paddy nursery to box nursery designed for machine-transplanting. The spread of rice transplanting machines has caused increase of seedborne diseases. Among seedborne diseases, Bakanae disease has remarkably increased and causes much damage recently. In order to counter this trend, seed disinfectants must also be diversified. First, effective non-selective disinfectants need to be developed, and second, appropriate control methods always need to be prepared in parallel with the development of new techniques for cultivation.

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Investigation of Behaviours of Wall and Adjacent Ground Considering Shape of Geosynthetic Retaining Wall (보강토 옹벽의 형상을 고려한 벽체 및 인접지반 거동 연구)

  • Lee, Jong-Hyun;Oh, Dong-Wook;Kong, Suk-Min;Jung, Hyuk-Sang;Lee, Yong-Joo
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.1
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    • pp.95-109
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    • 2018
  • Recently, GRS (Geosynthetic Retaining Segmental) wall has been widely used as a method to replace concrete retaining wall because of its excellent structural stability and economic efficiency. It has been variously applied for foundation, slope, road as well as retaining wall. The GRS wall system, however, has a weak point that is serious crack of wall due to stress concentration at curved part of it. In this study, therefore, behaviour of GRS wall according to shape of it, shich has convex and concave, are analysed and compared using Finite Element analysis as the fundamental study for design optimization. Results including lateral deflection, settlements of ground surface and wall obtained from 2D FE analysis are compared between straight and curved parts from 3D FE analysis.

Forecast on Internal Condensation at Balcony Ceiling of Super-high Apartment Building Faced with Open Air (외기에 면한 초고층 아파트 발코니 천정 내부결로 예측)

  • Choi Yoon-Ki;Ahn Jae-Bong
    • Korean Journal of Construction Engineering and Management
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    • v.4 no.4 s.16
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    • pp.155-163
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    • 2003
  • There are a growing number of cases to expand balconies of apartments faced with open air in order to enhance functional satisfaction and efficiency of dwelling space. In case of the balcony expansion at the floor, however, it is difficult to exclude a possibility of bringing about internal condensation due to the difference of temperature between indoor air and outdoor air caused by the Inflow of outer low-temperature air through the upper part of ceilings by failure in completely putting together the outer composite wall panels on the aluminum curtain walls installed at outer walls This study is to forecast possible occurrence of internal condensation around parapets and H-beam located at the inside of balcony ceilings on the uppermost floor of super-high apartment buildings faced with open air in order to provide dwellers with more comfortable environment in the related space and get rid of their uneasiness about the condensation. In this study, we estimated internal condensation, which vary in accordance with humidity pressure distribution, at curtain walls, stone panels or lower parts of slabs that constitute outer space of the residence and are weak against heat, through temperature forecast and temperature distribution interpretation program at normal two-dimension temperature

Development of a CAS-Based Virtual Learning System for Personalized Discrete Mathematics Learning (개인 적응형 이산 수학 학습을 위한 CAS 기반의 가상 학습 시스템 개발)

  • Jun, Young-Cook;Kang, Yun-Soo;Kim, Sun-Hong;Jung, In-Chul
    • Journal of the Korean School Mathematics Society
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    • v.13 no.1
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    • pp.125-141
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    • 2010
  • The aim of this paper is to develop a web-based Virtual Learning System for discrete mathematics learning using CAS (Computer Algebra System), The system contains a series of contents that are common between secondary und university curriculum in discrete mathematics such as sets, relations, matrices, graphs etc. We designed and developed web-based virtual learning contents contained in the proposed system based on Mathematia, webMathematica and phpMath taking advantages of rapid computation and visualization. The virtual learning system for discrete math provides movie lectures and 'practice mode' authored with phpMath in order to enhance conceptual understanding of each movie lesson. In particular, matrix learning is facilitated with conceptual diagram that provides interactive quizzes. Once the quiz results are submitted, Bayesian inference network diagnoses strong and weak parts of learning nodes for generating diagnostic reports to facilitate personalized learning. As part of formative evaluation, the overall responses were collected for future revision of the system with 10 university students.

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A study on the compressive capacity of structural skin timber for the furniture manufacturing and heavy timber construction (가구 및 중목구조용 실대재 스킨팀버의 압축 성능에 관한 연구)

  • Kim, Gwang-Chul
    • Journal of the Korea Furniture Society
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    • v.21 no.4
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    • pp.273-283
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    • 2010
  • Structural larger timber have some weak points as like much longer drying time at lower MC(15%), a considerable check developing and the difficulty for the chemicals injection, so it is necessary to develop lighter structural size member for using the new Hanok, heavy timber construction, living necessaries, furniture and industrial goods. The developed skin timber can be a good raw material for those uses. Skin timber is a hollowed timber which be bored out of its considerable cross-sectional area. The intention of this study was the evaluation of compressive capacity of skin timber. Specially, skin timbers which have more than 200mm in sizes were used to analyze the compressive capacity. From the results of this study, the following conclusions have been made: 1. Though considerable inner parts were bored out, both pine skin timber and larch skin timber showed a good compressive capacity to that of non-bored solid timber. 2. According to ASTM, pine skin timber showed various failure types, but Splitting type, Brooming and end rolling type were main failure types for the larch skin timber. 3. Pine skin timber didn't show the significance between cylindrical shape and rectangular shape, but larch skin timber showed the significance between two shapes. Therefore, for the larch skin timber, cylindrical shape and rectangular shape should be used as a column uses and beam uses respectively. 4. Pine skin timber and larch skin timber didn't show the significance on the compressive capacity. There is not much difference of compressive capacity between them, so it can be possible to select on the user convenience.

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Motion Areas based Painterly Animation using Various Edges (다양한 에지를 이용한 모션영역 기반 회화적 애니메이션)

  • Park, Young-Sup;Yoon, Kyung-Hyun
    • Journal of the Korea Computer Graphics Society
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    • v.14 no.1
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    • pp.1-10
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    • 2008
  • In this paper, we present a novel method for creating a hand-painted painterly animation, starting from a video input. One of the most important aspects in painterly animation is to maintain the temporal coherence of brush strokes between frames, which plays a vital role to warrant a smooth transition between frames. Our unique utilization of motion areas enables users to produce a smooth movement of brush strokes. The motion areas are the parts where objects move between frames and they are categorized in two main types. A strong motion area is the part where the movement of real edges and hidden edges is determined by the motion vector between frames. The real edge is the outline of an object and the hidden edge is the boundary to represent the direction of a grain of intensity in the areas with gradations. A weak motion area is the remainder after subtracting the strong motion area from the entire motion area. Temporally coherent painterly animation is achieved by re-painting the brush strokes on the canvas using two motion areas, resulting in a natural and hand-painted appearance.

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Effects of Human Activities on Home Range Size and Habitat use of the Tsushima leopard Cat Prionailurus bengalensis euptilurus in a Suburban Area on the Tsushima Islands, Japan

  • Oh, Dae-Hyun;Moteki, Shusaku;Nakanish, Nozomi;Izawa, Masako
    • Journal of Ecology and Environment
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    • v.33 no.1
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    • pp.3-13
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    • 2010
  • The Tsushima leopard cat, Prionailurus bengalensis euptilurus, a small felid, inhabits only the Tsushima Islands in Japan. Previous studies of the Tsushima leopard cat revealed that natural factors; including sex, reproductive activity, season, and prey distribution and abundance affect leopard cat home range variation and habitat use. In this study, we focused on clarifying how anthropogenic factors influenced home range variation and habitat use of a male Tsushima leopard cat living near a suburban area in January, March, May and September 2005 using radio-tracking. The home range size (100% MCP) of this cat was $0.78\;{\pm}\;0.26\;km^2$ (mean ${\pm}$ SD, n = 4 tracking sessions) across the whole study period. However, the cat did not use all parts of its home range uniformly; rather it used some habitat types selectively. The cat avoided agriculture areas and residential areas in all of the tracking-sessions. On the other hand, the cat showed a weak preference for artificial structures and a strong preference for baiting sites in January and March, while it avoided them in May, and no baiting site was included in its home range in September. These results suggest that anthropogenic factors influenced the ranging patterns and habitat use of the leopard cat living near a suburban area. Artificial structures might provided good resting spaces for the cat in bad weather. When the density of its main prey was low in the winter, the cat tended to rely on artificial prey and had a small home range size.

Seasonal Variation Patterns of Tidal Flat Sediments in Semi-enclosed Hampyong and Kwangyang Bays, West and South Coasts of Korea (한반도 서해안과 남해안의 반페쇄된 만에서 조간대 퇴적물의 계절변화에 관한 비교 연구: 서해안의 함평만과 남해안의 광양만)

  • Ryu, Sang-Ock
    • Journal of the Korean earth science society
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    • v.24 no.6
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    • pp.578-591
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    • 2003
  • To investigate the seasonal variation patterns of tidal flat sediments in semi-enclosed Hampyong and Kwangyang Bays, respectively west and south coasts of Korea, accumulation rate and grain-size in the sediments were monitored during 2${\sim}$4 years. The mud flats in the northern and eastern parts of Hampyong Bay were eroded in summer and deposited in winter, but mixed flats in the southern part of the bay show reversed seasonal variations to the mud flats. These variations are most likely connected with wave actions induced by monsoon and physiographic setting of the tidal flats in the bay. In contrast, the tidal flats of Kwangyang Bay were eroded in summer and deposited in other seasons except summer, different from the case of Hampyong Bay. The physiography of Kwangyang Bay are characterized by dominant flood tides and weak wave actions. However, in summer, the surface sediments were abruptly eroded by occasional typhoons and heavy rainfall. These weather conditions appear to be important factors to accelerate erosion on the tidal flat in semi-enclosed bays, south coast of Korea.

The Fault Tolerant Evaluation Model due to the Periodic Automatic Fault Detection Function of the Safety-critical I&C Systems in the Nuclear Power Plants (원전 안전필수 계측제어시스템의 주기적 자동고장검출기능에 따른 고장허용 평가모델)

  • Hur, Seop;Kim, Dong-Hoon;Choi, Jong-Gyun;Kim, Chang-Hwoi;Lee, Dong-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.7
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    • pp.994-1002
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    • 2013
  • This study suggests a generalized availability and safety evaluation model to evaluate the influences to the system's fault tolerant capabilities depending on automatic fault detection function such as the automatic periodic testings. The conventional evaluation model of automatic fault detection function deals only with the self diagnostics, and supposes that the fault detection coverage of self diagnostics is always constant. But all of the fault detection methods could be degraded. For example, the periodic surveillance test has the potential human errors or test equipment errors, the self diagnostics has the potential degradation of built-in logics, and the automatic periodic testing has the potential degradation of automatic test facilities. The suggested evaluation models have incorporated the loss or erroneous behaviors of the automatic fault detection methods. The availability and the safety of each module of the safety grade platform have been evaluated as they were applied the automatic periodic test methodology and the fault tolerant evaluation models. The availability and safety of the safety grade platform were improved when applied the automatic periodic testing. Especially the fault tolerant capability of the processor module with a weak self-diagnostics and the process parameter input modules were dramatically improved compared to the conventional cases. In addition, as a result of the safety evaluation of the digital reactor protection system, the system safety of the digital parts was improved about 4 times compared to the conventional cases.

Improvement of Domestic Design Criteria of Tunnel Maintenance Monitoring and Latest Technology Trend (터널 유지관리 계측의 국내설계기준 개선 및 최신 기술동향)

  • Baek, Kyung Jong;Kwon, Young Eok
    • Journal of Korean Society of Disaster and Security
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    • v.7 no.2
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    • pp.9-16
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    • 2014
  • Though the maintenance monitoring of structurally weak parts of the tunnel structure in public service must be judged in connection with the monitoring during the construction period for analysis of the behavior of the ground and surrounding structures following the tunnel excavation for the effective management, the monitoring during the construction period and the maintenance monitoring are implemented separately on the basis of the periods of construction and maintenance, so the connectivity and systematic management of the related data are mostly inadequate. The improvement direction is suggested in this thesis, by analyzing the problems of tunnel monitoring in the domestic design criteria. And, it is anticipated that from now on the use of hi-tech sensors and wireless communications technology will proceed vigorously in the maintenance, so considering these situations, the development and application of the maintenance monitoring system and the revision of the domestic design criteria and specification are needed in the future.