• Title/Summary/Keyword: Race conditions

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Design Guidelines for the Automatic Ball Balancer in CD/DVD Systems with Varying Eccentricity (편심이 변하는 CD/DVD시스템의 자동 볼 평형장치 설계 지침)

  • 김보현;류제하
    • Journal of KSNVE
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    • v.9 no.2
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    • pp.387-392
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    • 1999
  • This paper presents design guidelines for the automatic ball balancer in CD/DVD systems with varying eccentricity. In these systems, the size of balancing balls should be limited by the restricted race space so that determination of the number and mass of balls should consider the radii of the race and the balls. In addition, the effects of viscosity and friction also should be taken into account for sufficient balancing. Based on the static equilibrium conditions, the number and mass of balls corresponding to the range of varying eccentricity have been determined. Dynamic simulation with viscosity and friction shows sufficient viscosity must exist to ensure stability and friction between balls and race must be minimized to guarantee accurate balancing.

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Incidence of Panicle Blast, Race Distribution During 1993??¡?1994 and Pathogenicity of New Races of Pyricularia grisea in Korea (벼 이삭도열병 발생정도 및 병원균 레이스의 분포 변동(1993~1994)과 새로운 레이스의 병원성)

  • 한성숙;라동수;김장규
    • Korean Journal Plant Pathology
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    • v.11 no.3
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    • pp.238-244
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    • 1995
  • Severity of panicle blast disease on the leading cultivars of rice was investigated at nine locations of Korea during summer in 1993 with frequent raining and low temperature conditions. Incidence of panicle blast was 26% on Jinmibyeo, 23% on Chuncheongbyeo and 40% on Odaebyeo. Race distribution of Pyricularia grisea was examined from 1993 to 1994. A total of 1,098 isolates of the fungus obtained from the blast nurseries and framers; fields were screened using Korean differential varieties. Twenty one races were identified in 1993 and 19 races in 1994. KI-181, KJ-103, KJ-104, KI-241 and KI-209 were identified as new races, and KJ-301 (15%), KJ-201 (13%), KJ-105 (12%) and KI-409 (12%) were major races during 1993 and 1994. Race KI-197, which has a wide spectrum of virulence on rice cultivars, was isolated in a ratio of 8.3% and evenly distributed in the whole country. Some of the major and newly identified races during 1993∼1994 were used for spray-inoculation on leading cultivars and differential varieties in a greenhouse. We found that most of the cultivars were resistant to the major races, KJ-301 and KI-409, but were very susceptible to the new races, KI-241, KI-209, KI-181 and KJ-103.

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A Labeling Scheme for Efficient On-the-fly Detection of Race Conditions in Parallel Programs (병렬프로그램의 경합조건을 수행 중에 효율적으로 탐지하기 위한 레이블링 기법)

  • Park, So-Hee;Woo, Jong-Jung;Bae, Jong-Min;Jun, Yong-Kee
    • The KIPS Transactions:PartA
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    • v.9A no.4
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    • pp.525-534
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    • 2002
  • Race conditions, races in short, need to be detected for debugging parallel programs, because the races result in unintended non-deterministic executions. To detect the races in an execution of program, previous techniques use a centralized data structure which may incur serious bottleneck in generating concurrency information, or show inefficient time complexity which depends on the degree of nested parallelism in comparing any two of them. We propose a new labeling scheme in this paper, which is scalable in generating the concurrency information without bottleneck by using private data structure, and improves time complexity into constant in checking concurrency. The scalability and time efficiency therfore makes on-the-fly race detection efficient not only for programs with either shared-memory or message-passing, but also for programs with mixed model of the two.

On-the-fly Detection of Race Conditions in Message-Passing Programs (메시지 전달 프로그램에서의 수행 중 경합탐지)

  • Park, Mi-Young;Kang, Moon-Hye;Jun, Yong-Kee;Park, Hyuk-Ro
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.7
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    • pp.267-275
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    • 2007
  • Message races should be detected for debugging message-passing parallel programs because they can cause non-deterministic executions. Specially, it is important to detect the first race in each process because the first race can cause the occurrence of the other races in the same process. The previous techniques for detecting the first races require more than two monitored runs of a program or analyze a trace file which size is proportional to the number of messages. In this paper we introduce an on-the-fly technique to detect the first race in each process without generating any trace file. In the experiment we test the accuracy of our technique with some benchmark programs and it shows that our technique detects the first race in each process in all benchmark programs.

Scalable Race Visualization for Debugging Message-Passing Programs (메시지전달 프로그램의 디버깅을 위한 경합의 확장적 시각화)

  • Park Mi-Young;Jun Yong-Kee
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.7
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    • pp.341-348
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    • 2005
  • Detecting unaffected race conditions is important for debugging message-passing programs effectively, because such races can influence other races to occur or not. The previous technique used in detecting unaffected races detects a race by halting the execution of a process at the receive event of the race that errors first in the process. However this technique does not guarantee that all of the detected races are unaffected, because halting the execution of processes does disconnect some chains of affects-relations among those races. Tn this paper. we improved the second pass algorithm of the previous technique by producing information about affects-relations of the races that occur first in each Process. Then we effectively visualize affect-relations among the races detected in each process. This visualization is effective in detecting visually unaffected races by simplifying affects-relations among the races which occur first In each Process.

Development of Efficient Screening Methods for Resistance of Tomato to Fusarium oxysporum f. sp. lycopersici (토마토 시들음병에 대한 효율적인 저항성 검정법 확립)

  • Park, Myung-Soo;Jeong, Bo-Ram;Jang, Kyoung-Soo;Choi, Yong-Ho;Kim, Jin-Cheol;Choi, Gyung-Ja
    • Horticultural Science & Technology
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    • v.30 no.4
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    • pp.426-431
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    • 2012
  • This study was conducted to establish an efficient screening method for resistant tomato to Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL). The resistance degrees of the six commercial cultivars of tomato to the pathogen were evaluated by dipping roots of the seedlings in spore suspension of five FOL isolates. On the basis of the results, two cultivars (Dotaerangmaster, resistant cultivar to FOL race 1; Supersunload, resistant cultivar to FOL race 2) and two isolates (KACC40043, FOL race 2; TF104, FOL race 3) were selected for system establishment. The disease development of the FOL isolates on the cultivars according to several conditions including root wounding, incubation temperature, inoculum concentration and dipping period of roots in spore suspension was investigated. The resistance of each cultivar to the disease was a race-specific response and hardly affected by the tested conditions except for incubation temperature of $20^{\circ}C$. The optimum temperature for disease development caused by FOL was 25 to $30^{\circ}C$. On the basis of the results, we suggest that an efficient screening method for resistant tomato cultivars to Fusarium wilt is to dip the non-cut roots of tomato seedlings at two-leaf stage in spore suspension of $1{\times}10^7\;conidia{\cdot}mL^{-1}$ for 0.5 hours and transplant the seedling to plastic pot with horticulture nursery media, and then to cultivate the plants in a growth room at $25^{\circ}C$ for 3 weeks with 12 hours light a day.

Epidemic Outbreak of Blast Disease in the Resistant Variety of Rice, 'Kwanok' (저항성품종인 '관옥'의 도열병 격발원인)

  • Lee E. C.
    • Korean journal of applied entomology
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    • v.11 no.1
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    • pp.41-43
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    • 1972
  • 1. In order to investigate the epidemic outbreak of rice blast disease on the resistant variety Kwankon in 1969, this investigation was undertaken as a basis for breeding resistant varieties. 2. The 16 isolates collected from Kyunggi area were inoculated at the 3-4 leaf stage on 12 Japanese differential varieties used for identifying races under greenhouse conditions. Out of 16 isolates 15 were identified as C race group and one as N race group. Of the 15 rates, nine were C-8, two were C-7 and two were C-1. Of the remaining two isolates, one was similar to C-1, and the other was similar to C-5. 3. It is concluded that the epidemic in the resistant variety 'Kwanok' was due to the occurrence of the C race group, which can infect the Chinese type varieties.

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Occurrence of Root-knot Nematodes on Fruit Vegetables Under Greenhouse Conditions in Korea (과채류 시설재배지의 뿌리혹선충 문제)

  • 김동근
    • Research in Plant Disease
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    • v.7 no.2
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    • pp.69-79
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    • 2001
  • Meloidogyne arenaria race 2 (59%) is widely distributed, followed by M. incognita race 1 (23%), and an unknown race of M. incognita (18 %) in greenhouses in southern Korea. The key character to distinguish between M. arenaria and M. incognita is excretory pore in female head. When oriental melon, Cucumis melo L., grafted on Shintozoa (Cucurbit maxima x Cu. moschata) is transplanted in February in a plastic tunnel inside a greenhouse infested with M. arenaria, nematodes produced egg masses on roots at 40 days after transplanting and the soil juveniles (J2) population reach maximum in July to 3,817/100 ㎤. Juveniles are distributed relatively uniform over the 180-cm-wide row horizontally and the highest density occurs at 0-25 cm soil depth. For the control of root-knot nematodes, rice rotation, solarization, and soil addition treatments are the most effective (P=0.05); treatments reduce number of J2 over 90% and increase yield two times. Corn retation, fosthiazate, and soil drying treatment are moderately effective, while sesame and green onion rotations are not effective. The relationship between M. arenaria and yield of oriental melon is adequately described by a linear regression model. In the test with wild Cucumis genetic sources introduced from U.S.Dept. of Agriculture (USDA), one of C.heptadactylus, two of C.anguria, two of C. anguria var. longaculeatus, nine of C. metuliferus are resistant to both species of root-knot nematodes.

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Revisiting Transnational American Studies: Race and the Whale in Melville's Moby-Dick

  • Kang, Yeonhaun
    • Journal of English Language & Literature
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    • v.64 no.4
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    • pp.585-600
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    • 2018
  • Over the last three decades, the field of American Studies has increasingly paid attention to transnational approaches in an effort to diversify and expand the field's concerns beyond the narrow sense of the nation-state in today's globalizing world. Yet, the mediation of the transnational requires a careful analysis of the nation that is still in transit. In this context, this essay examines Herman Melville's novel Moby-Dick (1851) as a case study that vividly shows how reading American literature and culture through transnationalism not only offers new interpretations of canonical texts, but also helps us to better understand the historical roots and cultural contexts of contemporary issues such as global labor and migration, US citizenship and racial justice. To address the complexity of the text's circulation and reproduction, coupled with US national ideology and cultural conditions, I first turn to the canonization of Melville's Moby-Dick during the Cold War era as a national project and then explore the possibilities of transnational readings by focusing on the politics of race and global capitalism in the nineteenth century whaling industry. In doing so, I argue that critical transnationalism allows readers to keep questioning about their own understanding of race, nation, and cultural identity while remaining attentive to the destructive force of US imperialism and global capitalism in the twenty-first century.

Outbreak of Rice Blast Disease at Yeoju of Korea in 2020

  • Chung, Hyunjung;Jeong, Da Gyeong;Lee, Ji-Hyun;Kang, In Jeong;Shim, Hyeong-Kwon;An, Chi Jung;Kim, Joo Yeon;Yang, Jung-Wook
    • The Plant Pathology Journal
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    • v.38 no.1
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    • pp.46-51
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    • 2022
  • Rice blast is the most destructive disease threatening stable rice production in rice-growing areas. Cultivation of disease-resistant rice cultivars is the most effective way to control rice blast disease. However, the rice blast resistance is easy to breakdown within years by blast fungus that continually changes to adapt to new cultivars. Therefore, it is important to continuously monitor the incidence of rice blast disease and race differentiation of rice blast fungus in fields. In 2020, a severe rice blast disease occurred nationwide in Korea. We evaluated the incidence of rice blast disease in Yeoju and compared the weather conditions at the periods of rice blast disease in 2019 and 2020. We investigated the races and avirulence genes of rice blast isolates in Yeoju to identify race diversity and genetic characteristics of the isolates. This study will provide empirical support for rice blast control and the breeding of blast-resistant rice cultivars.