• Title/Summary/Keyword: Spider

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Description of Spheropistha melanosoma Yaginuma, 1957 (Araneae: Theridiidae) from Korea

  • Sue Yeon Lee;Jung Sun Yoo;Chang Moon Jang;Seung Tae Kim
    • Korean Journal of Environmental Biology
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    • v.41 no.1
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    • pp.14-17
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    • 2023
  • A male Spheropistha melanosoma Yaginuma, 1957 from Korea in the family Theridiidae Sundevall, 1833 is described with measurements and morphological photos of the diagnostic characteristics. This species was collected with a sweep net around arable lands in a mountainous mixed forest during the investigation of spider fauna on Ulleungdo Island in 2019.

Development of Korean Audio Caption System (한국어 오디오 캡션 시스템 개발)

  • Kang, Taeho;Kim, Juhee;Lee, Joonha
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2020.11a
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    • pp.364-367
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    • 2020
  • 오디오 캡셔닝(Audio Captioning)은 시스템이 입력으로 오디오 신호를 받아들이고 해당 신호의 텍스트 설명을 출력하는 중간 번역 작업이다. 이 논문에서는 컨볼루셔널 뉴럴 네트워크(CNN), 트랜스포머의 딥러닝 알고리즘을 사용하여 주변 환경 소리에 대한 오디오 캡셔닝을 자동으로 수행하고 한글화된 출력 결과를 제공하는 모델을 제시한다. 본 연구 결과, 모델의 성능 평가 척도인 SPIDEr 점수는 0.1977이 나왔다.

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Fumigant and Repellency Effects of Terpenes against the Two-Spotted Spider Mite, Tetranychus urticae (Acari: Tetranychidae) (점박이응애에 대한 Terpene류의 훈증과 기피효과)

  • 이소영;유정수;문선주;이상길;김철수;신상철;김길하
    • Korean journal of applied entomology
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    • v.42 no.3
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    • pp.249-255
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    • 2003
  • These studies were carried out to investigate fumigant, contact toxicity and repellency effects of 34 terpenes against acaricide susceptible the two-spotted spider mite, Tetranychus urticae. In addition, the efficacy was also tested against two acaricide-resistant strains. Two terpenes, isosafrole and safrole showed fumigant toxicity of 98.4%, at 10${\mu}\ell$/1 (air) concentration. LD$\_$50/ values of these two terpenes were 2.6${\mu}\ell$/1 and 4.3${\mu}\ell$l/1, respectively. Most terpenes showed low or no contact toxicity, except isosafrole showing 60.2% mortality against eggs. Hexanoic acid and limonene showed repellency effects of 79.1%, 87.8%, respectively, to the susceptible strain at concentration of 1,000 ppm in the lab conditions. Hexanoic acid (1,000 ppm) showed repellency effected of 77.8% and 83.3% to fenpropathrin and pyridaben resistant strains, respectively. However, limonene showed no repellency to the two resistant strains.

Ultrastructure of the Ampullate Gland in the Orb Web Spider, Nephila clavata L. Koch I. Excretory Duct of the Large Ampullate Gland (무당거미(Nephila clavata L. Koch) 병상선(甁狀腺)의 미세구조(微細構造) I. 대병상선(大甁狀腺)의 분비관(分泌管))

  • Moon, Myung-Jin;Kim, Chang-Shik;Kim, Woo-Kap
    • Applied Microscopy
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    • v.18 no.2
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    • pp.77-90
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    • 1988
  • The ultrastructure of the excretory duct of the large ampullate gland in the orb web spider, Nephila clavain L. Koch are studied with light and electron microscopes. The excretory ducts of the large ampullate glands connected with the large spinning tubes(spigots) on the anterior spinnerets are basically composed of three superposed types of the layers which are inner cuticles, monolayered epithelial cells and peripheral connective cells. According to the morphological characteristics of the cuticles and internal textures of the epithelial cells, the long excretory ducts are subdivided into three(distal, middle and proximal) portions. Especially, at the distal portion of the ducts near the spinning tubes, the electron lucent subcuticles which had the functions of water removal and orientation of silk fibers are well distributed, whereas at the middle and proximal portions these layers disappeared and instead of these, endocuticles are developed. The endocuticle contains two types of bands, which are electron dense and electron lucent. And along the length of the cuticular stem in the excretory duct, these two alternating bands are twisted spirally. In the cytoplasm of the columnar epithelial cells of the distal portion, rough endoplasmic reticula and Golgj complexes, related to the production of the cuticular materials are well developed. Between the adjacent epithelial cells, specialized septate junctions and desmosomes are formed along the plasma membranes. At the proximal portion of the duct, densely accumulated secretory materials appeared, and these are released to the inner canal by the apocrine secretion.

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Multi-body Dynamic Analysis for Tripod Constant Velocity Joint (트라이포드 타입 등속조인트의 다물체 동역학 해석)

  • Song, Myung-Eui;Lim, Young-Hun;Cho, Hui-Je;Bae, Dae-Sung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.1
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    • pp.1-7
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    • 2010
  • The paper proposes a multi-body dynamic simulation to numerically evaluate the generated axial force(G.A.F) and plunging resistant force(P.R.F) practically related to the shudder and idling vibration of an automobile. A numerical analysis of two plunging types of CV joints, tripod joint(TJ) and very low axial tripod joint(VTJ), is conducted using the commercial program DAFUL. User-defined subroutines of a friction model illustrating the contacted parts of the outboard and inboard joint are subsequently developed to overcome the numerical instability and improve the solution performance. The Coulomb friction effect is applied to describe the contact models of the lubricated parts in the rolling and sliding mechanisms. The numerical results, in accordance with the joint articulation angle variation, are validated with experimentation. The offset between spider and tulip housing is demonstrated to be the critical role in producing the 3rd order component of the axial force that potentially causes the noise and vibration in vehicle. The VTJ shows an excellent behavior for the shudder when compared with TJ. In addition, a flexible nonlinear contact analysis coupled with rigid multi-body dynamics is also performed to show the dynamic strength characteristics of the rollers, housing, and spider.

Evaluation of Insecticidal Efficacy of Plant Extracts Against Major Insect Pests (주요 해충에 대한 식물추출물의 살충력 평가)

  • Kim, Sam-Kyu;Jin, Joon-Ho;Lim, Chun-Keun;Hur, Jang-Hyun;Cho, Sae-Youll
    • The Korean Journal of Pesticide Science
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    • v.13 no.3
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    • pp.165-170
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    • 2009
  • Insecticidal efficacies of plant extracts and environmental friendly agro-materials against green peach aphids, two spotted spider mites, and diamondback moths were evaluated in the lab condition. Oxymatrine and matrine, derivatives of Sophora flavescens, were effective to all three tested pest insect species. Selected environmental friendly agro-materials available from the market mainly contained active ingredients of nicotine, azadirachtin, and matrine were all effective to control green peach aphids and two spotted spider mites.

Maternal Influence on Spiderlings' Emergence from the Cocoon: Observations in a Subsocial Spider

  • Kim, Kil-Won
    • Journal of Ecology and Environment
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    • v.32 no.1
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    • pp.33-39
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    • 2009
  • Brood caring behavior was observed in Amaurobius ferox (Araneae, Amaurobiidae), a semelparous subsocial spider, from cocoon construction until the emergence of spiderlings from the cocoon. Unlike most spiders, which emerge from cocoon by their own means, A. ferox mothers intervene in the process of the emergence of their young. I manipulated broods by removing the mother prior to emergence to determine the effects of maternal behavior on the emergence of spiderlings. My results showed that maternal intervention making the cocoon expansion and its exit, is not absolutely necessary for the emergence of A. ferox spiderlings from the cocoon. Nine clutches out of ten were able to get out of the cocoon by their own means without their mother's help. There was no difference between control groups ('with mother') and experimental groups ('without mother') in the number of spiderlings that emerged ($96.9{\pm}25.3$ vs. $90.4{\pm}14.2$, respectfully) and in the time from the beginning to the end of emergence ($36{\pm}12$ vs. $41{\pm}17$ hours). Time from eclosion until the emergence of the first individual in a clutch, however, was greater in the mother-absent group (3.5 days) than in the control group (2.0 days). The construction of the cocoon by the mother required always occurred in the same area within the retreat, and took approximately 6 hours, and the mother guarded the eggs during the incubation period. The emergence of the spiderlings followed a sigmoidal pattern. After emergence, the spiderlings formed a very compact group on the cocoon, which may be important in securing maternal care. The absence of cribellum and calamistrum, structures likely involved in their survival, observed in individuals of the first instar suggests that in the first stage of life, the spiderlings are dependent on their mother.

Stability of Dicofol Resistance of the Two-spotted Spider Mite, Tetranychus urticae Koch (Acarina: Tetranychidae) (Dicofol 저항성 점박이응애의 안정성)

  • Kim, Gil-Hah;Song, Cheol;Chang, Bu-Young;Park, No-Joong;Cho, Kwang-Yun
    • Korean journal of applied entomology
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    • v.34 no.1
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    • pp.61-64
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    • 1995
  • Stability of resistance of the two-spotted spider mite (Tetranychus urticae) to dicofol was investigated. Resistance level (23.0-fold) of adult females to dicofol was kept up to 1 year without selection by dicofol, but was decreased to 15.8-, 10.7-fold after 2 and 3 years, respectively. Susceptibility of adult females obtained from reciprocal crosses $(R_{female}\timesS_{male},R_{male}\times S_{female})$ of the R and S stains to dicofol was declined by the success of generation.

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Monitoring of Acaricide Resistance in Field-Collected Populations of Tetranychus urticae (Acari: Tetranychidae) in Korea (점박이응애 야외개체군의 살비제 저항성 모니터링)

  • Jum Bae Cho;Young Joon Kim;Young Joon Ahn;Jai Ki Yoo;Jeong Oon Lee
    • Korean journal of applied entomology
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    • v.34 no.1
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    • pp.40-45
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    • 1995
  • Eight field-collected populations of the two-spotted spider mites, Tetranychus urticae (Koch) from apple orchards of different geographical areas were tested for resistance to seven acaricides by leaf disk method in comparison with a susceptible strain. Marked regional variations of susceptibility were observed. Only low to moderate resistance to azocyclotin, fenpropathrin, propargite, and abamectin was obtained. However, high resistance to dicofol, fenpyroxymate, and pyridaen by eight field-collected populations was produced. Resistance to dicofol and fenpyroxymate was widespread. All of the strains tested were susceptible to one or more o the acaricides used. These results indicate that careful selection of the chemical used against any population of the two-spotted spider mite might result in satisfactory control.

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International Cooperation Organization for the Common Use of Space Resources in case of Disasters (재해.재난관련 우주자원 활용을 위한 국제협력기구 현황)

  • Kim, Sung-Kyu;Kim, Youn-Soo;Kim, Yong-Seung
    • Current Industrial and Technological Trends in Aerospace
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    • v.6 no.1
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    • pp.44-55
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    • 2008
  • Catalyzed by the recent development of space technology, various kinds of spacecrafts were launched and utilized with purposes in many developed countries. In case of emergency such as natural disasters, proper satellite images are required in order to help to mitigate and assess the effects of disasters on human life and property. Since there are limitations for a nation to single-handedly operate a satellite and fulfill complete demands, a development need of international cooperation organization to share satellite images among the member countries has risen. In this paper, preestablished four international organizations' background, objectives, and operating system, and their principal characteristics were analyzed and compared. Especially, the paper has focused on the analysis of on-going operating procedures and its cases for International Charter, UN SPIDER's development of local supporting network to support NFP, establishment of Web-GIS by Sentinel Asia under the goal of 'Digital Asia', and the utilization of GEO that is widely applied in natural disaster fields.

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