• Title/Summary/Keyword: Spider

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Optimum design of steel space structures using social spider optimization algorithm with spider jump technique

  • Aydogdu, Ibrahim;Efe, Perihan;Yetkin, Metin;Akin, Alper
    • Structural Engineering and Mechanics
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    • v.62 no.3
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    • pp.259-272
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    • 2017
  • In this study, recently developed swarm intelligence algorithm called Social Spider Optimization (SSO) approach and its enhanced version of SSO algorithm with spider jump techniques is used to develop a structural optimization technique for steel space structures. The improved version of SSO uses adaptive randomness probability in generating new solutions. The objective function of the design optimization problem is taken as the weight of a steel space structure. Constraints' functions are implemented from American Institute of Steel Construction-Load Resistance factor design (AISC-LRFD) and Ad Hoc Committee report and practice which cover strength, serviceability and geometric requirements. Three steel space structures are optimized using both standard SSO and SSO with spider jump (SSO_SJ) algorithms and the results are compared with those available in the literature in order to investigate the performance of the proposed algorithms.

Microstructure of Faecal Pellets and Silk of the Two Spotted Spider Mite, Tetranychus urticae (Tetranychidae: Acarina) (점박이응애 분비물의 미세구조)

  • Shin, Hee-Kwan;Yoo, Sea-Hee;Lee, Won-Koo;Park, Joong-Won;Lee, In-Yong
    • The Korean Journal of Soil Zoology
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    • v.11 no.1_2
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    • pp.7-12
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    • 2006
  • Asthma and allergic rhinitis due to outdoor spider mites are major health problems worldwide. The sensitization route to spider mites has not yet been well elucidated. We examined the microstructure of faecal pellets and silk of the two-spotted spider mite, Tetranychus urticae, using a field emission scanning electron microscope. Black and white pellets of the two-spotted spider mites faeces contain a large amount of plant pigment waste products. Black faecal pellets are strawberry-shaped. White faecal pellets are silken threads. These pellets are likely to be the source of allergens of relevant mites because desiccated faeces particles probably disintegrate and become incorporated into dust particles more readily than whole bodies or encased internal organs. We conclude that the importance of spider mites in respiratory allergy needs emphasis.

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Vegetation characteristics, conservation and ecotoursim strategies for water spider(Argyroneta aquatica) in small marsh, Korean Natural Monument (물거미가 서식하는 천연기념물 습지의 식생학적 특성과 보전 및 생태관광화 방안)

  • You, Young-Han;Yi, Hoon-Bok
    • Journal of Wetlands Research
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    • v.11 no.2
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    • pp.99-106
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    • 2009
  • Water spider(Argyroneta aquatica Clerck) is only spider that live under aquatic water. In korea, water spider distributed only in Undari Wetland, Yeochon County, Kyongii Proviance, where it is designated as Natural Monument. I counted the population density, analysed the ecological traits such as actual vegetation map, and suggested conservation strategy and eco-tourism planning for water spider. The population mean density of water spider was one individual/$m^2$ and 8,000 individuals/ha. The wetland inhabited by water spider was characterized by high water level fluctuation between rainy season and dry ones. Wetland plant community was dominated by Phragmites australis and Leersia oryzoides var. japonica with submersed plant, Utricularia japonica. It is need to supply water for inhibiting terrestial succession trend during the dry season and to connect three fragmented wetlands through ecological corridor. Also, It was suggested that ecotourism planning is important for conserving this wetland.

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Life History of a Colonial Spider Philoponella prominens (Araneae: Uloboridae) in Korea

  • Tae Soon Park;Jun Namkung;Jae Chun Choe
    • Animal cells and systems
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    • v.3 no.2
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    • pp.167-172
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    • 1999
  • We report for the first time the life history of a 'social' spider, Philoponella prominens, living in a temperate region. Philoponella prominens hibernated as immatures or subadults for 7-8 months in 1995 and 1996 from September-October to April-May in central Korea. When they emerged from their winter hibernation, a majority began their lives as commensals in the webs of other species. As the mating season approached, however, commensal spiders switched to become colonial or solitary. The mating season began in early June and lasted until early August. Newly-hatched spiderlings began to appear in the field in late June. They formed a colony by building their webs connected to the mother's by using pan of the mother's web as supporting substrates. As the season progressed, however, some of the colonial spiderlings became commensal or solitary individuals. Our field observations suggest that Philoponella prominens form colonies or commensal associations to reduce the web-building cost.

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Spider Fauna of Mt. Yongmunsan, Gyeonggi-do in Korea

  • Kim, Seung Tae;Im, Moon-Soon;Lee, Sue-Yeon;Koo, Han-Mo
    • Journal of Forest and Environmental Science
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    • v.28 no.4
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    • pp.282-288
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    • 2012
  • Spider fauna of Mt. Yongmunsan located in Yangpyeong-gun, Gyeonggi-do, was surveyed from April to October in 1996. A total of 75 species of 51 genera in 22 families from 996 individuals of spiders were identified. Species richness of each family, there were 17 Araneid species (22.7%), followed by each of the 7 Thomisid and Tetragnathid species (9.3%), 6 Salticid species (8.0%), and 5 Lycosid species (6.7%). Zoogeographically, spider fauna of Mt. Yongmunsan represented 1 cosmopolitan species (1.3%), 2 holarctic region species (2.6%), and 9 palearctic region species (12.0%), and 4 Korean endemic species (4.0%). Thus it is suggested that spider fauna of Mt. Yongmunsan was under northern regional influence.

Individual physical variables involved in the stabilimentum decoration in the wasp spider, Argiope bruennichi

  • Kim, Kil Won
    • Journal of Ecology and Environment
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    • v.38 no.2
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    • pp.157-162
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    • 2015
  • The physical factors of Argiope bruennichi (Araneae, Araneidae) that influence the stabilimentum decoration on the web, a conspicuous white silk structure reflecting much more ultraviolet light than other spider silks in the web, have been poorly understood. In this study, individual variables involved in decorating the webs with stabilimenta by A. bruennichi were examined. The results revealed that the physical condition of the female A. bruennichi affected the behaviors of the stabilimentum decoration on the web. Among the 82 female spiders building their webs, the 49 female spiders adding upper and lower stabilimenta on their web weighed less, and had a narrower cephalothorax and shorter abdomen than the 33 female spiders that did not use stabilimentum. The heavier females decorated their webs with stabilimentum of greater widths. There were also significant positive relationships between the stabilimentum area and the female spider's cephalothorax width, and between the stabilimentum area and female spider's abdomen length. Taken together, this study suggests that spiders allocate their resources in stabilimentum decoration as a functional response to the spider's physical conditions, and also supports the "prey-attraction hypothesis," which states that the use of stabilimentum increases the foraging success by attracting more prey to the web.

Classification of Gripping Movement in Daily Life Using EMG-based Spider Chart and Deep Learning (근전도 기반의 Spider Chart와 딥러닝을 활용한 일상생활 잡기 손동작 분류)

  • Lee, Seong Mun;Pi, Sheung Hoon;Han, Seung Ho;Jo, Yong Un;Oh, Do Chang
    • Journal of Biomedical Engineering Research
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    • v.43 no.5
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    • pp.299-307
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    • 2022
  • In this paper, we propose a pre-processing method that converts to Spider Chart image data for classification of gripping movement using EMG (electromyography) sensors and Convolution Neural Networks (CNN) deep learning. First, raw data for six hand gestures are extracted from five test subjects using an 8-channel armband and converted into Spider Chart data of octagonal shapes, which are divided into several sliding windows and are learned. In classifying six hand gestures, the classification performance is compared with the proposed pre-processing method and the existing methods. Deep learning was performed on the dataset by dividing 70% of the total into training, 15% as testing, and 15% as validation. For system performance evaluation, five cross-validations were applied by dividing 80% of the entire dataset by training and 20% by testing. The proposed method generates 97% and 94.54% in cross-validation and general tests, respectively, using the Spider Chart preprocessing, which was better results than the conventional methods.

Capture silk scaffold production in the cribellar web spider

  • Yan Sun;Seung-Min Lee;Bon-Jin Ku;Eun-Ah Park;Myung-Jin Moon
    • Applied Microscopy
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    • v.51
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    • pp.11.1-11.9
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    • 2021
  • Spider capture silk is a natural scaffolding material that outperforms most synthetic materials in terms of its combination of strength and elasticity. Among the various kinds of silk threads, cribellar thread is the most primitive prey-capturing type of spider web material. We analyzed the functional organization of the sieve-like cribellum spigots and specialized calamistral comb bristles for capture thread production by the titanoecid spider Nurscia albofasciata. The outer cribellar surface is covered with thousands of tiny spigots, and the cribellar plate produces non-sticky threads composed of thousands of fine nanofibers. N. albofasciata cribellar spigots are typically about 10 ㎛ long, and each spigot appears as a long individual shaft with a pagoda-like tiered tip. The five distinct segments comprising each spigot is a defining characteristic of this spider. This segmented and flexible structure not only allows for spigots to bend individually and join with adjacent spigots, but it also enables spigots to draw the silk fibrils from their cribella with rows of calamistral leg bristles to form cribellar prey-capture threads.

Seasonal Occurrence of Spot Clothing Wax Cicada, Lycorma delicatula(Hemiptera: Fulgoridae) and It's Control Efficacy Using EFAM at the Vineyards (포도원 꽃매미(Lycorma delicatula) 발생소장 및 친환경농자재 살충력 평가)

  • Lee, Ki-Yeol;Kim, Sun-Kook;Kim, Ik-Hawn;Kim, Kyung-Su
    • The Korean Journal of Pesticide Science
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    • v.15 no.3
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    • pp.303-309
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    • 2011
  • This study was carried out to investigate the evaluation of insecticidal efficacy and control effect in field of 10 environmental-friendly agricultural materials (EFAM) and seasonal occurrence at the vineyards to the Lycorma delicatula. L. delicatula nymphs occurred from late May to late August the highest early June (1st nymph) while adults occurred from late July to November with the highest peak of early October (preovipositing female) in 2010. Total population density of L. delicatula was the highest in early June. For the 3rd~4th nymphal instars and adults, EFAM (Spider, Jindikap-plus and Byejin-${\alpha}$) showed perfect insecticidal activity 2hour after treatment. Seoncho showed insecticidal activities 96.7% within 48 hour. Residual effects between EFAM showed 55.5% Spider at recommended concentration at 7 days after treatment(DAT), the other EFAM had low efficacy. Jindikap-plus and Spider showed 99% control value on nymphs in the field test at 3DAT, appeared control value more than 90% at 7DAT. Also, the control effects of Jindikap-plus and Spider were showed the adult mortality of 100% and 98.2% respectively at 3DAT, 90.6% and 84.6% respectively at 7DAT. Whereas the other EFAM had low efficacy. Jindikap-plus and Spider were excellent control effects compared with Acetamiprid WP.

Heat Treatment Effects on the Thermal Stability and Mechanical Property of Spider Silks from Nephila clavata and Bassaniana decorata (무당거미와 나무껍질게거미줄의 열 안정성 및 기계적 성질에 관한 열처리 효과)

  • Chang, So-Yeon;Lee, Ji-Hye;Lee, Ju-Ha
    • Korean journal of applied entomology
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    • v.48 no.1
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    • pp.109-115
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    • 2009
  • The thermal stability and mechanical properties of Nephila clavata and Bassaniana decorata spider silks were measured and compared with those of aramid and polyester fibers. The thermal stability of the spider silk was lower than those of the commercial aramid and polyester fibers. However, the mechanical properties of the spider silk were far superior to that of the polyester fiber. The effect of the water content of the spider silk on its thermal stability and mechanical property was examined by conducting the silk to heat treatment at $100^{\circ}C$ under vacuum for various times. The results indicated that spider silk subjected to heat treatment for 1.5 hr had excellent thermal stability and mechanical property.