• Applied Microscopy
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• v.19 no.1
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• pp.59-69
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• 1989

Ultrastructure of the secretory portion of the small ampullate gland in the orb web spider, Nephila clavata, has been investigated using the electron microscope. The secretory portion of this gland comprise two different regions which are a S-shaped storage sac and a long, convoluted tail. By the internal textures of the secretory granules, the sac is subdivided into two regions ; the proximal region near the tail and the distal region near the duct. Commonly single layered connectives cover the basal portion of the sac epithelium, and apical portion of the epithelial cells is occupied by the thick cuticles. Within the epithelial cells of both the proximal and distal region, several types of the secretory granules surrounded by a limiting membrane and had characteristic crystalloid are scattered throughout the cytoplasm. The granular size and its electron densities are not coincide with each other according to the maturation level of the granules. The wall of the tail is composed of single layer of columnar epithelial cells, and their nuclei are found at the basal portion of the cells. Dissimilar to the epithelial cells of the sac, apical cuticles are not found at this portion. In the cytoplasm of these cells, numerous secretory granules, synthesized from the rough endoplasmic reticula commonly and had fine fibrous materials, are found. At the cell surface bordering the lumen, microvilli are seen, arid along the cellular boundaries specialized septate junctions and desmosomes appeared.

• Applied Microscopy
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• v.19 no.1
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• pp.49-58
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• 1989

Ultrastructure of the excretory duct of the small ampullate gland in the orb web spider, Nephila clavata L. Koch are studied with light and electron microscopes. The small ampullate glands, located near the midline portion of the abdominal cavity, are connected with the spigots(large spinning tubes) on the middle spinnerets and composed of three parts which are the excretory duct, the storage sac and the convoluted tail. The excretory duct of this gland is enclosed by a thin layer of the outer connective tissues. By the morphology of the apical cuticles and internal textures of the epithelial cells, the duct is subdivided into two regions which are proximal duct region near the sac and distal duct region near the spinnerets. At the distal region of the ducts, the subcuticle which had the function of water removal form the progenetive silk material is well developed, whereas at the proximal region this cuticle disappeared and instead of these, endocuticle is developed. Moreover the epithelium of the distal duct region is composed of columnar epithelial cells, but at the proximal region the epithelium is changed to squamous or cuboidal forms. In the cytoplasm of the epithelial cells, rough endoplasmic reticula, Golgi comlexes and large secretory vesicles related to the production of the cuticular materials are well developed. And between the adjacent epithelial cells, specialized septate junction and desmosomes are formed along the plasma membrane.

• Journal of Wetlands Research
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• v.13 no.1
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• pp.139-148
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• 2011

Web structure of spiders is a foraging strategy as well as an investment to get prey. In order to make a good foraging decision spiders should change its foraging strategy in the basis of sensory information provided by potential prey species. We conducted experiments to demonstrate whether a wasp spider, Argiope bruennichi modifies its web-building behavior after experiencing sensory information emitted by a cricket species, Teleogryllus emma. To know how the web structures would be modified, we quantified web characteristics after providing sensory information of the cricket and compared to the control group. Web construction decreased in the course of the experiment in both, control group(without stimulus) and experimental group(with stimuli). The results did not show remarkable differences between two groups. However, on the first day after providing sensory information of the cricket, the web-building behavior of A. bruennichi decreased only in 3.7% of the experimental group individuals against 11.8% of the control group individuals. The number of the stabilimentum constructions decreased overall in both groups. On the first day the decreasing proportion was doubled in the control group(14.7%), comparing to the experimental group(7.4%). The individuals did not lower its web height and did not extend its web area according to sensory information of the prey.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.6
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• pp.393-396
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• 2014

Recently, the internet of things (IoT) has become increasingly attractive in many areas to realize smart worlds. JavaScript has become prevalent for IoT programming because of its familiarity with web programmers. On the other hand, JavaScript does not allow the direct control of IoT hardware due to its language limitation. This paper proposes the IoT software platform for JavaScript programming to resolve the limitation. For proof of concept, the platform based on SpiderMonkey and Raspberry Pi was implemented.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.262-274
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• 2018

Spider fauna of Demilitarized Zone (DMZ) and adjacent areas in Korea was surveyed in 2001-2003, 2013-2015, and 2017. Total of 34 surveyed areas across 10 provinces were divided into four main regions (east coast, mid-east mountain, midland, and west coast areas) in accordance with administrative districts and topography. Total of 273 species of 145 genera in 32 families were identified from 10,886 collected spiders. In conclusion, the spider fauna in the DMZ is 281 species of 147 genera in 32 families with 162 species of 99 genera in 23 families in the previous reports. This corresponds to about 37.6% of the Korean spiders as of 2015. The species richness among surveyed localities was ranged 45 species to 92 species. The species richness of each taxon is high in Araneidae, Salticidae, Linyphiidae and Theridiidae. Habitat generalists were 22 species and habitat specialists were 69 species. The 143 species were web builders and 130 species were wanderers by the outlined life style. In DMZ spiders, only 7 species, Thymoites ulleungensis, Arcuphantes pennatus, Lycosa coreana, Allagelena koreana, Cybaeus mosanensis and Cybaeus triangulus, Kishidaia coreana, were recognized as Korean endemic. Five species, Scytodes thoracica, T. ulleungensis, Lycosa labialis, Takeoa nishimurai, and Phrynarachne katoi, are rare species with a trend of decreasing density in recent years. Araneus rotundicornis has been discovered for the first time since its first report. This study may be useful in the conservative management and will contribute to knowledge of the distribution and biogeography of DMZ areas in the future.

• Applied Microscopy
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• v.37 no.2
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• pp.53-63
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• 2007

The culticular substructure of the venom apparatus in the orb-web spider Araneus ventricosus are studied with scanning electron microscopy. The apparatus is composed of chelicera and paired venom glands in the cephalothorax. Each chelicera consists of a basal segment and a movable fang that articulates with each other. The chelicera of this spider is labidognathous form that moves at right angles to the body axis, and has two segments similar to that of a folding jackknife. Each cylindrical fang has a specialized hinge joint which articulate with the cheliceral groove which contains numerous small protrusions. In addition, each side of cheliceral groove is covered with a total of 7 cuticular teeth in two rows which composed of 4 promarginal and 3 retromarginal teeth. It has been also observed that a single venom pore is always located toward the direction of retromarginal teeth, and surface cuticular pits are distributed on the cuticular depressive area of cheliceral groove.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.49-57
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• 2014

Orb-web spiders can be considered as an effective bio-indicative animal to monitor the ecological air pollution of certain habitat since they have limited shifting ability during their life spans. In this study we revealed the fine structural characteristics of booklung in the orb-web spider Nephila clavata, and its bio-indicative significance in the monitoring environmental asbestos exposure. The high resolution scanning electron microscopy results suggest that the cuticular spikes near the atrium could be act as an effective filtering structure for dust materials. Furthermore, inner cuticular spikes which protruded across the air sacs, have the functions not only sustaining appropriate respiratory volume of each air sac but also help to enhance respiratory capacity by maximizing the gross surface area for gas exchange. Interestingly, in spite of short exposure, the asbestose fibrils were effectively captured on the surface of the atrial cuticular spikes. Furthermore, histologic damages were observed due to penetration of asbestos fibrils through air sacs and fixed on the hemolymph space. In addition, although accumulated mass of hemocytes were observed near the fibrils, there were no asbestos bodies or coagulated hemocytes were found on the surface of the fibrils, This could be mainly due to the short exposure period towards asbestos. Briefly, these results indicate the spider's booklung could be valuable tool in the detection ecological air pollutants.

• Journal of KIISE
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• v.43 no.1
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• pp.34-39
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• 2016

JavaScript is widely used in web pages with HTML. Many JavaScript engines adopt Just-in-time compilers to accelerate the execution of JavaScript programs. Recently, many newly introduced devices are adopting 64-bit CPUs instead of 32-bit and Just-in-time compilers for 64-bit CPU are slowly being introduced in JavaScript engines. However, there are many inefficiencies in the currently available Just-in-time compilers for 64-bit devices. Especially, the size of code is significantly increased compared to 32-bit devices, mainly due to 64-bit wide addresses in 64-bit devices. In this paper, we are going to address the inefficiencies introduced by 64-bit wide addresses and values in the Just-in-time compiler for the V8 JavaScript engine and propose more efficient ways of generating constant values and addresses to reduce the size of code. We implemented the proposed optimization in the V8 JavaScript engine and measured the size of code as well as performance improvements with Octane and SunSpider benchmarks. We observed a 3.6% performance gain and 0.7% code size reduction in Octane and a 0.32% performance gain and 2.8% code size reduction in SunSpider.

• 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.

• Journal of the Korea Computer Industry Society
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• v.4 no.12
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• pp.1093-1102
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• 2003

The dynamic nature of the World Wide Web challenges Search engines to find relevant and recent pages. Obtaining important pages rapidly can be very useful when a crawler cannot visit the entire Web in a reasonable amount of time. In this paper we study way spiders that should visit the URLs in order to obtain more “important” pages first. We define and apply several metrics, ranking formula for improving crawling results. The comparison between our result and Breadth-first Search (BFS) method shows the efficiency of our experiment system.