Web Spider Research Articles

Design and Implementation of an Intelligent Searching Robot for Radioactive Sources Based on Edge Computing

In recent years, the worldwide nuclear industry has developed vigorously. At the same time, incidents of radioactive source loss have also occurred frequently. At present, most of the search for radioactive sources uses manual search, which is inefficient and the search personnel are vulnerable to radiation damage. Sending the robot into the area where the uncontrolled radioactive source may be located for search is different. Not only the efficiency can be improved, but the personnel are also prevented from being exposed to radiation. Therefore, designing a radioactive source search robot has great practical significance. This paper mainly introduces the design and implementation of an intelligent search robot for radioactive sources based on edge computing, and intends to provide some ideas and directions for the research of intelligent robots for searching for radioactive sources. This paper proposes a research method for the design and implementation of a radioactive source intelligent search robot based on edge computing, including intelligent edge computing and gamma ray imaging algorithms, which are used to carry out related experiments on the design and implementation of a radioactive source intelligent search robot based on edge computing. The experimental results in this paper show that the average resolution of the radioactive source search robot is 90.55%, and the resolution results are more prominent.

Agelena orientalis (Araneae: Agelenidae: Ageleninae) Huni Ağ Örümceğinin Ağ Yapısı ve Örü Aygıtının Morfolojisi

Örümceklerin ağ yapma özelliği çok eski yıllardan beri insanoğlunu etkilemiştir. Ancak bütün örümcekler ağ örmezler. Örümcekler ağ örme yeteneklerini örü aygıtlarına sahip olmalarına borçludur. Örü aygıtı ipek salgısını üreten ağ bezleri ve bu bezlere bağlı örü memelerinden oluşmaktadır. Örü memeleri, ipeğin çıkartılması ve iplik haline getirilerek işlenmesi için kullanılmaktadır. Örümceklerin ağları çok dikkat çekse de örü aygıtları hakkında çok fazla çalışma bulunmamaktadır. Bu çalışmada, oldukça dikkat çekici ağ yapısına sahip olan Agelena orientalis (C.L. Koch, 1837) huni ağ örümceğinin ağ yapısı ve ağ örme aygıtının morfolojisi taramalı elektron mikroskobu (SEM) ile çalışılmıştır. Çalışmamızda, A. orientalis’in ağ yapısı, örü memeleri ve spigotların yapısı gösterilmiş ve elde edilen veriler tartışılmıştır.

Neurophysiological action of centrally-acting spider toxin polypeptides derived from Hadronyche versuta and Tegenaria agrestis venoms

Established dogma concerning the action of insecticidal arthropod-derived peptides (e.g., scorpion toxins), was that they acted on the peripheral nervous system and were excluded from the central nervous system (CNS) by barrier systems. Initial evidence for a CNS-directed toxicological effect following parenteral administration was for a novel peptide from the Hobo spider, Tegeneria agrestis. This toxin was inactive on peripheral sensory and motor nerves, but had a potent excitatory effect on the CNS of larval Musca domestica. Recently, a commercialized formulation of GS-omega/kappa-Hxtx-Hv1a (HXTX), derived from the venom of the Australian blue mountain funnel web spider (Hadronyche versuta) was introduced for use in agriculture by Vestaron Corp. Its primary mode of action was found to be central neuroexcitation via positive allosteric modulation of nicotinic acetylcholine receptors (nAchR) of cockroach neurons. In the present study, this peptide showed hyperexcitation followed by a decrease in firing of the Drosophila melanogaster larval CNS that was prevented by co-exposure to 100 nM α-bungarotoxin (α-BGTX), a classical nAchR noncompetitive antagonist. This effect was mirrored in isobologram analysis, which showed clear antagonism between the two toxins when injected into adult houseflies. Interestingly, U1-agatoxin-Ta1b-QA derived from Tegeneria agrestis (VST-7304) had a similar biphasic action, but showed increased nerve discharge when co-exposed with 100 nM α-BGTX, and had additive effects when injected together with α-BGTX in isobologram analyses. Binary mixtures of HXTX or VST-7304 with 30 nM nicotine showed clear evidence of synergized nerve block, which was also observed for mixtures of HXTX and VST-7304. Taken together, these data suggest that HXTX and VST-7304 have somewhat different and complementary modes of action.

Semantic Grounding for Long-Term Autonomy of Mobile Robots Toward Dynamic Object Search in Home Environments

In this article, we presents an effective semantic grounding scheme to long-term mobile robots for dynamic object search in open/dynamic home environments. The challenge of this strategy lies in dealing with situations where the robot suffers the home environment with an unknown layout of the object and the target object is moved without the robot’s knowledge. Therefore, a general probabilistic model and a semantic model are established by investigating typical spatial location relations between object and room type, in order to guide the robot to prioritize the search effort for spaces that are most promising to find the target object. Furthermore, a semantic grounding solution is proposed to address the mutual independence between objects, endowing the robot with inference capability for dynamic object search. Also, our proposal can be shared with other robots that have not explored the environment in order to perform object search tasks. The presented scheme is fully evaluated by extensive experiments in the real-world environment. The results demonstrate the validity of our approach by comparing it with the other three schemes in terms of search time and trajectory length, and show that the proposed method allows the mobile robot to efficiently and robustly find the dynamic object while achieving the human-like performance.

Perancangan Software Robot Pencari dan Penyusun Menara Lagori pada ABU Robocon 2022

Lagori is a traditional game and one of the games originating from southern India. This game is played by two teams, where the first team is the seeker and the second team is the pitcher. The game starts by throwing the ball by the seeker to break the stone tower called Lagori. While the seeker tries to pile up more stones, the hitter throws the ball to annoy them. The purpose of this final project is to design a search robot and a Lagori tower to take part in the Indonesian Robot Contest (KRI) 2022. This search robot and Lagori tower are designed based on the Contest procedure using the Atmega2560 microcontroller as a microcontroller, pneumatics are used to pull and remove the gripper, robot The search engine and the Lagori tower use a semi-automatic system, so a wireless joystick is used as a controller, making it easier for users to control it. The results of the search robot and tower testing are in accordance with the algorithm that has been embedded in the 2560, for the pwm setting it varies between 100 and 110 and is used as a speed controller and the robot moves directions such as forward, backward, forward, backward, left, and to the right. The I/O ports on the microcontroller are given logic (logic 1), while for pneumatics repelling and pulling the gripper arm, gripper motors, gripper motors, bohh ball drive motors, and off logic firing motors (logic 0).

Aggregate attack surface management for network discovery of operational technology

Interconnectivity has become a substratum of technology as the benefits of data-driven functionality are being realized in nearly all industries. Increased connectivity of Operational Technology (OT) exacerbates cyber risks because Industrial Control Systems (ICS) are becoming exposed to the Internet. These exposures are often done inadvertently through misconfigurations as additional network devices come online. Attack surface management (ASM) platforms can be used to identify vulnerabilities by performing external network discovery over the Internet using web spiders. These web spiders enable big data analytics of Internet of Things (IoT) devices as identifiable information of Internet-exposed equipment are archived in searchable databases that are made publicly available. There are a multitude of ASM service providers on the market. This study was conducted to evaluate several commonly known tools to determine the aggregate attack surface of control systems. Queries were crafted by targeting commonly known manufacturers and communication protocols found in OT networks. Identified devices were that categorized based on technology types. Each query was replicated between several tools to target identical ICS equipment. Findings in this paper suggested a significant variance in the exposures discovered by each tool, but unique contributions were identified for each tool when a merged attack surface was derived. Therefore, all tools should be used in aggregate.

Population level variation in silk chemistry but not web architecture in a widely distributed orb web spider

Abstract Spider webs are iconic examples of extended phenotypes that are remarkably plastic across different environments. Orb webs are not only effective traps for capturing prey, but can also provide information to potential mates and, in some cases, potential predators and prey through silk-based chemicals. As with regular phenotypic traits, variability in the properties of spider webs is thought to be mediated by a combination of genetic and environmental effects. Here, we examined variation in several key features of the webs of the orb-weaving spider Argiope keyserlingi across five geographically disparate populations. We documented variation in web architecture and chemical properties of webs collected directly from the field. We then probed the potential for the underlying environmental driver of local insect abundance to explain this variation, by analysing the properties of orb webs constructed by the spiders from these different populations, but under identical laboratory conditions. We found no evidence of variation across populations in the architecture of webs constructed in the laboratory, despite the large geographic distances. Nonetheless, we discovered between population variation in the composition of chemicals found on the surface of silk and in the taxonomic distribution of available prey. Furthermore, there was a positive correlation between the quantity of nitrogenous compounds in web silks and female body condition. When combined, these findings suggest that environmental mechanisms can drive variation in web traits across spider populations.

Design and Implementation of a Radioactive Source Intelligent Search Robot Based on Artificial Intelligence Edge Computing

Artificial intelligence is a very broad science, which consists of different fields, such as machine learning, and computer vision. In recent years, the world nuclear industry has developed vigorously. At the same time, incidents of loss of radioactive sources also occur from time to time. At present, most of the search for radioactive sources adopt manual search, which is inefficient, and the searchers are vulnerable to radiation damage. Sending a robot to the search an area where there may be an uncontrolled radioactive source is different. Not only does it improve efficiency, it also protects people from radiation. Therefore, it is of great practical significance to design a radioactive source search robot. This paper mainly introduces the design and implementation of a radioactive source intelligent search robot based on artificial intelligence edge computing, aiming to provide some ideas and directions for the research of radioactive source intelligent search robot. In this paper, a research method for the design and implementation of a radioactive source intelligent search robot based on artificial intelligence edge computing is proposed, including intelligent edge computing and gamma-ray imaging algorithms, which are used to carry out related experiments on the design and implementation of radioactive sources, an intelligent search robot based on edge computing. The experimental results of this paper show that the average resolution of the radioactive source search robot is 90.55%, and the resolution results are more prominent.

Boss Brigade Bot 85-17

A technological innovation project is presented based on the design and manufacture of a robot prototype that supports studies oriented to the understanding and application of scientific methodology in rescue areas, as a support for the safety of brigades, which promotes it as relevant research. The use of nanotechnological resources leads it as a study of original technological innovation. The objective of this project is to innovate a search and rescue robot prototype so that in case of disasters the lives of the rescue brigades are not put at risk and in this way contribute to society. In order to contribute to the effort made by the nations in the face of the environmental impact, PEEK plastic, which is resistant to high temperatures, shocks, and is also considered a biomaterial, is contemplated as a material for the robot's structure.

The Use of Tuning Forks for Studying Behavioural Responses in Orb Web Spiders

Simple SummarySpiders are common predators found in almost every type of environment, and are used as model organisms in studies ranging from communication and signalling to biochemical studies on their silk. Orb spiders are particularly interesting, as their web provides a cost-effective way to obtain information on their foraging behaviour. However, studies on short-term behaviours including prey capture and escape behaviours are rare and usually take place in artificial settings, such as laboratories. In this study, we tested a simple methodology using tuning forks that can be used consistently and reliably in the field. The two tuning forks are capable of producing attack (440 Hz) and escape (256 Hz) responses from the spiders. We also used a metal wire as a mechanical stimulus for comparison, which as predicted, was less reliable. We demonstrate the usefulness of the methodology by quantitatively investigating how the size of the spider and the size of its web affect predatory and escape response rates in the autumn spider, although no significant effects of either were found. However, our results confirm the ease by which this simple method can be used to conduct behavioural studies of orb spiders in the wild.Spiders and their webs are often used as model organisms to study a wide range of behaviours. However, these behavioural studies are often carried out in the laboratory, and the few field studies usually result in large amounts of video footage and subsequent labour-intensive data analysis. Thus, we aimed to devise a cost- and time-effective method for studying the behaviour of spiders in the field, using the now almost forgotten method of stimulating webs with tuning forks. Our study looked at the viability of using 256 Hz and 440 Hz tuning forks to stimulate, anti-predatory and predatory responses in the orb web spider Metellina segmentata, respectively. To assess the consistency of the behaviours produced, we compared these to direct mechanical stimulation with a metal wire. The results suggest that the tuning forks produce relatively consistent behaviours within and between two years in contrast to the metal wire. We furthermore found no significant effects of spider length or web area on spider reaction times. However, we found significant differences in reaction times between escape and prey capture behaviours, and between tuning forks and the wire. Thus, we demonstrated the potential of tuning forks to rapidly generate quantitative data in a field setting.

Spiders in Brazil: from arachnidism to potential therapeutic use of their venom part 1 of 2

Spider envenomation, generically known as arachnidism, is described in many places around the world. In terms of medical importance, the following genera of animals stand out as the main origin of the morbid condition: Atrax (Sidney funnel web spider), Steatoda (false black widow), Latrodectus (black widow), Loxosceles (brown spider) and Phoneutria (armed spider), the last three causing accidents involving spiders in Brazil. This article, part 1 of 2, aims to present the main aspects of arachnidism in the country, with an emphasis on the biology and geographical distribution of spiders, biochemistry of the venom, pathogenesis and epidemiology of arachnidism, as well as prevention of the morbid condition. KEY WORDS: Arachnidism; araneae; spider bites; spider venoms.

Autonomous Aerial Robot for High-Speed Search and Intercept Applications

In recent years, high-speed navigation and environment interaction in the context of aerial robotics has become a field of interest for several academic and industrial research studies. In particular, Search and Intercept (SaI) applications for aerial robots pose a compelling research area due to their potential usability in several environments. Nevertheless, SaI tasks involve a challenging development regarding sensory weight, onboard computation resources, actuation design, and algorithms for perception and control, among others. In this work, a fully autonomous aerial robot for high-speed object grasping has been proposed. As an additional subtask, our system is able to autonomously pierce balloons located in poles close to the surface. Our first contribution is the design of the aerial robot at an actuation and sensory level consisting of a novel gripper design with additional sensors enabling the robot to grasp objects at high speeds. The second contribution is a complete software framework consisting of perception, state estimation, motion planning, motion control, and mission control in order to rapidly and robustly perform the autonomous grasping mission. Our approach has been validated in a challenging international competition and has shown outstanding results, being able to autonomously search, follow, and grasp a moving object at 6 m/s in an outdoor environment.

Mechanism Design and Motion Analysis of a Flapping-Wing Air Vehicle

Micro flapping-wing air vehicles (FWAV) are highly appreciated by scientists and scholars around the world due to their small size, high flexibility, and better manoeuvrability. There are huge potential applications of flapping-wing robots in rescue, survey, and search, as they can enter more dangerous and narrow spaces to accomplish tasks that were previously impossible for people. In this paper, we first analyze the flapping motion of birds by reviewing a large amount of information and literature and identifying the sources of lift and thrust during flight. Then, the double crank and double rocker mechanisms are optimized as the flapping mechanism. Proper flapping-wing size is further determined by analyzing the relative position between the driving mechanism and the flapping mechanism. Moreover, a pitch mechanism consisting of ball hinges is designed to realize the wing’s pitching motion for additional thrust. The fuselage and landing gear of the flapping-wing robot are designed for low air resistance and lightweight, and the tail mechanism are designed to have both roll and pitch freedoms, offering excellent manoeuvrability during flight. Simulation results show positive lift force is generated based on the novel pitching design for the small wing. The research in this paper is an important resource for novice researchers to design and study the advanced and complex problems of flapping-wing air vehicles.

Information-Based Control of Robots in Search-and-Rescue Missions With Human Prior Knowledge

Multirobot systems provide a scalable and robust solution for monitoring tasks. In time-intensive missions such as search and rescue, the inclusion of a human has the potential advantage of incorporating prior knowledge about the target location or dynamics. In this article, we develop a general information-theoretic framework to control multiple autonomous robots in search and rescue missions that include a human teleoperator. Human prior knowledge is modeled to capture the target location and dynamics, and mutual-information-based control is formulated to let autonomous robots weigh between two strategies: independent search or assisting the human by staying in proximity. The control actions optimize a weighted sum of normalized mutual information calculated using particle-filtered estimates of the target and the reference robot. We implement the framework to simulate two widely different scenarios designed after search-and-rescue missions from literature, and incorporate varying levels of accuracy in human prior knowledge. Our results indicate that the mission performance depends on how robots weigh between the two strategies, with the amount of the optimal control effort shared between strategies affected by prior knowledge and the number of robots. Comparison with existing strategies points to the benefits of an information-based control in situations where human prior knowledge is inaccurate. The proposed information-theoretic abstraction of the human–robot interaction can be implemented on a wide variety of scenarios and the results highlight the role of human prior knowledge toward effective robotic assistance in time-intensive missions.

An autonomous navigation approach for unmanned vehicle in outdoor unstructured terrain with dynamic and negative obstacles

AbstractAt present, the study on autonomous unmanned ground vehicle navigation in an unstructured environment is still facing great challenges and is of great significance in scenarios where search and rescue robots, planetary exploration robots, and agricultural robots are needed. In this paper, we proposed an autonomous navigation method for unstructured environments based on terrain constraints. Efficient path search and trajectory optimization on octree map are proposed to generate trajectories, which can effectively avoid various obstacles in off-road environments, such as dynamic obstacles and negative obstacles, to reach the specified destination. We have conducted empirical experiments in both simulated and real environments, and the results show that our approach achieved superior performance in dynamic obstacle avoidance tasks and mapless navigation tasks compared to the traditional 2-dimensional or 2.5-dimensional navigation methods.

Distributed Measurement of Deformation Magnitude and Location with a Pair of Soft Sensors

Skin‐like sensitivity, or the capability to recognize tactile information, is essential for future robots in elder care, search and rescue, entertainment and other applications involving unstructured environments. In this paper, we propose the design of a flexible one‐dimensional pressure‐sensing system that can localize deformation along a long strip and measure its magnitude with an integrated pair of sensors. The sensor system is fabricated with piezoresistive conductive foils and copper sheets encapsulated by adhesive tape with a total thickness of 0.7 mm. For the purpose of demonstration, the sensor is used to monitor the location and magnitude of kink deformation of an inflatable tube. Finite‐element modeling and simulation are conducted to investigate the behavior of the soft sensor system when subjected to kink deformation. The model‐predicted sensor output achieves good agreement with the experimental data for different deformation magnitudes. Finally, extensive experiments on a sensor prototype with dimensions of mounted on an inflatable tube are conducted to demonstrate the capability of the proposed scheme in simultaneous measurement of deformation location and magnitude. It is shown that the specific design approach minimizes the coupling of location and magnitude measurements, resulting in minimal complexity for data processing.

Bringing Tegenaria boitanii stat. rev. back to life with a review of the Tegenaria percuriosa-complex (Araneae: Agelenidae), description of a new species and insight into their phylogenetic relationships and evolutionary history

The funnel web spiders (Agelenidae) are a diverse and taxonomically challenging worldwide distributed family. The genus Tegenaria Latreille, 1804, includes more than 100 valid species, mostly circumscribed to Europe and western Asia, although some species may have been subsequently introduced to other regions by anthropogenic action. Here we revise and investigate phylogenetic relationships of a group of morphologically similar species from the south-western Black Sea region and Anatolia. We remove the species Tegenaria boitanii Brignoli, 1978 stat. rev. and Tegenaria bithyniae Brignoli, 1978 from synonymy of Tegenaria percuriosa Brignoli, 1972. Tegenaria boitanii stat. rev. is restored as a valid species, re-described and re-diagnosed, and T. bithyniae syn. nov. is placed as its junior synonym. We also provide an updated diagnosis for T. percuriosa, describe a new species, Tegenaria euxinica Dimitrov sp. nov. from the mesophilic beech forests (Fagus orientalis) in Bulgaria, and review the members of T. percuriosa complex. We provide new photographs for selected species, and a map of the updated distribution ranges of all the species in the complex. The phylogenetic position and internal structure of T. percuriosa species-complex is investigated by combining available morphological and molecular (target sequencing) data with new data from the species of interest. Finally, we propose to test in future studies the hypothesis that major climatic changes during the Miocene drove diversification of the group and imprinted its biogeography. http://zoobank.org/urn:lsid:zoobank.org:pub:08A77B59-ACFE-4C16-BBCB-BC45BE981360

More intraguild prey than pest species in arachnid diets may compromise biological control in apple orchards

Understanding the full diet of natural enemies is necessary for evaluating their role as biocontrol agents, because many enemy species do not only feed on pests but also on other natural enemies. Such intraguild predation can compromise pest control if the consumed enemies are actually better for pest control than their predators. In this study, we used gut metabarcoding to quantify diets of all common arachnid species in Swedish and Spanish apple orchards. For this purpose, we designed new primers that reduce amplification of arachnid predators while retaining high amplification of all prey groups. Results suggest that most arachnids consume a large range of putative pest species on apple but also a high proportion of other natural enemies, where the latter constitute almost a third of all prey sequences. Intraguild predation also varied between regions, with a larger content of heteropteran bugs in arachnid guts from Spanish orchards, but not between orchard types. There was also a tendency for cursorial spiders to have more intraguild prey in the gut than web spiders. Two groups that may be overlooked as important biocontrol agents in apple orchards seem to be theridiid web spiders and opilionids, where the latter had several small-bodied pest species in the gut. These results thus provide important guidance for what arachnid groups should be targets of management actions, even though additional information is needed to quantify all direct and indirect interactions occurring in the complex arthropod food webs in fruit orchards.

A hyper-heuristic methodology for coordinating swarms of robots in target search

Target search aims to discover elements of various complexity in a physical environment, by minimizing the overall discovery time. Different swarm intelligence algorithms have been proposed in the literature, inspired by biological species. Despite the success of bio-inspired techniques (bio-heuristics), there are relevant algorithm selection and parameterization costs associated with every new type of mission and with new instances of known missions. In this paper, evolutionary optimization is proposed for achieving significant improvements of the mission performance. Although adaptive, the logic of bio-heuristics is nevertheless constrained by models of biological species. To generate more adaptable logics, a novel design approach based on hyper-heuristics is proposed, in which the differential evolution optimizes the aggregation and tuning of modular heuristics for a given application domain. A modeling and optimization testbed has been developed and publicly released. Experimental results on real-world scenarios show that the hyper-heuristics based on stigmergy and flocking significantly outperform the adaptive bio-heuristics.

Separate immobilization of glucose oxidase and trehalase, and optimization of enzyme-carbon nanotube layers for the anode of enzymatic fuel cells utilizing trehalose

Insect cyborgs can be used as search robots in disaster areas and as environmental monitoring robots. In this study, we aimed to develop an anode for compact enzymatic fuel cells (EFCs) utilizing trehalose to power electronic devices implanted in such insects. Conventional trehalose-EFCs are fabricated by co-immobilization of glucose oxidase (GOx) and trehalase (TREH) on the surface of the anode. Here, we showed that current generation can be enhanced by separate immobilization of GOx and TREH using agarose. The effects of GOx-redox mediator layers, TREH loading, and the incorporation of single-walled carbon nanotubes (SWCNTs) on the performance of GOx-TREH anodes were investigated. The optimal arrangement of GOx-redox mediator layers with or without SWCNTs was determined. The highest oxidation current density (494 μA/cm2) was obtained at an electrode composed of three GOx-redox mediator layers and three GOx-redox mediator-SWCNTs layers, and agarose containing TREH. The bilirubin oxidase (BOD)-redox mediator layers and SWCNTs also influenced the performance of cathode. The highest reduction current intensity was obtained for the cathode with six BOD-redox mediator-SWCNTs layers. EFCs with the optimized anode and cathode showed a power density of ca. 15 μW/cm2 at a cell voltage of 0.3 V under a discharge current density of 50 μA/cm2.