Deep Webs Research Articles

Towards Detecting Influential Members and Critical Topics from Dark Web Forums

Conventionally, the Internet consists of three parts: Surface, Deep, and Dark Webs. Inthe last two decades, a massive increase in illicit activities took place on the differentplatforms of the Dark Web. Moreover, social networks on Dark Web implicateextremism dissemination on a wide scale. In this paper, we propose an approach togenerate textual patterns from discussions on Dark Web terrorist forums employingData Mining techniques. The discovered patterns help identify the influential membersand extract critical topics. We describe our system modules that perform datapreprocessing, text preprocessing with TF-IDF weighting, outlier detection, clusteringevaluation, clustering, and clustering validation, implemented with the RapidMinertool. We apply K-Means as the Clustering method with different distance metrics,evaluate the clustering process using Elbow and Silhouette methods, and validate itusing Davies-Bouldin Index. Furthermore, we investigate the effects of altering thedistance metrics for outlier detection on the Clustering results.

Gelatinous cephalopods as important prey for a deep-sea fish predator

We quantified cephalopods consumed by longnose lancetfish (Alepisaurus ferox, n = 1267 stomachs containing cephalopod remains) from 2009 to 2018 in the central North Pacific Ocean (between 0–35° N and 135–175° W). When cephalopods identified from beak remains in the stomach contents were included in diet analyses, clear increases in the abundance of gelatinous taxa and the inferred foraging depths of lancetfish were evident. Ontogeny in cephalopod consumption was evident for lancetfish, corroborating past diet studies. Small lancetfish (fork length < 97 cm) fed on smaller, muscular cephalopods from shallow habitats (0–500 m, e.g., Ommastrephidae, Onychoteuthidae), while large lancetfish (fork length ≥ 97 cm) consumed larger, gelatinous cephalopods from deeper waters (depths greater than 500 m, e.g., Amphitretidae, Cranchiidae). Cephalopod beaks were more abundant in the diets of large lancetfish, representing 37.8% of identified cephalopods, numerically. Although beaks likely remain in stomachs longer than soft tissues, they did not simply accumulate with increasing predator size. Cephalopods identified from beaks were also significantly larger than those identified from soft tissues. Despite having low average energy densities, large gelatinous cephalopods are important prey for lancetfish in deep habitats, with energetic values that are comparable to smaller, more muscular cephalopods (95.3 ± 125.8 kJ and 120.2 ± 169.4 kJ, respectively). Holistic consideration of cephalopod beaks in diet analyses will help to elucidate predator foraging behaviors and the trophic and ecological roles of gelatinous cephalopods in deep pelagic food webs.

Deep zooplankton rely on small particles when particle fluxes are low

AbstractThe fate of organic matter (OM) in the deep ocean remains enigmatic, with little understood regarding the flux and its utilization by deep food webs. We used compound‐specific nitrogen stable isotope ratios of source amino acids measured in particle size classes and deep zooplankton (700–1500 m) to determine the contribution of small (0.7–53 μm) vs. large particles (&gt; 53 μm) to their diet at four sites in the North Pacific. Our results show that small particles constitute between 9% and 98% of zooplankton diets, being the contribution higher at sites with lower flux regimes. The contribution of small particles to the diet of deep zooplankton was also higher when biomass of vertical migrators, and therefore actively transported OM, was lower. Climate‐driven changes in primary production and export are expected to shift particle fluxes to smaller size classes, and thus their importance in midwater food webs may become more widespread.

Connected macroalgal‐sediment systems: blue carbon and food webs in the deep coastal ocean

AbstractMacroalgae drive the largest CO2 flux fixed globally by marine macrophytes. Most of the resulting biomass is exported through the coastal ocean as detritus and yet almost no field measurements have verified its potential net sequestration in marine sediments. This gap limits the scope for the inclusion of macroalgae within blue carbon schemes that support ocean carbon sequestration globally, and the understanding of the role their carbon plays within distal food webs. Here, we pursued three lines of evidence (eDNA sequencing, Bayesian Stable Isotope Mixing Modeling, and benthic‐pelagic process measurements) to generate needed, novel data addressing this gap. To this end, a 13‐month study was undertaken at a deep coastal sedimentary site in the English Channel, and the surrounding shoreline of Plymouth, UK. The eDNA sequencing indicated that detritus from most macroalgae in surrounding shores occurs within deep, coastal sediments, with detritus supply reflecting the seasonal ecology of individual species. Bayesian stable isotope mixing modeling [C and N] highlighted its vital role in supporting the deep coastal benthic food web (22–36% of diets), especially when other resources are seasonally low. The magnitude of detritus uptake within the food web and sediments varies seasonally, with an average net sedimentary organic macroalgal carbon sequestration of 8.75 g C·m−2·yr−1. The average net sequestration of particulate organic carbon in sediments is 58.74 g C·m−2·yr−1, the two rates corresponding to 4–5% and 26–37% of those associated with mangroves, salt marshes, and seagrass beds, systems more readily identified as blue carbon habitats. These novel data provide important first estimates that help to contextualize the importance of macroalgal‐sedimentary connectivity for deep coastal food webs, and measured fluxes help constrain its role within global blue carbon that can support policy development. At a time when climate change mitigation is at the foreground of environmental policy development, embracing the full potential of the ocean in supporting climate regulation via CO2 sequestration is a necessity.

Deep Web: A Residual of e-Public Administration

This article intention was to understand more about deep web, including dark web, as a critical part of stateless-based Public Administration paradigm. Therefore, the objectives of this research are as follows: (1) to investigate basic data and rough classification of deep webs, and (2) to suggest the solution for e-Public Administration. Documentary research and descriptive statistics like frequency and percentage were used in this study. The findings found that the top four of live deep webs were Non-English696 Sites (14.8%), Cryptocurrency 685 sites (14.5%), Media and Forum for uploading, downloading, and discussion 653 sites (13.8%), and Hosting 473 sites (10.0%). The activities in deep web were Non-English, Cryptocurrency, Media and Forum, Hosting, Under construction/Blank/Seized, Marketplace Drugs, Search Engines, Marketplace Commercial Services, Marketplace Financial, Blogs, Messaging, Private Web Site, Tutorials, Libraries and Wiki, Closed Website, Hacking, Whistle Blowing, Security, Marketplace Betting, P2P File Sharing, Cybercriminals, Dangerous threats, and Boards. In addition, Neural Network and Genetic Algorithm of AI and foundation of an autonomous public organization for controlling deep web in form of self-directed team under starfish organization-based structure were the best solutions for coping with the severe change in Public Administration.

Web bend-buckling strength of plate girders with two longitudinal web stiffeners

More than one longitudinal web stiffener may be economical in the design of plate girders that have considerably high width-to-thickness ratio of webs. In this study, the bend-buckling strength of relatively deep webs with two horizontal lines of flat plate-shaped single-sided stiffeners was numerically investigated. Linear eigenvalue buckling analyses were conducted for specially selected hypothetical models of stiffened web panels, in which top and bottom junctions of a web with flanges were assumed to have simply supported boundary conditions. Major parameters in the analyses were the locations of two longitudinal stiffeners, stress ratios in the web, slenderness ratios and aspect ratios of web panels. Based on the application of assumptions on the combined locations of the two longitudinal web stiffeners, simplified equations were proposed for the bend-buckling coefficients and compared to the case of one longitudinal stiffener. It was found that bend-buckling coefficients can be doubled by adopting two longitudinal stiffeners instead of one longitudinal stiffener. For practical design purposes, additional equations were proposed for the required bending rigidity of the longitudinal stiffeners arranged in two horizontal lines on a web.

Design and implementation of crawling algorithm to collect deep web information for web archiving

PurposeThe purpose of this paper is to describe the development of an algorithm for realizing web crawlers that automatically collect dynamically generated webpages from the deep web.Design/methodology/approachThis study proposes and develops an algorithm to collect web information as if the web crawler gathers static webpages by managing script commands as links. The proposed web crawler actually experiments with the algorithm by collecting deep webpages.FindingsAmong the findings of this study is that if the actual crawling process provides search results as script pages, the outcome only collects the first page. However, the proposed algorithm can collect deep webpages in this case.Research limitations/implicationsTo use a script as a link, a human must first analyze the web document. This study uses the web browser object provided by Microsoft Visual Studio as a script launcher, so it cannot collect deep webpages if the web browser object cannot launch the script, or if the web document contains script errors.Practical implicationsThe research results show deep webs are estimated to have 450 to 550 times more information than surface webpages, and it is difficult to collect web documents. However, this algorithm helps to enable deep web collection through script runs.Originality/valueThis study presents a new method to be utilized with script links instead of adopting previous keywords. The proposed algorithm is available as an ordinary URL. From the conducted experiment, analysis of scripts on individual websites is needed to employ them as links.

Deep pelagic food web structure as revealed by in situ feeding observations.

Food web linkages, or the feeding relationships between species inhabiting a shared ecosystem, are an ecological lens through which ecosystem structure and function can be assessed, and thus are fundamental to informing sustainable resource management. Empirical feeding datasets have traditionally been painstakingly generated from stomach content analysis, direct observations and from biochemical trophic markers (stable isotopes, fatty acids, molecular tools). Each approach carries inherent biases and limitations, as well as advantages. Here, using 27 years (1991–2016) of in situ feeding observations collected by remotely operated vehicles (ROVs), we quantitatively characterize the deep pelagic food web of central California within the California Current, complementing existing studies of diet and trophic interactions with a unique perspective. Seven hundred and forty-three independent feeding events were observed with ROVs from near-surface waters down to depths approaching 4000 m, involving an assemblage of 84 different predators and 82 different prey types, for a total of 242 unique feeding relationships. The greatest diversity of prey was consumed by narcomedusae, followed by physonect siphonophores, ctenophores and cephalopods. We highlight key interactions within the poorly understood ‘jelly web’, showing the importance of medusae, ctenophores and siphonophores as key predators, whose ecological significance is comparable to large fish and squid species within the central California deep pelagic food web. Gelatinous predators are often thought to comprise relatively inefficient trophic pathways within marine communities, but we build upon previous findings to document their substantial and integral roles in deep pelagic food webs.

Characterization of food web structure of the upper continental slope of the Celtic Sea highlighting the trophic ecology of five deep-sea fishes

Summary In marine ecosystems, the study of trophic relationships has extensively benefited from the development of stable isotope analyses (SIA) as dietary tracers. SIA are particularly useful in elucidating the structure of deep sea food webs given the constraints involved in obtaining gut-content data from deep trawling. We used carbon and nitrogen stable isotope analyses and Stable Isotope Bayesian Ellipses in R (SIBER) and Stable Isotope Analysis in R (SIAR) routines, to determine the trophic ecology of five deep-sea fishes from the upper continental slope of the Celtic Sea. SIA made it possible to deduce some general tendencies in food-web structure and species trophic interactions and confirmed diet determined by gut-content analysis for the same species, in other ecoregions. More specifically, mixing models revealed that the deep sea species considered are omnivorous and are able to feed on all the sampled taxa. Based on isotopic ratio, no clear differences in fish diet could be detected from one species to another except for rabbit fish, which has benthic affinities. Three species, blackbelly rosefish, greater forkbeard and softhead grenadier showed overlapping isotopic niches. This study is the first attempt to describe the trophic ecology of deep sea species on the Celtic Sea upper continental slope. In the context of the development of ecosystem integrated modeling approaches for managing fisheries in the Celtic sea, and considering the vulnerability of deep-water species, improving the knowledge on the trophic ecology of these local species is of importance in order to allow their sustainable exploitation.

Vertical gradients in species richness and community composition across the twilight zone in the North Pacific Subtropical Gyre

Although metazoan animals in the mesopelagic zone play critical roles in deep pelagic food webs and in the attenuation of carbon in midwaters, the diversity of these assemblages is not fully known. A metabarcoding survey of mesozooplankton diversity across the epipelagic, mesopelagic and upper bathypelagic zones (0-1500m) in the North Pacific Subtropical Gyre revealed far higher estimates of species richness than expected given prior morphology-based studies in the region (4,024 OTUs, 10-fold increase), despite conservative bioinformatic processing. Operational taxonomic unit (OTU) richness of the full assemblage peaked at lower epipelagic-upper mesopelagic depths (100-300m), with slight shoaling of maximal richness at night due to diel vertical migration, in contrast to expectations of a deep mesopelagic diversity maximum as reported for several plankton groups in early systematic and zoogeographic studies. Four distinct depth-stratified species assemblages were identified, with faunal transitions occurring at 100m, 300m and 500m. Highest diversity occurred in the smallest zooplankton size fractions (0.2-0.5mm), which had significantly lower % OTUs classified due to poor representation in reference databases, suggesting a deep reservoir of poorly understood diversity in the smallest metazoan animals. A diverse meroplankton assemblage also was detected (350 OTUs), including larvae of both shallow and deep living benthic species. Our results provide some of the first insights into the hidden diversity present in zooplankton assemblages in midwaters, and a molecular reappraisal of vertical gradients in species richness, depth distributions and community composition for the full zooplankton assemblage across the epipelagic, mesopelagic and upper bathypelagic zones.

Automated Data Extraction with Multiple Ontologies

Current search engines require an accurate yet fast automated extractor to extract relevant information from deep web for the users. Human users usually enter search queries and the search engines will then locate the desire information of interest by disambiguate the search query accordingly. The queries will then be passed on to multiple search engines for further processing. These search engines will then return the search results to the main search engine. However, data returned from these search engines are usually varied and presented in numerous formats and layouts. To extract them, we need automated extractor to filter out irrelevant information and locate the correct information. Current trends focused on using ontologies to automatically extract this information with high accuracy. To the best of our knowledge, no works have been made on using multiple ontologies (using many ontology techniques) to automatically extract information from deep webs. In this paper, we demonstrate that multiple ontologies technique can achieve higher accuracy when extracting data from the deep web. Our method outperforms existing state of the art systems and is able to robustly extract data from deep web.

Deep-ocean foraging northern elephant seals bioaccumulate persistent organic pollutants

As top predators in the northeast Pacific Ocean, northern elephant seals (Mirounga angustirostris) are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Our study examined a suite of POPs in blubber (inner and outer) and blood (serum) of free-ranging northern elephant seals. For adult females (N=24), we satellite tracked and sampled the same seals before and after their approximately seven month long foraging trip. For males, we sampled different adults and sub-adults before (N=14) and after (N=15) the same foraging trip. For females, we calculated blubber burdens for all compounds. The highest POP concentrations in males and females were found for ∑DDTs and ∑PCBs. In blubber and serum, males had significantly greater concentrations than females for almost all compounds. For males and females, ∑DDT and ∑PBDEs were highly correlated in blubber and serum. While ∑PCBs were highly correlated with ∑DDTs and ∑PBDEs in blubber and serum for males, ∑PCBs showed weaker correlations with both compounds in females. As females gained mass while foraging, concentrations of nearly all POPs in inner and outer blubber significantly decreased; however, the absolute burden in blubber significantly increased, indicating ingestion of contaminants while foraging. Additionally, we identified three clusters of seal foraging behavior, based on geography, diving behavior, and stable carbon and nitrogen isotopes, which corresponded with differences in ∑DDTs, ∑PBDEs, MeO-BDE 47, as well as the ratio of ∑DDTs to ∑PCBs, indicating the potential for behavior to heighten or mitigate contaminant exposure. The greatest concentrations of ∑DDTs and ∑PBDEs were observed in the cluster that foraged closer to the coast and had blood samples more enriched in 13C. Bioaccumulation of POPs by elephant seals supports mesopelagic food webs as a sink for POPs and highlights elephant seals as a potential sentinel of contamination in deep ocean food webs.

Degrading detritus: Changes in food quality of aging kelp tissue varies with species

Export of detrital kelp from the photic zone is thought to provide an important trophic subsidy to adjacent food webs. In the San Juan Archipelago, Washington, deep habitats (e.g. >90m) contain abundant, senescent kelp detritus that presumably is colonized by microbes as it sinks. Such aging algal pieces may be of greater nutritional value than fresh material, and may have reduced levels of polyphenolic compounds, which in living kelps deter both bacterial colonization and herbivory. We report here on a diverse set of experiments designed to test the value to consumers of fresh and aged tissue of two kelps with very different biochemical compositions, Nereocystis luetkeana (low polyphenolics) and Agarum fimbriatum (high polyphenolics). We tested 1) short-term food preference and assimilation efficiency in adult isopods; 2) growth rates of juvenile isopods over 10weeks; 3) gonad development in urchins over 18weeks; 4) population growth of copepods over 4weeks and subsequent egg-hatching time; and 5) caloric content, fatty acids, and C:N ratios of fresh and aged tissue of these two kelps, with some additional data for a third kelp species. In a food-choice situation, Nereocystis is strongly preferred over Agarum, and is a superior food by a number of metrics. Aging kelp blades in the dark led to Nereocystis degrading much faster than Agarum. Overall, aging of the two kelp species tended to have opposite effects in various metrics of their value to consumers, so that in many experiments there was a species×age interaction term. Fresh Nereocystis was slightly ‘better’ than aged in terms of isopod growth and preference, gonad development in urchins, and population growth metrics in copepods, while aged Agarum was ‘better’ than fresh in a number of these metrics at least over the time scales of our studies. Degrading kelps show broad changes in fatty acids that differed among species, but we did not find a general increase in N as has been suggested elsewhere. In combination with several other recent studies, our data suggest that the value of different types of detritus to deep trophic webs is likely to be both species- and time-dependent.

A Deep Web Data Extraction and Application System Based on Cloud Technology

There are so many Deep Webs in Internet, which contains a large amount of valuable data, This paper proposes a Deep Web data extraction and service system based on the principle of cloud technology. We adopt a kind of multi-node parallel computing system structure and design a task scheduling algorithm in the data extraction process, in above foundation, balance the task load of among nodes to accomplish data extraction rapidly; The experimental results show that cloud parallel computing and dispersed network resources are used to extract data in Deep Web system is valid and improves the data extraction efficiency of Deep Web and service quality.

Crawling the Deep Web: A Study

Search interfaces are only the mode to retrieve the information on the web, which is becoming enormous day by day. One has to key in the set of keywords in search form to retrieve pages from the website. These hidden web pages do not have static links[1], hence, search engines are unable to get and index such pages and thus no result is returned. As per recent studies many of the deep webs are of tremendous high quality, which can be extremely useful to the users. These pages are often referred to as the Hidden Web or the Deep Web. A powerful web crawler can discover and download hidden web pages. The main challenge that a hidden web crawler has to face is to make meaningful queries to issue to the site as the only entry point to the hidden website is query interface. Here a theoretical framework to investigate the query generation problem is provided for the hidden web and effective policies for generating queries automatically studies.

Data Extraction for Deep Web Using WordNet

Our survey shows that the techniques used in data extraction from deep webs need to be improved to achieve the efficiency and accuracy of automatic wrappers. Further investigations indicate that the development of a lightweight ontological technique using existing lexical database for English (WordNet) is able to check the similarity of data records and detect the correct data region with higher precision using the semantic properties of these data records. The advantages of this method are that it can extract three types of data records, namely, single-section data records, multiple-section data records, and loosely structured data records, and it also provides options for aligning iterative and disjunctive data items. Experimental results show that our technique is robust and performs better than the existing state-of-the-art wrappers. Tests also show that our wrapper is able to extract data records from multilingual web pages and that it is domain independent.

Significance of non‐sinking particulate organic carbon and dark CO2 fixation to heterotrophic carbon demand in the mesopelagic northeast Atlantic

It is generally assumed that sinking particulate organic carbon (POC) constitutes the main source of organic carbon supply to the deep ocean's food webs. However, a major discrepancy between the rates of sinking POC supply (collected with sediment traps) and the prokaryotic organic carbon demand (the total amount of carbon required to sustain the heterotrophic metabolism of the prokaryotes; i.e., production plus respiration, PCD) of deep‐water communities has been consistently reported for the dark realm of the global ocean. While the amount of sinking POC flux declines exponentially with depth, the concentration of suspended, buoyant non‐sinking POC (nsPOC; obtained with oceanographic bottles) exhibits only small variations with depth in the (sub)tropical Northeast Atlantic. Based on available data for the North Atlantic we show here that the sinking POC flux would contribute only 4–12% of the PCD in the mesopelagic realm (depending on the primary production rate in surface waters). The amount of nsPOC potentially available to heterotrophic prokaryotes in the mesopelagic realm can be partly replenished by dark dissolved inorganic carbon fixation contributing between 12% to 72% to the PCD daily. Taken together, there is evidence that the mesopelagic microheterotrophic biota is more dependent on the nsPOC pool than on the sinking POC supply. Hence, the enigmatic major mismatch between the organic carbon demand of the deep‐water heterotrophic microbiota and the POC supply rates might be substantially smaller by including the potentially available nsPOC and its autochthonous production in oceanic carbon cycling models.

Effects of overheight truck impacts on intermediate diaphragms in prestressed concrete bridge girders

This paper studies the capacity of prestressed concrete bridge girders to withstand overheight truck impacts. The numerical model of the bridge was validated with the existing experimental data in the literature. The elastic-plastic modeling of concrete damage and quasi-static impact simulation of the bridge were considered. Parametric studies were then conducted with respect to the spacing and depth of intermediate diaphragms as well as girder types from which the role of intermediate diaphragms in protection and enhancement of prestressed concrete bridge girders from truck impacts is obtained. From the simulation results, it was concluded that the optimum spacing of intermediate diaphragms (that is, 25.0 ft [7.62 m]) is consistent with the results reported for previous studies. The depth of intermediate diaphragms should be extended to the top edge of the bottom flange of girders to provide maximum impact protection. Wide flanges in girders increase the bending stiffness and reduce the horizontal deflection and correspondingly decrease damage areas. However, deep webs in girders introduce a large rotation with respect to the deck, and thus increase the deflection under the truck impact. Design guidelines for typical parameters for intermediate diaphragms in prestressed concrete bridges are provided. The numerical finite-element parametric study provides a better understanding of placement and size of intermediate diaphragms in prestressed concrete bridges and their role in protecting girders from overheight truck impacts.

Uso de isotopos estables de carbono y nitrógeno para estudios de ecología acuática

Two distinct pathways of carbon flow are currently recognized in deep sea aquatic food webs: a short pathway based on phytoplankton production known as planktonic and a longer one, which also includes bacteria, protozoans, and the process known as the microbial loop, referred to collectively as the microbial food web. Considering the microbial loop complements the current vision of aquatic food webs, which today continues to be limited in this respect. In this sense, the analysis of natural abundance of the steady isotopes of carbon and nitrogen in aquatic organisms is a technique which permits the definition of the role of the trophic groups which are part of food web. The proportion of isotopes of carbon indicates the autotrophic energy source of an organism while the proportion of nitrogen isotopes, permits to infer, based on the process of trophic breaking, the level of the organisms studied.

Side-Face Reinforcement for Flexural and Diagonal Cracking in Large Concrete Beams

The current American Concrete Institute (ACI) Building Code and American Association of State Highway and Transportation Officials (AASHTO) Bridge Code requirements for side-face reinforcement are meant to control flexural cracking in the webs of large concrete beams and may not provide adequate diagonal crack control for certain exposure conditions. Twenty-one large concrete beam elements with 1,200-mm deep webs were tested in a specially constructed apparatus to study the influence of amount and arrangement of side-face reinforcement in controlling both flexural and diagonal cracking in large concrete beams. The amount of side-face reinforcement was varied from 50% to 300% of what is required by the current ACI Building Code and AASHTO Bridge Code. Deformed reinforcing bars, welded wire fabric, and hooked steel fiber were included in the study. Over 11,000 crack widths were measured with a microscope on the 21 specimens, and an analysis of the crack data revealed the relationship between crack width and average strain and the ratio of maximum to average crack widths. A procedure is presented for estimating diagonal crack widths in the webs of large beams caused by service level shear stresses, and a general design procedure is presented for the amount of side-face reinforcement needed to control both flexural and diagonal cracking in the webs of large concrete beams. The required spacing of side-face longitudinal reinforcing bars depends on the maximum acceptable crack width, strain of the longitudinal reinforcement on the flexural tension side, magnitude of the applied shear stress, amount of transverse reinforcement, and the diameter of and cover to the side-face reinforcing bars. A design example illustrates the proposal.