nils-herrmann/clean_scirepeval huggingface dataset:
Detector developments at DESY.
Venue: Journal of synchrotron radiation

With the increased brilliance of state of the art synchrotron radiation sources and the advent of free electron lasers (FELs) enabling revolutionary science with EUV to X ray photons comes an urgent need for suitable photon imaging detectors. Requirements include high frame rates, very large dynamic range, single photon sensitivity with low probability of false positives and (multi) megapixels. At DESY, one ongoing development project in collaboration with RAL/STFC, Elettra Sincrotrone Trieste, Diamond, and Pohang Accelerator Laboratory is the CMOS based soft X ray imager PERCIVAL. PERCIVAL is a monolithic active pixel sensor back thinned to access its primary energy range of 250 eV to 1 keV with target efficiencies above 90% According to preliminary specifications, the roughly 10 cm x 10 cm, 3.5k x 3.7k monolithic sensor will operate at frame rates up to 120 Hz (commensurate with most FELs) and use multiple gains within 27 um pixels to measure 1 to ~100000 (500 eV) simultaneously arriving photons. DESY is also leading the development of the AGIPD, a high speed detector based on hybrid pixel technology intended for use at the European XFEL. This system is being developed in collaboration with PSI, University of Hamburg, and University of Bonn. The AGIPD allows single pulse imaging at 4.5 MHz frame rate into a 352 frame buffer, with a dynamic range allowing single photon detection and detection of more than 10000 photons at 12.4 keV in the same image. Modules of 65k pixels each are configured to make up (multi)megapixel cameras. This review describes the AGIPD and the PERCIVAL concepts and systems, including some recent results and a summary of their current status. It also gives a short overview over other FEL relevant developments where the Photon Science Detector Group at DESY is involved.
The Structure of a Moderate Scale Methanol Pool Fire

A series of measurements was made to characterize the structure of a moderate sized methanol pool fire steadily burning in a quiescent environment. Time averaged local measurements of temperature and gas species concentrations were made in a steadily burning methyl alcohol (methanol; CH3OH) pool fire. Temperatures were measured using fine wire thermocouples corrected for radiative losses. Gaseous species were measured using extractive sampling through a cooled probe and the samples analyzed using a gas chromatograph. The species measured included the reactants (the fuel, methanol, and oxygen) combustion intermediates such as CO and combustion products such as H2O and CO2. It is anticipated that these data will be useful for model validation.
Are Enchytraeidae (Oligochaeta, Annelida) good indicators of agricultural management practices?

Anthropogenic activities and particularly agricultural management may harm soil organisms such as enchytraeids (Enchytraeidae, Oligochaeta, Annelida) also known as potworms. These small relatives of earthworms are widely distributed in different soils and land use forms, where they play an important role due to their burrowing activity, their fecal pellet production as well as their transport, ingestion and mixing of mineral and organic soil particles. However, relatively few studies have been performed with these organisms at crop sites and this widely scattered information has not yet been compiled. Thus, this paper aims (i) to assess the relevance of enchytraeids as indicators of agricultural practices and cropping systems, and (ii) to pinpoint the knowledge gaps and the needs for further research. Out of 250 papers identified in a literature search about 70 were reviewed in detail. Contrasted results and no clear relationships between agricultural practices and the composition and activity of enchytraeid communities have been found in this review, since rarely one factor affecting enchytraeids has been studied alone, meaning that the study context is usually very complex, with several interactions which are difficult to assess. Almost never information about all factors potentially influencing enchytraeids is available and, finally, there are very few studies which had the same aims or designs, making them very difficult to compare even without considering the heterogeneity of agricultural sites in space and time. However, this review concludes that enchytraeids can be considered as indicators of management practices (e.g. soil tillage, inorganic fertilizers) since they are sensitive to changes, both in terms of abundance and species composition. Finally, it is recommended to perform a monitoring program at representative, well documented European sites in which not only the enchytraeid communities but also as many as possible factors influencing them are measured over a period of at least five years.
Fast Unsupervised Online Drift Detection Using Incremental Kolmogorov Smirnov Test
Venue: KDD

Data stream research has grown rapidly over the last decade. Two major features distinguish data stream from batch learning: stream data are generated on the fly, possibly in a fast and variable rate; and the underlying data distribution can be non stationary, leading to a phenomenon known as concept drift. Therefore, most of the research on data stream classification focuses on proposing efficient models that can adapt to concept drifts and maintain a stable performance over time. However, specifically for the classification task, the majority of such methods rely on the instantaneous availability of true labels for all already classified instances. This is a strong assumption that is rarely fulfilled in practical applications. Hence there is a clear need for efficient methods that can detect concept drifts in an unsupervised way. One possibility is the well known Kolmogorov Smirnov test, a statistical hypothesis test that checks whether two samples differ. This work has two main contributions. The first one is the Incremental Kolmogorov Smirnov algorithm that allows performing the Kolmogorov Smirnov hypothesis test instantly using two samples that change over time, where the change is an insertion and/or removal of an observation. Our algorithm employs a randomized tree and is able to perform the insertion and removal operations in O(log N) with high probability and calculate the Kolmogorov Smirnov test in O(1) where N is the number of sample observations. This is a significant speed up compared to the O(N log N) cost of the non incremental implementation. The second contribution is the use of the Incremental Kolmogorov Smirnov test to detect concept drifts without true labels. Classification algorithms adapted to use the test rely on a limited portion of those labels just to update the classification model after a concept drift is detected.
Power/freedom on the dark web: A digital ethnography of the Dark Web Social Network
Venue: New Media Soc.

This essay is an early ethnographic exploration of the Dark Web Social Network (DWSN) a social networking site only accessible to Web browsers equipped with The Onion Router. The central claim of this essay is that the DWSN is an experiment in power/freedom, an attempt to simultaneously trace, deploy, and overcome the historical conditions in which it finds itself: the generic constraints and affordances of social networking as they have been developed over the past decade by Facebook and Twitter, and the ideological constraints and affordances of public perceptions of the dark web, which hold that the dark web is useful for both taboo activities and freedom from state oppression. I trace the DWSN's experiment with power/freedom through three practices: anonymous/social networking, the banning of child pornography, and the productive aspects of techno elitism. I then use these practices to specify particular forms of power/freedom on the DWSN.
Satellite: Joint Analysis of CDNs and Network Level Interference
Venue: USENIX Annual Technical Conference

Satellite is a methodology, tool chain, and data set for understanding global trends in website deployment and accessibility using only a single or small number of standard measurement nodes. Satellite collects information on DNS resolution and resource availability around the Internet by probing the IPv4 address space. These measurements are valuable in their breadth and sustainability they do not require the use of a distributed measurement infrastructure, and therefore can be run at low cost and by multiple organizations. We demonstrate a clustering procedure which accurately captures the IP footprints of CDN deployments, and then show how this technique allows for more accurate determination of correct and incorrect IP resolutions. Satellite has multiple applications. It reveals the prevalence of CDNs by showing that 20% of the top 10,000 Alexa domains are hosted on shared infrastructure, and that CloudFlare alone accounts for nearly 10% of these sites. The same data set detects 4,819 instances of ISP level DNS hijacking in 117 countries.
Learning Invariant Representation for Malicious Network Traffic Detection
Venue: ECAI

Statistical learning theory relies on an assumption that the joint distributions of observations and labels are the same in training and testing data. However, this assumption is violated in many real world problems, such as training a detector of malicious network traffic that can change over time as a result of attacker's detection evasion efforts. We propose to address this problem by creating an optimized representation, which significantly increases the robustness of detectors or classifiers trained under this distributional shift. The representation is created from bags of samples (e.g. network traffic logs) and is designed to be invariant under shifting and scaling of the feature values extracted from the logs and under permutation and size changes of the bags. The invariance is achieved by combining feature histograms with feature self similarity matrices computed for each bag and significantly reduces the difference between the training and testing data. The parameters of the representation, such as histogram bin boundaries, are learned jointly with the classifier. We show that the representation is effective for training a detector of malicious traffic, achieving 90% precision and 67% recall on samples of previously unseen malware variants.
Beaver: A Decentralized Anonymous Marketplace with Secure Reputation
Venue: IACR Cryptol. ePrint Arch.

Amid growing concerns of government surveillance and corporate data sharing, web users increasingly demand tools for preserving their privacy without placing trust in a third party. Unfortunately, existing centralized reputation systems need to be trusted for either privacy, correctness, or both. Existing decentralized approaches, on the other hand, are either vulnerable to Sybil attacks, present inconsistent views of the network, or leak critical information about the actions of their users. In this paper, we present Beaver, a decentralized anonymous marketplace that is resistant against Sybil attacks on vendor reputation, while preserving user anonymity. Beaver allows its participants to enjoy open enrollment, and provides every user with the same global view of the reputation of other users through public ledger based consensus. Various cryptographic primitives allow Beaver to offer high levels of usability and practicality, along with strong anonymity guarantees. Operations such as creating a listing, purchasing an item, and leaving feedback take just milliseconds to compute and require generating just a few kilobytes of state while often constructing convenient anonymity sets of hundreds of transactions.
A Possible Role for End Stopped V1 Neurons in the Perception of Motion: A Computational Model
Venue: PloS one

We present a model of the early stages of processing in the visual cortex, in particular V1 and MT, to investigate the potential role of end stopped V1 neurons in solving the aperture problem. A hierarchical network is used in which the incoming motion signals provided by complex V1 neurons and end stopped V1 neurons proceed to MT neurons at the next stage. MT neurons are categorized into two types based on their function: integration and segmentation. The role of integration neurons is to propagate unambiguous motion signals arriving from those V1 neurons that emphasize object terminators (e.g. corners) Segmentation neurons detect the discontinuities in the input stimulus to control the activity of integration neurons. Although the activity of the complex V1 neurons at the terminators of the object accurately represents the direction of the motion, their level of activity is less than the activity of the neurons along the edges. Therefore, a model incorporating end stopped neurons is essential to suppress ambiguous motion signals along the edges of the stimulus. It is shown that the unambiguous motion signals at terminators propagate over the rest of the object to achieve an accurate representation of motion.
DEcryption Contract ENforcement Tool (DECENT) A Practical Alternative to Government Decryption Backdoors
Venue: IACR Cryptol. ePrint Arch.

A cryptographic contract and enforcement technology would guarantee release of a data decryption key to an authorized party if and only if predetermined contract requirements are satisfied. Threshold secret sharing can be used to eliminate the need for access to the hidden key under normal circumstances. It can also eliminate the liability and burden normally carried by device manufacturers or service providers when they store the decryption keys of their customers. Blockchain technology provides a mechanism for a public audit trail of the creation and release of the hidden key. The use of peer to peer mix net network overlay technology can be added to insure that the blockchain audit trail documents the release of the key even if an all powerful entity forces actors to act under duress.
Journey of Web Search Engines: Milestones, Challenges Innovations

Past few decades have witnessed an informat ion big bang in the form of World Wide Web leading to gigantic repository of heterogeneous data. A humble journey that started with the network connection between few computers at ARPANET project has reached to a level wherein almost all the computers and other communication devices of the world have joined together to form a huge global in formation network that makes availab le most of the information related to every possible heterogeneous domain. Not only the managing and indexing of th is repository is a big concern but to provide a quick answer to the user's query is also of critical importance. Amazingly, rather miraculously, the task is being done quite efficiently by the current web search engines. This miracle has been possible due to a series of mathematical and technological innovations continuously being carried out in the area of search techniques. This paper takes an overview of search engine evolution from primitive to the present
Onions in the queue: an integral networking perspective on anonymous communication systems

Performance is a pivot point in the design of anonymity overlays. Due to their growing popularity, they are faced with increasing load, which makes design problems imminent. The special requirements and complex architecture of anonymity overlays renders the topic a challenging but likewise inspiring object of research. In this work, we discuss the design of low latency anonymous communication systems in general and the Tor network as the de facto standard in particular. We develop solutions to a number of research questions, all collectively following the aim of enhancing and securing such networks. By doing this we create a fundamental technical understanding of networking aspects in anonymity overlays and tackle the most prevalent performance issue experienced today: network congestion. To this end, we systematically explore the design space of data transport in anonymity overlays and reveal serious performance issues. This exploration provides insights in how (not) to design a transport protocol for anonymity overlays. In order to support future design decisions, we additionally present a methodology to measure networks in a privacy preserving manner. The fundamental results of this thesis include the discovery of a destructive denial of service attack and the associated design flaw of performing hop by hop reliability and end to end flow control. Moreover, we emphasize the central role of fairness. In particular, we show that gross unfairness between circuits may arise and lead to poor performance. While these kind of issues are difficult to fix, we provide respective security measures and a fully distributed scheduling algorithm that implicitly achieves global fairness. These issues clearly demonstrate the inadequacy of currently employed congestion control in anonymity overlays. In particular, we identify a feedback "gap" between incoming and outgoing connections as the primary cause of performance issues. Aware of the requirements and the problems of anonymity overlays, we develop a tailored transport protocol. It combines congestion control with a backpressure based flow control mechanism. The resulting overlay is able to react locally and thus rapidly to varying network conditions. It yields superior performance and a resilient overlay network. With our work, we contribute an integral perspective on networking aspects of anonymity overlays and tackle the root cause of performance issues.
Anxiety Related to Nonsurgical Root Canal Treatment: A Systematic Review.
Venue: Journal of endodontics

Anxiety is an emotion characterized by feelings of tension, worried thoughts, and physical changes. Dental anxiety has been associated with pain, fear, care avoidance, and more invasive treatments including nonsurgical root canal treatment (NSRCT) The very words root canal are deeply embedded in societal consciousness. Better understanding of dental anxiety may prevent treatment avoidance. The purpose of this study was to conduct a systematic review of NSRCT associated anxiety.  Inclusion/exclusion criteria defined MEDLINE, Cochrane Library, psychINFO, manual, and citation searches. Title lists and abstracts were read to determine utility; data were extracted, summarized, and compiled into an evidence table, and meta analyses were performed.  Defined searching produced 835 titles; 36 articles were included, mostly representing modern populations from countries with very high human development indices. Major sources of heterogeneity included differing study aims, outcome measures, clinical settings, locations, operators, sample selection, and sample size. Meta analysis of 18 articles including 1989 subjects gave a pretreatment anxiety rating of 39 (standard deviation, 9) on a normalized 100 point scale. Meta analysis of 4 articles including 232 subjects gave a post treatment anxiety rating of 27 (standard deviation, 5) on a normalized 100 point scale, representing a 30% reduction. A L'Abbe plot of 5 studies also showed that anxiety decreased after NSRCT. Limited data indicated that gender, age, and prior NSRCT experience influenced NSRCT associated anxiety. NSRCT associated anxiety was ranked high among dental treatments, often close to oral surgery.  NSRCT associated anxiety was generally moderate. Anxiety decreased after NSRCT. Limited evidence suggested that anxiety is influenced by patient and treatment factors.
Real Effects of the Audit Choice

We hypothesize that the choice to obtain a financial statement audit provides external financiers with incremental information about the firm, which helps reduce information asymmetry and financing frictions. Using a natural experiment, we show that when external financiers observe a firm's choice to voluntarily obtain an audit, the firms obtaining an audit significantly increase their debt, investment, and operating performance, and become more responsive to their investment opportunities. Further, we find that these effects are stronger for firms that are financially constrained and weaker for firms with other means to reduce financing frictions. Overall, our evidence suggests that the audit choice conveys information to capital providers, which reduces financing frictions and improves performance.
The Influence of Introducing Unrestricted Access to Sugammadex and Quantitative Neuromuscular Monitors on the Incidence of Residual Neuromuscular Block at a Tertiary Teaching Hospital. An Audit of 'Real Life'
Venue: Anaesthesia and intensive care

Residual neuromuscular block (RNMB) is a common phenomenon and has been identified as a significant risk factor for adverse postoperative patient outcome. The outcome of a recent randomised, controlled trial suggests that monitor guided, sugammadex based reversal of neuromuscular blocking agents (NMBA) may be able to completely eliminate the risk of RNMB1. However, it is unclear whether such results could be achieved in a 'real life' clinical setting. Prior to the availability of quantitative neuromuscular transmission monitors and the unrestricted availability of sugammadex (2011) the incidence of RNMB at the Royal Perth Hospital after timing, neostigmine or sugammadex based reversal was 53% 59% and 8% respectively2. As a result, Royal Perth Hospital introduced quantitative neuromuscular monitors for each anaesthesia workstation as well as unhindered access to sugammadex. To investigate the effects of these changes four years on (2015) we conducted an audit including all patients receiving NMBA over a two week period. Ethics approval was obtained from the Royal Perth Hospital Ethics Committee for Human Research (RPH HREC A 15.002) RNMB was assessed by an independent researcher using a quantitative neuromuscular transmission monitor (train of four [TOF] supramaximal stimulation of the ulnar nerve) (NMT monitor, GE Healthcare, Helsinki, Finland) once the anaesthetist had declared the patient 'fit for extubation' Choice of NMBA, monitoring and reversal were left to the anaesthetist. Data from 140 cases were analysed. Sugammadex, neostigmine or no reversal were used in 80.7% 2.1% and 17.2% respectively. Monitoring was used in 79% The overall incidence of RNMB was 15% However, failure (versus compliance) to monitor the effects of reversal resulted in 19% (versus 4% P=0.02) severe RNMB (TOF ratio <0.7) and 33% (versus 13% P=0.02) of overall RNMB (TOF ratio <0.9) From 2011 to 2015 the use of neuromuscular transmission monitoring increased from 62% to 78% and the use of sugammadex from 39% to 81% Using the same audit format utilised in 20112, it appears likely that the observed changes in clinical practice contributed to the significantly reduced risk of RNMB found in 2015. However, the results also underline the crucial role of neuromuscular transmission monitoring. Without this, even the unrestricted use of sugammadex appears to be unable to completely abolish the risk of RNMB. Thus, more emphasis and continuous staff education about the dangers of RNMB as well the benefits Correspondence
,Lean" und ,agil" im Buro Neue Formen der Organisation von Kopfarbeit in der digitalen Transformation

Die digitale Transformation reicht tief in die so genannten ,indirekten" Kopfarbeitsbereiche der Angestellten hinein. Im Zuge dieses Umbruchs sind die Unternehmen gegenwartig dabei sich neu zu erfinden. Als Leitbild kristallisiert sich hier die ,agile Organisation" heraus, die einen Gegenentwurf zum fordistisch burokratischen Unternehmen mit seinen hierarchischen Entscheidungsprozessen darstellt. In vielen Unternehmen finden sich gegenwartig strategische Suchprozesse, in deren Rahmen insbesondere fur die Kopfarbeit neue Organisationskonzepte zur Bewaltigung der Herausforderungen der Digitalisierung erprobt werden. Der Ubertragung von Lean Konzepten aus der Fertigung und von ,agilen Methoden" aus der Software Entwicklung kommt dabei eine strategische Bedeutung zu.