bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic vertical memory scalability for OpenJDK cloud applications
Authors: Bruno Rodrigo , Ferreira Paulo , Synytsky Ruslan , Fydorenchyk Tetiana , Rao Jia , Huang Hang , Wu Song
Published: December 2018

The cloud is an increasingly popular platform to deploy applications as it lets cloud users to provide resources to their applications as needed. Furthermore, cloud providers are now starting to offer a "pay-as-you-use" model in which users are only charged for the resources that are really used instead of paying for a statically sized instance. This new model allows cloud users to save money, and cloud providers to better utilize their hardware.

However, applications running on top of runtime environments such as the Java Virtual Machine (JVM) cannot benefit from this new model because they cannot dynamically adapt the amount of used resources at runtime. In particular, if an application needs more memory than what was initially predicted at launch time, the JVM will not allow the application to grow its memory beyond the maximum value defined at launch time. In addition, the JVM will hold memory that is no longer being used by the application. This lack of dynamic vertical scalability completely prevents the benefits of the "pay-as-you-use" model, and forces users to over-provision resources, and to lose money on unused resources.

We propose a new JVM heap sizing strategy that allows the JVM to dynamically scale its memory utilization according to the application's needs. First, we provide a configurable limit on how much the application can grow its memory. This limit is dynamic and can be changed at runtime, as opposed to the current static limit that can only be set at launch time. Second, we adapt current Garbage Collection policies that control how much the heap can grow and shrink to better fit what is currently being used by the application.

The proposed solution is implemented in the OpenJDK 9 HotSpot JVM, the new release of OpenJDK. Changes were also introduced inside the Parallel Scavenge collector and the Garbage First collector (the new by-default collector in HotSpot). Evaluation experiments using real workloads and data show that, with negligible throughput and memory overhead, dynamic vertical memory scalability can be achieved. This allows users to save significant amounts of money by not paying for unused resources, and cloud providers to better utilize their physical machines.
mPart: miss-ratio curve guided partitioning in key-value stores
Authors: Byrne Daniel , Onder Nilufer , Wang Zhenlin
Published: December 2018

Web applications employ key-value stores to cache the data that is most commonly accessed. The cache improves an web application's performance by serving its requests from memory, avoiding fetching them from the backend database. Since the memory space is limited, maximizing the memory utilization is a key to delivering the best performance possible. This has lead to the use of multi-tenant systems, allowing applications to share cache space. In addition, application data access patterns change over time, so the system should be adaptive in its memory allocation.

In this work, we address both multi-tenancy (where a single cache is used for multiple applications) and dynamic workloads (changing access patterns) using a model that relates the cache size to the application miss ratio, known as a miss ratio curve. Intuitively, the larger the cache, the less likely the system will need to fetch the data from the database. Our efficient, online construction of the miss ratio curve allows us to determine a near optimal memory allocation given the available system memory, while adapting to changing data access patterns. We show that our model outperforms an existing state-of-the-art sharing model, Memshare, in terms of overall cache hit ratio and does so at a lower time cost. We show that for a typical system, overall hit ratio is consistently 1 percentage point greater and 99.9th percentile latency is reduced by as much as 2.9% under standard web application workloads containing millions of requests.
A memory-bounded, deterministic and terminating semantics for the synchronous programming language Céu
Authors: Santos Rodrigo C. M. , Lima Guilherme F. , Sant'Anna Francisco , Ierusalimschy Roberto , Haeusler Edward H.
Published: December 2018

Céu is a synchronous programming language for embedded soft real-time systems. It focuses on control-flow safety features, such as safe shared-memory concurrency and safe abortion of lines of execution, while enforcing memory bounded, deterministic, and terminating reactions to the environment. In this work, we present a small-step structural operational semantics for Céu and a proof that reactions have the properties enumerated above: that for a given arbitrary timeline of input events, multiple executions of the same program always react in bounded time and arrive at the same final finite memory state.
Decoupling address generation from loads and stores to improve data access energy efficiency
Authors: Stokes Michael , Baird Ryan , Jin Zhaoxiang , Whalley David , Onder Soner
Published: December 2018

Level-one data cache (L1 DC) accesses impact energy usage as they frequently occur and use significantly more energy than register file accesses. A memory access instruction consists of an address generation operation calculating the location where the data item resides in memory and the data access operation that loads/stores a value from/to that location. We propose to decouple these two operations into separate machine instructions to reduce energy usage. By associating the data translation lookaside buffer (DTLB) access and level-one data cache (L1 DC) tag check with an address generation instruction, only a single data array in a set-associative L1 DC needs to be accessed during a load instruction when the result of the tag check is known at that point. In addition, many DTLB accesses and L1 DC tag checks are avoided by memoizing the DTLB way and L1 DC way with the register that holds the memory address to be dereferenced. Finally, we are able to often coalesce an ALU operation with a load or store data access using our technique to reduce the number of instructions executed.
Verification of coarse-grained reconfigurable arrays through random test programs
Authors: Egger Bernhard , Song Eunjin , Lee Hochan , Shin Daeyoung
Published: December 2018

We propose and evaluate a framework to test the functional correctness of coarse-grained reconfigurable array (CGRA) processors for pre-silicon verification and post-silicon validation. To reflect the reconfigurable nature of CGRAs, an architectural model of the system under test is built directly from the hardware description files. A guided place-and-routing algorithm is used to map operations and operands onto the heterogeneous processing elements (PE). Test coverage is maximized by favoring unexercised parts of the architecture. Requiring no explicit knowledge about the semantics of operations, the random test program generator (RTPG) framework seamlessly supports custom ISA extensions.

The proposed framework is applied to the Samsung Reconfigurable Processor, a modulo-scheduled CGRA integrated in smartphones, cameras, printers, and smart TVs. Experiments demonstrate that the RTPG is versatile, efficient, and quickly achieves a high coverage. In addition to detecting all randomly inserted faults, the generated test programs also exposed two yet unknown actual faults in the architecture.
Generic programming of all kinds
Authors: Serrano Alejandro , Miraldo Victor Cacciari
Published: December 2018

Datatype-generic programming is a widely used technique to define functions that work regularly over a class of datatypes. Examples include deriving serialization of data, equality or even functoriality. The
state-of-the-art
of generic programming still lacks handling GADTs, multiple type variables, and some other features. This paper exploits modern GHC extensions, including TypeInType, to handle arbitrary number of type variables, constraints, and existentials. We also provide an Agda model of our construction that does
not
require Russel’s paradox, proving the construction is consistent.
AutoBench: comparing the time performance of Haskell programs
Authors: Handley Martin A. T. , Hutton Graham
Published: December 2018

Two fundamental goals in programming are correctness (producing the right results) and efficiency (using as few resources as possible). Property-based testing tools such as QuickCheck provide a lightweight means to check the correctness of Haskell programs, but what about their efficiency? In this article, we show how QuickCheck can be combined with the Criterion benchmarking library to give a lightweight means to compare the time performance of Haskell programs. We present the design and implementation of the
AutoBench
system, demonstrate its utility with a number of case studies, and find that many QuickCheck correctness properties are also efficiency improvements.
Coherent explicit dictionary application for Haskell
Authors: Winant Thomas , Devriese Dominique
Published: December 2018

Type classes are one of Haskell's most popular features and extend its type system with ad-hoc polymorphism. Since their conception, there were useful features that could not be offered because of the desire to offer two correctness properties: coherence and global uniqueness of instances. Coherence essentially guarantees that program semantics are independent from type-checker internals. Global uniqueness of instances is relied upon by libraries for enforcing, for example, that a single order relation is used for all manipulations of an ordered binary tree.

The features that could not be offered include explicit dictionary application and local instances, which would be highly useful in practice. In this paper, we propose a new design for offering explicit dictionary application, without compromising coherence and global uniqueness. We introduce a novel criterion based on GHC's type argument roles to decide when a dictionary application is safe with respect to global uniqueness of instances. We preserve coherence by detecting potential sources of incoherence, and prove it formally. Moreover, our solution makes it possible to use local dictionaries. In addition to developing our ideas formally, we have implemented a working prototype in GHC.
Type variables in patterns
Authors: Eisenberg Richard A. , Breitner Joachim , Peyton Jones Simon
Published: December 2018

For many years, GHC has implemented an extension to Haskell that allows type variables to be bound in type signatures and patterns, and to scope over terms. This extension was never properly specified. We rectify that oversight here. With the formal specification in hand, the otherwise-labyrinthine path toward a design for binding type variables in patterns becomes blindingly clear. We thus extend ScopedTypeVariables to bind type variables explicitly, obviating the Proxy workaround to the dustbin of history.
Ghosts of departed proofs (functional pearl)
Authors: Noonan Matt
Published: December 2018

Library authors often are faced with a design choice: should a function with preconditions be implemented as a partial function, or by returning a failure condition on incorrect use? Neither option is ideal. Partial functions lead to frustrating run-time errors. Failure conditions must be checked at the use-site, placing an unfair tax on the users who have ensured that the function's preconditions were correctly met.

In this paper, we introduce an API design concept called ``ghosts of departed proofs'' based on the following observation: sophisticated preconditions can be encoded in Haskell's type system with no run-time overhead, by using proofs that inhabit phantom type parameters attached to newtype wrappers. The user expresses correctness arguments by constructing proofs to inhabit these phantom types. Critically, this technique allows the library user to decide when and how to validate that the API's preconditions are met.

The ``ghosts of departed proofs'' approach to API design can achieve many of the benefits of dependent types and refinement types, yet only requires some minor and well-understood extensions to Haskell 2010. We demonstrate the utility of this approach through a series of case studies, showing how to enforce novel invariants for lists, maps, graphs, shared memory regions, and more.
Embedding invertible languages with binders: a case of the FliPpr language
Authors: Matsuda Kazutaka , Wang Meng
Published: December 2018

This paper describes a new embedding technique of invertible programming languages, through the case of the FliPpr language. Embedded languages have the advantage of inheriting host languages' features and supports; and one of the influential methods of embedding is the tagless-final style, which enables a high level of programmability and extensibility. However, it is not straightforward to apply the method to the family of invertible/reversible/bidirectional languages, due to the different ways functions in such domains are represented. We consider FliPpr, an invertible pretty-printing system, as a representative of such languages, and show that Atkey et al.'s unembedding technique can be used to address the problem. Together with a reformulation of FliPpr, our embedding achieves a high level of interoperability with the host language Haskell, which is not found in any other invertible languages. We implement the idea and demonstrate the benefits of the approach with examples.
A high-performance multicore IO manager based on libuv (experience report)
Authors: Han Dong , He Tao
Published: December 2018

We present a high performance multicore I/O manager based on libuv for Glasgow Haskell Compiler (GHC). The new I/O manager is packaged as an ordinary Haskell package rather than baked into GHC's runtime system(GHC RTS), yet takes advantage of GHC RTS's comprehensive concurrent support, such as lightweight threads and safe/unsafe FFI options. The new I/O manager's performance is comparable with existing implementation, with greater stability under high load. It also can be easily extended to support all of libuv's callback-based APIs, allowing us to write a complete high performance I/O toolkit without spending time on dealing with OS differences or low-level I/O system calls.
Suggesting valid hole fits for typed-holes (experience report)
Authors: Gissurarson Matthías Páll
Published: December 2018

Type systems allow programmers to communicate a partial specification of their program to the compiler using types, which can then be used to check that the implementation matches the specification. But can the types be used to aid programmers during development? In this experience report I describe the design and implementation of my lightweight and practical extension to the typed-holes of GHC that improves user experience by adding a list of
valid hole fits
and
refinement hole fits
to the error message of typed-holes. By leveraging the type checker, these fits are selected from identifiers in scope such that if the hole is substituted with a valid hole fit, the resulting expression is guaranteed to type check.
Elastoplastic Analysis of Circular Opening Based on a New Strain‐Softening Constitutive Model and Its Engineering Application in Hydraulic Fracturing
Authors: Yang T. , Ye Q. S.
Published: December 2018

Constitutive effect is extremely important for the research of the mechanical behavior of surrounding rock in hydraulic fracturing engineering. In this paper, based on the triaxial test results, a new elastic‐peak plastic‐softening‐fracture constitutive model (EPSFM) is proposed by considering the plastic bearing behavior of the rock mass. Then, the closed‐form solution of a circular opening is deduced with the nonassociated flow rule under the cavity expansion state. Meanwhile, the parameters of the load‐bearing coefficient and brittles coefficient are introduced to describe the plastic bearing capacity and strain‐softening degrees of rock masses. When the above two parameters take different values, the new solution of EPSFM can be transformed into a series of traditional solutions obtained based on the elastic‐perfectly plastic model (EPM), elastic‐brittle plastic model (EBM), elastic‐strain‐softening model (ESM), and elastic‐peak plastic‐brittle plastic model (EPBM). Therefore, it can be applied to a wider range of rock masses. In addition, the correctness of the solution is validated by comparing with the traditional solutions. The effect of constitutive relation and parameters on the mechanical response of rock mass is also discussed in detail. The research results show that the fracture zone radii of circular opening presents the characteristic of EBM > EPBM > ESM > EPSFM; otherwise, it is on the contrast for the critical hydraulic pressure at the softening‐fracture zone interface; the postpeak failure radii show a linear decrease with the increase of load‐bearing coefficients or a nonlinear increase with the increasing brittleness coefficient. This study indicates that the rock mass with a certain plastic bearing capacity is more difficult to be cracked by hydraulic fracturing; the higher the strain‐softening degree of rock mass is, the easier it is to be cracked. From a practical point of view, it provides very important theoretical values for determining the fracture range of the borehole and providing a design value of the minimum pumping pressure in hydraulic fracturing engineering.
The Effect of Kinesiology Taping on the Hemiplegic Shoulder Pain: A Randomized Controlled Trial
Authors: Yang Lin , Yang Jingyi , He Chengqi
Published: December 2018

Objective. The purpose of the study was to explore the effect of kinesiology taping on hemiplegic shoulder pain (HSP) in terms of pain intensity, magnitude of subluxation, muscle activity, and active range of motion (AROM). Design. Double-blind, placebo-controlled clinical trial. Setting. the Rehabilitation Center of the West China Hospital. Participants. Nineteen individuals suffering from HSP were recruited in this study. Intervention. Patients were randomly assigned into the taping group or control group. The taping group received therapeutic kinesiology taping and conventional treatment, while the control group received placebo taping (applied without tension) and conventional treatment. Main Outcome Measures. The shoulder pain intensity (numerical pain rating scale), magnitude of subluxation, muscle activity (measured by surface electromyography (sEMG)), and shoulder active range of movement (AROM) were assessed at the baseline, on the first day (immediately after taping) and 4 weeks after treatment (without taping). Results. All patients completed the trials. There were no significant differences between groups at the baseline. The taping group showed immediate improvement on the first day after taping in terms of pain intensity, magnitude of subluxation, and muscle activity (p<0.05), whereas no significant changes seen in the control group (p>0.05). After 4 weeks of treatment, the taping group showed significant changes in pain intensity, magnitude of subluxation, muscle activity, and AROM (p<0.05). And significant differences in pain intensity and muscle activity could be seen between the two groups (p<0.05). Conclusion. The results indicate that the kinesiology taping is effective in reducing the shoulder pain and subluxation and increasing muscle activity and AROM for patients with HSP after stroke.
Drak/STK17A Drives Neoplastic Glial Proliferation through Modulation of MRLC Signaling
Authors: Chen Alexander S. , Wardwell-Ozgo Joanna , Shah Nilang N. , Wright Deidre , Appin Christina L. , Vigneswaran Krishanthan , Brat Daniel J. , Kornblum Harley I. , Read Renee D.
Published: December 2018

Glioblastoma (GBM) and lower grade gliomas (LGG) are the most common primary malignant brain tumors and are resistant to current therapies. Genomic analyses reveal that signature genetic lesions in GBM and LGG include copy gain and amplification of chromosome 7, amplification, mutation, and overexpression of receptor tyrosine kinases (RTK) such as EGFR, and activating mutations in components of the PI3K pathway. In Drosophila melanogaster, constitutive co-activation of RTK and PI3K signaling in glial progenitor cells recapitulates key features of human gliomas. Here we use this Drosophila glioma model to identify death-associated protein kinase (Drak), a cytoplasmic serine/threonine kinase orthologous to the human kinase STK17A, as a downstream effector of EGFR and PI3K signaling pathways. Drak was necessary for glial neoplasia, but not for normal glial proliferation and development, and Drak cooperated with EGFR to promote glial cell transformation. Drak phosphorylated Sqh, the Drosophila ortholog of nonmuscle myosin regulatory light chain (MRLC), which was necessary for transformation. Moreover, Anillin, which is a binding partner of phosphorylated Sqh, was upregulated in a Drak-dependent manner in mitotic cells and colocalized with phosphorylated Sqh in neoplastic cells undergoing mitosis and cytokinesis, consistent with their known roles in nonmuscle myosin-dependent cytokinesis. These functional relationships were conserved in human GBM. Our results indicate that Drak/STK17A, its substrate Sqh/MRLC, and the effector Anillin/ANLN regulate mitosis and cytokinesis in gliomas. This pathway may provide a new therapeutic target for gliomas.

Significance: These findings reveal new insights into differential regulation of cell proliferation in malignant brain tumors, which will have a broader impact on research regarding mechanisms of oncogene cooperation and dependencies in cancer.

See related commentary by Lathia, p. 1036
Ensaio: Um toque na Poesia Concreta.
Authors: Espel de Oliveira Mariana Rodrigues de Almeida
Published: December 2018

O ensaio apresenta uma proposta de exposição que recria obras da Poesia Concreta utilizando tecnologia em impressão 3D. Pretende sugerir estudos de viabilidade para facilitar o acesso a públicos invisuais por meio do toque ao ensino tipográfico, com suporte de áudio descrição e letras impressas em 3D. A intenção é facilitar a inclusão deste público em eventos culturais no universo da literatura, contribuir para o dinamismo na oferta de atividades desta temática em equipamentos culturais e desenvolvimento de habilidades sensoriais.
A procura de imagens de resistência
Authors: Silva Naiene Sanchez
Published: December 2018

Cultura e valor possuem uma relação sinonímica. Logo, se a cultura contemporânea opera sob a égide da imagem, certamente podemos identificar e refletir os sobre valores que constituem uma possível cultura da imagem. Neste artigo, faremos o cotejo entre os valores que fundam a ideia de cultura na sociedade do espetáculo e os valores que constituem o conceito de imagem-enigma. A ideia é verificar se existe a possibilidade de encontrar maneiras de identificar uma imagem de resistência em contextos avessos à essa ideia.
Museus: riscos e riscas
Authors: França Lourenço Maria Cecília
Published: December 2018

As artes em geral constituem práticas com ampla duração e, embora possam se ligar ao poder, por vezes desvelam indeterminações obscuras e indizíveis, em particular, ao se unir criação e instituição em função crítica a tempos soturnos. Sem reduzir obras a fetiche, o par ao se conectar enseja revisar limites, fronteiras, regras fixadas por dogma, retórica, preconceito, brilho aparente e ditado por espetáculo midiático. Há muito, domínio e classes sociais abonadas agregam imagem pessoal com arte colecionada, depois aberta ao público em diversos tempos e regiões. Não obstante, política de Estado em locais como Argentina e Portugal vêm enfrentado passado histórico e atos funestos por iniciativas públicas. O domínio de tais agentes em amplo espectro, uns a conservar e outros a transformar, seria etéreo ou sinalizaria apenas novas coalizões no topo social? Nestas configurações, entre forças opostas, resistirão sistemas sensíveis, museus e criadores, como definidos na atualidade?
Editorial
Authors: França Lourenço Maria Cecília
Published: December 2018

Este Editorial da Revista ARA, do Grupo Museu/Patrimônio – GMP da Faculdade de Arquitetura e Urbanismo da Universidade de São Paulo FAU-USP, com satisfação, expõe a quinta edição, subordinada ao tema “Configurações: entre limites e indeterminação”. O texto de “Apresentação”, elaborado pelo Prof. Dr. Celso Favaretto, em sua trama trouxe reflexões conceituais, a desafiar a criação, tanto textuais quanto visuais, em variadas latitudes. Cumpre-se, assim, papel ambicionado, em sonho coletivo, tanto dos membros do GMP e do Conselho Editorial quanto de colaboradores e pareceristas. Efetiva-se a intenção em se debater temas e indagações sobre a cultura contemporânea. Afinal, o que amanhã nos representará?
A tragédia do Paissandú, entre o perene e o efêmero
Authors: Mello Regina Lara Silveira
Published: December 2018

O recente incêndio e desabamento de um edifício no centro de São Paulo propiciou reflexões quanto a efemeridade do patrimônio constituído na cidade. A súbita mudança no sistema material da paisagem revelou as recorrentes transformações daquele espaço. Um vazio surgiu entre camadas de tempo sobrepostas, entre o que já foi e o que ainda não é: não mais, mas ainda não. Os fatos vão se acomodando no esquecimento das pessoas que circulam por ali, sugerindo outras identificações com aquilo que permaneceu, novos significados recriam a identidade do lugar, que por hora, não é lá nem cá.
Is Time From Last Hospitalization for Heart Failure to Placement of a Primary Prevention Implantable Cardioverter-Defibrillator Associated With Patient Outcomes?
Authors: Ambrosy Andrew P. , Parzynski Craig S. , Friedman Daniel J. , Fudim Marat , Hernandez Adrian F. , Fonarow Gregg C. , Masoudi Frederick A. , Al-Khatib Sana M.
Published: December 2018

Background:

Landmark studies have demonstrated the safety and efficacy of implantable cardioverter-defibrillators (ICDs) in selected stable ambulatory patients with heart failure (HF) with a reduced ejection fraction receiving optimal medical therapy. It is not known whether a recent hospitalization for HF before ICD placement is associated with subsequent outcomes.

Methods:

A post hoc analysis was performed of Medicare beneficiaries enrolled in the National Cardiovascular Data Registry’s ICD Registry with a known diagnosis of HF and an ejection fraction ≤35% underdoing a new ICD placement for primary prevention. Patients were grouped based on the timing of ICD placement from the last hospitalization for HF. The association between timing of ICD placement and outcomes was assessed by using multivariable logistic regression models.

Results:

The final analytic cohort included 81 180 patients undergoing initial ICD placement for primary prevention who were currently hospitalized for HF (n=11 563, 14%), hospitalized for HF within 3 months (n=6252, 8%), or hospitalized for HF >3 months previously or had no previous hospitalizations for HF (n=63 365, 78%). Patients currently or recently hospitalized for HF had a higher unadjusted composite periprocedural complication rate (2.60% versus 1.71% versus 1.25%,
P
<0.001). After adjusting for potential confounders, patients currently hospitalized for HF were at higher risk for death (odds ratio, 2.25; 95% CI, 2.02–2.52;
P
<0.001) and all-cause readmission (odds ratio, 1.89; 95% CI, 1.79–1.99;
P
<0.001) at 90 days.

Conclusion:

Older patients currently or recently hospitalized for HF undergoing initial ICD placement for primary prevention experienced a higher rate of periprocedural complications and were at increased risk of death in comparison with those receiving an ICD without recent HF hospitalization. Additional prospective, real-world, pragmatic, comparative effectiveness studies should be conducted to define the optimal timing of ICD placement.
Joint Semantic Synthesis and Morphological Analysis of the Derived Word
Authors: Cotterell Ryan , Schütze Hinrich
Published: December 2018

Much like sentences are composed of words, words themselves are composed of smaller units. For example, the English word questionably can be analyzed as question+ able+ ly. However, this structural decomposition of the word does not directly give us a semantic representation of the word’s meaning. Since morphology obeys the principle of compositionality, the semantics of the word can be systematically derived from the meaning of its parts. In this work, we propose a novel probabilistic model of word formation that captures both the analysis of a word w into its constituent segments and the synthesis of the meaning of w from the meanings of those segments. Our model jointly learns to segment words into morphemes and compose distributional semantic vectors of those morphemes. We experiment with the model on English CELEX data and German DErivBase (Zeller et al., 2013) data. We show that jointly modeling semantics increases both segmentation accuracy and morpheme F1 by between 3% and 5%. Additionally, we investigate different models of vector composition, showing that recurrent neural networks yield an improvement over simple additive models. Finally, we study the degree to which the representations correspond to a linguist’s notion of morphological productivity.
Representation Learning for Grounded Spatial Reasoning
Authors: Janner Michael , Narasimhan Karthik , Barzilay Regina
Published: December 2018

The interpretation of spatial references is highly contextual, requiring joint inference over both language and the environment. We consider the task of spatial reasoning in a simulated environment, where an agent can act and receive rewards. The proposed model learns a representation of the world steered by instruction text. This design allows for precise alignment of local neighborhoods with corresponding verbalizations, while also handling global references in the instructions. We train our model with reinforcement learning using a variant of generalized value iteration. The model outperforms state-of-the-art approaches on several metrics, yielding a 45% reduction in goal localization error.
Learning Structured Text Representations
Authors: Liu Yang , Lapata Mirella
Published: December 2018

In this paper, we focus on learning structure-aware document representations from data without recourse to a discourse parser or additional annotations. Drawing inspiration from recent efforts to empower neural networks with a structural bias (Cheng et al., 2016; Kim et al., 2017), we propose a model that can encode a document while automatically inducing rich structural dependencies. Specifically, we embed a differentiable non-projective parsing algorithm into a neural model and use attention mechanisms to incorporate the structural biases. Experimental evaluations across different tasks and datasets show that the proposed model achieves state-of-the-art results on document modeling tasks while inducing intermediate structures which are both interpretable and meaningful.
Event Time Extraction with a Decision Tree of Neural Classifiers
Authors: Reimers Nils , Dehghani Nazanin , Gurevych Iryna
Published: December 2018

Extracting the information from text when an event happened is challenging. Documents do not only report on current events, but also on past events as well as on future events. Often, the relevant time information for an event is scattered across the document.

In this paper we present a novel method to automatically anchor events in time. To our knowledge it is the first approach that takes temporal information from the complete document into account. We created a decision tree that applies neural network based classifiers at its nodes. We use this tree to incrementally infer, in a stepwise manner, at which time frame an event happened. We evaluate the approach on the TimeBank-EventTime Corpus (Reimers et al., 2016) achieving an accuracy of 42.0% compared to an inter-annotator agreement (IAA) of 56.7%. For events that span over a single day we observe an accuracy improvement of 33.1 points compared to the state-of-the-art CAEVO system (Chambers et al., 2014). Without retraining, we apply this model to the SemEval-2015 Task 4 on automatic timeline generation and achieve an improvement of 4.01 points F1-score compared to the state-of-the-art. Our code is publically available.
Unsupervised Grammar Induction with Depth-bounded PCFG
Authors: Jin Lifeng , Doshi-Velez Finale , Miller Timothy , Schuler William , Schwartz Lane
Published: December 2018

There has been recent interest in applying cognitively- or empirically-motivated bounds on recursion depth to limit the search space of grammar induction models (Ponvert et al., 2011; Noji and Johnson, 2016; Shain et al., 2016). This work extends this depth-bounding approach to probabilistic context-free grammar induction (DB-PCFG), which has a smaller parameter space than hierarchical sequence models, and therefore more fully exploits the space reductions of depth-bounding. Results for this model on grammar acquisition from transcribed child-directed speech and newswire text exceed or are competitive with those of other models when evaluated on parse accuracy. Moreover, grammars acquired from this model demonstrate a consistent use of category labels, something which has not been demonstrated by other acquisition models.
Questionable Answers in Question Answering Research: Reproducibility and Variability of Published Results
Authors: Crane Matt
Published: December 2018

“Based on theoretical reasoning it has been suggested that the reliability of findings published in the scientific literature decreases with the popularity of a research field” (Pfeiffer and Hoffmann, 2009). As we know, deep learning is very popular and the ability to reproduce results is an important part of science. There is growing concern within the deep learning community about the reproducibility of results that are presented. In this paper we present a number of controllable, yet unreported, effects that can substantially change the effectiveness of a sample model, and thusly the reproducibility of those results. Through these environmental effects we show that the commonly held belief that distribution of source code is all that is needed for reproducibility is not enough. Source code without a reproducible environment does not mean anything at all. In addition the range of results produced from these effects can be larger than the majority of incremental improvement reported.
Constructing Datasets for Multi-hop Reading Comprehension Across Documents
Authors: Welbl Johannes , Stenetorp Pontus , Riedel Sebastian
Published: December 2018

Most Reading Comprehension methods limit themselves to queries which can be answered using a single sentence, paragraph, or document. Enabling models to combine disjoint pieces of textual evidence would extend the scope of machine comprehension methods, but currently no resources exist to train and test this capability. We propose a novel task to encourage the development of models for text understanding across multiple documents and to investigate the limits of existing methods. In our task, a model learns to seek and combine evidence — effectively performing multihop, alias multi-step, inference. We devise a methodology to produce datasets for this task, given a collection of query-answer pairs and thematically linked documents. Two datasets from different domains are induced, and we identify potential pitfalls and devise circumvention strategies. We evaluate two previously proposed competitive models and find that one can integrate information across documents. However, both models struggle to select relevant information; and providing documents guaranteed to be relevant greatly improves their performance. While the models outperform several strong baselines, their best accuracy reaches 54.5% on an annotated test set, compared to human performance at 85.0%, leaving ample room for improvement.
The NarrativeQA Reading Comprehension Challenge
Authors: Kočiský Tomáš , Schwarz Jonathan , Blunsom Phil , Dyer Chris , Hermann Karl Moritz , Melis Gábor , Grefenstette Edward
Published: December 2018

Reading comprehension (RC)—in contrast to information retrieval—requires integrating information and reasoning about events, entities, and their relations across a full document. Question answering is conventionally used to assess RC ability, in both artificial agents and children learning to read. However, existing RC datasets and tasks are dominated by questions that can be solved by selecting answers using superficial information (e.g., local context similarity or global term frequency); they thus fail to test for the essential integrative aspect of RC. To encourage progress on deeper comprehension of language, we present a new dataset and set of tasks in which the reader must answer questions about stories by reading entire books or movie scripts. These tasks are designed so that successfully answering their questions requires understanding the underlying narrative rather than relying on shallow pattern matching or salience. We show that although humans solve the tasks easily, standard RC models struggle on the tasks presented here. We provide an analysis of the dataset and the challenges it presents.
Finding Convincing Arguments Using Scalable Bayesian Preference Learning
Authors: Simpson Edwin , Gurevych Iryna
Published: December 2018

We introduce a scalable Bayesian preference learning method for identifying convincing arguments in the absence of gold-standard ratings or rankings. In contrast to previous work, we avoid the need for separate methods to perform quality control on training data, predict rankings and perform pairwise classification. Bayesian approaches are an effective solution when faced with sparse or noisy training data, but have not previously been used to identify convincing arguments. One issue is scalability, which we address by developing a stochastic variational inference method for Gaussian process (GP) preference learning. We show how our method can be applied to predict argument convincingness from crowdsourced data, outperforming the previous state-of-the-art, particularly when trained with small amounts of unreliable data. We demonstrate how the Bayesian approach enables more effective active learning, thereby reducing the amount of data required to identify convincing arguments for new users and domains. While word embeddings are principally used with neural networks, our results show that word embeddings in combination with linguistic features also benefit GPs when predicting argument convincingness.
Detecting Institutional Dialog Acts in Police Traffic Stops
Authors: Prabhakaran Vinodkumar , Griffiths Camilla , Su Hang , Verma Prateek , Morgan Nelson , Eberhardt Jennifer L. , Jurafsky Dan
Published: December 2018

We apply computational dialog methods to police body-worn camera footage to model conversations between police officers and community members in traffic stops. Relying on the theory of institutional talk, we develop a labeling scheme for police speech during traffic stops, and a tagger to detect institutional dialog acts (Reasons, Searches, Offering Help) from transcribed text at the turn (78% F-score) and stop (89% F-score) level. We then develop speech recognition and segmentation algorithms to detect these acts at the stop level from raw camera audio (81% F-score, with even higher accuracy for crucial acts like conveying the reason for the stop). We demonstrate that the dialog structures produced by our tagger could reveal whether officers follow law enforcement norms like introducing themselves, explaining the reason for the stop, and asking permission for searches. This work may therefore inform and aid efforts to ensure the procedural justice of police-community interactions.
Probabilistic Verb Selection for Data-to-Text Generation
Authors: Zhang Dell , Yuan Jiahao , Wang Xiaoling , Foster Adam
Published: December 2018

In data-to-text Natural Language Generation (NLG) systems, computers need to find the right words to describe phenomena seen in the data. This paper focuses on the problem of choosing appropriate verbs to express the direction and magnitude of a percentage change (e.g., in stock prices). Rather than simply using the same verbs again and again, we present a principled data-driven approach to this problem based on Shannon’s noisy-channel model so as to bring variation and naturalness into the generated text. Our experiments on three large-scale real-world news corpora demonstrate that the proposed probabilistic model can be learned to accurately imitate human authors’ pattern of usage around verbs, outperforming the state-of-the-art method significantly.
Appellative in altniederländischen Ortsnamen
Authors: Quak Arend
Published: December 2018

In connection with the work on the Old Dutch dictionary (onw) the appellatives in Old Dutch place names from C7–12 were also examined. On the basis of the place names beginning with F from the lexicon of Dutch place names before 1200, the method of finding appellatives in them is explained. For some unexplained place names, possible explanations are proposed.

Im Rahmen der Arbeit am altniederländischen Wörterbuch (onw) wurden auch die Appellative in Ortsnamen aus der altiederländischen Periode (7. bis 12. Jh.) in das Wörterbuch aufgenommen. Anhand der mit F anlautenden Ortsnamen im Lexikon der niederländischen Ortsnamen vor 1200 wird das Verfahren dabei erläutert. Auch werden Vorschläge gemacht für die Deutung einiger dunkler Ortsnamen.

This article is in German language.
Traces of Suffix Ablaut in Germanic wō-stems
Authors: de Vaan Michiel , Kroonen Guus
Published: December 2018

Many of the jō-stems of Germanic were in fact ī/jō-stems that go back to ablauting iH/ieH-stems of Proto-Indo-European. The Germanic wō-stems go back to pie uH/ueH-stems with parallel ablaut behaviour to the iH/ieH-stems. Whereas the suffix variant in -ū has nowhere been preserved as such in Germanic, some traces of ablaut and accent variation remain in the Germanic wō-stems. Some such traces were first identified by Kroonen (2013); in this paper, the authors present a more detailed collection of the evidence for ablauting uH-stems in Germanic.
Marking Boundaries in Beowulf: Æschere’s Head, Grendel’s Arm and the Dragon’s Corpse
Authors: Porck Thijs , Stolk Sander
Published: December 2018

In the Old English poem Beowulf, several body parts are put on display, including Grendel’s arm at Heorot and Æschere’s head on top of a cliff. The first instance has been widely discussed by various scholars, who have tried to find out why and where the arm was hung. By contrast, scholarly treatments of the second instance are relatively scarce. This article places the exhibition of Æschere’s head by Grendel’s mother in the context of similar practices of decapitation and display in Anglo-Saxon England. It will be argued that the placement of the head of Æschere on top of the cliff towering over Grendel’s mere resembles the Anglo-Saxon heafod stoccan, ‘head stakes’, which acted as boundary markers. The monster’s act, therefore, would not strike as foreign to the Anglo-Saxon audience, but would be familiar. As we will show, the identification of Æschere’s head as a boundary marker, placed at the edge of the monsters’ domain, also has some bearing on the interpretation of other potential boundary markers in the poem, including Grendel’s arm and the dragon’s corpse. Lastly, we will argue for a new reading of two textual cruces in Beowulf’s speech prior to his fight with Grendel.
Sprachmischung in den ‘Malbergischen Glossen’
Authors: Quak Arend
Published: December 2018

In den sogenannten ‘Malbergischen Glossen’ finden sich einige lateinisch-fränkische Mischformen: ort(o)fogal, ort(o)baum, ort(o)pund, ōlagart, vialacina und ein Lehnwort aus dem galloromanischen: pōdor. Sie werden hier nach Herkunft behandelt. Dazu kommt noch ein weiteres solches Wort hofporcus, das in flämischen Quellen des 12. Jahrhunderts erscheint und keine Entsprechung im Mittelniederländischen zu haben scheint. Auch dieses Wort dürfte nur eine beschränkte Verbreitung gehabt haben. Weiter werden einige frühe Lehnwörter aus dem Romanischen ins Altniederländische behandelt.
Retextualisation through Contextualisation
Authors: Holtzhauer Sebastian
Published: December 2018

On the basis of Cod. pal. germ. 60 (ub Heidelberg) the author shows how strategies and concepts for the arrangement of texts in medieval manuscripts can call forth and highlight certain connotations of the separate texts in a manuscript. Several texts and their included illustrations in this manuscript, among them a prose version of ‘The Voyage of Saint Brendan’, and also a German translation of the ‘Tractatus de purgatorio Sancti Patricii’, by their interference point at a ‘Narrative of the Purgatory’, which is spread like a net over the entire manuscript. Consequently, the interpretation goes beyond the usual textual analysis of the works and asks for retextualisation within the framework of a concrete manuscript context, and therefore also for their ‘status in life’. Central in the research are the strategies of legitimization of fictional contents, which take the codex into account as the communicator of text and illustrations and so draw the reality of the recipients into it, by which they are drawn into the narrated world.
Varieties of Contextualism: Standards and Descriptions
Authors: Baumann Peter
Published: December 2018

Most contextualists agree that contexts differ with respect to relevant epistemic standards. In this paper, I discuss the idea that the difference between more modest and stricter standards should be explained in terms of the closeness or remoteness of relevant possible worlds. I argue that there are serious problems with this version of contextualism. In the second part of the paper, I argue for another form of contextualism that has little to do with standards and a lot with the well-known problem of the reference class. This paper also illustrates the fact that contextualism comes in many varieties.
Contextualism Between Scepticism and Common-Sense
Authors: Kallestrup Jesper
Published: December 2018

This paper examines two recent objections against contextualism. The first is that contextualists are unable to assert their own position, and the second is that contextualists are forced to side with common-sense against scepticism. It is argued that once we get clear on the commitments of contextualism, neither objection succeeds in what it aims to show.
Illokution und Konvention, oder auch: Was steckt nun wirklich hinter Austins ,,securing of uptake"?
Authors: Petrus Klaus
Published: December 2018

In this article, I would like to clarify Austin's thesis that illocutionary acts are essentially conventional and to show, how this idea is connected with his concept of securing uptake. Contrary to what most critics believe, I will show that Austin provides a criterion characterising the nature of all illocutionary acts and allowing to distinguish them from perlocutionary acts.
Tyler Burge's Self-Knowledge
Authors: Warfield Ted A.
Published: December 2018

The question of whether externalism about mental content is compatible with privileged access is a question of ongoing concern within philosophy of mind. Some philosophers think that Tyler Burge's early work on what he calls "basic self-knowledge" shows that externalism and privileged access are compatible. I critically assess this claim, arguing that Burge's work does not establish the compatbility thesis.
The Problem of Context-Relativity in Semantics
Authors: Gauker Christopher
Published: December 2018

Context-relativity may be conceived as a problem in formal semantics. The several aspects of the problem are here surveyed. This survey serves as an introduction to a symposium on this topic in this issue.
Hybrid Evaluatives: In Defense of a Presuppositional Account
Authors: Cepollaro Bianca , Stojanovic Isidora
Published: December 2018

In this paper, the authors present a presuppositional account for a class of evaluative terms that encode both a descriptive and an evaluative component: slurs and thick terms. The authors discuss several issues related to the hybrid nature of these terms, such as their projective behavior, the ways in which one may reject their evaluative content, and the ways in which evaluative content is entailed or implicated (as the case may be) by the use of such terms.