bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalized ultrasonic scattering model for arbitrary transducer configurations
Authors: Arguelles Andrea P. , Turner Joseph A.
Published: December 2019

Ultrasonic scattering in polycrystalline media is directly tied to microstructural features. As a result, modeling efforts of scattering from microstructure have been abundant. The inclusion of beam modeling for the ultrasonic transducers greatly simplified the ability to perform quantitative, fully calibrated experiments. In this article, a theoretical scattering model is generalized to allow for arbitrary source and receiver configurations, while accounting for beam behavior through the total propagation path. This extension elucidates the importance and potential of out-of-plane scattering modes in the context of microstructure characterization. The scattering coefficient is explicitly written for the case of statistical isotropy and ellipsoidal grain elongation, with a direct path toward expansion for increased microstructural complexity. Materials with crystallites of any symmetry can be studied with the present model; the numerical results focus on aluminum, titanium, and iron. The amplitude of the scattering response is seen to vary across materials, and to have varying sensitivity to grain elongation and orientation depending on the transducer configuration selected. The model provides a pathway to experimental characterization of microstructure with optimized sensitivity to parameters of interest.
Low frequency propagation through random polydisperse assemblies of cylindrical or spherical poroelastic obstacles
Authors: Gnadjro D. , Franklin H. , d'Almeida A.
Published: December 2019

The effective wavenumbers, moduli, and mass densities are found for polydisperse assemblies of poroelastic obstacles (considering fluid flow and solid deformation in the porous medium). The obstacles are infinite length cylinders and spheres. To achieve this, recent formulas for the effective wavenumbers, given by Linton and Martin [SIAM J. Appl. Math. 66(5), 1649–1668 (2006)] and Norris and Conoir [J. Acoust. Soc. Am. 129(1), 104–113 (2011)] in the dilute monodisperse case (obstacles of identical sizes in a fluid matrix), have been modified. Given the uncertainty in predicting the distribution in size of the obstacles, three quite different probability density functions are studied and compared: uniform, Schulz, and lognormal. Specifically, the Rayleigh approximation (low frequency regime) is considered, in which the wavelengths can be assumed very large compared to the size of the obstacles. Within this limit, simplified formulas are provided for the concentrations depending on the parameter characterizing the size dispersion.
Transfer matrix analysis of a duct with gradually varying arbitrary cross-sectional area
Authors: Pillai Minu A. , Ebenezer D. D. , Deenadayalan Ezhilarasi
Published: December 2019

A method is presented to determine the low-frequency sound field in a duct with a cross-section of arbitrary shape and area that varies gradually without discontinuities. The duct is modeled as several fictitious segments, each of which has a cross-sectional area that is a quadratic function of position along its axis. A closed-form solution does not exist for arbitrary quadratic variation. Therefore, a series solution with two coefficients that depend on the boundary conditions and the radius of convergence (ROC) of the series is presented. Losses due to absorption are included. The solution corresponds to standing waves and is recast in terms of traveling waves. A transfer matrix is developed and used to express the pressure and velocity at the throat of a segment in terms of the pressure and velocity at its mouth. The series solution converges very rapidly when the length of the segment is less than half the ROC. The transfer matrix for the entire duct is the product of the transfer matrices of the segments. Numerical results are presented for open-closed ducts with the same length but different variations in area to illustrate the effect of the latter on the lowest resonance frequency and the pressure amplification.
Population Pharmacokinetics and Dosing of Ethionamide in Children with Tuberculosis
Authors: Bjugård Nyberg Henrik , Draper Heather R. , Garcia-Prats Anthony J. , Thee Stephanie , Bekker Adrie , Zar Heather J. , Hooker Andrew C. , Schaaf H. Simon , McIlleron Helen , Hesseling Anneke C. , Denti Paolo
Published: December 2019

Ethionamide has proven efficacy against both drug-susceptible and some drug-resistant strains ofMycobacterium tuberculosis. Limited information on its pharmacokinetics in children is available, and current doses are extrapolated from weight-based adult doses. Pediatric doses based on more robust evidence are expected to improve antituberculosis treatment, especially in small children.
Early life exposure to coal mine fire and tobacco smoke affect subclinical vascular function
Authors: Zhao Bing , Johnston Fay H , O’Sullivan Tierney , Williamson Grant J , Melody Shannon , Dalton Marita , Venn Alison , Negishi Kazuaki
Published: December 2019

Objective

To evaluate whether vascular health in young children was associated with exposure to a 6-week episode of coal mine fire smoke or environmental tobacco smoke (ETS) in a retrospective cohort study.

Methods

Three years after a coal mine fire in Victoria, Australia, we investigated the vascular health of children either in utero (n=75) or aged <2 years (postnatal exposure, n=96) at the time of the fire. The outcomes were the carotid intima-media thickness (IMT) and pulse wave velocity (PWV). The mean and peak daily particulate matter <2.5 µm in diameter (PM2.5) exposures were estimated based on their daily locations throughout the fire period. Multivariable linear regression models were used to test for associations between the fire-related PM2.5 and outcomes adjusted for relevant covariates including ETS.

Results

In the postnatal-exposure group, each 10 µg/m³ increase in mean PM2.5 level was independently positively associated with PWV (β=0.116, p=0.028). When these two groups were combined, there was an association between mean PM2.5 and increased PWV in those children who had ETS exposure (β=0.148, p=0.033) or whose mothers smoked (β=0.151, p=0.011), but not in those not exposed to ETS or maternal smoking.

Conclusions

Three years after a coal mine fire, infants aged up to 2 years at the time of exposure have increases in vascular stiffness. Although no adverse effects were observed in the in uterus exposure group, further follow-up study is needed to elucidate the long-term effects of coal mine fire smoke exposure.
Something hazy drifting in the air…
Authors: McCreary David , McArdle Jane , Minks David , Horridge Karen
Published: December 2019

­

A 7-year-old boy with a background of autism presented to the
paediatric emergency department with his left arm ‘feeling strange’
then became difficult to rouse. On examination, he was found to have
left arm weakness and a left-sided facial droop without forehead
muscle involvement. Three hours later, his symptoms had completely
resolved and he was suspected to have had a first seizure. He was
admitted for observation and an electroencephalography which showed
slower rhythms in the right posterior quadrant, which was reported
as within normal appearances for his age. He was discharged home the
following day. Three days later he became lethargic and vomited. His
parents reported dysphasia with use of single-word phrases only, he
also appeared confused. He re-presented to the paediatric emergency
department, where he was found to have increased tone in the left
arm, ankle clonus and an upgoing plantar reflex on the left hand
side.

Questions

What are the differential diagnoses and what investigations
should be considered?

What type of imaging modality has been used for figures 1
and 2 and what do they show?

What type of imaging is used in figures 3 and 4 and what do
they show?

What is the difference between moyamoya disease and moyamoya
syndrome?

Histologically in what way does MMD affect the cerebral
vasculature?

What are the different types of MMD?

What are the management strategies used in MMD?

Figure 1

MRI angiogram (MRA) showing the internal carotid arteries
(ICA). The left ICA is extremely stenotic at the skull base. The
right ICA is occluded at the skull base. The basilar artery is
occluded.

Figure 2

MRI angiogram demonstrating extensive reconstitution of the
intracranial internal carotid arteries via collateralisation
from recurrent facial, orbital and skull base branches of the
eonline xternal carotid arteries. Supply to the posterior
circulation is via the posterior communicating arteries, and
also via multiple small collaterals arising from the distal
vertebral arteries, the posterior inferior cerebellar arteries
(PICA) and deep cervical branches.

Figure 3

Fluid-attenuated inversion recovery (FLAIR) MRI image
demonstrating multifocal bilateral acute infarcts of varying
sizes, the largest of which affects the posterior right
hemisphere. Many of the infarcts are watershed in
distribution.

Figure 4

T2 MRI image demonstrating multifocal bilateral acute
infarcts of varying sizes, the largest of which affects the
posterior right hemisphere.

Answers can be found on page 2.
Sertraline-induced hypersensitivity pneumonitis
Authors: Virdee Gursharan , Bleasdale John , Ikramullah Mohammed , Graham-Clarke Emma
Published: December 2019

Hypersensitivity pneumonitis (HP), also known as extrinsic allergic alveolitis, is a granulomatous, non-IgE-mediated hypersensitivity reaction of the alveoli and distal bronchioles presenting as an acute, subacute or chronic condition. It is most commonly associated with exposure to extrinsic allergens (eg, avian dust, mould and tobacco) and medications including antiarrhythmics (eg, amiodarone), cytotoxics (eg, methotrexate) and antiepileptics (eg, carbamazepine). Individuals diagnosed with this condition can present with severe hypoxia and respiratory failure. The fundamental principle of management is to remove the causative allergen. Evidence implicating selective serotonin reuptake inhibitors as a causative agent is limited, and this case report describes a rare clinical presentation of HP associated with sertraline, how it was diagnosed and subsequently treated. It is anticipated that raising awareness of this interaction will assist multidisciplinary teams, managing patients diagnosed with HP, to be more cognisant of sertraline as being an aetiological factor for this condition.
Primary seminal vesicle adenocarcinoma: a lethal yet cryptic malignancy with review of literature
Authors: Bhat Abhishek , Banerjee Indraneel , Kryvenko Oleksandr N , Satyanarayana Ramgopal
Published: December 2019

The rarity of primary seminal vesical adenocarcinoma (PSVA) coupled with mostly late and advanced presentation with high mortality makes it an unanticipated malignancy with poor prognosis. Although there has been sporadic reporting of cases, the dearth of literature makes standardised care a challenge. The detection has incorporated immunohistochemistry for establishing the site of origin as well as the differentiation of primary from metastatic cancer. Surgical management with seminal vesiculectomy continues to be the mainstay of treatment, but difficult anatomy and delayed intervention do lead to an increased chance of residual disease that may warrant further adjuvant chemoradiation. We present a case report where PSVA developed in a patient with Zinner syndrome—an observation that is extremely rare with a literature review of PSVA including the various aspects of management including contemporary diagnosis techniques.
The supervisory relationships of community health workers in primary health care: social network analysis of ward-based outreach teams in Ngaka Modiri Molema District, South Africa
Authors: Assegaai Tumelo , Schneider Helen
Published: December 2019

Introduction

Supportive supervision remains a key challenge to the sustainability of community health worker (CHW) programmes globally. The aim of the study was to identify critical actors and patterns of relationships in the supervision of ward-based outreach teams (WBOT) in a rural South African district.

Methods

A cross-sectional study of social and professional relationships of WBOTs with other primary health care (PHC) system actors was conducted using a social network analysis (SNA) approach. A structured questionnaire was distributed to CHWs (37), WBOT team leaders (3), PHC facility managers (5) and PHC local area managers (2) (total n=47) assessing interaction patterns of supportive supervision, namely management, development and support.

Results

The supportive supervision system pivoted around team leaders, who were nurse cadres and who ensured internal cohesion and support among WBOT members. The network patterns also showed the extent of peer support between CHWs in WBOTs. PHC facility staff and middle managers in the subdistrict did not appear to play active roles in the supervision of CHWs and their team leaders. However, there were exceptions, with WBOTs drawing on sympathetic cadres identified among the PHC facility staff for support.

Conclusion

Supportive supervision of CHWs can be thought of as a system of horizontal and vertical relationships that go beyond just one supervisor–supervisee interaction. In this study, supervisory relationships within teams functioned better than those between teams and the rest of the PHC system. Understanding these relationships is key to designing effective supportive supervision in CHW programmes. SNA can be a valuable approach in identifying the relationships to be strengthened.
Sociodemographic and clinical risk factors for paediatric typical haemolytic uraemic syndrome: retrospective cohort study
Authors: Adams Natalie , Byrne Lisa , Rose Tanith , Adak Bob , Jenkins Claire , Charlett Andre , Violato Mara , O'Brien Sarah , Whitehead Margaret , Barr Benjamin , Taylor-Robinson David , Hawker Jeremy
Published: December 2019

Objectives

Haemolytic uraemic syndrome (HUS) following Shiga toxin-producingEscherichia coli(STEC) infection is the the most common cause of acute renal failure among children in the UK. This study explored differential progression from STEC to HUS by social, demographic and clinical risk factors.

Methods

We undertook a retrospective cohort study linking two datasets. We extracted data on paediatric STEC and HUS cases identified in the Public Health England National Enhanced Surveillance System for STEC and British Paediatric Surveillance Unit HUS surveillance from 1 October 2011 to 31 October 2014. Using logistic regression, we estimated the odds of HUS progression by risk factors.

Results

1059 paediatric STEC cases were included in the study, of which 207 (19.55%, 95% CI 17% to 22%) developed HUS. In the fully adjusted model, the odds of progression to HUS were highest in those aged 1–4 years (OR 4.93, 95% CI 2.30 to 10.56, compared with 10–15 years), were infected with an Shiga toxin (stx)2-only strain (OR 5.92, 95% CI 2.49 to 14.10), were prescribed antibiotics (OR 8.46, 95% CI 4.71 to 15.18) and had bloody diarrhoea (OR 3.56, 95% CI 2.04 to 6.24) or vomiting (OR 4.47, 95% CI 2.62 to 7.63), but there was no association with progression to HUS by socioeconomic circumstances or rurality.

Conclusion

Combining data from an active clinical surveillance system for HUS with the national enhanced STEC surveillance system suggests that 20% of diagnosed paediatric STEC infections in England resulted in HUS. No relationship was found with socioeconomic status or rurality of cases, but differences were demonstrated by age,stxtype and presenting symptoms.
Laboratory assessment of vitamin K status
Authors: Card David John , Gorska Renata , Harrington Dominic Jon
Published: December 2019

Vitamin K is required for the ɣ-carboxylation of specific glutamic acid residues within the Gla domain of the 17 vitamin K-dependent proteins (VKDPs). The timely detection and correction of vitamin K deficiency can protect against bleeding. Vitamin K also plays a role in bone metabolism and vascular calcification. Patients at increased risk of vitamin K deficiency include those with a restricted diet or malnutrition, lipid malabsorption, cancer, renal disease, neonates and the elderly. Coagulation assays such as the prothrombin time have been used erroneously as indicators of vitamin K status, lacking sufficient sensitivity and specificity for this application. The measurement of phylloquinone (K1) in serum is the most commonly used marker of vitamin K status and reflects abundance of the vitamin. Concentrations <0.15 µg/L are indicative of deficiency. Disadvantages of this approach include exclusion of the other vitamin K homologues and interference from recent dietary intake. The cellular utilisation of vitamin K is determined through measurement of the prevalence of undercarboxylated VKDPs. Most commonly, undercarboxylated prothrombin (Protein Induced by Vitamin K Absence/antagonism, PIVKA-II) is used (reference range 17.4–50.9 mAU/mL (Abbott Architect), providing a retrospective indicator of hepatic vitamin K status. Current clinical applications of PIVKA-II include supporting the diagnosis of vitamin K deficiency bleeding of the newborn, monitoring exposure to vitamin K antagonists, and when used in combination with α-fetoprotein, as a diagnostic marker of hepatocellular carcinoma. Using K1and PIVKA-II in tandem is an approach that can be used successfully for many patient cohorts, providing insight into both abundance and utilisation of the vitamin.
Big and bad: how relative predator size and dietary information influence rusty crayfish (Faxonius rusticus) behavior and resource-use decisions
Authors: Wood Tyler C. , Moore Paul A.
Published: December 2019

Prey animals use the information that they extract from predator cues to assess risk. Animals can obtain information about the relative size of predators and their dietary constituents from odor cues that predators deposit in the environment. However, it is currently unknown how prey animals respond when presented with two or more pieces of information about a predator. Rusty crayfish (Faxonius rusticus (Girard, 1852)) were exposed to odors from predatory largemouth bass (Micropterus salmoides (Lacepède, 1802)) that were fed four different diets and also varied in size relative to the crayfish subjects. A series of analyses of covariance (ANCOVA) indicated that rusty crayfish altered their macrophyte consumption, foraging behavior, and shelter-use behavior depending on the relative size and dietary information presented by the largemouth bass. This study demonstrates that prey consider and respond to multiple aspects of a predatory threat when making resource-use decisions.
Laser cladding of Ni60 + 17 − 4PH composite for a cracking-free and corrision resistive coating
Authors: Chen Zhaohui , Li Ruifeng , Gu Jiayang , Zhang Zhongyu , Tao Yanwu , Tian Yingtao
Published: December 2019

In order to obtain a laser-cladded coating with no cracking and good corrosion resistance, this paper investigated laser cladding of a mixture of 17-4PH stainless steel and Ni60 powders on ASTM 1045 steel substrate. The surface cracking, mechanical properties and corrosion resistance of the coatings were assessed by various characterization methods. The experimental results demonstrated that a crack-free coating can be obtained by adding 30% (or above) 17-4PH stainless steel into Ni60 alloy. The mechanical properties of the coatings were determined by adding 17-4PH, but stabilized at about 79% of pure Ni60 alloy, which is acceptable considering the benefit of elimination of surface cracking. Decrease in the mechanical properties were caused by the dilution of the strengthening elements and reduction of population of hard phases. Composite coating having 30% of 17-4PH also exhibited the smallest corrosion current, lowest corrosion potential and slowest corrosion rate, and therefore the best corrosion resistance.
High-efficiency CIGS solar cell by optimization of doping concentration, thickness and energy band gap
Authors: Ghavami Fatemeh , Salehi Alireza
Published: December 2019

In this paper, the performance of copper-indium-gallium-diselenide Cu(In,Ga)Se2 solar cell, with ZnO window layer, ZnSe buffer layer, CIGS absorber layer and InGaP reflector layer was studied. The study was performed using the TCAD Silvaco simulator. The effects of grading the band gap of CIGS absorber layer, the various thicknesses and doping concentrations of different layers have been investigated. By optimizing the solar cell structure, we have obtained a maximum open circuit voltage of 0.91901 V, a short circuit current density of 39.89910 mA/cm2, a fill factor (FF) of 86.67040% and an efficiency of 31.78% which is much higher than the values for similar CIGS solar cells reported so far.
HgCdTe Quantum Dot Over Interdigitated Electrode for Mid-Wave Infrared Photon Detection and Its Noise Characterization
Authors: Chatterjee Abhijit , Jagtap Amardeep , Pendyala Naresh , Rao K. S. R. Koteswara
Published: December 2019

In this paper, we report the development of mid-wave infrared (MWIR) photon sensor using solution-processed mercury cadmium telluride (Hg[Formula: see text]CdxTe) semiconductor colloidal quantum dots (CQDs) coated over interdigitated metallic electrode structure, having significant response in the MWIR spectral band range ([Formula: see text]–5.0[Formula: see text][Formula: see text]m) at room temperature. HgCdTe CQD has been chemically synthesized. We have characterized the optical and [Formula: see text] noise performances of the developed sensor to understand its behaviors at different operating biases as an introductory step toward development of large-format MWIR focal-plane arrays having similar pixel structure. The optimum biasing conditions have been experimentally evaluated at room temperature. We have achieved a noise equivalent power (NEP) of 2.5[Formula: see text]pW at 1.5-V bias voltage which corresponds to detectivity ([Formula: see text]) in the order of 108. This work highlights the development of low-cost colloidal HgCdTe quantum dot photodetectors and their utility in the monolithic infrared focal-plane arrays.
The distinction problem for metaplectic case
Authors: Lu Hengfei
Published: December 2019

We use the theta lifts between [Formula: see text] and [Formula: see text] to study the distinction problems for the pair [Formula: see text] where [Formula: see text] is a quadratic field extension over a nonarchimedean local field [Formula: see text] of characteristic zero and [Formula: see text] is a quaternion algebra. With a similar strategy, we give a conjectural formula for the multiplicity of distinction problem related to the pair [Formula: see text]
Stimulating Interest in School Physics with the Help of Kids’ Toys
Authors: Kulaga Igor
Published: December 2019

The article shows the role of a scientific toy in the methodology of teaching physics and describes graphic examples in various sections. The significance of homemade toys is highlighted, examples of such toys are also given.
Ethics of technology needs more political philosophy
Authors: Himmelreich Johannes
Published: December 2019

Incorporating considerations of reasonable pluralism, individual agency, and legitimate authority.
Intuitionistic Linear Temporal Logics
Authors: Balbiani Philippe , Boudou Joseph , Diéguez Martín , Fernández-Duque David
Published: December 2019

We consider intuitionistic variants of linear temporal logic with “next,” “until,” and “release” based on
expanding posets
: partial orders equipped with an order-preserving transition function. This class of structures gives rise to a logic that we denote ITL
e
, and by imposing additional constraints, we obtain the logics ITL
p
of
persistent posets
and ITL
ht
of
here-and-there temporal logic,
both of which have been considered in the literature. We prove that ITL
e
has the effective finite model property and hence is decidable, while ITL
p
does not have the finite model property. We also introduce notions of bounded bisimulations for these logics and use them to show that the “until” and “release” operators are not definable in terms of each other, even over the class of persistent posets.
Logarithmic Communication for Distributed Optimization in Multi-Agent Systems
Authors: London Palma , Vardi Shai , Wierman Adam
Published: December 2019

Classically, the design of multi-agent systems is approached using techniques from distributed optimization such as dual descent and consensus algorithms. Such algorithms depend on convergence to global consensus before any individual agent can determine its local action. This leads to challenges with respect to communication overhead and robustness, and improving algorithms with respect to these measures has been a focus of the community for decades.

This paper presents a new approach for multi-agent system design based on ideas from the emerging field of local computation algorithms. The framework we develop, LOcal Convex Optimization (LOCO), is the first local computation algorithm for convex optimization problems and can be applied in a wide-variety of settings. We demonstrate the generality of the framework via applications to Network Utility Maximization (NUM) and the distributed training of Support Vector Machines (SVMs), providing numerical results illustrating the improvement compared to classical distributed optimization approaches in each case.
Social Learning in Multi Agent Multi Armed Bandits
Authors: Sankararaman Abishek , Ganesh Ayalvadi , Shakkottai Sanjay
Published: December 2019

Motivated by emerging need of learning algorithms for large scale networked and decentralized systems, we introduce a distributed version of the classical stochastic Multi-Arm Bandit (MAB) problem. Our setting consists of a large number of agents n that collaboratively and simultaneously solve the same instance of K armed MAB to minimize the average cumulative regret over all agents. The agents can communicate and collaborate among each other only through a pairwise asynchronous gossip based protocol that exchange a limited number of bits. In our model, agents at each point decide on (i) which arm to play, (ii) whether to, and if so (iii) what and whom to communicate with. Agents in our model are decentralized, namely their actions only depend on their observed history in the past. We develop a novel algorithm in which agents, whenever they choose, communicate only arm-ids and not samples, with another agent chosen uniformly and independently at random. The per-agent regret scaling achieved by our algorithm is $\BigO łeft( \fracłceil\fracK n \rceil+łog(n) Δ łog(T) + \fracłog^3(n) łog łog(n) Δ^2 \right) $. Furthermore, any agent in our algorithm communicates (arm-ids to an uniformly and independently chosen agent) only a total of Θ(łog(T))$ times over a time interval of T. We compare our results to two benchmarks - one where there is no communication among agents and one corresponding to complete interaction, where an agent has access to the entire system history of arms played and rewards obtained of all agents. We show both theoretically and empirically, that our algorithm experiences a significant reduction both in per-agent regret when compared to the case when agents do not collaborate and each agent is playing the standard MAB problem (where regret would scale linearly in K), and in communication complexity when compared to the full interaction setting which requires T communication attempts by an agent over T arm pulls. Our result thus demonstrates that even a minimal level of collaboration among the different agents enables a significant reduction in per-agent regret.
I Know What You Did Last Summer
Authors: Ivkin Nikita , Basat Ran Ben , Liu Zaoxing , Einziger Gil , Friedman Roy , Braverman Vladimir
Published: December 2019

Modern network telemetry systems collect and analyze massive amounts of raw data in a space efficient manner. These require advanced capabilities such as drill down queries that allow iterative refinement of the search space. We present a first integral solution that (i) enables multiple measurement tasks inside the same data structure, (ii) supports specifying the time frame of interest as part of its queries, and (iii) is sketch-based and thus space efficient. Namely, our approach allows the user to define both the measurement task (e.g., heavy hitters, entropy estimation, count distinct, etc.) and the time frame of relevance (e.g., 5PM-6PM) at query time. Our approach provides accuracy guarantees and is the only space-efficient solution that offers such capabilities. Finally, we demonstrate how our system can be used for accurately pinpointing the start of a realistic DDoS attack.
Deterministic parallel fixpoint computation
Authors: Kim Sung Kook , Venet Arnaud J. , Thakur Aditya V.
Published: December 2019

Abstract interpretation is a general framework for expressing static program analyses. It reduces the problem of extracting properties of a program to computing an approximation of the least fixpoint of a system of equations. The de facto approach for computing this approximation uses a sequential algorithm based on weak topological order (WTO). This paper presents a deterministic parallel algorithm for fixpoint computation by introducing the notion of weak partial order (WPO). We present an algorithm for constructing a WPO in almost-linear time. Finally, we describe Pikos, our deterministic parallel abstract interpreter, which extends the sequential abstract interpreter IKOS. We evaluate the performance and scalability of Pikos on a suite of 1017 C programs. When using 4 cores, Pikos achieves an average speedup of 2.06x over IKOS, with a maximum speedup of 3.63x. When using 16 cores, Pikos achieves a maximum speedup of 10.97x.
Relational proofs for quantum programs
Authors: Barthe Gilles , Hsu Justin , Ying Mingsheng , Yu Nengkun , Zhou Li
Published: December 2019

Relational verification of quantum programs has many potential applications in quantum and post-quantum security and other domains. We propose a relational program logic for quantum programs. The interpretation of our logic is based on a quantum analogue of probabilistic couplings. We use our logic to verify non-trivial relational properties of quantum programs, including uniformity for samples generated by the quantum Bernoulli factory, reliability of quantum teleportation against noise (bit and phase flip), security of quantum one-time pad and equivalence of quantum walks.
Seminaïve evaluation for a higher-order functional language
Authors: Arntzenius Michael , Krishnaswami Neel
Published: December 2019

One of the workhorse techniques for implementing bottom-up Datalog engines is seminaïve evaluation. This optimization improves the performance of Datalog's most distinctive feature: recursively defined predicates. These are computed iteratively, and under a naïve evaluation strategy, each iteration recomputes all previous values. Seminaïve evaluation computes a safe approximation of the difference between iterations. This can asymptotically improve the performance of Datalog queries.

Seminaïve evaluation is defined partly as a program transformation and partly as a modified iteration strategy, and takes advantage of the first-order nature of Datalog code. This paper extends the seminaïve transformation to higher-order programs written in the Datafun language, which extends Datalog with features like first-class relations, higher-order functions, and datatypes like sum types.
The fire triangle: how to mix substitution, dependent elimination, and effects
Authors: Pédrot Pierre-Marie , Tabareau Nicolas
Published: December 2019

There is a critical tension between substitution, dependent elimination and effects in type theory. In this paper, we crystallize this tension in the form of a no-go theorem that constitutes the fire triangle of type theory. To release this tension, we propose ∂CBPV, an extension of call-by-push-value (CBPV) —a general calculus of effects—to dependent types. Then, by extending to ∂CBPV the well-known decompositions of call-by-name and call-by-value into CBPV, we show why, in presence of effects, dependent elimination must be restricted in call-by-name, and substitution must be restricted in call-by-value. To justify ∂CBPV and show that it is general enough to interpret many kinds of effects, we define various effectful syntactic translations from ∂CBPV to Martin-Löf type theory: the reader, weaning and forcing translations.
Detecting floating-point errors via atomic conditions
Authors: Zou Daming , Zeng Muhan , Xiong Yingfei , Fu Zhoulai , Zhang Lu , Su Zhendong
Published: December 2019

This paper tackles the important, difficult problem of detecting program inputs that trigger large floating-point errors in numerical code. It introduces a novel, principled
dynamic analysis
that leverages the mathematically rigorously analyzed
condition numbers
for atomic numerical operations, which we call
atomic conditions
, to effectively guide the search for large floating-point errors. Compared with existing approaches, our work based on atomic conditions has several distinctive benefits: (1) it does not rely on high-precision implementations to act as approximate oracles, which are difficult to obtain in general and computationally costly; and (2) atomic conditions provide accurate, modular search guidance. These benefits in combination lead to a highly effective approach that detects more significant errors in real-world code (e.g., widely-used numerical library functions) and achieves several orders of speedups over the state-of-the-art, thus making error analysis significantly more practical. We expect the methodology and principles behind our approach to benefit other floating-point program analysis tasks such as debugging, repair and synthesis. To facilitate the reproduction of our work, we have made our implementation, evaluation data and results publicly available on GitHub at https://github.com/FP-Analysis/atomic-condition.
Computation Offloading with Multiple Agents in Edge-Computing–Supported IoT
Authors: Shen Shihao , Han Yiwen , Wang Xiaofei , Wang Yan
Published: December 2019

With the development of the Internet of Things (IoT) and the birth of various new IoT devices, the capacity of massive IoT devices is facing challenges. Fortunately, edge computing can optimize problems such as delay and connectivity by offloading part of the computational tasks to edge nodes close to the data source. Using this feature, IoT devices can save more resources while still maintaining the quality of service. However, since computation offloading decisions concern joint and complex resource management, we use multiple Deep Reinforcement Learning (DRL) agents deployed on IoT devices to guide their own decisions. Besides, Federated Learning (FL) is utilized to train DRL agents in a distributed fashion, aiming to make the DRL-based decision making practical and further decrease the transmission cost between IoT devices and Edge Nodes. In this article, we first study the problem of computation offloading optimization and prove the problem is an NP-hard problem. Then, based on DRL and FL, we propose an offloading algorithm that is different from the traditional method. Finally, we studied the effects of various parameters on the performance of the algorithm and verified the effectiveness of both the DRL and FL in the IoT system.
Multilevel and Multiscale Feature Aggregation in Deep Networks for Facial Constitution Classification
Authors: Huan Er-Yang , Wen Gui-Hua
Published: December 2019

Constitution classification is the basis and core content of TCM constitution research. In order to improve the accuracy of constitution classification, this paper proposes a multilevel and multiscale features aggregation method within the convolutional neural network, which consists of four steps. First, it uses the pretrained VGG16 as the basic network and then refines the network structure through supervised feature learning so as to capture local image features. Second, it extracts the image features of different layers from the fine-tuned VGG16 model, which are then dimensionally reduced by principal component analysis (PCA). Third, it uses another pretrained NASNetMobile network for supervised feature learning, where the previous layer features of the global average pooling layer are outputted. Similarly, these features are dimensionally reduced by PCA and then are fused with the features of different layers in VGG16 after the PCA. Finally, all features are aggregated with the fully connected layers of the fine-tuned VGG16, and then the constitution classification is performed. The conducted experiments show that using the multilevel and multiscale feature aggregation is very effective in the constitution classification, and the accuracy on the test dataset reaches 69.61%.
CBR-Based Decision Support Methodology for Cybercrime Investigation: Focused on the Data-Driven Website Defacement Analysis
Authors: Han Mee Lan , Kwak Byung Il , Kim Huy Kang
Published: December 2019

Criminal profiling is a useful technique to identify the most plausible suspects based on the evidence discovered at the crime scene. Similar to offline criminal profiling, in-depth profiling for cybercrime investigation is useful in analysing cyberattacks and for speculating on the identities of the criminals. Every cybercrime committed by the same hacker or hacking group has unique traits such as attack purpose, attack methods, and target. These unique traits are revealed in the evidence of cybercrime; in some cases, these unique traits are well hidden in the evidence such that it cannot be easily perceived. Therefore, a complete analysis of several factors concerning cybercrime can provide an investigator with concrete evidence to attribute the attacks and narrow down the scope of the criminal data and grasp the criminals in the end. We herein propose a decision support methodology based on the case-based reasoning (CBR) for cybercrime investigation. This study focuses on the massive data-driven analysis of website defacement. Our primary aim in this study is to demonstrate the practicality of the proposed methodology as a proof of concept. The assessment of website defacement was performed through the similarity measure and the clustering processing in the reasoning engine based on the CBR. Our results show that the proposed methodology that focuses on the investigation enables a better understanding and interpretation of website defacement and assists in inferring the hacker’s behavioural traits from the available evidence concerning website defacement. The results of the case studies demonstrate that our proposed methodology is beneficial for understanding the behaviour and motivation of the hacker and that our proposed data-driven analytic methodology can be utilized as a decision support system for cybercrime investigation.
A Survey on True Random Number Generators Based on Chaos
Authors: Yu Fei , Li Lixiang , Tang Qiang , Cai Shuo , Song Yun , Xu Quan
Published: December 2019

With the rapid development of communication technology and the popularization of network, information security has been highly valued by all walks of life. Random numbers are used in many cryptographic protocols, key management, identity authentication, image encryption, and so on. True random numbers (TRNs) have better randomness and unpredictability in encryption and key than pseudorandom numbers (PRNs). Chaos has good features of sensitive dependence on initial conditions, randomness, periodicity, and reproduction. These demands coincide with the rise of TRNs generating approaches in chaos field. This survey paper intends to provide a systematic review of true random number generators (TRNGs) based on chaos. Firstly, the two kinds of popular chaotic systems for generating TRNs based on chaos, including continuous time chaotic system and discrete time chaotic system are introduced. The main approaches and challenges are exposed to help researchers decide which are the ones that best suit their needs and goals. Then, existing methods are reviewed, highlighting their contributions and their significance in the field. We also devote a part of the paper to review TRNGs based on current-mode chaos for this problem. Finally, quantitative results are given for the described methods in which they were evaluated, following up with a discussion of the results. At last, we point out a set of promising future works and draw our own conclusions about the state of the art of TRNGs based on chaos.
Increased Heart Rate Variability following Elective Percutaneous Coronary Intervention in Patients with Stable Coronary Artery Disease and Preprocedural Anxiety
Authors: Oktaramdani Tessa , Mudjaddid E. , Muhadi  , Shatri Hamzah
Published: December 2019

Background. There is a strong association between chronic ischemia and autonomic imbalance. Percutaneous coronary intervention (PCI) may restore autonomic balance in patients with stable coronary artery disease (SCAD), which is characterized by increased heart rate variability (HRV). Anxiety is often found in patients who are going to undergo invasive procedures and has been identified to induce autonomic imbalance. The aim of our study is to identify the impact of preprocedural anxiety on increased HRV following an elective PCI. Methods. Our study was a pretest and post-test correlation study involving 44 SCAD patients who underwent elective PCI at Cipto Mangunkusumo National Hospital. The HRV was measured before and after PCI. Anxiety symptoms were evaluated using Hospital Anxiety Depression Score (HADS) questionnaires. Results. We found a higher increase on HRV parameter following the PCI of subjects in the nonanxiety group compared with the anxiety group (median = 9.11 vs. 2.83; U = 154.00; p=0.043). Conclusions. Preprocedural anxiety may inhibit HRV increase following PCI procedure.
Prognostic Value of Oxidative Stress Markers in Patients with Pulmonary Arterial or Chronic Thromboembolic Pulmonary Hypertension
Authors: Smukowska-Gorynia Anna , Rzymski Piotr , Marcinkowska Justyna , Poniedziałek Barbara , Komosa Anna , Cieslewicz Artur , Slawek-Szmyt Sylwia , Janus Magdalena , Araszkiewicz Aleksander , Jankiewicz Stanislaw , Tomaszewska-Krajniak Iga , Mularek-Kubzdela Tatiana
Published: December 2019

Oxidative stress is regarded to play a crucial role in the pathophysiology of pulmonary arterial hypertension (PAH) and inoperable chronic thromboembolic pulmonary hypertension (CTEPH). This study evaluated the prognostic value of serum oxidative stress markers (malondialdehyde (MDA), total antioxidant capacity (TAC), catalase activity (CAT), and superoxide activity (SOD)) in patients with PAH and CTEPH (n=45). During 13 months of follow-up (median 9 months), clinical deterioration occurred in 14 patients (including 2 deaths). On the Cox regression analysis, MDA, TAC, and CAT were associated with clinical deterioration (p=0.0068,HR=1.42, 95% CI: 1.10-1.82;p=0.0038,HR=0.033, 95% CI: 0.0032-0.33; andp=0.046,HR=0.20, 95% CI: 0.04-0.98, respectively). There was no significant difference in SOD (p=0.53,HR=0.97, 95% CI: 0.87-1.08). The cut-off value derived from ROC curve analysis was 3.79 μM (p=0.0048,AUC=0.76, 95% CI: 0.62-0.91) for MDA, 0.49 mM (p=0.027,AUC=0.71, 95% CI: 0.18-0.47) for TAC, and 1.34 U/L (p=0.029,AUC=0.71, 95% CI: 0.55-0.86) for CAT. MDA in the group with deterioration was higher (p=0.0041), while TAC as well as CAT were lower (p=0.027andp=0.028, respectively) when compared to stable patients. Survival without clinical deterioration was significantly longer in patients with lower MDA (p=0.037,HR=0.37, 95% CI: 0.12-1.14, log-rank), higher TAC (p=0.0018,HR=0.19, 95% CI: 0.06-0.60, log-rank), and higher CAT (p=0.044,HR=0.3195% CI: 0.11-0.88, log-rank). Markers of oxidative stress such as MDA, TAC, and CAT were associated with adverse clinical outcomes in patients with PAH and inoperable or residual CTEPH.
Investigation of 23 Bile Acids in Liver Bile in Benign and Malignant Biliary Stenosis: A Pilot Study
Authors: Rejchrt Stanislav , Hroch Milos , Repak Rudolf , Fejfar Tomas , Douda Tomas , Kohoutova Darina , Peterova Eva , Bures Jan
Published: December 2019

Differential diagnosis between benign and malignant biliary stenosis can be difficult in clinical practice. Histology of biopsy specimens is often indeterminate. Laboratory markers (serum bilirubin>75 μmol/L, carbohydrate antigen 19-9>400 U/mL) and the length of stenosis (>15 mm) can be helpful but are not specific enough. The aim of this study was to investigate bile acids in liver bile of patients with benign and malignant biliary stenosis and controls without stenosis. A total of 73 patients entered the study: 7 subjects with benign biliary stenosis (6 men, 1 woman; 68±13 years old), 21 with malignant biliary stenosis (15 men, 6 women; 72±14 years old), and 45 patients without biliary stenosis (22 men, 23 women; 70±13 years old); out of those, 25 subjects have and 20 do not have choledocholithiasis. Twenty-three different bile acids were investigated by high-performance liquid chromatography/mass spectrometry. Serum total bilirubin was significantly higher in patients with malignant biliary stenosis compared with nonstenotic controls (p=0.005). Significant relationship (r>0.7) was found between several pairs of bile acids. Significantly lower bile acid concentrations in malignant biliary stenosis compared to controls without stenosis were found for GLCA (p=0.032), GUDCA (p=0.032), GCDCA (p=0.006), GDCA (p=0.031), GHCA (p=0.005), TUDCA (p=0.044), and TDCA (p=0.036). Significant difference in cholic acid was found between benign and malignant stenosis (p=0.022). Analysis of bile acids might be helpful in the differential diagnosis of malignant and benign biliary stenosis. More patients need to be enrolled in further studies so that the real diagnostic yield of bile acids can be determined.
Clinical Characteristics of 76 Patients with IgG4-Related Hypophysitis: A Systematic Literature Review
Authors: Li Yujuan , Gao Hua , Li Zhen , Zhang Xinxin , Ding Yizhi , Li Fengao
Published: December 2019

Background. IgG4-related hypophysitis (IgG4-RH) is a rare disease, and its prevalence remains unclear. In recent years, an increasing number of cases have been reported because of the increasing recognition of this disease. We aimed to summarize case reports of IgG4-RH and outline the clinical features and outcomes. Methods. We performed PubMed search of articles using the search terms “hypophysitis [AND] IgG4.” Consequently, only 54 English articles (76 cases) met Leporati’s diagnostic criteria. Results. Of the 76 cases, the ratio of men to women was 1.5 : 1, and the age at diagnosis was 54.1 ± 17.8 years. The median IgG4 concentration was 405.0 mg/dl. Anterior hypopituitarism, isolated central diabetes insipidus, and panhypopituitarism were observed in 14 (18.4%), 12 (15.8%), and 44 (57.9%) cases, respectively. The sequence of anterior hormone deficiency was as follows: gonadotropin (68.4%), ACTH (63.2%), TSH (59.2%), GH (48.7%), and prolactin (42.1%). The median number of involved organs was 1.5, and the lung (18.4%), retroperitoneum (17.1%), kidney (15.8%), submandibular glands (14.5%), and pancreas (13.2%) were the common involved organs. Elevated IgG4 concentration and normal IgG4 level were in 42 (76.4%) and 13 (23.6%) cases, respectively. Patients with elevated serum IgG4 concentration were older (60.9 ± 14.3 vs 45.6 ± 17.4, p=0.001) and male-prone (78.6% vs 40.4%, p=0.003) and had a susceptibility of multiple organ involvement (78.6% vs 35.0%, p=0.001) compared to those with normal serum IgG4 levels. Males were older at disease onset (61.5 ± 12.6 vs 42.9 ± 18.8, p<0.001) and had a higher IgG4 concentration (425.0 vs 152.5, p=0.029) and a greater number of involved organs (2.0 vs 0.0, p=0.001), while isolated hypophysitis was more prominent in female (63.3% vs 26.1%, p=0.001). Conclusion. In this review, we found that there were different characteristics between different genders. Patients with elevated serum IgG4 level in terms of some clinical features were also different from those with normal serum IgG4 level. However, the data in this review were limited by bias and confounding. Further clinical studies with larger sample sizes are warranted.