bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling induced polarization effects in helicopter time domain electromagnetic data: Synthetic case studies
Authors: Viezzoli Andrea , Kaminski Vladislav , Fiandaca Gianluca
Published: January 2017

We have developed a synthetic multiparametric modeling and inversion exercise undertaken to study the robustness of inverting airborne time-domain electromagnetic (TDEM) data to extract Cole-Cole parameters. The following issues were addressed: nonuniqueness, ill posedness, dependency on manual processing and the effect of constraints, and a priori information. We have used a 1D layered earth model approximation and lateral constraints. Synthetic simulations were performed for several models and the corresponding Cole-Cole parameters. The possibility to recover these models by means of laterally constrained multiparametric inversion was evaluated, including recovery of chargeability distributions from shallow and deep targets based on analysis of induced polarization (IP) effects, simulated in airborne TDEM data. Different scenarios were studied, including chargeable targets associated with the conductive and resistive environments. In particular, four generic models were considered for the exercise: a sulfide model, a kimberlite model, and two generic models focusing on the depth of investigation. Our study indicated that, in cases when relaxation time ([Formula: see text]) values are in the range to which the airborne electromagnetic is most sensitive (e.g., approximately 1 ms), it is possible to recover deep chargeable targets (to depths more than 130 m) in association with high electrical conductivity and in resistive environments. Furthermore, it was found that the recovery of a deep conductor, masked by a shallower chargeable target, became possible only when full Cole-Cole modeling was used in the inversion. Lateral constraints improved the recoverability of model parameters. Finally, modeling IP effects increased the accuracy of recovered electrical resistivity models.
Viscoelastic reverse time migration with attenuation compensation
Authors: Zhu Tieyuan , Sun Junzhe
Published: January 2017

We have developed a theory of viscoelastic reverse time migration (RTM). The main feature of viscoelastic RTM is a compensation for P- and S-wave attenuation effects in seismic images during migration. The forward modeling engine is based on a viscoelastic wave equation involving fractional Laplacians. Because of the decoupled attenuation property, wave propagation can be simulated in three scenarios, i.e., only the amplitude loss effect, only the phase dispersion effect, or both effects simultaneously. This separation brings practical flexibility to studying attenuation effects on wave propagation and imaging. The backward modeling operator is constructed by reversing the sign of first-order time derivative amplitude loss operators. Synthetic examples determine the ability of viscoelastic RTM to illuminate degraded areas and shadow zones caused by attenuation. Numerical experiments also reveal that [Formula: see text]-compensated imaging is noticeably more accurate in kinematics and dynamics than elastic imaging in the presence of high attenuation. Results from a synthetic 3D model determine the superiority of viscoelastic RTM over elastic RTM in imaging salt flanks and delineation of salt boundaries, which are dimmed in elastic images.
Predicting acoustic-wave velocities and fluid sensitivity to elastic properties in fractured carbonate formation
Authors: Xu Jingjing , Tan Maojin , Wang Xiaochang , Wu Chunping
Published: January 2017

Estimation of S-wave velocity is one of the most critical steps for prestack seismic inversion. Based on the petrophysical model of fractured carbonate rocks, theoretical methods are firstly investigated for estimating P- and S-wave velocities in the presence of fractures. Then, the methods of calculating elastic properties in fractured carbonate rocks are discussed. The mineral concentration, total porosity, and fracture porosity from core X-ray diffraction and routine core measurements or log interpretation results are used to estimate the P- and S-wave velocities. In the given carbonate rock model, the elastic properties of carbonate rocks with different porosity and fractures are calculated. Two field tests prove that the proposed new method is effective and accurate. Furthermore, the model is useful for fluid identification, which is one of the most outstanding problems for carbonate reservoir description. The simulation results suggest that the larger the fracture porosity is, the easier fluid typing. In Tahe Oilfield, the elastic properties of different fluid zones indicate that bulk modulus and Young’s modulus are more sensitive to fluid than shear modulus, the Lamé constant, and Poisson’s ratio.
Genetics of multiple endocrine neoplasia type 1 syndrome: what's new and what's old
Authors: Falchetti Alberto
Published: January 2017

Despite its identification in 1997, the functions of the MEN1 gene—the main gene underlying multiple endocrine neoplasia type 1 syndrome—are not yet fully understood. In addition, unlike the RET—MEN2 causative gene—no hot-spot mutational areas or genotype–phenotype correlations have been identified. More than 1,300 MEN1 gene mutations have been reported and are mostly "private” (family specific). Even when mutations are shared at an intra- or inter-familial level, the spectrum of clinical presentation is highly variable, even in identical twins. Despite these inherent limitations for genetic counseling, identifying MEN1 mutations in individual carriers offers them the opportunity to have lifelong clinical surveillance schemes aimed at revealing MEN1-associated tumors and lesions, dictates the timing and scope of surgical procedures, and facilitates specific mutation analysis of relatives to define presymptomatic carriers.
Supporting patients with type 1 diabetes
Authors: Phillips Anne
Published: January 2017

Patients with this autoimmune condition, and the health professionals who care for them, must be educated on ways to manage their condition, allowing them greater independence and lower the risk of complications. By Anne Phillips

Type 1 diabetes is an autoimmune condition that is mediated by genetic, immunological and environmental factors. Its prevalence is further complicated by increasing obesity levels, and this can make diagnosis complicated. Health professionals play a key role in enabling and optimising person-centred care approaches to educate and augment the essential skills required for successful self-management of this lifelong condition. This article reflects on the physiology and aetiology of type 1 diabetes and prevalence and considers recent guidance from the National Institute for Health and Care Excellence for adults with type 1 diabetes (NG17) and for children and young people with type 1 and type 2 diabetes (NG18).
Research Roundup
Authors: Winter George
Published: January 2017

George Winter provides an overview of recently published articles that may be of interest to practice nurses. Should you wish to look at any of the papers in more detail, a full reference is provided.
Personalised approaches for preventing asthma attacks
Authors: Marsh Viv
Published: January 2017

Asthma is still potentially lethal, despite deaths from the condition being largely avoidable. Viv Marsh explores how management could be improved by personalised care

It is poorly understood but asthma can be fatal. However most asthma deaths are avoidable. Avoidable factors relating to patients, health professionals and healthcare systems have been demonstrated. Recognition, identification and modification of avoidable factors could result in lives being saved.

This article will explore the risk factors for asthma death and discuss therapeutic approaches to help patients of all ages achieve asthma control and avoid asthma attacks.
Evaluation of the Effectiveness of a Patient Centered Educational Mailer Designed
to Improve Statin Adherence: A Pragmatic Trial
Authors: Nord John W. , Berry Alalia , Stults Barry , Burningham Zachary , Beddhu Srinivasan , Sauer Brian C.
Published: January 2017

Background: Patients with high total cholesterol have increased risk of
cardiovascular disease. National Cholesterol Education Program (NCEP) and American
Hearth Association (AHA) guidelines recommend cholesterol lowering with statin
medications; however, statin adherence remains poor. We hypothesized that
patient-centered education on the 10-year risk for each of the major constituents of
Cardiovascular Disease would increase statin adherence and achievement of low-density
lipoprotein cholesterol (LDL-C) goal.Methods: Veterans within the Salt Lake City
Veterans Affairs (VA) Medical Center initiating statin therapy during October 2008 to
December 2011 were randomized in a pragmatic design to either receive an educational
mailer or usual care. The mailer outlined their 10-year global cardiovascular risk,
separated into coronary heart disease, stroke, and congestive heart failure. The study
was unblinded and followed an intention-to-treat analysis where outcome measures were
obtained during normal care process. The primary outcome measure was achievement of
LDL-C goal during the 12-month follow-up.Results: Two hundred and seven patients were
randomly assigned to either the intervention arm (95) or control arm (112). No
differences in the proportion of patients meeting LDL-C goal were detected during
12-months [Relative Risk (RR): 0.95 (95%CI: 0.77-1.17)] or 18-months [RR: 1.03 (95%CI:
0.84, 1.25)]. Patients in the intervention arm had higher adherence on average, e.g.,
intervention patients were more likely to have 70% or more days of statin therapy
compared to patients who received standard care though this did not reach statistical
significance. [RR: 1.33(95%CI: 1.00, 1.78)] There were no statistical differences in
cardiovascular outcomes or mortality.Conclusion: Patient education mailers sent to
patients starting statin treatment did not have a clear impact on LDL-C goal achievement
or adherence to statin therapy.
Ursodeoxycholic acid in neonatal sepsis-associated cholestasis
Authors: Rina Rita Mey , Oswari Hanifah , Amalia Pustika
Published: January 2017

Background Sepsis-associated cholestasis (SAC) is an intrahepatic cholestasis caused by inflammatory cytokines. Patients with this condition have poor prognoses. Antibiotics are the mainstay of therapy, however, other adjuvant therapies, such as ursodeoxycholic acid (UDCA), have not been well established.Objective To assess the effect ofUDCA for treatment ofneonatal sepsis-associated cholestasis.Methods We performed a randomized, double-blind, controlled trial in 3 7 neonates who were diagnosed with sepsis-associated cholestasis in the Neonatal Care Unit of Cipto Mangunkusumo Hospital. Subjects were divided into two groups, with 19 neonates randomly allocated to the intervention group (received UDCA at 30 tngikg/day divided into 3 doses for 7 days) and 18 neonates to the control group (received placebo) . After 7 days of treatment, we evaluated the subjects' liver function parameters and performed asurvival analysis.Results Liver function parameter improvements at day 7 were not significantly different between the UDCA group and the control group, including for mean decrease of total bilirubin (TB) levels [2.2 (SD 2.9) mg/dL vs 1.7 (SD 4.6) mg/dL; P=0.080), mean decrease of direct bilirubin (DB) levels [1.1 (SD 2.3) mg/dL vs 0.6 (SD 3.6) mg/dL; P=0.080), median indirect bilirubin (lB) levels [0.4 (range 0.1- 5.6) mg/dL vs 0.9 (range 0.1-4.1) mg/dL; P=0.358) , mean decrease of alanine aminotransferase (ALT) levels [0.5 (-80.0 -21.0) U/L vs -2.0 (ranged -167 .0 - 85.0) U/L; P= 0.730), median aspartate aminotransferase (AST) levels [ 43 .0 (range 14.0-297 .0) U/L vs 150.0 (range 24.0-840.0) U/L; P=0.081), and median gamma-glutamyl transpeptidase (GGf) levels [125.0 (48.0-481.0) U/L vs 235.0 (56.0-456.0) U/L; P=0.108)). Five neonates in control group died compared to two in the UDCA group (P=0.232). In addition, UDCA did not significantly lengthen the survival time (hazard ratio/HR 3.62; 95%CI 0.69 to 18.77) .Conclusion Ursodeoxycholic acid tends to improve total bilirubin, direct bilirubin, and AST levels in sepsis associated cholestasis .
Risk factors for neonatal mortality at Moewardi Hospital, Surakarta
Authors: Hidayah Dwi , Hafidh Yulidar
Published: January 2017

Background Neonatal mortality remains a major concern indeveloping countries. Identifying potential risk factors is importantin order to decrease the neonatal mortality rate. In MoewardiHospital, Surakarta, the risk factors for neonatal mortality havenot been assessed.Objective To evaluate potential risk factors of n eonatalmortality.Methods We reviewed medical records of all neonates hospitalizedin the neonatal intensive care unit (NICU) at Dr. MoewardiHospital from January to December 2011. Analyzed variables weresex, birth weight, gestational age, maternal age, place of delivery,mode of delivery, and sepsis. Data were analyzed by Chi square andbinary logistic regression with 95% confidence intervals (CI).Results Out of841 neonates, the mortality rate was 212 (25.2%).Univariate logistic regression revealed that the significant riskfactors for neonatal mortality were preterm (OR 4.41 ; 95%CI4.24 to 4.57; P=0.0001) , low bir th weight (OR 4.30; 95%CI4.13 to 4.47; P=0.0001), sepsis (OR 2.99; 95%CI 2.81 to 3.17;P=0.0001), maternal age 2:35 years (OR 1.53; 95%CI 1.37 to1.70), and non-spontaneous delivery (OR 1.67; 95%CI 1.50 to1.84). Further multivariate regression analysis revealed that thesignificant risk factors were preterm (OR 2.2 7; 95%CI 2.05 to 2.48;P=0.0001), low birth weight (OR 2.49; 95%CI 2.27 to 2.71; P=0.0001), and sepsis (OR 2.50; 95%CI 2.30 to 2.69; P= 0.0001).Conclusion The risk factors for neonatal mortality in the NICUare preterm, low birth weight, and sepsis.
Agreement between the Denver II and Parents’ Evaluation of Developmental Status tests, with and without the assistance of a table of categorical responses
Authors: Priambodo Arief , Dhamayanti Meita , Fadlyana Eddy
Published: January 2017

Background Among standardized developmental screening tools, the Denver II is commonly used by Indonesian pediatricians, but the Parent’s Evaluation of Developmental Status (PEDS) test has gained in popularity. The Denver II test is filled by physicians, while the PEDS test is meant to be filled by parents. From a practical standpoint, however, parents often require assistance from doctors when filling out the PEDS forms. Hence, the advantage of the PEDS test over the Denver II test is not fully realized.Objective To compare the agreement between Denver II and PEDS tests, with and without parental use of a table of categorical responses taken from the PEDS manual.Methods We conducted a cross-sectional study in children aged 6 months to 5 years in Bandung from November 2015 to March 2016. Subjects were divided into two groups using block randomization. One group of subjects’ parents filled the PEDS questionnaires with the assistance of a table of categorical responses taken from the PEDS manual, while the other group of subjects’ parents filled PEDS forms without this table. All subjects underwent Denver II screening by pediatricans. The agreement between the PEDS and Denver II results were assessed by Kappa score.Results Of 254 children, 239 were analyzed. Kappa scores between the Denver II and PEDS tests were 0.05 (95%CI: -0.10 to 0.20) without the table of categorical responses, and -0.06 (-0.23 to 0.10) with the table of categorical responses.Conclusion Agreement between the Denver II and PEDS tests is poor. The table of categorical responses does not increase the agreement between Denver II and PEDS.
Iron profiles of preterm infants at two months of chronological age
Authors: Puspitasari Henny Adriani , Windiastuti Endang , Hendarto Aryono
Published: January 2017

Background Preterm infants are vulnerable to iron deficiency (ID) due to lack of maternal iron stores, repeated phlebotomy, and the body’s increased demand for iron during growth. The risk of ID increases at 2 months of age, when hemoglobin (Hb) levels start to decrease. Adequacy of body iron level is assessed by ferritin, serum iron (SI), transferrin saturation (Tfsat), total iron-binding capacity (TIBC), and Hb measurements.Objective To describe iron profiles in preterm infants at 2 months of chronological age (CA).Methods This cross-sectional study was conducted in 2-month-old infants, born at 32-36 weeks of gestational age, and who visited the Growth and Development Clinics at Cipto Mangunkusumo, Fatmawati, or Budi Kemuliaan Hospitals. Parental interviews and medical record reviews were done during the clinic visits. Complete blood count, blood smear, SI, TIBC, Tfsat, and ferritin level tests were performed.Results Eighty-three subjects were enrolled in this study. Most subjects were male (51%) and born to mothers >20 years of age (93%). Subjects’ birth weights ranged from 1,180 g to 2,550 g. The prevalence of iron deficiency anemia (IDA) was 6% and that of ID was 10%. The lowest Hb level found in IDA infants was 6.8 g/dL, while the lowest ferritin level was 8.6 ng/mL. Median values for the other tests were as follows: SI 48 µg/dL, TIBC 329µg/dL, and Tfsat 17%. Subjects with IDA were all male (5/5), mostly achieved more than twice their birth weight (4/5), were non-iron supplemented (3/5), born to mothers with low educational background (3/5), and of low socioeconomic status (3/5).Conclusion The prevalence of IDA is 6% and that of ID is 10%. Most subjects with ID and IDA have low SI, high TIBC, low Tfsat, and low ferritin level. Most of the all-male IDA subjects weigh more than twice their birth weight, are non-iron supplemented, and born to mothers with low educational background and low socioeconomic status.
Nutritional status of infants with cow's milk allergy who consume breast milk vs. hypoallergenic formula
Authors: Safri Mulya , Putra Aulia Rahman , Mulya Vidya Chatmayani
Published: January 2017

Background Infants with CMA are prone to suffer malnutrition because of the inability to absorb nutrients due to bowel inflammation. Breast milk and hypoallergenic formula is the best nutritional intake in CMA infants.Objective To compare the nutritional status of CMA infants who were consumed breast milk and hypoallergenic milk.Methods We conducted a cross-sectional study included a total of 63 CMA infants aged 3-6 months collected by consecutive sampling. Infant’s nutritional status measured by anthropometric exam were divided into well-nourished (-2 to 2 SD) or malnourished (<-2 or >2 SD). Type of milk consumption were asked directly to parents/caregivers through interviews.Results Most of our subject are well-nourished (75%). The number of CMA infants who were consumed breast milk or hypoallergenik milk is not a lot of difference, 51% vs 49%, respectively. There is no significant difference between the nutritional status of CMA infants who consumed breast milk and hypoallergenic milk (P=0.61).Conclusion because there were no differences between the nutritional status of CMA infants who consumed breast milk and hypoallergenic milk. Therefore it is recommended giving breast milk or hypoallergenic milk for the first 6 months of life to reduce cow’s milk protein exposure.
Scoring system to distinguish between rotavirus and non-rotavirus diarrhea in children
Authors: Akbari Atika , Salwan Hasri , Bakri Achirul , Bahar Erial
Published: January 2017

Background Distinguishing rotavirus from non-rotavirus diarrhea is helpful for managing the illness. However, definitively diagnosing rotavirus diarrhea from serology is difficult and expensive.Objectives To distinguish between the clinical manifestations of rotavirus and non-rotavirus diarrhea, and to assess the accuracy of using such clinical manifestations to predict the type of diarrhea in children.Methods A cross-sectional study was performed from April to October 2015 in all children less than five years of age who presented with acute diarrhea at the Pediatric Outpatient Clinic of the Department of Child Health and Emergency Department, Dr. Mohammad Hoesin and Bari Hospitals, Palembang, South Sumatera. Clinical manifestations were collected from history and physical examinations; stool specimens were examined by immunochromatography. Clinical parameters were analyzed by multivariate analysis, and scores given to each significant parameter. The accuracy of the scoring system based in these parameters was analyzed by means of receiver-operating characteristic (ROC) area under the curve (AUC).Results Of 184 children, 92 had rotavirus and 92 had non-rotavirus diarrhea. Multivariate analysis showed 3 clinical parameters commonly seen in the rotavirus diarrhea cases: male sex (OR 2.718; 95%CI 1.373 to 5.382), cough (OR 3.500; 95%CI 1.788 to 6.582), and yellow-greenish stool (OR 4.009; 95%CI 2.061 to 7.797). A scoring system was constructed based on the parameters: male (score of 1), cough (score of 2), and yellow-greenish stool (score of 3). From ROC analysis, the AUC was 0.755. Using a cut-off score of > 3, the sensitivity was 81.5%, specificity 51.1%, and PPV 62.5%.Conclusion Cough, yellow-greenish stool, and male are significant parameters for differentiating rotavirus from non-rotavirus diarrhea. A scoring system from these parameters is sensitive for predicting rotavirus vs. non-rotavirus diarrhea in children less than five years of age.
Thermal properties of cubic zincblende thallium-phosphide from quasi-harmonic Debye model approximation
Authors: Daoud Salah
Published: January 2017

The thermal properties of cubic zincblende (B3) thallium - phosphide (TlP) compound under high pressure up to 12 GPa have been studied using the quasi-harmonic Debye model approximation. The relative unit cell volume, the isothermal bulk modulus, the first order derivative isothermal bulk modulus, the Debye temperature and the GrÃ¼neisen parameter are studied at zero-temperature and at standard ambient temperature (298 K) respectively. Our obtained values of the different previous quantities are in general in agreement compared to other theoretical data of the literature.
Remember where you came from
Authors: Wu Yubao , Bian Yuchen , Zhang Xiang
Published: January 2017

Measuring the proximity between different nodes is a fundamental problem in graph analysis. Random walk based proximity measures have been shown to be effective and widely used. Most existing random walk measures are based on the first-order Markov model, i.e., they assume that the next step of the random surfer only depends on the current node. However, this assumption neither holds in many real-life applications nor captures the clustering structure in the graph. To address the limitation of the existing first-order measures, in this paper, we study the second-order random walk measures, which take the previously visited node into consideration. While the existing first-order measures are built on node-to-node transition probabilities, in the second-order random walk, we need to consider the edge-to-edge transition probabilities. Using incidence matrices, we develop simple and elegant matrix representations for the second-order proximity measures. A desirable property of the developed measures is that they degenerate to their original first-order forms when the effect of the previous step is zero. We further develop Monte Carlo methods to efficiently compute the second-order measures and provide theoretical performance guarantees. Experimental results show that in a variety of applications, the second-order measures can dramatically improve the performance compared to their first-order counterparts.
Adaptive NUMA-aware data placement and task scheduling for analytical workloads in main-memory column-stores
Authors: Psaroudakis Iraklis , Scheuer Tobias , May Norman , Sellami Abdelkader , Ailamaki Anastasia
Published: January 2017

Non-uniform memory access (NUMA) architectures pose numerous performance challenges for main-memory column-stores in scaling up analytics on modern multi-socket multi-core servers. A NUMA-aware execution engine needs a strategy for data placement and task scheduling that prefers fast local memory accesses over remote memory accesses, and avoids an imbalance of resource utilization, both CPU and memory bandwidth, across sockets. State-of-the-art systems typically use a static strategy that always partitions data across sockets, and always allows inter-socket task stealing.

In this paper, we show that adapting data placement and task stealing to the workload can improve throughput by up to a factor of 4 compared to a static approach. We focus on highly concurrent workloads dominated by operators working on a single table or table group (copartitioned tables). Our adaptive data placement algorithm tracks the resource utilization of tasks, partitions of tables and table groups, and sockets. When a utilization imbalance across sockets is detected, the algorithm corrects it by moving or repartitioning tables. Also, inter-socket task stealing is dynamically disabled for memory-intensive tasks that could otherwise hurt performance.
Effective indexing for approximate constrained shortest path queries on large road networks
Authors: Wang Sibo , Xiao Xiaokui , Yang Yin , Lin Wenqing
Published: January 2017

In a
constrained shortest path (CSP)
query, each edge in the road network is associated with both a length and a cost. Given an origin
s
, a destination
t
, and a cost constraint
θ
, the goal is to find the shortest path from
s
to
t
whose total cost does not exceed
θ
. Because exact CSP is NP-hard, previous work mostly focuses on approximate solutions. Even so, existing methods are still prohibitively expensive for large road networks. Two main reasons are (i) that they fail to utilize the special properties of road networks and (ii) that most of them process queries without indices; the few existing indices consume large amounts of memory and yet have limited effectiveness in reducing query costs.

Motivated by this, we propose
COLA
, the first practical solution for approximate CSP processing on large road networks.
COLA
exploits the facts that a road network can be effectively partitioned, and that there exists a relatively small set of landmark vertices that commonly appear in CSP results. Accordingly,
COLA
indexes the vertices lying on partition boundaries, and applies an on-the-fly algorthm called
α
-
Dijk
for path computation within a partition, which effectively prunes paths based on landmarks. Extensive experiments demonstrate that on continent-sized road networks,
COLA
answers an approximate CSP query in sub-second time, whereas existing methods take hours. Interestingly, even without an index, the
α-Dijk
algorithm in
COLA
still outperforms previous solutions by more than an order of magnitude.
Sapprox
Authors: Zhang Xuhong , Wang Jun , Yin Jiangling
Published: January 2017

In this paper, we aim to enable both efficient and accurate approximations on arbitrary sub-datasets of a large dataset. Due to the prohibitive storage overhead of caching offline samples for each sub-dataset, existing offline sample based systems provide high accuracy results for only a limited number of sub-datasets, such as the popular ones. On the other hand, current online sample based approximation systems, which generate samples at runtime, do not take into account the uneven storage distribution of a sub-dataset. They work well for uniform distribution of a sub-dataset while suffer low sampling efficiency and poor estimation accuracy on unevenly distributed sub-datasets.

To address the problem, we develop a distribution aware method calledSapprox. Our idea is to collect the occurrences of a sub-dataset at each logical partition of a dataset (storage distribution) in the distributed system, and make good use of such information to facilitate online sampling. There are three thrusts in Sapprox. First, we develop a probabilistic map to reduce the exponential number of recorded sub-datasets to a linear one. Second, we apply thecluster sampling with unequal probability theoryto implement a distribution-aware sampling method for efficient online sub-dataset sampling. Third, we quantitatively derive the optimal sampling unit size in a distributed file system by associating it with approximation costs and accuracy. We have implemented Sapprox into Hadoop ecosystem as an example system and open sourced it on GitHub. Our comprehensive experimental results show that Sapprox can achieve a speedup by up to 20× over the precise execution.
Finding persistent items in data streams
Authors: Dai Haipeng , Shahzad Muhammad , Liu Alex X. , Zhong Yuankun
Published: January 2017

Frequent item mining, which deals with finding items that occur frequently in a given data stream over a period of time, is one of the heavily studied problems in data stream mining. A generalized version of frequent item mining is the persistent item mining, where a persistent item, unlike a frequent item, does not necessarily occur more frequently compared to other items over a short period of time, rather
persists
and occurs more frequently over a long period of time. To the best of our knowledge, there is no prior work on mining persistent items in a data stream. In this paper, we address the fundamental problem of finding persistent items in a given data stream during a given period of time at any given observation point. We propose a novel scheme, PIE, that can accurately identify each persistent item with a probability greater than any desired false negative rate (FNR) while using a very small amount of memory. The key idea of PIE is that it uses Raptor codes to encode the ID of each item that appears at the observation point during a measurement period and stores only a few bits of the encoded ID in the memory of that observation point during that measurement period. The item that is persistent occurs in enough measurement periods that enough encoded bits for the ID can be retrieved from the observation point to decode them correctly and get the ID of the persistent item. We implemented and extensively evaluated PIE using three real network traffic traces and compared its performance with two prior adapted schemes. Our results show that not only PIE achieves the desired FNR in every scenario, its FNR, on average, is 19.5 times smaller than the FNR of the best adapted prior art.
VIP-Tree
Authors: Shao Zhou , Cheema Muhammad Aamir , Taniar David , Lu Hua
Published: January 2017

Due to the growing popularity of indoor location-based services, indoor data management has received significant research attention in the past few years. However, we observe that the existing indexing and query processing techniques for the indoor space do not fully exploit the properties of the indoor space. Consequently, they provide below par performance which makes them unsuitable for large indoor venues with high query workloads. In this paper, we propose two novel indexes called Indoor Partitioning Tree (IP-Tree) and Vivid IP-Tree (VIP-Tree) that are carefully designed by utilizing the properties of indoor venues. The proposed indexes are lightweight, have small pre-processing cost and provide near-optimal performance for shortest distance and shortest path queries. We also present efficient algorithms for other spatial queries such asknearest neighbors queries and range queries. Our extensive experimental study on real and synthetic data sets demonstrates that our proposed indexes outperform the existing algorithms by several orders of magnitude.
Lifting the haze off the cloud
Authors: Wang Yue , Meliou Alexandra , Miklau Gerome
Published: January 2017

The availability of public computing resources in the cloud has revolutionized data analysis, but requesting cloud resources often involves complex decisions for consumers. Estimating the completion time and cost of a computation and requesting the appropriate cloud resources are challenging tasks even for an expert user. We propose a new market-based framework for pricing computational tasks in the cloud. Our framework introduces an
agent
between consumers and cloud providers. The agent takes data and computational tasks from users, estimates time and cost for evaluating the tasks, and returns to consumers
contracts
that specify the price and completion time. Our framework can be applied directly to existing cloud markets without altering the way cloud providers offer and price services. In addition, it simplifies cloud use for consumers by allowing them to compare contracts, rather than choose resources directly. We present design, analytical, and algorithmic contributions focusing on pricing computation contracts, analyzing their properties, and optimizing them in complex workflows. We conduct an experimental evaluation of our market framework over a real-world cloud service and demonstrate empirically that our market ensures three key properties: (a) that consumers benefit from using the market due to competitiveness among agents, (b) that agents have an incentive to price contracts fairly, and (c) that inaccuracies in estimates do not pose a significant risk to agents' profits. Finally, we present a fine-grained pricing mechanism for complex workflows and show that it can increase agent profits by more than an order of magnitude in some cases.
Skipping-oriented partitioning for columnar layouts
Authors: Sun Liwen , Franklin Michael J. , Wang Jiannan , Wu Eugene
Published: January 2017

As data volumes continue to grow, modern database systems increasingly rely on data skipping mechanisms to improve performance by avoiding access to irrelevant data. Recent work [39] proposed a fine-grained partitioning scheme that was shown to improve the opportunities for data skipping in row-oriented systems. Modern analytics and big data systems increasingly adopt columnar storage schemes, and in such systems, a row-based approach misses important opportunities for further improving data skipping. The flexibility of column-oriented organizations, however, comes with the additional cost of tuple reconstruction. In this paper, we develop Generalized Skipping-Oriented Partitioning (GSOP), a novel hybrid data skipping framework that takes into account these row-based and column-based tradeoffs. In contrast to previous column-oriented physical design work, GSOP considers the tradeoffs between horizontal data skipping and vertical partitioning jointly. Our experiments using two public benchmarks and a real-world workload show that GSOP can significantly reduce the amount of data scanned and improve end-to-end query response times over the state-of-the- art techniques.
Clay
Authors: Serafini Marco , Taft Rebecca , Elmore Aaron J. , Pavlo Andrew , Aboulnaga Ashraf , Stonebraker Michael
Published: January 2017

Transaction processing database management systems (DBMSs) are critical for today's data-intensive applications because they enable an organization to quickly ingest and query new information. Many of these applications exceed the capabilities of a single server, and thus their database has to be deployed in a distributed DBMS. The key factor affecting such a system's performance is how the database is partitioned. If the database is partitioned incorrectly, the number of distributed transactions can be high. These transactions have to synchronize their operations over the network, which is considerably slower and leads to poor performance. Previous work on elastic database repartitioning has focused on a certain class of applications whose database schema can be represented in a hierarchical tree structure. But many applications cannot be partitioned in this manner, and thus are subject to distributed transactions that impede their performance and scalability.

In this paper, we present a new on-line partitioning approach, called Clay, that supports both tree-based schemas and more complex "general" schemas with arbitrary foreign key relationships. Clay dynamically creates blocks of tuples to migrate among servers during repartitioning, placing no constraints on the schema but taking care to balance load and reduce the amount of data migrated. Clay achieves this goal by including in each block a set of hot tuples and other tuples co-accessed with these hot tuples. To evaluate our approach, we integrate Clay in a distributed, main-memory DBMS and show that it can generate partitioning schemes that enable the system to achieve up to 15× better throughput and 99% lower latency than existing approaches.
Integrated Cloud-Based Services for Medical Workflow Systems
Authors: Gharbi Nada , Kirikova Mārīte , Bouzguenda Lotfi
Published: January 2017

Recent years have witnessed significant progress of workflow systems in different business areas. However, in the medical domain, the workflow systems are comparatively scarcely researched. In the medical domain, the workflows are as important as in other areas. In fact, the flow of information in the healthcare industry is even more critical than it is in other industries. Workflow can provide a new way of looking at how processes and procedures are completed in particular medical systems, and it can help improve the decision-making in these systems. Despite potential capabilities of workflow systems, medical systems still often perceive critical challenges in maintaining patient medical information that results in the difficulties in accessing patient data by different systems. In this paper, a new cloud-based service-oriented architecture is proposed. This architecture will support a medical workflow system integrated with cloud services aligned with medical standards to improve the healthcare system.
Simulation of Rock Mass Horizontal Displacements with Usage of Cellular Automata Theory.
Authors: Sikora Paweł
Published: January 2017

In the article there was presented two dimensional rock mass model as a deterministic finite cellular automata. Used to describe the distribution of subsidence of rock mass inside and on its surface the theory of automata makes it relatively simple way to get a subsidence trough profile consistent with the profile observed by geodetic measurements on the land surface. As a development of an existing concept of the rock mass model, as a finite cellular automaton, there was described distribution function that allows, simultaneously with the simulation of subsidence, to simulate horizontal displacements inside the rock mass model and on its surface in accordance with real observations. On the basis of the results of numerous computer simulations there was presented fundamental mathematical relationship that determines the ratio of maximum horizontal displacement and maximum subsidence, in case of full subsidence trough, in relation to the basic parameters of the rock mass model. The possibilities of presented model were shown on the example of simulation results of deformation distribution caused by extraction of abstract coal panel. Obtained results were consistent with results obtained by geometric-integral theory.
New Analytical Approaches for Evaluating the Performance of Systematic Pre-Tensioned Fully Grouted Rockbolts in Tunnel Stabilization
Authors: Ranjbarnia Masoud , Fahimifar Ahmad , Oreste Pierpaolo
Published: January 2017

In this paper, two new analytical approaches are presented on the basis of convergence-confinement method to compute both the ultimate convergence of circular tunnel and its plastic zone having been reinforced by systematically pre-tensioned fully grouted rockbolts. The models have two basic assumptions: (1) the grouted rockbolts increase the radial internal pressure within a broken rock mass by both the pre-tensioned force and the probable following induced force due to rock mass movement (2) tunnel convergence (specially short-term) occurs only due to reducing and diminishing of the radial constrained stress on tunnel surface provided by the working face. Hence, the values of both the pre-tensioned pressure and the mentioned radial constrained stress are specially taken into consideration in this paper. That is, according to their magnitudes, two different conditions occur: the magnitude of pre-tensioned pressure is greater than that of the constrained stress at bolt installation time and vice versa. The solutions are extended to each of conditions, and illustrative examples are solved. The proposed approaches predicting almost identical results show that pre-tensioning of grouted rockbolts will increase the efficiency and effectiveness of rockbolts.
Proposal of Economic Assessment of Hard Coal Mines Operation Conducted in Polish Conditions with the Use of Cost Benefit Analysis
Authors: Krawczyk Piotr , Majer Marzena , Krzemień Joanna
Published: January 2017

The paper presents possibilities of an economic evaluation of hard coal mines, using Cost Benefit Analysis (CBA). Suggested methodology for CBA applied to the economic evaluation of a mine allows to conduct a complex evaluation of mine’s functionality in connection to Polish conditions. Additionally to financial aspects, significant from the point of view of the mine’s owner, the paper includes social and environmental effects as a result of mining activities. Proposed methodology has undergone tests which used averaged data obtained from two selected hard coal mines located in the Upper Silesian Coal Basin. Presented results confirm the validity of social costs and benefits, and environmental losses resulting from mining operation, which were included in analysis comprehensively evaluating the efficiency of hard coal mines.
Visualizing EFL teacher identity (re)construction in materials design and implementation
Authors: de Laurentiis Brandão Ana Carolina
Published: January 2017

This study visually explores the process of identity (re)construction experienced by a pre-service EFL teacher as she designed and implemented English activities at Brazilian state schools. The theoretical framework draws from language teacher development, and narrative concepts on professional identity, teacher knowledge and context. Visual narratives, contextualized by written and oral narratives, are analysed for their holistic-content, taking into account a critical visual approach and a narrative inquiry methodology. The pre-service EFL teacher, whose experience is the focus of this paper, developed a metaphor to describe her process of identity (re)construction: the invisible English teacher. Stories of designing and implementing her own materials, and being part of different teaching landscapes play an important role in her search for visibility as an English teacher.
What Extent of Welfare Loss is Caused by the Disparity between Perceived and Scientific Risks? A Case Study of Food Irradiation
Authors: Watanabe Masahide , Kawata Yukichika
Published: January 2017

An individual perceived risk often differs from an objective risk based on the scientific evidence; risks about nuclear power generation and food technology including genetic modification and food irradiation are typical such cases. However, the extent to which welfare loss is caused by the disparity between perceived and scientific risks is unclear. Based on this gap in the literature, we conduct a discrete choice experiment to estimate the welfare loss. At the same time, we must tackle two issues arising in the estimation: endogeneity and ambiguity in the perceived risk. We construct an empirical model based on maxmin expected utility to consider ambiguity and apply a control function approach to alleviate endogeneity bias. The results show that 1) the disparity between perceived and scientific risks causes a significant welfare loss; 2) the ambiguity in the perceived risk exacerbates the welfare loss; and 3) endogeneity largely biases welfare measurement.
On the Topics and Style of Soviet Animated Films
Authors: Pikkov Ülo
Published: January 2017

This article provides a survey of Soviet animation and analyses the thematic and stylistic course of its development. Soviet animated film emerged and materialised in synch with the fluctuations of the region’s political climate and was directly shaped by it. A number of trends and currents of Soviet animation also pertain to other Eastern European countries. After all, Eastern Europe constituted an integrated cultural space that functioned as a single market for the films produced across it by filmmakers who interacted in a professional regional network of film education, events, festivals, publications etc.

Initially experimental, post-revolutionary Russian animation soon fell under the sway of the Socialist Realist discourse, along with the rest of Soviet art, and quickly crystallised as a didactic genre for children. Disney’s paradigm became its major source of inspiration both in terms of visual style and thematic scope, despite the fact that Soviet Union was regarded as the ideological opposite of the Western way of life and mindset. The Soviet animation industry was spread across different studios and republics that adopted slightly varied production practices and tolerated different degrees of artistic freedom. Studios in the smaller republics, such as Estonia, Latvia and Lithuania in particular, stood out for making films that were more ideologically complicated than those produced in Moscow.
Alternative Networks of Globalisation: Latvian Neorealism in the Films of Laila Pakalniņa
Authors: Brūveris Klāra
Published: January 2017

This paper examines the development of neorealist tendencies in the oeuvre of contemporary Latvian filmmaker Laila Pakalnina. Her work is positioned within the global dissemination of cinematic neorealism, and its local manifestations, which, it is argued, develop in specific national contexts in reaction to dramatic societal and political changes. Pakalniņa’s films are examined as a documentation of the change from a communist satellite state to an independent democratic, capitalist country. Heavily influenced by the Riga School of Poetic Documentary, a movement in Latvian cinema that adhered to the conventions of poetic documentary filmmaking, the article analyses how her films replicate and further develop the stylistic and aesthetic devices of the Italian neorealists and the succeeding cinematic new waves. In doing so the argument is put forth that Pakalnina has developed neorealism Latvian style.
‘All the Necessary Information is Provided by Russia’s Channels’. Russian-language Radio and TV in Latvia: Audiences and Content
Authors: Rozukalne Anda
Published: January 2017

After the Maidan events in Kiev and the annexation of Crimea in March 2014, discussions in Latvia expanded regarding the extent to which the Russian-speaking population in Latvia, whose daily information is obtained mainly from Russia’s TV channels, can get well-balanced and objective information. Opinion polls showed that a large proportion (41%) of the non-Latvians supported the annexation of Crimea and Russia’s President Vladimir Putin’s policy (SKDS 2014a). The aim of this article is to analyse the structure of the audiovisual media in the Russian language and media usage habits of the Russian-speaking audience using secondary and primary data. And thereby assess whether diversified information is available in the Russian language to this societal group. The research results show that the Russian-speaking population in Latvia does not feel a need for additional information channels, because they believe that the variety of information obtained from Russia’s TV and radio channels is sufficient.