bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond Completion Rate: Evaluating the Passing Ability of Footballers
Authors: Szczepański Łukasz , McHale Ian
Published: April 2015

Passing the ball is one of the key skills of a football player yet the metrics commonly used to evaluate passing ability are crude and largely limited to various forms of a pass completion rate. These metrics can be misleading for two general reasons: they do not account for the difficulty of the attempted pass nor the various levels of uncertainty involved in empirical observations based on different numbers of passes per player. We address both these deficiencies by building a statistical model in which the success of a pass depends on the skill of the executing player as well as other factors including the origin and destination of the pass, the skill of his teammates and the opponents, and proxies for the defensive pressure put on the executing player as well as random chance. We fit the model by using data from the 2006–2007 season of the English Premier League provided by Opta, estimate each player's passing skill and make predictions for the next season. The model predictions considerably outperform a naive method of simply using the previous season's completion rate as a predictor of the following season's completion rate. In particular, we show how a change in the difficulty of passes attempted in both seasons explains a significant proportion of the shift in the observed performance of some players—a fact that is ignored if the raw completion rate is used to evaluate player skill.
Modelling the Type and Timing of Consecutive Events: Application to Predicting Preterm Birth in Repeated Pregnancies
Authors: Shih Joanna H. , Albert Paul S. , Mendola Pauline , Grantz Katherine L.
Published: April 2015

Predicting the occurrence and timing of adverse pregnancy events such as preterm birth is an important analytical challenge in obstetrical practice. Developing statistical approaches that can be used to assess the risk and timing of these adverse events will provide clinicians with tools for individualized risk assessment that account for a woman's prior pregnancy history. Often adverse pregnancy outcomes are subject to competing events; for example, interest may focus on the occurrence of pre-eclampsia-related preterm birth, where preterm birth for other reasons may serve as a competing event. We propose modelling the type and timing of adverse outcomes in repeated pregnancies. We formulate a joint model, where types of adverse outcomes across repeated pregnancies are modelled by using a polychotomous logistic regression model with random effects, and gestational ages at delivery are modelled conditionally on the types of adverse outcome. The correlation between gestational ages conditional on the adverse pregnancies is modelled by the semiparametric normal copula function. We present a two-stage estimation method and develop the asymptotic theory for the estimators proposed. The model and estimation procedure proposed are applied to the National Institute of Child Health and Human Development consecutive pregnancies study data and evaluated by simulations.
Diagnosis, pathophysiology and management of premenstrual syndrome
Authors: Walsh Sally , Ismaili Elgerta , Naheed Bushra , O'Brien Shaugn
Published: April 2015

Key content

An overview of current information available on premenstrual syndrome (PMS), which is in accordance with the new RCOG Green‐top Guideline.

Definition of PMS and explanation about the different types of premenstrual disorders.

How to accurately diagnose PMS.

Discussion about various treatment options available in accordance with the current literature.

Learning objectives

Develop an understanding of the pathophysiology behind PMS.

How to diagnose PMS accurately and understand the different classifications of PMS.

How to treat PMS, including the different treatment options available and discussion about side effects and benefits.

Ethical issues

Discussion about the long‐term risks of GnRH analogue use, and the impact of long‐term estrogen deficiency following a bilateral salpingoophorectomy.

Misdiagnosed PMS in patients with underlying psychiatric and medical conditions.
Acute kidney injury in severe sepsis: Pathophysiology, diagnosis, and treatment recommendations
Authors: Keir Iain , Kellum John A.
Published: April 2015

Objective

To review the unique pathophysiology of sepsis‐induced acute kidney injury (AKI) and highlight the relevant aspects of the Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for Acute Kidney Injury that may apply to veterinary patients.

Data Sources

Electronic search of MEDLINE database.

Human Data Synthesis

Sepsis‐induced AKI is diagnosed in up to 47% of human ICU patients and is seen as a major public health concern associated with increased mortality and increased progression to chronic kidney disease (CKD). Consensus criteria for the definition and classification of AKI has allowed for accurate description of the epidemiology of patients with AKI. AKI develops from a complex relationship between the initial insult and activation of inflammation and coagulation. In contrast to the traditional view, clinical and experimental data dispute the role of renal ischemia‐reperfusion in the development of sepsis‐induced AKI. Renal tubular dysfunction with activation of the tubuloglomerular feedback mechanism appears to be a crucial contributor to sepsis‐induced AKI. Furosemide and n‐acetylcysteine (NAC) do not appear to be helpful in the treatment of AKI. Hydroxyethyl starches (HES), dopamine, and supraphysiological concentrations of chloride are harmful in patients with AKI.

Veterinary Data Synthesis

Community and hospital‐acquired AKI is a significant factor affecting survival in critical ill patients. Sepsis‐induced AKI occurs in 12% of dogs with abdominal sepsis and is an important contributor to mortality. Early detection of AKI in hospitalized patients currently offers the best opportunity to improve patient outcome. The use of urinary biomarkers to diagnose early AKI should be evaluated in critical care patients.

Conclusion

Veterinary clinical trials comparing treatment choices with the development of AKI are needed to make evidence‐based recommendations for the prevention and treatment of AKI.
Preferentially Filled Foam Core Corrugated Steel Sandwich Structures for Improved Blast Performance
Authors: Yazici Murat , Wright Jefferson , Bertin Damien , Shukla Arun
Published: April 2015

The mechanisms by which different morphologies of preferentially foam filled corrugated panels deform under planar blast loading, transmit shock, and absorb energy are investigated experimentally and numerically for the purpose of mitigating back-face deflection (BFD). Six foam filling configurations were fabricated and subjected to shock wave loading generated by a shock tube. Shock tube experimental results obtained from high-speed photography were used to validate the numerical models. The validated numerical model was further used to analyze 24 different core configurations. The experimental and numerical results show that soft/hard arrangements (front to back) are the most effective for blast resistivity as determined by the smallest BFDs. The number of foam filled layers in each specimen affected the amount of front-face deflections (FFDs), but did relatively little to alter BFDs, and results do not support alternating foam filling layers as a valid method to attenuate shock impact.
Rational Interpolation of Car Motions
Authors: Selig J. M.
Published: April 2015

This work introduces a general approach to the interpolation of the rigid-body motions of cars by rational motions. A key feature of the approach is that the motions produced automatically satisfy the kinematic constraints imposed by the car wheels, that is, cars cannot instantaneously translate sideways. This is achieved by using a Cayley map to project a polynomial curve in the Lie algebra se(2) to SE(2) the group of rigid displacements in the plane. The differential constraint on se(2), which expresses the kinematic constraint on the car, is easily solved for one coordinate if the other two are given, in this case as polynomial functions. In this way, families of motions obeying the constraint can be found. Several families are found here and examples of their use are shown. It is shown how rest-to-rest motions can be generated in this way and also how these motions can be joined so that the motion is continuous and differentiable across the join. A final section discusses the optimization of these motions. For some cost functions, the optimal motions are known but can be rather impractical to use. By optimizing over a family of motions which satisfy the boundary conditions for the motion, it is shown that rational motions can be found simply and are close to the overall optimal motion.
A Smart Cloud-Based System for the WEEE Recovery/Recycling
Authors: Vincent Wang Xi , Lopez N Brenda N. , Ijomah Winifred , Wang Lihui , Li Jinhui
Published: April 2015

Waste electrical and electronic equipment (WEEE) is both valuable and harmful since it contains a large number of profitable and hazardous materials and elements at the same time. At component level, many parts of the discarded equipment are still functional and recoverable. Thus, it is necessary to develop a distributed and intelligent system to support WEEE component recovery and recycling. In recent years, the Cloud concept has gained increasing popularity since it provides a service-oriented architecture (SOA) that integrates various resources over the network. Cloud manufacturing systems are proposed worldwide to support operational manufacturing processes. In this research, Cloud manufacturing is further extended to the WEEE recovery and recycling context. The Cloud services are applied in WEEE recovery and recycling processes by tracking and management services. These services include all the stakeholders from the beginning to the end of life of the electric and electronic equipment. A Cloud-based WEEE recovery system is developed to provide modularized recovery services on the Cloud. A data management system is developed as well, which maintains the knowledge throughout the product lifecycle. A product tracking mechanism is also proposed with the help of the Quick Respond code method.
Exact Multiple Solutions for the Slip Flow and Heat Transfer in a Converging Channel
Authors: Turkyilmazoglu Mustafa
Published: April 2015

A special case of Falkner–Skan flows past stretching boundaries is considered when the momentum and thermal slip boundary conditions are allowed at the boundary. Exact analytical solutions are found for the converging channel (wedge nozzle). The solutions are shown to be unique, double, or triple depending on the slip parameter and wall moving parameter. The provided closed-form analytical solutions are rare class of exact solutions for the Falkner–Skan flow equations. Thresholds of existence of multiple solutions are determined. For each flow solutions, the corresponding energy equation is also exactly solved when the internal heat generated by viscous dissipation can be neglected or numerically integrated when the viscous dissipation is significant. Analytic and numeric values of the rate of heat transfer affected by the presence of a surface temperature jump are also worked out. The possibility of realistic physical solution out of multiple solutions is finally discussed.
Non-Linear Model for Compression Tests on Articular Cartilage
Authors: Grillo Alfio , Guaily Amr , Giverso Chiara , Federico Salvatore
Published: April 2015

Hydrated soft tissues, such as articular cartilage, are often modeled as biphasic systems with individually incompressible solid and fluid phases, and biphasic models are employed to fit experimental data in order to determine the mechanical and hydraulic properties of the tissues. Two of the most common experimental setups are confined and unconfined compression. Analytical solutions exist for the unconfined case with the linear, isotropic, homogeneous model of articular cartilage, and for the confined case with the non-linear, isotropic, homogeneous model. The aim of this contribution is to provide an easily implementable numerical tool to determine a solution to the governing differential equations of (homogeneous and isotropic) unconfined and (inhomogeneous and isotropic) confined compression under large deformations. The large-deformation governing equations are reduced to equivalent diffusive equations, which are then solved by means of finite difference (FD) methods. The solution strategy proposed here could be used to generate benchmark tests for validating complex user-defined material models within finite element (FE) implementations, and for determining the tissue's mechanical and hydraulic properties from experimental data.
Topographic and electronic structure of cleaved SrTiO3(001) surfaces
Authors: Sitaputra Wattaka , Skowronski Marek , Feenstra Randall M.
Published: April 2015

The topographic and electronic structure of cleaved SrTiO3(001) surfaces were studied, employing samples that either had or had not been coated with Ti on their outer surfaces prior to fracture. In both cases, SrO- and TiO2-terminated terraces were present on the cleavage surface, enabling in situ studies on either termination. However, the samples coated with Ti prior to fracture were found to yield a rougher morphology on TiO2-terminated terraces as well as a higher density of oxygen vacancies during an annealing (outgassing) step following the coating. The higher density of oxygen vacancies in the bulk of the Ti-coated samples also provides higher conductivity, which, in turn, improves a sensitivity of the spectroscopy and reduces the effect of tip-induced band bending. Nonetheless, similar spectral features, unique to each termination, were observed for samples both with and without the Ti coating. Notably, with moderate-temperature annealing following fracture, a strong discrete peak in the conductance spectra, arising from oxygen vacancies, was observed on the SrO-terminated terraces. This peak appears at slightly different voltages for coated and uncoated samples, signifying a possible effect of tip-induced band bending.
A dendritic cell vaccine increases the breadth and diversity of melanoma neoantigen-specific T cells
Authors: Carreno Beatriz M. , Magrini Vincent , Becker-Hapak Michelle , Kaabinejadian Saghar , Hundal Jasreet , Petti Allegra A. , Ly Amy , Lie Wen-Rong , Hildebrand William H. , Mardis Elaine R. , Linette Gerald P.
Published: April 2015

Giving antitumor T cells a boost

Mutations allow tumors to divide, escape death, and resist treatment. But mutations can also cause tumors to express mutant proteins, which could potentially be exploited to drive antitumor T cell responses. Carreno
et al.
report the results of a small phase I trial seeking to do just this (see the Perspective by Delamarre
et al.
). They vaccinated three patients with advanced melanoma with personalized dendritic cell–based vaccines designed to activate T cells specific for mutations in the patients' cancer. T cells specific for mutant peptides did indeed expand. A next step will be to determine whether this promising strategy improves patient outcomes.

Science
, this issue p.
803
; see also p.
760
Do cognitive interventions improve general cognition in dementia? A meta-analysis and meta-regression
Authors: Huntley J D , Gould R L , Liu K , Smith M , Howard R J
Published: April 2015

Objectives

To review the efficacy of cognitive interventions on improving general cognition in dementia.

Method

Online literature databases and trial registers, previous systematic reviews and leading journals were searched for relevant randomised controlled trials. A systematic review, random-effects meta-analyses and meta-regression were conducted. Cognitive interventions were categorised as: cognitive stimulation (CS), involving a range of social and cognitive activities to stimulate multiple cognitive domains; cognitive training (CT), involving repeated practice of standardised tasks targeting a specific cognitive function; cognitive rehabilitation (CR), which takes a person-centred approach to target impaired function; or mixed  CT and stimulation (MCTS). Separate analyses were conducted for general cognitive outcome measures and for studies using ‘active’ (designed to control for non-specific therapeutic effects) and non-active (minimal or no intervention) control groups.

Results

33 studies were included. Significant positive effect sizes (Hedges’ g) were found for CS with the mini-mental state examination (MMSE) (g=0.51, 95% CI 0.29 to 0.69; p<0.001) compared to non-active controls and (g=0.35, 95% CI 0.06 to 0.65; p=0.019) compared to active controls. Significant benefit was also seen with the Alzheimer's disease Assessment Scale-Cognition (ADAS-Cog) (g=−0.26, 95% CI −0.445 to −0.08; p=0.005). There was no evidence that CT or MCTS produced significant improvements on general cognition outcomes and not enough CR studies for meta-analysis. The lowest accepted minimum clinically important difference was reached in 11/17 CS studies for the MMSE, but only 2/9 studies for the ADAS-Cog. Additionally, 95% prediction intervals suggested that although statistically significant, CS may not lead to benefits on the ADAS-Cog in all clinical settings.

Conclusions

CS improves scores on MMSE and ADAS-Cog in dementia, but benefits on the ADAS-Cog are generally not clinically significant and difficulties with blinding of patients and use of adequate placebo controls make comparison with the results of dementia drug treatments problematic.
Lack of weight recording in patients being administered narrow therapeutic index antibiotics: a prospective cross-sectional study
Authors: Charani Esmita , Gharbi Myriam , Hickson Mary , Othman Shokri , Alfituri Aisha , Frost Gary , Holmes Alison
Published: April 2015

Objectives

Patient weight is a key measure for safe medication management and monitoring of patients. Here we report the recording of patient's body weight on admission in three hospitals in West London and its relationship with the prescription of antibiotic drugs where it is essential to have the body weight of the patient.

Methods

A prospective cross-sectional study was conducted in three teaching hospitals in West London. Data were collected during March 2011–September 2011 and July 2012–August 2012, from adult admissions units, medical and surgical wards. Data from each ward were collected on a single day to provide a point prevalence data on weight recording. Patient medication charts, nursing and medical notes were reviewed for evidence of weight and height recording together with all the medication prescribed for the patients. An observational study collecting data on the weight recording process was conducted on two randomly selected wards to add context to the data.

Results

Data were collected on 1012 patients. Weight was not recorded for 46% (474) of patients. Eighty-nine patients were prescribed a narrow therapeutic antibiotic, in 39% (35/89) of these weight was not recorded for the patient. Intravenous vancomycin was the most commonly prescribed antibiotic requiring therapeutic monitoring. In total 61 patients were receiving intravenous vancomycin and of these 44% (27/61) did not have their weight recorded. In the observational study, the most frequently identified barrier to weight not being recorded was interruptions to the admission process.

Conclusions

Despite the clinical importance of body weight measurement it is poorly recorded in hospitalised patients, due to interruptions to the workflow and heavy staff workloads. In antibiotics a correct, recent patient weight is required for accurate dosing and to keep drugs within the narrow therapeutic index, to ensure efficacy of prescribing and reduce toxicity.
The association between obesity and severe disability among adults aged 50 or over in nine high-income, middle-income and low-income countries: a cross-sectional study
Authors: Koyanagi Ai , Moneta Maria Victoria , Garin Noe , Olaya Beatriz , Ayuso-Mateos Jose Luis , Chatterji Somnath , Leonardi Matilde , Sainio Päivi , Galas Aleksander , Haro Josep Maria
Published: April 2015

Objective

The association between obesity and disability may differ between high-income and low-income/middle-income countries but there are no studies comparing this association between these settings. The aim of the study was to assess this association in nine countries using nationally-representative data from the Collaborative Research on Ageing in Europe (COURAGE) study and the WHO's Study on global AGEing and Adult Health (SAGE).

Design

Population-based cross-sectional study

Setting

The survey was conducted in China, Finland, Ghana, India, Mexico, Poland, Russia, South Africa and Spain between 2007 and 2012.

Participants

42 116 individuals 50 years and older. The institutionalised and those with limited cognition were excluded.

Primary outcome measure

Disability was defined as severe or extreme difficulty in conducting at least one of six types of basic activities of daily living (ADL).

Results

The mean body mass index (BMI) ranged from 20.4 kg/m2in India to 30.7 kg/m2in South Africa. Compared to normal BMI (18.5–24.9 kg/m2), BMI≥35 kg/m2was associated with significantly higher odds for ADL disability in Finland (OR 4.64), Poland (OR 2.77), South Africa (OR 2.19) and Spain (OR 2.42). Interaction analysis showed that obese individuals in high-income countries were more likely to have ADL limitations than those in low-income or middle-income countries.

Conclusions

The higher odds for disability among obese individuals in high-income countries may imply longer life lived with disability due to factors such as the decline in cardiovascular disease mortality. In South Africa, this may have been due to the exceptionally high prevalence of class III obesity. These findings underscore the importance of obesity prevention to reduce the disability burden among older adults.
Database improvements for motor vehicle/bicycle crash analysis
Authors: Lusk Anne C , Asgarzadeh Morteza , Farvid Maryam S
Published: April 2015

Background

Bicycling is healthy but needs to be safer for more to bike. Police crash templates are designed for reporting crashes between motor vehicles, but not between vehicles/bicycles. If written/drawn bicycle-crash-scene details exist, these are not entered into spreadsheets.

Objective

To assess which bicycle-crash-scene data might be added to spreadsheets for analysis.

Methods

Police crash templates from 50 states were analysed. Reports for 3350 motor vehicle/bicycle crashes (2011) were obtained for the New York City area and 300 cases selected (with drawings and on roads with sharrows, bike lanes, cycle tracks and no bike provisions). Crashes were redrawn and new bicycle-crash-scene details were coded and entered into the existing spreadsheet. The association between severity of injuries and bicycle-crash-scene codes was evaluated using multiple logistic regression.

Results

Police templates only consistently include pedal-cyclist and helmet. Bicycle-crash-scene coded variables for templates could include: 4 bicycle environments, 18 vehicle impact-points (opened-doors and mirrors), 4 bicycle impact-points, motor vehicle/bicycle crash patterns, in/out of the bicycle environment and bike/relevant motor vehicle categories. A test of including these variables suggested that, with bicyclists who had minor injuries as the control group, bicyclists on roads with bike lanes riding outside the lane had lower likelihood of severe injuries (OR, 0.40, 95% CI 0.16 to 0.98) compared with bicyclists riding on roads without bicycle facilities.

Conclusions

Police templates should include additional bicycle-crash-scene codes for entry into spreadsheets. Crash analysis, including with big data, could then be conducted on bicycle environments, motor vehicle potential impact points/doors/mirrors, bicycle potential impact points, motor vehicle characteristics, location and injury.
Sexual dimorphism and condition dependence in the anal pad of the small Indian mongoose (Herpestes auropunctatus)
Authors: Owen M.A. , Lahti D.C.
Published: April 2015

Secondary sexual traits tend to be sexually dimorphic, and theory predicts that such traits should also be condition-dependent in a sex-specific manner. We investigate these phenomena in a field study of the small Indian mongoose (Herpestes auropunctatus (Hodgson, 1836); formerly Herpestes javanicus (É. Geoffroy Saint-Hillaire, 1818)), in the first attempt at understanding secondary sexual traits and sexual selection in this species. Small Indian mongooses are solitary and nonterritorial, and they likely depend on chemical (scent) rather than visual or acoustic signals for communication. Additionally, they possess a fleshy projection around their anus, the anal pad, thought to aid in scent-marking. Our results revealed strong male-biased sexual dimorphism in mass, skull and body lengths, canine diameters, and anal pad area. After controlling for the influence of body length, males were 31% heavier and possessed anal pads that were 68% larger than females’. Additionally, anal pad size was positively related to body size in males but not in females and was condition-dependent in males but not in females. Taken together, our findings provide indirect evidence that the anal pad might have evolved, at least in part, via sexual selection.
Latent Support Vector Machine Modeling for Sign Language Recognition with Kinect
Authors: Sun Chao , Zhang Tianzhu , Xu Changsheng
Published: April 2015

Vision-based sign language recognition has attracted more and more interest from researchers in the computer vision field. In this article, we propose a novel algorithm to model and recognize sign language performed in front of a Microsoft Kinect sensor. Under the assumption that some frames are expected to be both discriminative and representative in a sign language video, we first assign a binary latent variable to each frame in training videos for indicating its discriminative capability, then develop a latent support vector machine model to classify the signs, as well as localize the discriminative and representative frames in each video. In addition, we utilize the depth map together with the color image captured by the Kinect sensor to obtain a more effective and accurate feature to enhance the recognition accuracy. To evaluate our approach, we conducted experiments on both word-level sign language and sentence-level sign language. An American Sign Language dataset including approximately 2,000 word-level sign language phrases and 2,000 sentence-level sign language phrases was collected using the Kinect sensor, and each phrase contains color, depth, and skeleton information. Experiments on our dataset demonstrate the effectiveness of the proposed method for sign language recognition.
Parallelizing Data Processing on FPGAs with Shifter Lists
Authors: Woods Louis , Alonso Gustavo , Teubner Jens
Published: April 2015

Parallelism is currently seen as a mechanism to minimize the impact of the power and heat dissipation problems encountered in modern hardware. Data parallelism—based on partitioning the data—and pipeline parallelism—based on partitioning the computation—are the two main approaches to leverage parallelism on a wide range of hardware platforms.

Unfortunately, not all data processing problems are susceptible to either of those strategies. An example is the
skyline
operator [Börzsönyi et al. 2001], which computes the set of Pareto-optimal points within a multidimensional dataset. Existing approaches to parallelize the skyline operator are based on data parallelism. As a result, they suffer from a high overhead when merging intermediate results because of the lack of a global view of the problem inherent to partitioning the input data.

In this article, we show how to combine pipeline with data parallelism on a Field-Programmable Gate Array (FPGA) for a more efficient utilization of the available hardware parallelism. As we show in our experiments, skyline computation using our proposed technique scales linearly with the number of processing elements, and the performance we achieve on a rather small FPGA is comparable to that of a 64-core high-end server running a state-of-the-art
data parallel
implementation of
skyline
[Park et al. 2009].

The proposed approach to parallelize the skyline operator can be generalized to a wider range of data processing problems. We demonstrate this through a novel, highly parallel data structure, a
shifter list
, that can be efficiently implemented on an FPGA. The resulting template is easy to parametrize to implement a variety of computationally intensive operators such as
frequent items
,

n
-closest pairs

, or
K-means
.
An Experimental Study on Approximating
k
Shortest Simple Paths
Authors: Frieder Asaf , Roditty Liam
Published: April 2015

We have conducted an extensive experimental study on approximation algorithms for computing
k
shortest simple paths in weighted directed graphs. Very recently, Bernstein [2010] presented an algorithm that computes a 1 + ε approximated
k
shortest simple path in
O
(ε
-1
k
(
m
+
n
log
n
)
log
2
n
) time. We have implemented Bernstein’s algorithm and tested it on synthetic inputs and real-world graphs (road maps). Our results reveal that Bernstein’s algorithm has a practical value in many scenarios. Moreover, it produces in most of the cases exact paths rather than approximated. We also present a new variant for Bernstein’s algorithm. We prove that our new variant has the same upper bounds for the running time and approximation as Bernstein’s original algorithm. We have implemented and tested this variant as well. Our testing shows that this variant, which is based on a simple theoretical observation, is better than Bernstein’s algorithm in practice.
Pattern Matching Techniques for Replacing Missing Sections of Audio Streamed across Wireless Networks
Authors: Doherty Jonathan , Curran Kevin , McKevitt Paul
Published: April 2015

Streaming media on the Internet can be unreliable. Services such as audio-on-demand drastically increase the loads on networks; therefore, new, robust, and highly efficient coding algorithms are necessary. One method overlooked to date, which can work alongside existing audio compression schemes, is that which takes into account the semantics and natural repetition of music. Similarity detection within polyphonic audio has presented problematic challenges within the field of music information retrieval. One approach to deal with bursty errors is to use self-similarity to replace missing segments. Many existing systems exist based on packet loss and replacement on a network level, but none attempt repairs of large dropouts of 5 seconds or more. Music exhibits standard structures that can be used as a forward error correction (FEC) mechanism. FEC is an area that addresses the issue of packet loss with the onus of repair placed as much as possible on the listener's device. We have developed a server--client-based framework (SoFI) for automatic detection and replacement of large packet losses on wireless networks when receiving time-dependent streamed audio. Whenever dropouts occur, SoFI swaps audio presented to the listener between a live stream and previous sections of the audio stored locally. Objective and subjective evaluations of SoFI where subjects were presented with other simulated approaches to audio repair together with simulations of replacements including varying lengths of time in the repair give positive results.
A Network Behavior-Based Botnet Detection Mechanism Using PSO and K-means
Authors: Li Shing-Han , Kao Yu-Cheng , Zhang Zong-Cyuan , Chuang Ying-Ping , Yen David C.
Published: April 2015

In today's world, Botnet has become one of the greatest threats to network security. Network attackers, or Botmasters, use Botnet to launch the Distributed Denial of Service (DDoS) to paralyze large-scale websites or steal confidential data from infected computers. They also employ “phishing” attacks to steal sensitive information (such as users’ accounts and passwords), send bulk email advertising, and/or conduct click fraud. Even though detection technology has been much improved and some solutions to Internet security have been proposed and improved, the threat of Botnet still exists. Most of the past studies dealing with this issue used either packet contents or traffic flow characteristics to identify the invasion of Botnet. However, there still exist many problems in the areas of packet encryption and data privacy, simply because Botnet can easily change the packet contents and flow characteristics to circumvent the Intrusion Detection System (IDS). This study combines Particle Swarm Optimization (PSO) and K-means algorithms to provide a solution to remedy those problems and develop, step by step, a mechanism for Botnet detection. First, three important network behaviors are identified: long active communication behavior (ActBehavior), connection failure behavior (FailBehavior), and network scanning behavior (ScanBehavior). These behaviors are defined according to the relevant prior studies and used to analyze the communication activities among the infected computers. Second, the features of network behaviors are extracted from the flow traces in the network layer and transport layer of the network equipment. Third, PSO and K-means techniques are used to uncover the host members of Botnet in the organizational network. This study mainly utilizes the flow traces of a campus network as an experiment. The experimental findings show that this proposed approach can be employed to detect the suspicious Botnet members earlier than the detection application systems. In addition, this proposed approach is easy to implement and can be further used and extended in the campus dormitory network, home networks, and the mobile 3G network.
Pattern-Based Survey and Categorization of Network Covert Channel Techniques
Authors: Wendzel Steffen , Zander Sebastian , Fechner Bernhard , Herdin Christian
Published: April 2015

Network covert channels are used to hide communication inside network protocols. Various techniques for covert channels have arisen in the past few decades. We surveyed and analyzed 109 techniques developed between 1987 and 2013 and show that these techniques can be reduced to only 11 different patterns. Moreover, the majority (69.7%) of techniques can be categorized into only four different patterns (i.e., most techniques we surveyed are similar). We represent the patterns in a hierarchical catalog using a pattern language. Our pattern catalog will serve as a base for future covert channel novelty evaluation. Furthermore, we apply the concept of pattern variations to network covert channels. With pattern variations, the context of a pattern can change. For example, a channel developed for IPv4 can automatically be adapted to other network protocols. We also propose the pattern-based covert channel optimizations pattern hopping and pattern combination. Finally, we lay the foundation for pattern-based countermeasures: whereas many current countermeasures were developed for specific channels, a pattern-oriented approach allows application of one countermeasure to multiple channels. Hence, future countermeasure development can focus on patterns, and the development of real-world protection against covert channels is greatly simplified.
Who Influenced You? Predicting Retweet via Social Influence Locality
Authors: Zhang Jing , Tang Jie , Li Juanzi , Liu Yang , Xing Chunxiao
Published: April 2015

Social influence occurs when one’s opinions, emotions, or behaviors are affected by others in a social network. However, social influence takes many forms, and its underlying mechanism is still unclear. For example, how is one’s behavior influenced by a group of friends who know each other and by the friends from different ego friend circles? In this article, we study the social influence problem in a large microblogging network. Particularly, we consider users’ (re)tweet behaviors and focus on investigating how friends in one’s ego network influence retweet behaviors. We propose a novel notion of
social influence locality
and develop two instantiation functions based on pairwise influence and structural diversity. The defined influence locality functions have strong predictive power. Without any additional features, we can obtain an F1-score of 71.65% for predicting users’ retweet behaviors by training a logistic regression classifier based on the defined influence locality functions. We incorporate social influence locality into a factor graph model, which can further leverage the network-based correlation. Our experiments on the large microblogging network show that the model significantly improves the precision of retweet prediction. Our analysis also reveals several intriguing discoveries. For example, if you have six friends retweeting a microblog, the average likelihood that you will also retweet it strongly depends on the structure among the six friends: The likelihood will significantly drop (only ⅙) when the six friends do not know each other, compared with the case when the six friends know each other.
Universal and Distinct Properties of Communication Dynamics
Authors: Melo Pedro O. S. Vaz De , Faloutsos Christos , Assunção Renato , Alves Rodrigo , Loureiro Antonio A. F.
Published: April 2015

With the advancement of information systems, means of communications are becoming cheaper, faster, and more available. Today, millions of people carrying smartphones or tablets are able to communicate practically any time and anywhere they want. They can access their e-mails, comment on weblogs, watch and post videos and photos (as well as comment on them), and make phone calls or text messages almost ubiquitously. Given this scenario, in this article, we tackle a fundamental aspect of this new era of communication: How the time intervals between communication events behave for different technologies and means of communications. Are there universal patterns for the Inter-Event Time Distribution (IED)? How do inter-event times behave differently among particular technologies? To answer these questions, we analyzed eight different datasets from real and modern communication data and found four well-defined patterns seen in all the eight datasets. Moreover, we propose the use of the Self-Feeding Process (SFP) to generate inter-event times between communications. The SFP is an extremely parsimonious point process that requires at most two parameters and is able to generate inter-event times with all the universal properties we observed in the data. We also show three potential applications of the SFP: as a framework to generate a synthetic dataset containing realistic communication events of any one of the analyzed means of communications, as a technique to detect anomalies, and as a building block for more specific models that aim to encompass the particularities seen in each of the analyzed systems.
On Data Publishing with Clustering Preservation
Authors: Vlachos Michail , Schneider Johannes , Vassiliadis Vassilios G.
Published: April 2015

The emergence of cloud-based storage services is opening up new avenues in data exchange and data dissemination. This has amplified the interest in right-protection mechanisms to establish ownership in the event of data leakage. Current right-protection technologies, however, rarely provide strong guarantees on dataset utility after the protection process. This work presents techniques that explicitly address this topic and provably preserve the outcome of certain mining operations. In particular, we take special care to guarantee that the outcome of hierarchical clustering operations remains the same before and after right protection. Our approach considers all prevalent hierarchical clustering variants: single-, complete-, and average-linkage. We imprint the ownership in a dataset using watermarking principles, and we derive tight bounds on the expansion/contraction of distances incurred by the process. We leverage our analysis to design fast algorithms for right protection without exhaustively searching the vast design space. Finally, because the right-protection process introduces a user-tunable distortion on the dataset, we explore the possibility of using this mechanism for data obfuscation. We quantify the tradeoff between obfuscation and utility for spatiotemporal datasets and discover very favorable characteristics of the process. An additional advantage is that when one is interested in both right-protecting and obfuscating the original data values, the proposed mechanism can accomplish both tasks simultaneously.
Dynamic MIPS Rate Stabilization for Complex Processors
Authors: Suh Jinho , Huang Chieh-Ting , Dubois Michel
Published: April 2015

Modern microprocessor cores reach their high performance levels with the help of high clock rates, parallel and speculative execution of a large number of instructions, and vast cache hierarchies. Modern cores also have adaptive features to regulate power and temperature and avoid thermal emergencies. All of these features contribute to highly unpredictable execution times. In this article, we demonstrate that the execution time of in-order (IO), out-of-order (OoO), and OoO simultaneous multithreaded processors can be stable and predictable by stabilizing their mega instructions executed per second (MIPS) rate via a proportional, integral, and differential (PID) gain feedback controller and dynamic voltage and frequency scaling (DVFS).

Processor cores in idle cycles are continuously consuming power, which is highly undesirable in systems, especially in real-time systems. In addition to meeting deadlines in real-time systems, our MIPS rate stabilization framework can be applied on top of it to reduce power and energy by avoiding idle cycles. If processors are equipped with MIPS rate stabilization, the execution time can be predicted. Because the MIPS rate remains steady, a stabilized processor meets deadlines on time in real-time systems or in systems with quality-of-service execution latency requirements at the lowest possible frequency.

To demonstrate and evaluate this capability, we have selected a subset of the MiBench benchmarks with the widest execution rate variations. We stabilize their MIPS rate on a 1GHz Pentium III--like OoO single-thread microarchitecture, a 1.32GHz StrongARM-like IO microarchitecture, and the 1GHz OoO processor augmented with two-way and four-way simultaneous multithreading. Both IO and OoO cores can take advantage of the stabilization framework, but the energy per instruction of the stabilized OoO core is less because it runs at a lower frequency to meet the same deadlines.

The MIPS rate stabilization of complex processors using a PID feedback control loop is a general technique applicable to environments in which lower power or energy coupled with steady, predictable performance are desirable, although we target more specifically real-time systems in this article.
Generalized Task Parallelism
Authors: Streit Kevin , Doerfert Johannes , Hammacher Clemens , Zeller Andreas , Hack Sebastian
Published: April 2015

Existing approaches to automatic parallelization produce good results in specific domains. Yet, it is unclear how to integrate their individual strengths to match the demands and opportunities of complex software. This lack of integration has both practical reasons, as integrating those largely differing approaches into one compiler would impose an engineering hell, as well as theoretical reasons, as no joint cost model exists that would drive the choice between parallelization methods.

By reducing the problem of generating parallel code from a program dependence graph to integer linear programming, generalized task parallelization integrates central aspects of existing parallelization approaches into a single unified framework. Implemented on top of LLVM, the framework seamlessly integrates enabling technologies such as speculation, privatization, and the realization of reductions.

Evaluating our implementation on various C programs from different domains, we demonstrate the effectiveness and generality of generalized task parallelization. On a quad-core machine with hyperthreading we achieve speedups of up to 4.6 ×.
Efficiently Deciding μ-Calculus with Converse over Finite Trees
Authors: Genevès Pierre , Layaïda Nabil , Schmitt Alan , Gesbert Nils
Published: April 2015

We present a sound and complete satisfiability-testing algorithm and its effective implementation for an alternation-free modal μ-calculus with converse, where formulas are cycle-free and are interpreted over finite ordered trees. The time complexity of the satisfiability-testing algorithm is 2

O(
n
)

in terms of formula size
n
. The algorithm is implemented using symbolic techniques (BDD). We present crucial implementation techniques and heuristics that we used to make the algorithm as fast as possible in practice. Our implementation is available online and can be used to solve logical formulas of significant size and practical value. We illustrate this in the setting of XML trees.
MAGIC
Authors: Karimi Naghmeh , Kanuparthi Arun Karthik , Wang Xueyang , Sinanoglu Ozgur , Karri Ramesh
Published: April 2015

The performance of an IC degrades over its lifetime, ultimately resulting in IC failure. In this article, we present a hardware attack (called MAGIC) to maliciously accelerate NBTI aging effects in cores. In this attack, we identify the input patterns that maliciously age the pipestages of a core. We then craft a program that generates these patterns at the inputs of the targeted pipestage. We demonstrate the MAGIC-based attack on the OpenSPARC processor. Executing this program dramatically accelerates the aging process and degrades the processor’s performance by 10.92% in 1 month, bypassing existing aging mitigation and timing-error correction schemes. We also present two low-cost techniques to thwart the proposed attack.
On the Variable Hierarchy of First-Order Spectra
Authors: Kopczyński Eryk , Tan Tony
Published: April 2015

The
spectrum
of a first-order logic sentence is the set of natural numbers that are cardinalities of its finite models. In this article, we study the hierarchy of first-order spectra based on the number of variables. It has been conjectured that it collapses to three variables. We show the opposite: it forms an infinite hierarchy. However, despite the fact that more variables can express more spectra, we show that to establish whether the class of first-order spectra is closed under complement, it is sufficient to consider sentences using only three variables and binary relations.
Comparative Analysis of Traditional and Object-Oriented Software Testing
Authors: Gulia Preeti , Chugh Jyoti
Published: April 2015

Software testing is an important phase of the software development life cycle. Testing is the process of executing the program with the goal of finding errors. The purpose of testing is not only to find the bugs in software but also to improve the quality of software. This paper compares traditional and object-oriented software testing. Today, object-oriented concepts are used throughout software engineering. Testing of object-oriented software is different from testing of traditional software. Object-oriented software testing offers new challenges to the software testing team, because the object-oriented approach supports several new and powerful features. This paper focuses on the need for adopting an object-oriented software-testing approach and the challenges that occur in object-oriented testing.