bluuebunny/crossref_metadata_2025 huggingface dataset:
EXTERNAL SHOCKS, STRUCTURAL BREAKS AND UNEMPLOYMENT HYSTERESIS IN SELECTED ASIAN COUNTRIES
Authors: MUNIR QAISER , KOK SOOK CHING , MANSUR KASIM
Published: June 2016

This paper re-examines the hypothesis of unemployment hysteresis using panel data for 11 Asian countries for the period from 1980 to 2008. This study employs a variety of panel data unit root tests recently advanced by Bai and Ng (2004), Pesaran (2007) and Chang and Song (2009). The advantage of these tests is that they are able to exploit the cross-section variations of the series. In addition to these tests, a new powerful panel stationarity test proposed by Carrión-i-Silvestre et al. (2005) is applied which exploits the cross-section variations of the series and also allows for different numbers of endogenous breakpoints in the series. Our findings stress the importance of accounting exogenous shocks in the series and provide stronger evidence against the hypothesis of unemployment hysteresis for the countries analyzed. We also discover critical economic affairs which may cause the unemployment rates to fluctuate significantly. Policy implications are proposed through our observations.
Effect of cross-sectional geometry on thermal conductivity of Si1−xGex nanowires
Authors: Qu Peixin
Published: June 2016

By incorporating the direction-dependent phonon-boundary scattering from the surface of the nanowires with different cross-sectional shapes into the linearized phonon Boltzmann transport equation, we theoretically investigate the effect of cross-sectional geometry on the thermal conductivity of [Formula: see text] nanowires. It is demonstrated that the surface-to-volume ratio (SVR) is a universal gauge for both pure silicon nanowires (SiNWs) and silicon–germanium nanowires (SiGe NWs), and the thermal conductivity of nanowires decreases monotonically with the increase of SVR. We also find that the thermal conductivity of high-frequency phonons in nanowires is more strongly SVR dependent than that of low-frequency phonons, and the thermal conductivity of high-frequency phonons is severely suppressed by alloy scattering, therefore the SVR dependence on thermal conductivity of [Formula: see text] NWs decreases with the increase of Ge atom concentration [Formula: see text] [Formula: see text]. These findings are useful for understanding and tuning the thermal conductivity of nanowires by geometry.
Determination of the activation enthalpy for migration of dislocations in plastically deformed 8006 Al-alloy by positron annihilation lifetime technique
Authors: Salah Mohammed , Abdel-Rahman M. , Badawi Emad A. , Abdel-Rahman M. A.
Published: June 2016

The activation enthalpy for migration of dislocations of plastically deformed 8006 Al-alloy was investigated by positron annihilation lifetime technique. Plastic deformation using a hydraulic press produces mainly dislocations and may produce point defects. The type of defect was studied by isochronal annealing which determines the temperature range of recovery of each type. Only one type of defect (dislocations) was observed for the investigated sample and was found to be recovered within the range 455–700 K. Isothermal annealing by slow cooling was performed through this range and used in determination of the activation enthalpy of migration of dislocations which was found to be 0.26 ± 0.01 eV.
Relativistic currents on ideal Aharonov–Bohm cylinders
Authors: Cotăescu Ion I. , Băltăţeanu Doru-Marcel S. , Cotăescu Ion I.
Published: June 2016

The relativistic theory of the Dirac fermions moving on cylinders in external Aharonov–Bohm (AB) field is built starting with a suitably restricted Dirac equation whose spin degrees of freedom are not affected. The exact solutions of this equation on finite or infinite AB cylinders allow one to derive the relativistic circular and longitudinal currents pointing out their principal features. It is shown that all the circular currents are related to the energy in the same manner on cylinders or rings either in the relativistic approach or in the nonrelativistic one. The specific relativistic effect is the saturation of the circular currents for high values of the total angular momentum. Based on this property some approximative closed formulas are deduced for the total persistent current at [Formula: see text] on finite AB cylinders. Moreover, it is shown that all the persistent currents on finite cylinders or rings have similar nonrelativistic limits.
THE ELECTROCHEMICAL BEHAVIOR OF DOPED SILANE PRE-TREATMENTS ON GALVANIZED STEEL SUBSTRATES
Authors: ZHAO QILIANG , GUO WEI , ZHONG QINGDONG , ZHANG JUNLIANG , SUN JINHU , LI HUI
Published: June 2016

In this paper, galvanized steel substrates were pre-treated in [Formula: see text]-(2,3-epoxypropoxy)propyl trimethoxy silane solutions containing salts ((NH[Formula: see text]TiF6, K2ZrF6 and NaVO[Formula: see text] and SiO2. The surface microstructures of the coated substrates were evaluated by scanning electron microscopy (SEM). The anti-corrosion performance of the modified silane film applied on galvanized steel substrates was evaluated by potentio-dynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS). The electrochemical results reveal that the addition of salts ((NH[Formula: see text]TiF6, K2ZrF6 and NaVO[Formula: see text] may produce a more stable and protective fluoride combined with their oxides in the silane layer. The results also reveal that the addition of the SiO2 nanoparticles reinforced the barrier properties of the silane films and imparted its corrosion inhibition ability.
Integral almost square-free modular categories
Authors: Dong Jingcheng , Li Libin , Dai Li
Published: June 2016

We study integral almost square-free modular categories; i.e., integral modular categories of Frobenius–Perron dimension [Formula: see text], where [Formula: see text] is a prime number, [Formula: see text] is a square-free natural number and [Formula: see text]. We prove that, if [Formula: see text] or [Formula: see text] is prime with [Formula: see text], then they are group-theoretical. This generalizes several results in the literature and gives a partial answer to the question posed by the first author and Tucker. As an application, we prove that an integral modular category whose Frobenius–Perron dimension is odd and less than [Formula: see text] is group-theoretical.
A Competitive Divide-and-Conquer Algorithm for Unconstrained Large-Scale Black-Box Optimization
Authors: Mei Yi , Omidvar Mohammad Nabi , Li Xiaodong , Yao Xin
Published: June 2016

This article proposes a competitive divide-and-conquer algorithm for solving large-scale black-box optimization problems for which there are thousands of decision variables and the algebraic models of the problems are unavailable. We focus on problems that are partially additively separable, since this type of problem can be further decomposed into a number of smaller independent subproblems. The proposed algorithm addresses two important issues in solving large-scale black-box optimization: (1) the identification of the independent subproblems without explicitly knowing the formula of the objective function and (2) the optimization of the identified black-box subproblems. First, a Global Differential Grouping (GDG) method is proposed to identify the independent subproblems. Then, a variant of the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) is adopted to solve the subproblems resulting from its rotation invariance property. GDG and CMA-ES work together under the cooperative co-evolution framework. The resultant algorithm, named CC-GDG-CMAES, is then evaluated on the CEC’2010 large-scale global optimization (LSGO) benchmark functions, which have a thousand decision variables and black-box objective functions. The experimental results show that, on most test functions evaluated in this study, GDG manages to obtain an ideal partition of the index set of the decision variables, and CC-GDG-CMAES outperforms the state-of-the-art results. Moreover, the competitive performance of the well-known CMA-ES is extended from low-dimensional to high-dimensional black-box problems.
Examining Additivity and Weak Baselines
Authors: Kharazmi Sadegh , Scholer Falk , Vallet David , Sanderson Mark
Published: June 2016

We present a study of which baseline to use when testing a new retrieval technique. In contrast to past work, we show that measuring a statistically significant improvement over a weak baseline is not a good predictor of whether a similar improvement will be measured on a strong baseline. Sometimes strong baselines are made worse when a new technique is applied. We investigate whether conducting comparisons against a range of weaker baselines can increase confidence that an observed effect will also show improvements on a stronger baseline. Our results indicate that this is not the case -- at best, testing against a range of baselines means that an experimenter can be more confident that the new technique is unlikely to significantly harm a strong baseline. Examining recent past work, we present evidence that the information retrieval (IR) community continues to test against weak baselines. This is unfortunate as, in light of our experiments, we conclude that the only way to be confident that a new technique is a contribution is to compare it against nothing less than the state of the art.
Group Norms for Multi-Agent Organisations
Authors: Aldewereld Huib , Dignum Virginia , Vasconcelos Wamberto W.
Published: June 2016

Normative multi-agent systems offer the ability to integrate social and individual factors to provide increased levels of fidelity with respect to modelling social phenomena, such as cooperation, coordination, group decision making, and organization, in both human and artificial agent systems. An important open research issue refers to group norms, that is, norms that govern groups of agents. Depending on the interpretation, group norms may be intended to affect the group as a whole, each member of a group, or some members of the group. Moreover, upholding group norms may require coordination among the members of the group. We have identified three sets of agents affected by group norms, namely, (i) the addressees of the norm, (ii) those that will act on it, and (iii) those that are responsible for ensuring norm compliance. We present a formalism to represent these, connecting it to a minimalist agent organisation model. We use our formalism to develop a reasoning mechanism that enables agents to identify their position with respect to a group norm to further support agent autonomy and coordination when deciding on possible courses of action.
Controlling Negative Emergent Behavior by Graph Analysis at Runtime
Authors: Kantert Jan , Tomforde Sven , Kauder Melanie , Scharrer Richard , Edenhofer Sarah , Hähner Jörg , Müller-Schloer Christian
Published: June 2016

Self-organized systems typically consist of distributed autonomous entities. An increasing part of such systems is characterized by openness and heterogeneity of participants. For instance, open desktop computing grids provide a framework for unrestrictedly joining in. However, openness and heterogeneity present severe challenges to the overall system’s stability and efficiency since uncooperative and even malicious participants are free to join. A promising solution for this problem is to introduce technical trust as a basis; however, in turn, the utilization of trust opens space for negative emergent behavior. This article introduces a system-wide observation and control loop that influences the self-organized behavior to provide a performant and robust platform for benevolent participants. Thereby, the observation part is responsible for gathering information and deriving a system description. We introduce a graph-based approach to identify groups of suspicious or malicious agents and demonstrate that this clustering process is highly successful for the considered stereotype agent behaviors. In addition, the controller part guides the system behavior by issuing norms that make use of incentives and sanctions. We further present a concept for closing the control loop and show experimental results that highlight the potential benefit of establishing such a control loop.
Sloth
Authors: Cheung Alvin , Madden Samuel , Solar-Lezama Armando
Published: June 2016

Many web applications store persistent data in databases. During execution, such applications spend a significant amount of time communicating with the database for retrieval and storing of persistent data over the network. These network round-trips represent a significant fraction of the overall execution time for many applications (especially those that issue a lot of database queries) and, as a result, increase their latency. While there has been prior work that aims to eliminate round-trips by batching queries, they are limited by (1) a requirement that developers manually identify batching opportunities, or (2) the fact that they employ static program analysis techniques that cannot exploit many opportunities for batching, as many of these opportunities require knowing precise information about the state of the running program.

In this article, we present S
loth
, a new system that extends traditional
lazy evaluation
to expose query batching opportunities during application execution, even across loops, branches, and method boundaries. Many such opportunities often require expensive and sophisticated static analysis to recognize from the application source code. Rather than doing so, S
loth
instead makes use of dynamic analysis to capture information about the program state and, based on that information, decides how to batch queries and when to issue them to the database. We formalize extended lazy evaluation and prove that it preserves program semantics when executed under standard semantics. Furthermore, we describe our implementation of S
loth
and our experience in evaluating S
loth
using over 100 benchmarks from two large-scale open-source applications, in which S
loth
achieved up to a 3 × reduction in page load time by delaying computation using extended lazy evaluation.
Transparent and Efficient Parallelization of Swarm Algorithms
Authors: Cicirelli Franco , Forestiero Agostino , Giordano Andrea , Mastroianni Carlo
Published: June 2016

This article presents an approach for the efficient and transparent parallelization of a large class of swarm algorithms, specifically those where the multiagent paradigm is used to implement the functionalities of bioinspired entities, such as ants and birds. Parallelization is achieved by partitioning the space on which agents operate onto multiple regions and assigning each region to a different computing node. Data consistency and conflict issues, which can arise when several agents concurrently access shared data, are handled using a purposely developed notion of logical time. This approach enables a transparent porting onto parallel/distributed architectures, as the developer is only in charge of defining the behavior of the agents, without having to cope with issues related to parallel programming and performance optimization. The approach has been evaluated for a very popular swarm algorithm, the ant-based spatial clustering and sorting of items, and results show good performance and scalability.
Measuring the Semantic Uncertainty of News Events for Evolution Potential Estimation
Authors: Luo Xiangfeng , Xuan Junyu , Lu Jie , Zhang Guangquan
Published: June 2016

The evolution potential estimation of news events can support the decision making of both corporations and governments. For example, a corporation could manage its public relations crisis in a timely manner if a negative news event about this corporation is known with large evolution potential in advance. However, existing state-of-the-art methods are mainly based on time series historical data, which are not suitable for the news events with limited historical data and bursty properties. In this article, we propose a purely content-based method to estimate the evolution potential of the news events. The proposed method considers a news event at a given time point as a system composed of different keywords, and the uncertainty of this system is defined and measured as the Semantic Uncertainty of this news event. At the same time, an uncertainty space is constructed with two extreme states: the most uncertain state and the most certain state. We believe that the Semantic Uncertainty has correlation with the content evolution of the news events, so it can be used to estimate the evolution potential of the news events. In order to verify the proposed method, we present detailed experimental setups and results measuring the correlation of the Semantic Uncertainty with the Content Change of news events using collected news events data. The results show that the correlation does exist and is stronger than the correlation of value from the time-series-based method with the Content Change. Therefore, we can use the Semantic Uncertainty to estimate the evolution potential of news events.
High Performance Packet Processing with FlexNIC
Authors: Kaufmann Antoine , Peter SImon , Sharma Naveen Kr. , Anderson Thomas , Krishnamurthy Arvind
Published: June 2016

The recent surge of network I/O performance has put enormous pressure on memory and software I/O processing sub systems. We argue that the primary reason for high memory and processing overheads is the inefficient use of these resources by current commodity network interface cards (NICs). We propose FlexNIC, a flexible network DMA interface that can be used by operating systems and applications alike to reduce packet processing overheads. FlexNIC allows services to install packet processing rules into the NIC, which then executes simple operations on packets while exchanging them with host memory. Thus, our proposal moves some of the packet processing traditionally done in software to the NIC, where it can be done flexibly and at high speed.

We quantify the potential benefits of FlexNIC by emulating the proposed FlexNIC functionality with existing hardware or in software. We show that significant gains in application performance are possible, in terms of both latency and throughput, for several widely used applications, including a key-value store, a stream processing system, and an intrusion detection system.
Maximizing Performance Under a Power Cap
Authors: Zhang Huazhe , Hoffmann Henry
Published: June 2016

Power and thermal dissipation constrain multicore performance scaling. Modern processors are built such that they could sustain damaging levels of power dissipation, creating a need for systems that can implement processor power caps. A particular challenge is developing systems that can maximize performance within a power cap, and approaches have been proposed in both software and hardware. Software approaches are flexible, allowing multiple hardware resources to be coordinated for maximum performance, but software is slow, requiring a long time to converge to the power target. In contrast, hardware power capping quickly converges to the the power cap, but only manages voltage and frequency, limiting its potential performance. In this work we propose PUPiL, a hybrid software/hardware power capping system. Unlike previous approaches, PUPiL combines hardware's fast reaction time with software's flexibility. We implement PUPiL on real Linux/x86 platform and compare it to Intel's commercial hardware power capping system for both single and multi-application workloads. We find PUPiL provides the same reaction time as Intel's hardware with significantly higher performance. On average, PUPiL outperforms hardware by from 1:18-2:4 depending on workload and power target. Thus, PUPiL provides a promising way to enforce power caps with greater performance than current state-of-the-art hardware-only approaches.
AxGames
Authors: Park Jongse , Amaro Emmanuel , Mahajan Divya , Thwaites Bradley , Esmaeilzadeh Hadi
Published: June 2016

Approximate computing trades quality of application output for higher efficiency and performance. Approximation is useful only if its impact on application output quality is acceptable to the users. However, there is a lack of systematic solutions and studies that explore users' perspective on the effects of approximation. In this paper, we seek to provide one such solution for the developers to probe and discover the boundary of quality loss that most users will deem acceptable. We propose AxGames, a crowdsourced solution that enables developers to readily infer a statistical common ground from the general public through three entertaining games. The users engage in these games by betting on their opinion about the quality loss of the final output while the AxGames framework collects statistics about their perceptions. The framework then statistically analyzes the results to determine the acceptable levels of quality for a pair of (application, approximation technique). The three games are designed such that they effectively capture quality requirements with various tradeoffs and contexts. To evaluate AxGames, we examine seven diverse applications that produce user perceptible outputs and cover a wide range of domains, including image processing, optical character recognition, speech to text conversion, and audio processing. We recruit 700 participants/users through Amazon's Mechanical Turk to play the games that collect statistics about their perception on different levels of quality. Subsequently, the AxGames framework uses the Clopper-Pearson exact method, which computes a binomial proportion confidence interval, to analyze the collected statistics for each level of quality. Using this analysis, AxGames can statistically project the quality level that satisfies a given percentage of users. The developers can use these statistical projections to tune the level of approximation based on the user experience. We find that the level of acceptable quality loss significantly varies across applications. For instance, to satisfy 90% of users, the level of acceptable quality loss is 2% for one application (image processing) and 26% for another (audio processing). Moreover, the pattern with which the crowd responds to approximation takes significantly different shape and form depending on the class of applications. These results confirm the necessity of solutions that systematically explore the effect of approximation on the end user experience.
TxRace
Authors: Zhang Tong , Lee Dongyoon , Jung Changhee
Published: June 2016

Detecting data races is important for debugging shared-memory multithreaded programs, but the high runtime overhead prevents the wide use of dynamic data race detectors. This paper presents TxRace, a new software data race detector that leverages commodity hardware transactional memory (HTM) to speed up data race detection. TxRace instruments a multithreaded program to transform synchronization-free regions into transactions, and exploits the conflict detection mechanism of HTM for lightweight data race detection at runtime. However, the limitations of the current best-effort commodity HTMs expose several challenges in using them for data race detection: (1) lack of ability to pinpoint racy instructions, (2) false positives caused by cache line granularity of conflict detection, and (3) transactional aborts for non-conflict reasons (e.g., capacity or unknown). To overcome these challenges, TxRace performs lightweight HTM-based data race detection at first, and occasionally switches to slow yet precise data race detection only for the small fraction of execution intervals in which potential races are reported by HTM. According to the experimental results, TxRace reduces the average runtime overhead of dynamic data race detection from 11.68x to 4.65x with only a small number of false negatives.
ProteusTM
Authors: Didona Diego , Diegues Nuno , Kermarrec Anne-Marie , Guerraoui Rachid , Neves Ricardo , Romano Paolo
Published: June 2016

The Transactional Memory (TM) paradigm promises to greatly simplify the development of concurrent applications. This led, over the years, to the creation of a plethora of TM implementations delivering wide ranges of performance across workloads. Yet, no universal implementation fits each and every workload. In fact, the best TM in a given workload can reveal to be disastrous for another one. This forces developers to face the complex task of tuning TM implementations, which significantly hampers their wide adoption. In this paper, we address the challenge of automatically identifying the best TM implementation for a given workload. Our proposed system, ProteusTM, hides behind the TM interface a large library of implementations. Underneath, it leverages a novel multi-dimensional online optimization scheme, combining two popular learning techniques: Collaborative Filtering and Bayesian Optimization.

We integrated ProteusTM in GCC and demonstrate its ability to switch between TMs and adapt several configuration parameters (e.g., number of threads). We extensively evaluated ProteusTM, obtaining average performance <3% from optimal, and gains up to 100x over static alternatives.
Interference Management for Distributed Parallel Applications in Consolidated Clusters
Authors: Han Jaeung , Jeon Seungheun , Choi Young-ri , Huh Jaehyuk
Published: June 2016

Consolidating multiple applications on a system can improve the overall resource utilization of data center systems. However, such consolidation can adversely affect the performance of some applications due to interference caused by resource contention. Despite many prior studies on the interference effects in single-node systems, the interference behaviors of distributed parallel applications have not been investigated thoroughly. With distributed applications, a local interference in a node can affect the whole execution of an application spanning many nodes. This paper studies an interference modeling methodology for distributed applications to predict their performance under interference effects in consolidated clusters. This study first characterizes the effects of interference for various distributed applications over different interference settings, and analyzes how diverse interference intensities on multiple nodes affect the overall performance. Based on the characterization, this study proposes a static profiling-based model for interference propagation and heterogeneity behaviors. In addition, this paper presents use case studies of the modeling method, two interference-aware placement techniques for consolidated virtual clusters, which attempt to maximize the overall throughput or to guarantee the quality-of-service.
Dirigent
Authors: Zhu Haishan , Erez Mattan
Published: June 2016

Latency-critical applications suffer from both average performance degradation and reduced completion time predictability when collocated with batch tasks. Such variation forces the system to overprovision resources to ensure Quality of Service (QoS) for latency-critical tasks, degrading overall system throughput. We explore the causes of this variation and exploit the opportunities of mitigating variation directly to simultaneously improve both QoS and utilization. We develop, implement, and evaluate Dirigent, a lightweight performance-management runtime system that accurately controls the QoS of latency-critical applications at fine time scales, leveraging existing architecture mechanisms. We evaluate Dirigent on a real machine and show that it is significantly more effective than configurations representative of prior schemes.
Sidewinder
Authors: Liaqat Daniyal , Jingoi Silviu , de Lara Eyal , Goel Ashvin , To Wilson , Lee Kevin , De Moraes Garcia Italo , Saldana Manuel
Published: June 2016

Applications that perform continuous sensing on mobile phones have the potential to revolutionize everyday life. Examples range from medical and health monitoring applications, such as pedometers and fall detectors, to participatory sensing applications, such as noise pollution, traffic and seismic activity monitoring. Unfortunately, current mobile devices are a poor match for continuous sensing applications as they require the device to remain awake for extended periods of time, resulting in poor battery life. This paper presents Sidewinder, a new approach towards offloading sensor data processing to a low-power processor and waking up the main processor when events of interest occur. This approach differs from other heterogeneous architectures in that developers are presented with a programming interface that lets them construct application specific wake-up conditions by linking together and parameterizing predefined sensor data processing algorithms. Our experiments indicate performance that is comparable to approaches that provide fully programmable offloading, but do so with a much simpler programming interface that facilitates deployment and portability.
COATCheck
Authors: Lustig Daniel , Sethi Geet , Martonosi Margaret , Bhattacharjee Abhishek
Published: June 2016

Modern computer systems include numerous compute elements, from CPUs to GPUs to accelerators. Harnessing their full potential requires well-defined, properly-implemented memory consistency models (MCMs), and low-level system functionality such as virtual memory and address translation (AT). Unfortunately, it is difficult to specify and implement hardware-OS interactions correctly; in the past, many hardware and OS specification mismatches have resulted in implementation bugs in commercial processors. In an effort to resolve this verification gap, this paper makes the following contributions. First, we present COATCheck, an address translation-aware framework for specifying and statically verifying memory ordering enforcement at the microarchitecture and operating system levels. We develop a domain-specific language for specifying ordering enforcement, for including ordering-related OS events and hardware micro-operations, and for programmatically enumerating happens-before graphs. Using a fast and automated static constraint solver, COATCheck can efficiently analyze interesting and important memory ordering scenarios for modern, high-performance, out-of-order processors. Second, we show that previous work on Virtual Address Memory Consistency (VAMC) does not capture every translation-related ordering scenario of interest, and that some such cases even fall outside the traditional scope of consistency. We therefore introduce the term transistency model to describe the superset of consistency which captures all translation-aware sets of ordering rules.
Prudent Memory Reclamation in Procrastination-Based Synchronization
Authors: Prasad Aravinda , Gopinath K.
Published: June 2016

Procrastination is the fundamental technique used in synchronization mechanisms such as Read-Copy-Update (RCU) where writers, in order to synchronize with readers, defer the freeing of an object until there are no readers referring to the object. The synchronization mechanism determines when the deferred object is safe to reclaim and when it is actually reclaimed. Hence, such memory reclamations are completely oblivious of the memory allocator state. This induces poor memory allocator performance, for instance, when the reclamations are ill-timed. Furthermore, deferred objects provide hints about the future that inform memory regions that are about to be freed. Although useful, hints are not exploited as deferred objects are not visible to memory allocators. We introduce Prudence, a dynamic memory allocator, that is tightly integrated with the synchronization mechanism to ensure visibility of deferred objects to the memory allocator. Such an integration enables Prudence to (i) identify the safe time to reclaim deferred objects' memory, (ii) have an inclusive view of the allocated, free and about-to-be-freed objects, and (iii) exploit optimizations based on the hints about the future during important state transitions. Our evaluation in the Linux kernel shows that Prudence integrated with RCU performs 3.9X to 28X better in micro-benchmarks compared to SLUB, a recent memory allocator in the Linux kernel. It also improves the overall performance perceptibly (4%-18%) for a mix of widely used synthetic and application benchmarks. Further, it performs better (up to 98%) in terms of object hits in caches, object cache churns, slab churns, peak memory usage and total fragmentation, when compared with the SLUB allocator.
CloudSeer
Authors: Yu Xiao , Joshi Pallavi , Xu Jianwu , Jin Guoliang , Zhang Hui , Jiang Guofei
Published: June 2016

Cloud infrastructures provide a rich set of management tasks that operate computing, storage, and networking resources in the cloud. Monitoring the executions of these tasks is crucial for cloud providers to promptly find and understand problems that compromise cloud availability. However, such monitoring is challenging because there are multiple distributed service components involved in the executions. CloudSeer enables effective workflow monitoring. It takes a lightweight non-intrusive approach that purely works on interleaved logs widely existing in cloud infrastructures. CloudSeer first builds an automaton for the workflow of each management task based on normal executions, and then it checks log messages against a set of automata for workflow divergences in a streaming manner. Divergences found during the checking process indicate potential execution problems, which may or may not be accompanied by error log messages. For each potential problem, CloudSeer outputs necessary context information including the affected task automaton and related log messages hinting where the problem occurs to help further diagnosis. Our experiments on OpenStack, a popular open-source cloud infrastructure, show that CloudSeer's efficiency and problem-detection capability are suitable for online monitoring.
Programmer Productivity in a World of Mushy Interfaces
Authors: Witchel Emmett
Published: June 2016

Since 1964, we had the notion that the instruction set architecture (ISA) is a useful and fairly opaque abstraction layer between hardware and software. Software rode hardware's performance wave while remaining gloriously oblivious to hardware's growing complexity. Unfortunately, the jig is up. We still have ISAs, but the abstraction no longer offers seamless portability---parallel software needs to be tuned for different core counts, and heterogeneous processing elements (CPUs, GPUs, accelerators) further complicate programmability. We are better at building large-scale heterogeneous processors than we are at programming them. Maintaining software across multiple current platforms is difficult and porting to future platforms is also difficult. There have been many technical responses: virtual ISAs (e.g., NVIDIA's PTX), higher-level programming interfaces (e.g., CUDA or OpenCL), and late-stage compilation and platform-specific tailoring (e.g., Android ART), etc.

A team of opinionated experts, drawn from the three ASPLOS communities will examine the problem of programmer productivity in the post-ISA world, first from the perspective of their area of expertise and then noting the contributions from the other two communities. What research will save us and how? This wide-ranging debate will frame important research areas for future work while being grounded in frank discussion about what has succeeded in the past. Attendees can expect actionable insight into important research issues as well an entertaining discussion.
TRPV1 Gene Polymorphisms Are Associated with Type 2 Diabetes by Their Interaction with Fat Consumption in the Korean Genome Epidemiology Study
Authors: Park Sunmin , Zhang Xin , Lee Na Ra , Jin Hyun-Seok
Published: June 2016

Background: Different transient receptor potential vanilloid 1 (TRPV1) variants may be differently activated by noxious stimuli. Aim: We investigated how TRPV1 variants modulated the prevalence of type 2 diabetes and specific gene-nutrient interactions. Methods: Among 8,842 adults aged 40-69 years in the Korean Genome Epidemiology Study, the associations between TRPV1 genotypes and the prevalence of type 2 diabetes as well as their gene-nutrient interactions were investigated after adjusting for the covariates of age, gender, residence area, body mass index, daily energy intake, and total activity. Results: The TRPV1 rs161364 and rs8065080 minor alleles lowered HOMA-IR and the risk of type 2 diabetes after adjusting for covariates. There were gene-nutrient interactions between TRPV1 variants rs161364 and rs8065080 and preference for oily taste, intake of oily foods, and fat intake after adjusting for covariates. Among subjects with the minor alleles of TRPV1 rs161364 and rs8065080, the group with a high preference for oily foods had a lower odds ratio for type 2 diabetes. Consistent with the preference for taste, among subjects with the minor alleles, the group with high fat intake from oily foods also exhibited a lower risk of type 2 diabetes than subjects with the major alleles. Conclusions: People with the minor alleles of the TRPV1 single nucleotide polymorphisms rs161364 and rs8065080 have a lower risk of diabetes with a high-fat diet, but people with the major alleles are at a higher risk of type 2 diabetes when consuming high-fat diets. The majority of people should be careful about a high fat intake.
A Case Report of Ischemic Stroke in a Patient with Metastatic Gastric Cancer Secondary to Treatment with the Vascular Endothelial Growth Factor Receptor-2 Inhibitor Ramucirumab
Authors: Christiansen Michael E. , Ingall Timothy , Lew Edward C. , Ramanathan Ramesh K. , Paripati Harshita R.
Published: June 2016

Ramucirumab is an antiangiogenesis agent targeting the vascular endothelial growth factor receptor-2 (VEGFR-2), approved to treat advanced gastric and colon cancer. In clinical trials, it was shown to cause a small increase in arterial thromboembolism compared to placebo, including cerebral and myocardial ischemia, which was not statistically significant. Detailed case reports are lacking and we here present one of the first case reports of stroke secondary to ramucirumab-induced in situ thrombosis.
The Effect of Synthetic Cannabinoids on P-Wave Dispersion: An Observational Study
Authors: Aydin Sunbul Esra , Sunbul Murat , Terzi Ayse , Calli Sumeyye , Koca Esra , Bilici Rabia , Citak Serhat
Published: June 2016

Objective: The aim of this study was to investigate the effect of synthetic cannabinoids (SC) on P-wave dispersion (PD) in patients who consume SC. Materials and Methods: The study population included 72 patients who consumed SC and 36 age- and sex-matched healthy controls. The severity of addiction was detected using the addiction profile index (BAPI). The PD was measured by 12-lead ECG obtained upon admission to hospital. Statistical analyses were performed using the SPSS v20.0 statistical software package. Results: The mean age of the patients and controls was 26.9 ± 7.0 and 26.3 ± 6.5 years, respectively. Mean duration of SC consumption was 1.7 ± 0.7 years. Mean BAPI score of patients who consumed SC was 12.8 ± 3.4. Patients who consumed SC had a significantly higher PD value than controls (37.7 ± 11.5 vs. 30.6 ± 6.4 ms, p < 0.001). The BAPI score was significantly correlated with PD value (r = 0.675, p < 0.001). In the linear regression model that included PD value, age and heart rate, PD value was significantly and independently correlated with BAPI score (r2 of the model = 0.339; p < 0.001). Conclusions: In this study, patients who consumed SC had significantly higher PD values than controls, and the BAPI score correlated with the PD value. Hence SC consumption could lead to an increased risk of cardiovascular disease through prolonged PD. We recommend the use of the simple and inexpensive ECG to assess cardiovascular risk in patients who consume SC.
INOVAÇÕES METODOLÓGICAS PARA CONSTRUÇÃO DE CENÁRIOS ESTRATÉGICOS EM BACIAS HIDROGRÁFICAS
Authors: Magalhães Rafael Caldeira , Barp Ana Rosa Baganha
Published: June 2016

A questão central deste artigo é investigar a teoria e metodologia de criação e simulação de cenários estratégicos dos recursos hídricos em bacia hidrográfica. Esta teoria está baseada em três elementos da álgebra linear, sendo as teorias de matrizes, dos grafos e dos jogos. A integração de tais teorias foi utilizada através de métodos de análise estrutural, análise de atores sociais e análise morfológica, voltados para o planejamento e gestão da água. Para facilitar a compreensão, a modelagem computacional trouxe contribuições importantes através de três softwares: MICMAC (matriz de impacto cruzado-multiplicação aplicado à classificação), MACTOR (atores, objetivos e relações de força) e MORPHOL (matriz morfológica). A área de estudo é a bacia hidrográfica do Rio Ararandeua, caracterizada predominantemente pela prática do desmatamento na Amazônia brasileira, com grande incidência de conflitos pelo uso da água. Este trabalho demonstra a necessidade de que o planejamento do uso da água deve considerar as dinâmicas sociais, econômicas e ambientais do território na visão de desenvolvimento sustentável. A partir do trabalho de campo realizado no âmbito da pesquisa, foi possível criar e simular os cenários da bacia do Rio Ararandeua. Entre os cenários criados, destacam-se duas alternativas de gestão de recursos hídricos: o cenário sustentável e o cenário tendencial de exploração de recursos naturais.
PROCESSO DE PLANEJAMENTO DE NEGÓCIO (PPNEG): COMPLEMENTANDO O PROCESSO DE PLANEJAMENTO TECNOLÓGICO (PPTEC) PARA A GERAÇÃO DE EMPRESAS DE BASE TECNOLÓGICA (EBT) DE ORIGEM ACADÊMICA (OA)
Authors: Reis Luciana Paula , Cheng Lin Chih , Ladeira Marcelo Bronzo , Fernandes June Marques
Published: June 2016

O objetivo deste artigo é o de descrever em detalhe o Processo de Planejamento de Negócio (PPNeg) em complemento ao Processo de Planejamento Tecnológico (PPTec) no contexto da geração de Empresas de Base Tecnológica (EBT) de Origem Acadêmica (OA). Para a construção dos pictogramas do PPTec e do PPNeg foram analisados 29 projetos de pesquisa acadêmica contemplados pelo Programa de Incentivo à Inovação (PII), no âmbito de cinco universidades mineiras (UFLA, UFJF, UNIFEI, UFV e UFMG). A estratégia de pesquisa adotada em cada um dos projetos de intervenção pode ser classificada como pesquisa-ação, com o uso combinado de métodos e técnicas de Gestão de Desenvolvimento de Produtos (GDP), logística e gestão de operações. Como resultado da pesquisa tem-se a identificação das atividades e das decisões tomadas ao longo das fases do PPNeg e a elaboração de pictogramas para a representação da interação entre os dois processos mencionados, importantes para a inovação tecnológica no contexto acadêmico. Como limitação, tem-se o reduzido número de casos que acabam por não contemplar toda a diversidade de empresas de base tecnológica existentes no País. Outra limitação do estudo está no fato de que os pictogramas não relatam os recursos necessários e as dificuldades enfrentadas pela equipe na superação das fases exploradas. Apesar das limitações, o estudo utiliza-se de uma metodologia robusta para auxiliar os pesquisadores na definição dos modelos de negócio e na estruturação das estratégias logísticas e de operações importantes para a configuração de um novo negócio tecnológico.
MODELO DE GERAÇÃO DE INOVAÇÕES EM UM AMBIENTE DE RECURSOS ESCASSOS (MGIARE): UMA APLICAÇÃO AO TURISMO
Authors: Tavares Jean Max , Salvador Regina Faia , Mores Giana De Vargas
Published: June 2016

Uma região turística menos desenvolvida (regiões seguidoras), deve construir seu modelo de geração de inovação de acordo com sua realidade e com o menor custo possível, pois competem com outras regiões dotadas de mais recursos e com atrações conhecidas mundialmente (regiões líderes). Esse modelo seria baseado na interação entre os agentes, na disseminação de ideias e na construção de um ambiente cooperativo, as quais tem recursos financeiros escassos, trabalhadores pouco qualificados e estão distantes de universidades e centros de pesquisa. Portanto, foi criado um modelo de geração de inovação em um ambiente de recursos escassos aplicado ao turismo, usando a experiência e a troca de informações entre os segmentos de suporte (hospedagem e alimentação) e o segmento essencial (entretenimento e agentes intermediários) como principais insumos. Espera-se que esse modelo possa ser validado em futuras pesquisas bem como estendido para outros setores da economia.
A CONTABILIZAÇÃO DO ATIVO INTANGÍVEL NAS 522 EMPRESAS LISTADAS NA BM&FBOVESPA
Authors: Mantovani Erick , Santos Fernando De Almeida
Published: June 2016

O trabalho estuda o impacto da contabilização do ativo intangível das empresas listadas na Bolsa de Valores de São Paulo (BM&FBovespa). O procedimento de avaliação e contabilização do intangível atende à legislação atual, conforme as Leis Nº 11.638/07 e Nº 11.941/09 e as Normas Brasileiras de Contabilidade, que buscam ampliar a transparência e atender a harmonização internacional contábil. A contabilização é fundamental, pois reflete diretamente a valoração do capital intelectual e da inovação da empresa. Para desenvolver a pesquisa foi realizado levantamento bibliográfico, além de consulta a legislação e às normas contábeis vigentes. Posteriormente, com base na coleta de dados dos balanços patrimoniais, referentes ao ano de 2012, das 522 empresas listadas, foi possível verificar os valores contabilizados dos ativos intangíveis destas sociedades e, por meio de análise estatística, compará-los com o ativo não circulante, com o ativo total e com o patrimônio líquido. O trabalho constatou que 26,05% das empresas listadas demonstraram não registrar nenhum valor em ativos intangíveis, logo afirmam não registrar seu capital intelectual, seu valor da marca ou institucional, sua capacidade de inovação, patentes e outros. Também, pode-se observar que as instituições financeiras são as empresas com maiores valores em ativos totais, porém seus ativos intangíveis representam menos de 2% destes ativos. As concessionárias de rodovias, por sua vez, são as empresas em que os ativos intangíveis registrados têm a maior representatividade em relação ao patrimônio total e as estatais que possuem os maiores valores reais, sendo que ocupam duas das cinco primeiras posições. .
GESTÃO SUSTENTÁVEL DA CADEIA DE SUPRIMENTOS E DESEMPENHO INOVADOR: UM ESTUDO MULTICASO NO SETOR MINERAL BRASILEIRO
Authors: Rocha Adilson Carlos da , Gomes Clandia Maffini , Kneipp Jordana Marques , Camargo Caroline Rossetto
Published: June 2016

O presente estudo teve como objetivo analisar a associação entre a gestão sustentável da cadeia de suprimentos e o desempenho inovador do processo produtivo em empresas do setor mineral brasileiro. Para atingir esse objetivo utilizou-se como base os pressupostos teóricos de Pagell e Wu (2009), Makkonen e Van Der Have (2012) e Gunday et al. (2011). O estudo possui uma abordagem qualitativa e natureza exploratória e descritiva. Como estratégia de pesquisa, utilizou-se o método de estudo multicaso, desenvolvido a partir de entrevistas exploratórias e pesquisa documental. Dentre os principais resultados, foi possível destacar, em dois casos, a disposição proativa em prol de políticas e ações que contribuam para a sustentabilidade da cadeia de suprimentos, tendo em vista que foi possível evidenciar a adoção de práticas sustentáveis e de inovação em processos nas empresas Carvão I e Ferro-Níquel. Por outro lado, na empresa Carvão II, o pressuposto orientador do estudo não pôde ser corroborado pelas evidências. Os resultados sugerem que parte das organizações que atuam no setor mineral brasileiro está buscando atender às demandas dos seus stakeholders, principalmente no que se refere ao investimento em ações sustentáveis ligadas as dimensões ambientais e sociais.