bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electric field induced crossings of energy terms of a Rydberg quasi molecule enhancing charge exchange and ionization
Authors: Kryukov N. , Oks E. 
Published: July 2012

Charge exchange is one of the most important atomic processes in plasmas. Charge exchange and crossings of corresponding energy levels that enhance charge exchange are strongly connected with problems of energy losses and of diagnostics in high temperature plasmas. Charge exchange was also proposed as an effective mechanism for population inversion in the soft X-ray and vacuum ultraviolet ranges. One of the most fundamental theoretical domains for studying charge exchange is the problem of electron terms in the field of two stationary Coulomb centers (TCC) of charges Z and Z′ separated by a distance R. It presents an intriguing atomic physics: the terms can have crossings and quasi crossings. These intrinsic features of the TCC problem also manifest in different areas of physics, such as plasma spectroscopy: a quasi crossing of the TCC terms, by enhancing charge exchange, can result in an unusual structure (a dip) in the spectral line profile emitted by a Z-ion from a plasma consisting of both Z- and Z′-ions, as was shown theoretically and experimentally. Before the year 2000, the paradigm was that the preceding sophisticated features of the TCC problem and its flourishing applications were inherently quantum phenomena. In 2000, a purely classical description of the crossings of energy terms was presented. In the present paper we study the effect of an electric field (along the internuclear axis) on circular Rydberg states of the TCC system. We provide analytical results for strong fields, as well as numerical results for moderate fields. We show that the electric field has several effects. First, it leads to the appearance of an extra energy term: the fourth classical energy term — in addition to the three classical energy terms at zero field. Second, but more importantly, the electric field creates additional crossings of these energy terms. We show that some of these crossings significantly enhance charge exchange, while other crossings enhance the ionization of the Rydberg quasi molecule.
AN ADAPTIVE RANDOM WALK BASED DISTRIBUTED CLUSTERING ALGORITHM
Authors: BUI ALAIN , KUDIRETI ABDURUSUL , SOHIER DEVAN 
Published: July 2012

In this paper, we present a fully distributed random walk based clustering algorithm intended to work on dynamic networks of arbitrary topologies. A bounded-size core is built through a random walks based procedure. Its neighboring nodes that do not belong to any cluster are recruited by the core as ordinary nodes. Using cores allow us to formulate constraints on the clustering and fulfill them on any topology. The correctness and termination of our algorithm are proven. We also prove that when two clusters are adjacent, at least one of them has a complete core (i.e. a core with the maximum size allowed by the parameter). One of the important advantages of our mobility-adaptive algorithm is that the re-clustering is local: the management of the connections or disconnections of links and reorganization of nodes affect only the clusters in which they are, possibly adjacent clusters, and at worst, the ordinary nodes of the clusters adjacent to the neighboring clusters. This allows us to bound the diameter of the portion of the network that is affected by a topological change.
THERMODYNAMICS OF A SCHWARZSCHILD BLACK HOLE IN PHANTOM COSMOLOGY WITH ENTROPY CORRECTIONS
Authors: JAMIL MUBASHER , MOMENI D. , BAMBA KAZUHARU , MYRZAKULOV RATBAY 
Published: July 2012

Motivated by some earlier works [G. Izquierdo and D. Pavon, Phys. Lett. B 639 (2006) 1; H. M. Sadjadi, Phys. Lett. B 645 (2007) 108.] dealing with the study of generalized second law (GSL) of thermodynamics for a system comprising of a Schwarzschild black hole accreting a test nonself-gravitating fluid namely phantom energy in FRW universe, we extend them when the entropy of horizons of black hole and the cosmological undergo quantum corrections. Two types of such corrections are relevant here including logarithmic and power-law, while both are motivated from different theoretical backgrounds. We obtain general mathematical conditions for the validity of GSL in each case. Further we find that GSL restricts the mass of black hole for accretion of phantom energy. As such we obtain upper bounds on the mass of black hole above which the black hole cannot accrete the phantom fluid, otherwise the GSL is violated.
ON THE NEWTON–KANTOROVICH THEOREM
Authors: CIARLET PHILIPPE G. , MARDARE CRISTINEL 
Published: July 2012

The Newton–Kantorovich theorem enjoys a special status, as it is both a fundamental result in Numerical Analysis, e.g., for providing an iterative method for computing the zeros of polynomials or of systems of nonlinear equations, and a fundamental result in Nonlinear Functional Analysis, e.g., for establishing that a nonlinear equation in an infinite-dimensional function space has a solution. Yet its detailed proof in full generality is not easy to locate in the literature. The purpose of this article, which is partly expository in nature, is to carefully revisit this theorem, by means of a two-tier approach. First, we give a detailed, and essentially self-contained, account of the classical proof of this theorem, which essentially relies on careful estimates based on the integral form of the mean value theorem for functions of class [Formula: see text] with values in a Banach space, and on the so-called majorant method. Our treatment also includes a careful discussion of the often overlooked uniqueness issue. An example of a nonlinear two-point boundary value problem is also given that illustrates the power of this theorem for establishing an existence theorem when other methods of nonlinear functional analysis cannot be used. Second, we give a new version of this theorem, the assumptions of which involve only one constant instead of three constants in its classical version and the proof of which is substantially simpler as it altogether avoids the majorant method. For these reasons, this new version, which captures all the basic features of the classical version could be considered as a good alternative to the classical Newton–Kantorovich theorem.
Knowledge Sharing and its Impact on Knowledge Creation
Authors: Akhavan Peyman , Ghojavand Somayeh , Abdali Roghayeh 
Published: July 2012

It is known that "knowledge management" is associated with significant benefits which can empower organisations to get more competitive advantages in their market. Knowledge sharing and knowledge creation are the two vital aspects of knowledge management which play an important role in creating organisational value. The value-creation of knowledge depends on level of sharing knowledge and skills among people across the organisation. So, most companies are focussed on enhancing their capability of knowledge sharing to create new knowledge. The aim of this paper is to test empirically the degree of influence of different knowledge-sharing mechanisms on the knowledge creation capability of Iranian manufacturing industries.A question survey was administered to a sample of manufacturing industries operating in Iran to elicit opinions of the personnel on the relationship between knowledge sharing and knowledge creation. The questions were structured mostly based on Sa'enz et al. (2009) and Choi and Lee (2002) studies. More than 400 respondents from 16 organisations responded to the survey. A short training course was held in all sample firms separately to explain importance and applications of knowledge management for respondents. SPSS and LISREL software were utilised to analyse research data using Regression tests and structural equation modelling (SEM). Results obtained show that knowledge sharing has a positive influence on the knowledge creation in Iranian manufacturing industries. However, a meaningful relationship was observed between information technology and management processes and two constructs of knowledge creation. The main contribution of the paper is to provide empirical evidence about the impact of knowledge sharing on knowledge creation. Moreover, it reveals what the most effective knowledge-sharing mechanisms are for this purpose, and provides companies with some implications in order to shape their knowledge management strategies.
Investigating the Persuasion Potential of Recommender Systems from a Quality Perspective
Authors: Cremonesi Paolo , Garzotto Franca , Turrin Roberto 
Published: July 2012

Recommender Systems (RSs) help users search large amounts of digital contents and services by allowing them to identify the items that are likely to be more attractive or useful. RSs play an important persuasion role, as they can potentially augment the users’ trust towards in an application and orient their decisions or actions towards specific directions. This article explores the persuasiveness of RSs, presenting two vast empirical studies that address a number of research questions.
First, we investigate if a design property of RSs, defined by the statistically measured quality of algorithms, is a reliable predictor of their potential for persuasion. This factor is measured in terms of perceived quality, defined by the overall satisfaction, as well as by how users judge the accuracy and novelty of recommendations. For our purposes, we designed an empirical study involving 210 subjects and implemented seven full-sized versions of a commercial RS, each one using the same interface and dataset (a subset of Netflix), but each with a different recommender algorithm. In each experimental configuration we computed the statistical quality (recall and F-measures) and collected data regarding the quality perceived by 30 users. The results show us that algorithmic attributes are less crucial than we might expect in determining the user’s perception of an RS’s quality, and suggest that the user’s judgment and attitude towards a recommender are likely to be more affected by factors related to the user experience.
Second, we explore the persuasiveness of RSs in the context of large interactive TV services. We report a study aimed at assessing whether measurable persuasion effects (e.g., changes of shopping behavior) can be achieved through the introduction of a recommender. Our data, collected for more than one year, allow us to conclude that, (1) the adoption of an RS can affect both the lift factor and the conversion rate, determining an increased volume of sales and influencing the user’s decision to actually buy one of the recommended products, (2) the introduction of an RS tends to diversify purchases and orient users towards less obvious choices (the long tail), and (3) the perceived novelty of recommendations is likely to be more influential than their perceived accuracy.
Overall, the results of these studies improve our understanding of the persuasion phenomena induced by RSs, and have implications that can be of interest to academic scholars, designers, and adopters of this class of systems.
A framework for the checking and refactoring of crosscutting concepts
Authors: Shonle Macneil , Griswold William G. , Lerner Sorin 
Published: July 2012

Programmers employ crosscutting concepts, such as design patterns and other programming idioms, when their design ideas cannot be efficiently or effectively modularized in the underlying programming language. As a result, implementations of these crosscutting concepts can be hard to change even when the code is well structured.
In this article, we describe Arcum, a system that supports the modular maintenance of crosscutting concepts. Arcum can be used to both check essential constraints of crosscutting concepts and to substitute crosscutting concept implementations with alternative implementations. Arcum is complementary to existing refactoring systems that focus on meaning-preserving program transformations at the programming-language-semantics level, because Arcum focuses on transformations at the conceptual level.
We present the underpinnings of the Arcum approach and show how Arcum can be used to address several classical software engineering problems.
Partially Evaluating Finite-State Runtime Monitors Ahead of Time
Authors: Bodden Eric , Lam Patrick , Hendren Laurie 
Published: July 2012

Finite-state properties account for an important class of program properties, typically related to the order of operations invoked on objects. Many library implementations therefore include manually written finite-state monitors to detect violations of finite-state properties at runtime. Researchers have recently proposed the explicit specification of finite-state properties and automatic generation of monitors from the specification. However, runtime monitoring only shows the presence of violations, and typically cannot prove their absence. Moreover, inserting a runtime monitor into a program under test can slow down the program by several orders of magnitude.
In this work, we therefore present a set of four static whole-program analyses that partially evaluate runtime monitors at compile time, with increasing cost and precision. As we show, ahead-of-time evaluation can often evaluate the monitor completely statically. This may prove that the program cannot violate the property on any execution or may prove that violations do exist. In the remaining cases, the partial evaluation converts the runtime monitor into a residual monitor. This monitor only receives events from program locations that the analyses failed to prove irrelevant. This makes the residual monitor much more efficient than a full monitor, while still capturing all property violations at runtime.
We implemented the analyses in Clara, a novel framework for the partial evaluation of AspectJ-based runtime monitors, and validated our approach by applying Clara to finite-state properties over several large-scale Java programs. Clara proved that most of the programs never violate our example properties. Some programs required monitoring, but in those cases Clara could often reduce the monitoring overhead to below 10%. We observed that several programs did violate the stated properties.
Turing, the internet and a theory for architecture
Authors: Trossen Dirk 
Published: July 2012

The late noughties have seen an influx of work in different scientific disciplines, all addressing the question of 'design' and 'architecture'. It is a battle between those advocating the theory of 'emergent properties' and others who strive for a 'theory for 'architecture'. We provide a particular insight into this battle, represented in the form of a story that focuses on the role of a possibly unusual protagonist and his influence on computer science, the Internet, architecture and beyond. We show his relation to one of the great achievements of system engineering, the Internet, and the possible future as it might unfold.
Note from the writer: The tale is placed in a mixture of reality and fiction, while postulating a certain likelihood for this fiction. There is no proof for the assertions made in this tale, leaving the space for a sequel to be told.
An automatic control interface for network-accessible embedded instruments
Authors: Smecher Graeme , Aubin François , George Elizabeth , de Haan Tijmen , Kennedy James , Dobbs Matt 
Published: July 2012

We describe a metaprogrammed control interface and support library for network-accessible embedded systems. Together, this project permits functions written in standard C code to be exposed via a network interface expressed in JSON. In turn, this JSON interface mates with a Python library that provides a high-level, user-friendly, and expressive development environment.
This control interface removes the need to explicitly code interactions at the Python and network layers. As a result, the volume of error-prone and redundant hand-written code (e.g. for error-checking and validation) is vastly reduced.
On benchmarking embedded Linux flash file systems
Authors: Olivier Pierre , Boukhobza Jalil , Senn Eric 
Published: July 2012

Due to its attractive characteristics in terms of performance, weight and power consumption, NAND flash memory became the main non volatile memory (NVM) in embedded systems. Those NVMs also present some specific characteristics/constraints: good but asymmetric I/O performance, limited lifetime, write/erase granularity asymmetry, etc.
Those peculiarities are either managed in hardware for flash disks (SSDs, SD cards, USB sticks, etc.) or in software for raw embedded flash chips. When managed in software, flash algorithms and structures are implemented in a specific flash file system (FFS). In this paper, we present a performance study of the most widely used FFSs in embedded Linux: JFFS2, UBIFS, and YAFFS. We show some very particular behaviors and large performance disparities for tested FFS operations such as mounting, copying, and searching file trees, compression, etc.
What is a good buffer cache replacement scheme for mobile flash storage?
Authors: Kim Hyojun , Ryu Moonkyung , Ramachandran Umakishore 
Published: July 2012

Smartphones are becoming ubiquitous and powerful. The Achilles' heel in such devices that limits performance is the storage. Low-end flash memory is the storage technology of choice in such devices due to energy, size, and cost considerations. In this paper, we take a critical look at the performance of flash on smartphones for mobile applications. Specifically, we ask the question whether the state-of-the-art buffer cache replacement schemes proposed thus far (both flash-agnostic and flash-aware ones) are the right ones for mobile flash storage. To answer this question, we first expose the limitations of current buffer cache performance evaluation methods, and propose a novel evaluation framework that is a hybrid between trace-driven simulation and real implementation of such schemes inside an operating system. Such an evaluation reveals some unexpected and surprising insights on the performance of buffer management schemes that contradicts conventional wisdom. Armed with this knowledge, we propose a new buffer cache replacement scheme called SpatialClock.
Using our evaluation framework, we show the superior performance of SpatialClock relative to the state-of-the-art for mobile flash storage.
Don't let the negatives bring you down
Authors: Cohen Edith , Cormode Graham , Duffield Nick 
Published: July 2012

Random sampling has been proven time and time again to be a powerful tool for working with large data. Queries over the full dataset are replaced by approximate queries over the smaller (and hence easier to store and manipulate) sample. The sample constitutes a flexible summary that supports a wide class of queries. But in many applications, datasets are modified with time, and it is desirable to update samples without requiring access to the full underlying datasets. In this paper, we introduce and analyze novel techniques for sampling over dynamic data, modeled as a stream of modifications to weights associated with each key.
While sampling schemes designed for stream applications can often readily accommodate positive updates to the dataset, much less is known for the case of negative updates, where weights are reduced or items deleted altogether. We primarily consider the turnstile model of streams, and extend classic schemes to incorporate negative updates. Perhaps surprisingly, the modifications to handle negative updates turn out to be natural and seamless extensions of the well-known positive update-only algorithms. We show that they produce unbiased estimators, and we relate their performance to the behavior of corresponding algorithms on insert-only streams with different parameters. A careful analysis is necessitated, in order to account for the fact that sampling choices for one key now depend on the choices made for other keys.

In practice, our solutions turn out to be efficient and accurate. Compared to recent algorithms for L
p
sampling which can be applied to this problem, they are significantly more reliable, and dramatically faster.
Content-aware traffic engineering
Authors: Frank Benjamin , Poese Ingmar , Smaragdakis Georgios , Uhlig Steve , Feldmann Anja 
Published: July 2012

Recent studies show that a large fraction of Internet traffic is originated by Content Providers (CPs) such as content distribution networks and hyper-giants. To cope with the increasing demand for content, CPs deploy massively distributed server infrastructures. Thus, content is available in many network locations and can be downloaded by traversing different paths in a network. Despite the prominent server location and path diversity, the decisions on how to map users to servers by CPs and how to perform traffic engineering by ISPs, are independent. This leads to a lose-lose situation as CPs are not aware about the network bottlenecks nor the location of end-users, and the ISPs struggle to cope with rapid traffic shifts caused by the dynamic CP server selection process.
In this paper we propose and evaluate Content-aware Traffic Engineering (CaTE), which dynamically adapts the traffic demand for content hosted on CPs by utilizing ISP network information and end-user location during the server selection process. This leads to a win-win situation because CPs are able to enhance their end-user to server mapping and ISPs gain the ability to partially influence the traffic demands in their networks. Indeed, our results using traces from a Tier-1 ISP show that a number of network metrics can be improved when utilizing CaTE.
Neutrophils Promote Liver Metastasis via Mac-1–Mediated Interactions with Circulating Tumor Cells
Authors: Spicer Jonathan D. , McDonald Braedon , Cools-Lartigue Jonathan J. , Chow Simon C. , Giannias Betty , Kubes Paul , Ferri Lorenzo E. 
Published: July 2012

Abstract
Although circulating neutrophils are associated with distant metastasis and poor outcome in a number of epithelial malignancies, it remains unclear whether neutrophils play an active causal role in the metastatic cascade. Using in vivo models of metastasis, we found that neutrophils promote cancer cell adhesion within liver sinusoids and, thereby, influence metastasis. Neutrophil depletion before cancer cell inoculation resulted in a decreased number of gross metastases in an intrasplenic model of liver metastasis. This effect was reversed when inflamed neutrophils were co-inoculated with cancer cells. In addition, early adhesion within liver sinusoids was inhibited in the absence of neutrophils and partially restored with a short perfusion of isolated activated neutrophils. Intravital microscopy showed that cancer cells adhered directly on top of arrested neutrophils, indicating that neutrophils may act as a bridge to facilitate interactions between cancer cells and the liver parenchyma. The adhesion of lipopolysaccharide-activated neutrophils to cancer cells was mediated by neutrophil Mac-1/ICAM-1. Our findings, therefore, show a novel role for neutrophils in the early adhesive steps of liver metastasis. Cancer Res; 72(16); 3919–27. ©2012 AACR.