bluuebunny/crossref_metadata_2025 huggingface dataset:
THE FORMATION OF LARGE GALACTIC DISKS THROUGH THE HIERARCHICAL SCENARIO: FURTHER CONSEQUENCES
Authors: HAMMER FRANCOIS , YANG YANBIN , FLORES HECTOR , PUECH MATHIEU
Published: October 2012

Using the deepest and most complete observations of distant galaxies, we investigate the progenitors of present-day large spirals. Observations include spatially-resolved kinematics, detailed morphologies and photometry from UV to mid-IR. Six billion years ago, half of the present-day spirals were starbursts experiencing major mergers, evidenced by their anomalous kinematics and morphologies. They are consequently modeled using hydrodynamic models of mergers and it perfectly matches with merger rate predictions by state-of-the-art-ΛCDM semi-empirical models. Furthermore imprints in the halo of local galaxies such as M31 or NGC5907 are likely caused by major merger relics. This suggests that the hierarchical scenario has played a major role in shaping the massive galaxies of the Hubble sequence. Linking galaxy properties at different epochs is the best way to fully understand galaxy formation processes and we have tested such a link through generated series of simulations of gas-rich mergers. Mergers have expelled material in galactic haloes and beyond, possibly explaining 60% of the missing baryons in Milky-Way (MW) mass galaxies. A past major merger in M31 might affect drastically our understanding of Local Group galaxies, including MW dwarves. We also propose future directions to observationally constrain the necessary ingredients in galaxy simulations.
RECENT STUDIES OF TOP QUARK PROPERTIES AND DECAYS AT HADRON COLLIDERS
Authors: CHIOCHIA V.
Published: October 2012

The top quark is the heaviest known elementary particle. Observed for the first time in 1995 at the Tevatron by the CDF and D0 experiments, it has become object of several studies aimed to fully characterize its properties and decays. Precise determinations of top quark characteristics verify the internal consistency of the Standard Model (SM) and are sensitive to new physics phenomena. With the advent of the large top quark production rates generated at the LHC, top quark studies have reached unprecedented statistical precision. This review summarizes the recent measurements of top quark properties and studies of its decays performed at the LHC and Tevatron.
TRANSFORMATION LAWS OF THE COMPONENTS OF CLASSICAL AND QUANTUM FIELDS AND HEISENBERG RELATIONS
Authors: ILIEV BOZHIDAR Z.
Published: October 2012

This paper recalls and shows the origin of the transformation laws of the components of classical and quantum fields. They are considered from the "standard" and fiber bundle point of view. The results are applied to the derivation of the Heisenberg relations in quite general setting, in particular, in the fiber bundle approach. All conclusions are illustrated in a case of transformations induced by the Poincaré group.
InN PHOTOCONDUCTORS ON DIFFERENT ORIENTATIONS OF Si SUBSTRATES
Authors: AMIRHOSEINY M. , HASSAN Z. , NG S. S. , CHUAH L. S. , AHMAD M. A. , YUSOF Y.
Published: October 2012

We have fabricated photoconductors of indium nitride (InN) grown by radio frequency (RF) sputtering. The InN thin films were deposited on Si (100), Si (110) and Si (111) substrates at room temperature. The Ag/Al contact has been deposited by thermal evaporation in vacuum (10-5 Torr ) and then annealed under the flowing of the nitrogen gas environment in order to relieve stress and also induce any favorable reactions between metals and the semiconductor. Current–voltage (I–V) measurements after heat treatment at 400°C were carried out for samples in dark and illumination conditions. It was found that Ag/Al formed a good ohmic contact on top of InN . In addition, the characteristics of the contacts were significantly affected by the orientation of substrates.
STRUCTURAL AND OPTICAL CHARACTERIZATION OF NANOCRYSTALLINE CuAlS2 CHALCOPYRITE SYNTHESIZED BY POLYOL METHOD IN AUTOCLAVE
Authors: VAHIDSHAD Y. , IRAJIZAD A. , GHASEMZADEH R. , MIRKAZEMI S. M. , MASOUD A.
Published: October 2012

Chalcopyrite CuAlS 2 nanoparticles were synthesized with polyol method. The solvothermal with autoclave nanoparticles synthesized are investigated. The amount and temperature of reducer, the solvent of salts could be important parameters that were studied. The nanoparticles were synthesized with CuCl , AlCl 3 and thiourea ( SC ( NH 2)2) as precursors, diethylene glycol (( CH 2 CH 2 OH )2 O ) and polyethylene glycol 600 ( HO ( C 2 H 4 O )n H ) as solvent and capping agent respectively, and ammonia ( NH 4 OH ) as reducing agent. The parameters of synthesis were studied by X-Ray diffraction (XRD) for analysis of structure, scanning electron microscope (SEM) for morphology and by ultraviolet–visible (UV–VIS) spectrophotometer for analysis of light structure. The possible formation mechanism is also discussed.
INFORMATION ASYMMETRY FLOWING IN COMPLEX NETWORKS
Authors: SHAO CHEN-XI , DOU HUI-LING , WANG BING-HONG
Published: October 2012

The concept of information asymmetry in complex networks is introduced on the basis of information asymmetry in economics and symmetry breaking. Information flowing between two nodes on a link is bidirectional, whose size is closely related to traffic dynamics on the network. Based on asymmetric information theory, we proposed information flow between network nodes is asymmetrical. We designed two methods to calculate the amount of information flow based on two mechanisms of complex network. Unequal flow of two opposite directions on the same link proved information asymmetry exists in the complex network. A complex network evolution model based on symmetry breaking is established, which is a truthful example for complex network mimicking nature. The evolution mechanism of symmetry breaking can best explain the phenomenon of the weak link and long tail theory in complex network.
AN EFFICIENT WEIGHTED ROUTING STRATEGY FOR SCALE-FREE NETWORKS
Authors: JIANG ZHONG-YUAN , LIANG MAN-GUI , HUANG JIAN-LING , LI QIAN
Published: October 2012

Considering the link congestion based traffic model, which can more accurately model the traffic diffusing process of many real complex systems such as the Internet, we propose an efficient weighted routing strategy in which each link's weight is assigned with the edge betweenness of the original un-weighted network with a tunable parameter α. As the links with the highest edge betweenness are susceptible to traffic congestion, our routing strategy efficiently redistribute the heavy traffic load from central links to noncentral links. The highest traffic capacity under this new routing strategy is achieved when compared with the shortest path routing strategy and the efficient routing strategy. Moreover, the average path length of our routing strategy is much smaller than that of the efficient routing strategy. Therefore, our weighted routing strategy is preferable to other routing strategies and can be easily implemented through software method.
ENTROPY ANALYSIS OF WORD-LENGTH SERIES OF NATURAL LANGUAGE TEXTS: EFFECTS OF TEXT LANGUAGE AND GENRE
Authors: KALIMERI MARIA , CONSTANTOUDIS VASSILIOS , PAPADIMITRIOU CONSTANTINOS , KARAMANOS KONSTANTINOS , DIAKONOS FOTIS K. , PAPAGEORGIOU HARIS
Published: October 2012

We estimate the n-gram entropies of natural language texts in word-length representation and find that these are sensitive to text language and genre. We attribute this sensitivity to changes in the probability distribution of the lengths of single words and emphasize the crucial role of the uniformity of probabilities of having words with length between five and ten. Furthermore, comparison with the entropies of shuffled data reveals the impact of word length correlations on the estimated n-gram entropies.
ENERGY–MOMENTUM DISTRIBUTIONS OF FIVE-DIMENSIONAL HOMOGENEOUS-ANISOTROPIC UNIVERSES
Authors: DOGRU MELİS ULU , BAYKAL DERYA , KIY GÜLİZ , TASER DOGUKAN , CAGLAR HALİFE , VARLIKLI NERİMAN
Published: October 2012

In this study, it has been investigated whether the energy and momentum can be localizable for five-dimensional homogeneous and anisotropic universes. In this connection, energy and momentum of five-dimensional Bianchi type-I, type-III and type-V spacetimes have been calculated in the framework of general relativity (GR) and teleparallel gravity (TG). Einstein, Bergmann–Thomson, Landau–Lifshitz, Papapetrou, Tolman and Møller energy–momentum complexes have been used to obtain these related quantities of given the spacetimes in GR, while Einstein, Bergmann–Thomson, Landau–Lifshitz and Møller prescriptions have been used to obtain these related quantities of the spacetimes in TG. It has been found that all of the energy and momentum distributions of five-dimensional Bianchi type-I spacetime are equal to zero in GR and TG. For five-dimensional Bianchi type-III and type-V spacetimes, Bergmann–Thomson, Einstein and Tolman energy and momentum components give the same results, however Møller, Landau–Lifshitz and Papapetrou energy–momentum distributions give different results in general relativity. Also, in TG, Bergmann–Thomson and Einstein energy and momentum components give the same results for the Bianchi type-III and type-V spacetimes, too. In this sense, it is seen that Einstein, Bergmann–Thomson and Landau–Lifshitz energy and momentum descriptions of these spacetimes have been given same results in both theories, GR and TG.
THERMODYNAMICS OF (2+1) FLAVOR QGP IN QUASIPARTICLE MODEL
Authors: BANNUR VISHNU M.
Published: October 2012

Using our recently developed one parameter quasiparticle model, we analyze more recent (refined) results of (2+1)-flavor quark–gluon plasma (QGP) in lattice simulation of quantum chromodynamics (QCD) by various groups [S. Borsanyi et al., arXiv:1007.2580v2; A. Bazavov et al., Phys. Rev. D80 (2009) 014504; T. Umeda et al., arXiv:1011.2548v1; C. DeTar et al., Phys. Rev. D81 (2010) 114504]. We got a remarkable good fit to lattice thermodynamics of [S. Borsanyi et al., arXiv:1007.2580v2] and reasonable good fit to [A. Bazavov et al., Phys. Rev. D80 (2009) 014504] by adjusting single parameter of the model which may be related QCD scale parameter. The same model also fits the lattice results of [S. Borsanyi et al., arXiv:1007.2580v2] on (2+1+1)-flavor QGP. Further, we extend our model for above system with zero chemical potential to nonzero chemical potential and predict quark density without any new parameters which may be compared with future lattice data.
CHARACTERISTICS OF GLOBAL PUBLICATIONS ABOUT WRIST ARTHROSCOPY: A BIBLIOMETRIC ANALYSIS
Authors: Fernandes Carlos Henrique , Meirelles Lia Myiamoto , Neto Jorge Raduan , dos Santos João Baptista Gomes , Faloppa Flavio , Albertoni Walter Manna
Published: October 2012

The objective of this study was to provide an assessment of published studies on the wrist arthroscopy. The search was performed from the "Web of Science (WoS) Science Citation Expanded Database" with studies published between January 1, 1990 and March 31, 2011. For research we used the following terms: "Wrist arthroscopy" and "Arthroscopy of the wrist". We located a total of 426 studies about wrist arthroscopic, published in 89 journals over the study period. Of all the publications retrieved (426), original articles were 387 (90.84%), but only two (0.47%) were randomised controlled trials, level 1 of evidence.

This study showed there are a large number of studies on wrist arthroscopy, but the level of methodological evidence is low.
SURGICAL MANAGEMENT OF CHRONIC BOUTONNIERE DEFORMITY
Authors: El-Sallakh Sameh , Aly Tarek , Amin Osama , Hegazi Mostafa
Published: October 2012

Purpose: Boutonniere deformity is caused by damage to the central slip of the extensor tendon hood with secondary palmer migration of the lateral bands. Accordingly, patients complain of disfigurement and impairment of function due to hyperextension of their DIP. The aim of this study is to evaluate the results of surgical treatment of chronic boutonniere deformity by using a modified technique.

Patients and methods: Twelve patients with posttraumatic boutonniere deformity were available for follow up as a retrospective study. They were treated by release of the extensor expansion proximal to the distal insertion of the oblique retinacular ligaments with proximal recession of the extensor tendon and lifting the lateral bands dorsally onto the PIP joint after separation of the transverse retinacular ligaments from their insertion volarly. All patients had closed injury. The mean age was 32 years (range: 16–48 years). The average follow-up period was 33 months (range: 26–38 months). We included only cases with deformities that were totally correctable passively with or without joint osteoarthritic changes.

Results: Preoperatively the average PIP joint extension deficit was 60° and postoperatively the average is reduced to 7°, preoperative the average DIP motion was 10° of hyperextension, post-surgery the average DIP active flexion was 75°. The final outcomes were 58.3% excellent, 33.3% good, and 8.3% poor.

Discussion: This modified technique gave (91.6%) excellent and good results. The extensor tendon acted mainly on the PIP joint and allowing the DIP joint to flex freely. The procedure is simple and provides long-term good results.

Level of evidence: Therapeutic case series, level 1V.
A LARGE NEURINOMA ORIGINATING FROM THE ANTERIOR INTEROSSEOUS NERVE
Authors: Inukai Tomoo , Uchida Kenzo , Baba Hisatoshi
Published: October 2012

We report an interesting case of a neurinoma originating from the anterior interosseous nerve. Magnetic resonance (MR) images showed an egg-shaped, well-circumscribed mass on the volar side of the forearm. On the enhanced three-dimensional computer tomography (3D-CT), it was clearly demonstrated that the tumour had arterial feeding from the anterior interosseous artery. The enhanced 3D-CT angiography was useful in the pre-operative diagnosis and surgical planning of peripheral neurinomas.
ISOLATED DISLOCATION OF THE TRAPEZOID
Authors: Ting Michelle H. X. , Tompson Jeffrey D. , Ek Eugene T. H.
Published: October 2012

Here we present a rare case of an isolated trapezoid dislocation secondary to a high-speed motor vehicle injury. In this case we highlight that the fact that these injuries are commonly missed on standard radiographs and management invariably requires open reduction and internal fixation.
TREATMENT OF KELOID FORMATION FOLLOWING SYNDACTYLY DIVISION: SURGICAL TECHNIQUE
Authors: Kong Bong Young , Baek Goo Hyun , Gong Hyun Sik
Published: October 2012

A strong association has been reported between keloid formation after syndactyly reconstruction and primary digital enlargement, and methotrexate (MTX) treatment has been shown to produce promising results in a few reported cases. However, detailed surgical technique for revision of keloid formation after syndactyly division has not been well described, and there is still no standard treatment protocol regarding use of MTX in such cases. In this paper, we describe the technical details of keloid excision and full thickness skin grafting followed by MTX medication for the treatment of massive keloid formation after syndactyly division. We also describe a case of unsuccessful use of MTX, and our experience of its prophylactic use for a patient with syndactyly with primary digital enlargement.
THE REACTION MECHANISMS OF ALDEHYDES AND NITROSTYRENE CATALYZED BY A CHIRAL SILYLATED PYRROLIDINE CATALYST
Authors: GAN LI-HUA , ZHOU JIN , GUO XIAO
Published: October 2012

The asymmetric Michael reaction of aldehydes and nitrostyrene catalyzed by a new (S)-tertbutyl-diphenyl-silyl-pyrrolidine catalyst has been investigated by using density functional theory calculations. The Re face of the enamine is effectively shielded, because of the bulky 2-substituent group on the pyrrolidine ring. For acetaldehyde, there are two different conformers of enamines. Based on the two conformers of enamines, four different reaction pathways have been considered. The calculated enantiomeric excess value is 80.27% in favor of the (R)-configuration product. For propanal, eight different reaction pathways have been considered and the eight corresponding transition states have been located. The calculated enantiomeric excess value is 98.96% in favor of the (2S, 3R)-configuration product. These calculated results are in good agreement with the experimental observations. In addition, the calculations also show that both the used solvent and the enamines play important roles in determining the stereochemical outcome of the product.
GENERALIZED FINITE ELEMENT METHOD ON NONCONVENTIONAL HYBRID-MIXED FORMULATION
Authors: GÓIS WESLEY , PROENÇA SERGIO PERSIVAL BARONCINI
Published: October 2012

The generalized finite element method (GFEM) is applied to a nonconventional hybrid-mixed stress formulation (HMSF) for plane analysis. In the HMSF, three approximation fields are involved: stresses and displacements in the domain and displacement fields on the static boundary. The GFEM–HMSF shape functions are then generated by the product of a partition of unity associated to each field and the polynomials enrichment functions. In principle, the enrichment can be conducted independently over each of the HMSF approximation fields. However, stability and convergence features of the resulting numerical method can be affected mainly by spurious modes generated when enrichment is arbitrarily applied to the displacement fields. With the aim to efficiently explore the enrichment possibilities, an extension to GFEM–HMSF of the conventional Zienkiewicz-Patch-Test is proposed as a necessary condition to ensure numerical stability. Finally, once the extended Patch-Test is satisfied, some numerical analyses focusing on the selective enrichment over distorted meshes formed by bilinear quadrilateral finite elements are presented, thus showing the performance of the GFEM–HMSF combination.
APPLICATION OF THE NEW SPECTRAL HOMOTOPY ANALYSIS METHOD (SHAM) IN THE NON-LINEAR HEAT CONDUCTION AND CONVECTIVE FIN PROBLEM WITH VARIABLE THERMAL CONDUCTIVITY
Authors: MOTSA S. S.
Published: October 2012

In this work, we demonstrate the efficiency of the newly developed spectral homotopy analysis method (SHAM) in solving non-linear heat transfer equations. We demonstrate the applicability of the method by solving the problem of steady conduction in a slab and the convective fin equation with variable thermal conductivity. New closed form explicit analytic solutions of the governing non-linear equations are obtained and compared with the SHAM results and numerical solutions. The results reveal that the new SHAM approach is very accurate and efficient and converges much faster than the standard homotopy analysis method.
NUMERICAL INVESTIGATIONS OF CAVITATION AROUND A HIGH SPEED SUBMARINE USING OPENFOAM WITH LES
Authors: SHANG ZHI , EMERSON DAVID R. , GU XIAOJUN
Published: October 2012

Under water cavitation occurs when the liquid changes the phase into its vapor due to the local pressure is lower than the water saturation pressure. If a body is moving very fast under water, the local pressure around it at a certain flow regime will be lower than the water saturation pressure. The cavitation around the body will occur. Following the increase of the intensity of the cavitation, a cloud cavitation will occur. Under the cloud cavitation occurrence, the cavitation is unsteady and periodic, which involves formation, detachment and collapse of sheet cavities. In this paper, large Eddy simulation (LES) is employed together with a mixture assumption and a finite rate mass transfer modeling into OpenFOAM to study the cavitation phenomena. The validation comparisons of numerical simulations with experiments of a sphere under water are performed. After the validation, a full submarine model with sail and appendages under water is studied. The submarine is under water around 450 m deep with a moving speed at 60 m/s. It is found that the cavitation changes under the different cavitation numbers (from 1.0 to 0.1). Small cavitation numbers induce a large area cavitation, whereas large ones reduce this phenomenon. A supercavitation, which can be described as a large bubble, is found around the high speed submarine at cavitation number equals to 0.1.
SILVER PHOSPHATE BASED PLASMONIC PHOTOCATALYST: HIGHLY ACTIVE VISIBLE-LIGHT-ENHANCED PHOTOCATALYTIC PROPERTY AND PHOTOSENSITIZED DEGRADATION OF POLLUTANTS
Authors: LEI YONGQIAN , WANG GUANHUA , GUO PENGRAN , SONG HUACAN
Published: October 2012

A stable silver phosphate based plasmonic photocatalyst ( Ag-Ag3PO4 ) was successfully fabricated, which can drive catalytic reaction under low-intensity visible light. The synthesized plasmonic photocatalyst shows high performance and stability on the photodegradation of RhB under visible-light irradiation, and represents obviously enhanced photocatalytic activity than the pure Ag3PO4 sample. The photosensitization process was carried out in the photodegradation of 2,4-DCP and RhB mixture, of which the photocatalyst shows the enhancement activity for 2,4-DCP while weaker for RhB . The investigation is likely to open up a new sight for the preparation of high efficient and stable plasmonic photocatalysts which utilizes visible light.
GRADED TRANSITIONS IN Ni-Ti SHAPE MEMORY ALLOYS PROCESSED BY SEVERE PLASTIC DEFORMATION
Authors: CRACIUNESCU CORNELIU M. , BRAZ FERNANDES FRANCISCO M.
Published: October 2012

NiTi shape memory alloys were subjected to a single step severe plastic deformation via the equal channel angular pressing (ECAP). The properties were analyzed by comparing the transformation characteristics for sections across the thickness of the deformed sample, with focus on the deformation gradient in the outer layers of the materials and the front surface that gradually engages in the deformation. A gradient related to the crystallinity and the state of stress was observed across the thickness of the deformed sample.
Hiroaki Aihara Elected Chair of IUPAP C11 Commission of Particles and Fields
Authors: APPN Editorial Office
Published: October 2012

The International Union of Pure and Applied Physics, IUPAP, at its General Assembly on 4th November 2011, elected Professor Hiroaki Aihara as the chair of Commission C11 of Particles and Fields.
Third International Symposium on Plasma Nanoscience
Authors: Xu Shuyan
Published: October 2012

Set in the background of the tropical sun and swaying coconut trees, the Pulai Desaru Beach Resort was the venue for the iPlasmaNano-III Symposium from 27 February to 1 March 2012. Delegates were picked up in a chartered coach and they arrived at the magnificent tropical resort of Pulai Desaru within two hours from Singapore, with a stopover at the Desaru Fruit Farm for sightseeing and lunch. More than 80 delegates, including many eminent and renowned scientists from 19 countries attended the symposium.
Case Study: Making the Move to AJAX
Authors: Norwalk Jeff
Published: October 2012

Small start-up companies often face a bewildering array of technical choices: how to deliver their application, what language to use, whether to employ existing components (either commercial or open source) or roll their own... and the list goes on. What’s more, the decisions surrounding these choices typically need to be made quickly. This case study offers a realistic representation of the sorts of challenges a young start-up company faces when working to deploy a product on the Web. As with many startups, this is also a story that does not have a happy ending.
CTO Roundtable: Cloud Computing
Authors: Creeger Mache
Published: October 2012

Many people reading about cloud computing in the trade journals will think it’s a panacea for all their IT problems. It is not. In this CTO Roundtable discussion we hope to give practitioners useful advice on how to evaluate cloud computing for their organizations. Our focus will be on the SMB (small- to medium-size business) IT managers who are underfunded, overworked, and have lots of assets tied up in out-of-date hardware and software. To what extent can cloud computing solve their problems? With the help of five current thought leaders in this quickly evolving field, we offer some answers to that question. We explore some of the basic principles behind cloud computing and highlight some of the key issues and opportunities that arise when computing moves from in-house to the cloud. Our sincere thanks to all who participated and to the ACM Professions Board for making this possible.
Cloud Computing: An Overview
Authors: Creeger Mache
Published: October 2012

Probably more than anything we’ve seen in IT since the invention of timesharing or the introduction of the PC, cloud computing represents a paradigm shift in the delivery architecture of information services. This overview presents some of the key topics discussed during the ACM Cloud Computing and Virtualization CTO Roundtables of 2008. While not intended to replace the in-depth roundtable discussions, the overview summarizes the fundamental issues generally agreed upon by the panels and should help readers to assess the applicability of cloud computing to their application areas.
Painting the Bike Shed
Authors: Neville-Neil George V.
Published: October 2012

Last week one of our newer engineers checked in a short program to help in debugging problems in the code that we’re developing. Even though this was a test program, several people read the code and then commented on the changes they wanted to see. The code didn’t have any major problems, but it seemed to generate a lot of e-mail for what was being checked in. Eventually the comments in the thread were longer than the program itself. At some point in the thread the programmer who submitted the code said, "Look, I’ve checked in the code; you can paint the bike shed any color you want now," and then refused to make any more changes to the code. I can understand his frustration at nitpicking comments, but what did he mean about painting the bike shed?
Selective replication
Authors: Vera Xavier , Abella Jaume , Carretero Javier , González Antonio
Published: October 2012

Soft errors are an important challenge in contemporary microprocessors. Modern processors have caches and large memory arrays protected by parity or error detection and correction codes. However, today's failure rate is dominated by flip flops, latches, and the increasing sensitivity of combinational logic to particle strikes. Moreover, as Chip Multi-Processors (CMPs) become ubiquitous, meeting the FIT budget for new designs is becoming a major challenge.

Solutions based on replicating threads have been explored deeply; however, their high cost in performance and energy make them unsuitable for current designs. Moreover, our studies based on a typical configuration for a modern processor show that focusing on the top 5 most vulnerable structures can provide up to 70% reduction in FIT rate. Therefore, full replication may overprotect the chip by reducing the FIT much below budget.

We propose
Selective Replication
, a lightweight-reconfigurable mechanism that achieves a high FIT reduction by protecting the most vulnerable instructions with minimal performance and energy impact. Low performance degradation is achieved by not requiring additional issue slots and reissuing instructions only during the time window between when they are retirable and they actually retire. Coverage can be reconfigured online by replicating only a subset of the instructions (the most vulnerable ones). Instructions' vulnerability is estimated based on the area they occupy and the time they spend in the issue queue. By changing the vulnerability threshold, we can adjust the trade-off between coverage and performance loss.

Results for an out-of-order processor configured similarly to Intel® Core™ Micro-Architecture show that our scheme can achieve over 65% FIT reduction with less than 4% performance degradation with small area and complexity overhead.
Workshop on large-scale distributed systems for information retrieval
Authors: Michel Sebastian , Skobeltsyn Gleb , Yee Wai Gen
Published: October 2012

Due to the dramatically increasing amount of available data, effective and scalable solutions for data organization and search are essential. Distributed solutions naturally provide promising alternatives to standard centralized approaches. With the computational power of thousands or millions of computers in clusters or peer-to-peer systems, the challenges that arise are manifold, ranging from efficient resource discovery to issues in load balancing and distributed query processing.

The 2008 edition of the Workshop on Large-Scale Distributed Systems for Information Retrieval (LSDS-IR'08) provided a forum for researchers to discuss these problems and to define new directions for the work on Distributed Information Retrieval. The Workshop program featured research contributions in the areas of similarity search, resource selection, network organization schemes, issues of data quality, result ranking techniques and query routing algorithms.
Book Review: 'Click: What Millions of People Are Doing Online and Why it Matters' by Bill Tancer
Authors: Shea Peter
Published: October 2012

Eery day millions of Internet users click on millions of web pages. This results in more than people being connected with websites. It creates a tremendous aggregation of data about what people are thinking about. Bill Tancer's book "Click: What Millions of People Are Doing Online and Why it Matters" is intended to be an introduction to Web mining.
Commitment Issues
Authors: Neville-Neil George
Published: October 2012

One of the other people on my project insists on checking in unrelated changes in large batches. When I say
unrelated
, what I mean is he will fix several unrelated bugs and then make a few minor changes to spacing and indentation across the entire source tree. He will then commit all of these changes at once, usually with a short commit message that lists only the bugs he claims to have fixed. Do you think I’m being too picky in wanting each checkin to address only one issue or problem?
CTO Roundtable: Malware Defense Overview
Authors: Creeger Mache
Published: October 2012

The Internet has enabled malware to progress to a much broader distribution model and is experiencing a huge explosion of individual threats. There are automated tools that find vulnerable sites, attack them, and turn them into distribution sites. As commerce and the business of daily living migrate online, attacks to leverage information assets for ill-gotten benefit have increased dramatically. Security professionals are seeing more sophisticated and innovative profit models on par with business models seen in the legitimate world.
Assessing the effectiveness of distributed pair programming for an online informatics curriculum
Authors: Edwards Richard L. , Stewart Jennifer K. , Ferati Mexhid
Published: October 2012

Studies have shown that distributed pair programming improves student performance and retention in online computer science (CS) courses. However, as online CS courses become more commonly offered in computer science and Informatics departments around the country, it is imperative that distributed pair programming becomes as effective as when performed in co-located spaces such as computer labs. The present study identifies a disparity in student attitudes towards pair programming in co-located versus online environments. This study identifies several qualitative measures that can impact the pedagogical advantages of pair programming when implemented into an existing online computer science curriculum. This on-going study focuses on the online Informatics curriculum at Indiana University Bloomington and Indiana University Purdue University Indianapolis. Begun in Spring 2009, the research focuses on student experiences and perceptions of pair programming, and utilizes both quantitative and qualitative assessment methods. In order to improve the effectiveness of distributed pair programming, it is crucial to properly assess teaching and learning practices that will improve student engagement and motivation in distributed pair programming exercises. Student experience surveys, using a modified Likert scale, demonstrate that student-centered perceptions of the ease and effectiveness of pair programming differs significantly between co-located and online activities. This paper identifies several key areas where there is a noticeable variance between co-located and online pair programming experiences, and argues that addressing and improving these key areas will be vital for the successful implementation and sustainability of distributed pair programming efforts.
A strategy, implementation and results of a flexible competency based curriculum
Authors: Pinto Yma
Published: October 2012

Computer science education faces two major problems -- the continuous evolvement of the discipline itself and the issue of appropriate employment of graduating students. Instructors and educators need to periodically reinvent and restructure their curriculum to keep their learners abreast. The question is, therefore: How do we design a curriculum that is flexible, yet targeted towards the learner acquiring the necessary knowledge and skill set to make him/her "employable"? An effective approach is to structure the curriculum by defining the requisite competencies as the instructional goals and subsequently defining the conceptual requirements to achieve these goals. The results of the effectiveness of this strategy are analyzed in the paper.
Concerns with Learning-Management Systems and Virtual Learning Environments
Authors: Little Bob
Published: October 2012

IMC (UK) Learning, an eLearning content solutions provider, published research on how organizations use learning-management systems (LMS) and virtual learning environments (VLE). The study examined how much functionality is being used and how beneficial LMSs are at meeting business needs. Bob Little, who writes frequently for eLearn Magazine on the state of e-learning in the U.K., summarizes some of the key takeaways of the report.
When and How to Save Money on e-Learning
Authors: Little Bob
Published: October 2012

Everyone wants value for money even from their e-learning solutions. But getting value for money can be confused with merely trying to save money, which is far from being the same thing. Bob Little has some pointers for helping you get the most out of your e-learning tools.
Styles of logic and thinking
Authors: Ellis Josephine
Published: October 2012

Researchers have long made connections between language and culture. More recently Nisbett's
Geography of Thought
has focused attention on the work of intercultural communication researchers who have proposed that there are fundamental and significant differences in the thinking processes of those influenced by the Western or Grecian style of logical thinking, in contrast to the Eastern or Confucian style of thinking. These differences can be demonstrated in the cognitive and affective domains, and even at the level of neural transmissions observed via MRI scans. While teachers regularly confront the grammar, vocabulary and other problems of Non-English-Speaking Background (NESB) students in our classes, perhaps it is also necessary to deal explicitly with the different styles of thinking that students may be unknowingly applying in their learning or assessment processes. This may challenge the logic presumed as the norm by teachers trained in Western rhetoric. These differences have significance for common assignments such as essay writing, argument presentation, and analytical report writing, plus wider implications for teaching or assessments, which implicitly presume monocultural definitions. This paper will background the relevant intercultural communication research and discuss implications for teaching strategies.
Intercultural competence in practice
Authors: Hitchcock Leo , Quan Vu Hai , Danh Tran Cong
Published: October 2012

As globalisation extends computing, information, and communications technologies across an increasing number of cultural boundaries, generating a corresponding need for cross-cultural education partnerships, the need for cultural sensitivity and understanding becomes paramount. It becomes paramount, not only in cross-cultural teams negotiating collaborative agreements, but also in cross-cultural teaching situations. It is imperative, therefore, that such crossing cultural boundaries is grounded in the ideals of intercultural competence (IcC), including an understanding of and adaptation to culturally-based norms and values. Underlying cultural assumptions affect the different negotiating teams' approach to the negotiation process, to teacher-student interaction techniques and relationships and to group work. This paper explores both the theoretical background and the actual experiences of a New Zealand and Vietnamese negotiating team, and the subsequent experiences of a New Zealand teacher in a Vietnamese classroom. This is but one of a plethora of examples of global intercultural collaboration in practice.
Optimization of dynamic languages using hierarchical layering of virtual machines
Authors: Yermolovich Alexander , Wimmer Christian , Franz Michael
Published: October 2012

Creating an interpreter is a simple and fast way to implement a dynamic programming language. With this ease also come major drawbacks. Interpreters are significantly slower than compiled machine code because they have a high dispatch overhead and cannot perform optimizations. To overcome these limitations, interpreters are commonly combined with just-in-time compilers to improve the overall performance. However, this means that a just-in-time compiler has to be implemented for each language.

We explore the approach of taking an interpreter of a dynamic language and running it on top of an optimizing trace-based virtual machine, i.e., we run a
guest VM
on top of a
host VM
. The host VM uses trace recording to observe the guest VM executing the application program. Each recorded trace represents a sequence of guest VM bytecodes corresponding to a given execution path through the application program. The host VM optimizes and compiles these traces to machine code, thus eliminating the need for a custom just-in-time compiler for the guest VM. The guest VM only needs to provide basic information about its interpreter loop to the host VM.
How to Help Teachers Use Technology in the Classroom
Authors: Burns Mary
Published: October 2012

Mary Burns of Education Development Center explains the five best practices used to train teachers to integrate technologyespecially computer useinto their instruction and course design. These universal methods, which have been used in places ranging from Indonesia to the United States, emphasize not only skills training, but also implementation.
A Science for e-Learning
Authors: Vargas Julie S.
Published: October 2012

The effectiveness and quality of online teaching would leap forward if it took more advantage of the science that originated in the work of psychologist B. F. Skinner, according to his daughter and learning expert Dr. Julie Vargas, in this eLearn exclusive article. One of Skinner's invention, the teaching machine (shown at left), was an early example of technology-based education.
Didactic transposition in computer science education
Authors: Hazzan Orit , Dubinsky Yael , Meerbaum-Salant Orni
Published: October 2012

This paper introduces the concept of
didactic transpositions
in the context of computer science education (CSE). In general, didactic transposition refers to the adaptation of professional knowledge to teaching situations. With respect to CSE, we illustrate the concept of didactic transpositions with two research works that examined a didactic transposition of software development methods to educational frameworks: the first one---in the university; the second---in the high school.
Visualizing Prolog
Authors: Mondshein Lee , Sattar Abdul , Lorenzen Torben
Published: October 2012

At Bridgewater State College, Prolog serves as a student's first introduction to programming in a declarative language. Students often find it difficult to understand how Prolog implements logical deduction and handles variable bindings as it processes a query. The authors show snapshots of the deduction process and present a graphical ("jigsaw puzzle") representation of the emerging logical relationships, which our students find to be helpful. Typical parent-child predicate relationships are used as introductory examples.
PlagDetect
Authors: Al-Khanjari Z. A. , Fiaidhi J. A. , Al-Hinai R. A. , Kutti N. S.
Published: October 2012

Practical computing courses that involve significant amount of programming assessment tasks suffer from e-Plagiarism. A pragmatic solution for this problem could be by discouraging plagiarism particularly among the beginners in programming. One way to address this is to automate the detection of plagiarized work during the marking phase. Our research in this context involves at first examining various metrics used in plagiarism detection in program codes and secondly selecting an appropriate statistical measure using attribute counting metrics (ATMs) for detecting plagiarism in Java programming assignments. The goal of this investigation is to study the effectiveness of ATMs for detecting plagiarism among assignment submissions of introductory programming courses.
The Relevancy of Twitter to Patron Usage and Workflow Processes in Libraries
Authors: Larson Michael
Published: October 2012

Libraries and Twitter have been united to transform the functional environment of libraries into a more effectual classroom, community, and workplace. Twitter has the potential to change the workflow processes in modern libraries and be a relevant teaching and research tool for library patrons.
Ubiquity symposium: What is the Right Computational Model for Continuous Scientific Problems?
Authors: Traub Joseph
Published: October 2012

In this tenth piece to the Ubiquity symposium discussing What is computation? Joseph Traub shares his views about using the Turing Machine model and the real number model for solving continuous scientific problems. --Editor
Computational thinking for youth in practice
Authors: Lee Irene , Martin Fred , Denner Jill , Coulter Bob , Allan Walter , Erickson Jeri , Malyn-Smith Joyce , Werner Linda
Published: October 2012

Computational thinking (CT) has been described as the use of abstraction, automation, and analysis in problem-solving [3]. We examine how these ways of thinking take shape for middle and high school youth in a set of NSF-supported programs. We discuss opportunities and challenges in both in-school and after-school contexts. Based on these observations, we present a "use-modify-create" framework, representing three phases of students' cognitive and practical activity in computational thinking. We recommend continued investment in the development of CT-rich learning environments, in educators who can facilitate their use, and in research on the broader value of computational thinking.
Fun to learn
Authors: Qidwai Uvais
Published: October 2012

This article shares my experiences with the project-based methodology of teaching the same material that a standard text in robotics would teach and will comparatively elaborate the improvement observed in the group of students involved. Other than the understanding of the course material, the use of project-based learning methodology has shown a great increase in motivation and focus on the subject in the students towards the engineering education. The performance improvement is presented in this work as a comparison with respect to underlying program educational outcomes between the previous years of teaching in conventional way, with past two years of experience using the projectbased approach. The work includes appropriate rubrics involved in evaluating the subject. While the work is seemingly undergraduate teaching exercise, it has proven so far to have very positive impact on the industrial research project performed by the author.
Technology-enhanced learning for Java programming
Authors: Ivanović Mirjana , PitnerI Tomáš
Published: October 2012

Background pedagogical theories and methods underpinning technology-enhanced learning in introductory programming courses at a university level attract teachers' community and foster continuous research at least since the end of the nineties. However, it still has not led to a generally applicable way of teaching and learning that would guarantee the best possible success under the given circumstances. This rather pessimistic fi nding intrigued and inspired authors of this paper to analyze, present, and compare selected experiences gathered during nearly a decade of technology-enhanced approach in teaching an object-oriented programming languages with specifi c focus on Java at two large universities in two countries. In this paper we have examined a number of issues affecting its positioning in the curriculum, learning design, and quality at both institutions. Based on quantitative and qualitative analysis, the history and current state is evaluated and key recommendations for planning, designing, deployment, and evaluation of similar courses are provided. Different traditions and independent development at both institutions allow us to draw generally applicable conclusions not infl uenced by specifi c properties of one particular educational system.
Hardware acceleration of transactional memory on commodity systems
Authors: Casper Jared , Oguntebi Tayo , Hong Sungpack , Bronson Nathan G. , Kozyrakis Christos , Olukotun Kunle
Published: October 2012

The adoption of transactional memory is hindered by the high overhead of software transactional memory and the intrusive design changes required by previously proposed TM hardware. We propose that hardware to accelerate software transactional memory (STM) can reside outside an unmodified commodity processor core, thereby substantially reducing implementation costs. This paper introduces Transactional Memory Acceleration using Commodity Cores (TMACC), a hardware-accelerated TM system that does not modify the processor, caches, or coherence protocol.

We present a complete hardware implementation of TMACC using a rapid prototyping platform. Using this hardware, we implement two unique conflict detection schemes which are accelerated using Bloom filters on an FPGA. These schemes employ novel techniques for tolerating the latency of fine-grained asynchronous communication with an out-of-core accelerator. We then conduct experiments to explore the feasibility of accelerating TM without modifying existing system hardware. We show that, for all but short transactions, it is not necessary to modify the processor to obtain substantial improvement in TM performance. In these cases, TMACC outperforms an STM by an average of 69% in applications using moderate-length transactions, showing maximum speedup within 8% of an upper bound on TM acceleration. Overall, we demonstrate that hardware can substantially accelerate the performance of an STM on unmodified commodity processors.
Hybrid NOrec
Authors: Dalessandro Luke , Carouge François , White Sean , Lev Yossi , Moir Mark , Scott Michael L. , Spear Michael F.
Published: October 2012

Transactional memory (TM) is a promising synchronization mechanism for the next generation of multicore processors. Best-effort Hardware Transactional Memory (HTM) designs, such as Sun's prototype Rock processor and AMD's proposed Advanced Synchronization Facility (ASF), can efficiently execute many transactions, but abort in some cases due to various limitations. Hybrid TM systems can use a compatible software TM (STM) in such cases.

We introduce a family of hybrid TMs built using the recent NOrec STM algorithm that, unlike existing hybrid approaches, provide both low overhead on hardware transactions and concurrent execution of hardware and software transactions. We evaluate implementations for Rock and ASF, exploring how the differing HTM designs affect optimization choices. Our investigation yields valuable input for designers of future best-effort HTMs.