bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of a kinetic-diffusive model to characterize pozzolanic reaction kinetics in sugar cane straw-clay ash/lime systems
Authors: Villar-Cociña E. , Frías Rojas M. , Valencia-Morales I. E. , Sánchez de  Rojas M.I.
Published: April 2010

A kinetic-diffusive model proposed by the authors in previous papers to describe pozzolanic reaction kinetics in sugar cane straw-clay ash (SCSCA)/calcium hydroxide (CH) systems is validated in this study. Two different methods (direct and indirect) for determining pozzolanic activity were applied and their effect on pozzolanic reaction rate kinetic constants evaluated. Determined by fitting a model to the data, these constants are used to quantitatively characterize pozzolanic activity. The values of the kinetic constants calculated with the model were similar for the two methods. Classic kinetic models, such as the Jander, modified Jander and Zhuravlev models, were also applied to the system studied and the results were compared to the figures calculated with the model proposed. The kinetic-diffusive approach proposed was found to be valid regardless of the method for determining pozzolanic activity used, and to be the most suitable model for describing pozzolanic reaction kinetics in the SCSCA/lime system.
Petrography and hydric characterization of the quarry material of the varieties of Borriol Stone (Castellón)
Authors: Ovejero M. , Queralt I. , De la Fuente C.
Published: April 2010

Borriol stone is one of the most widely used and well-known building materials in the Spanish province of Castellapn. It is a cretaceous limestone quarried in the El Abeller quarry, Borriol (Castellón). Since the seventeenth century it has been used in several historic buildings to be found both in the city of Castellaon and in nearby Valencia. Although it is commercially classified as a single rock type, two different lithologies or varieties can be distinguished in the Abeller outcrop; these represent vertical changes in the outcrop series andaré referred to in this paper as Ochre Borriol and Red Borriol. Petrographic, mineralogical and chemical studies were carried out, along with color determination. The stone s hydric parameters were obtained via the following tests: vacuum water absorption, free water absorption, desorption and capillary water absorption. Red Borriol is a reddish dolomitic grainstone with textures of dedolimitization. It is a low-porosity rock consisting mainly of calcite and dolomite, with quartz, illite, goethite and hematite as secondary minerals. As it has a low absorption coefficient, low capillarity index and rapid water desorption, it is expected to behave well under the action of weathering agents. Ochre Borriol is a yellowish packstonegrainstone with higher porosity. It is famed mainly of calcite and has less dolomite content than Red Borriol. Its accesory minerals are quartz, illite and goethite. It has a higher absorption coefficient and higher capillarity. Although it absorbs water more rapidly, its desorption is slower. As the hydric behavior of Ochre Borriol is less favorable, it is to be expected that its deterioration processes are encouraged by water circulation more than Red Borriol´sare.
Colour variations in graffiti-proofed ceramic materials
Authors: García Santos A. , Conci Rinaudo M.
Published: April 2010

The investigation analyses the variation of superficial properties, COLOUR and LUMINOSITY, hat the ceramic support protected by the incorporation of a protection with transparent painting undergoes, antigraffiti. The test pieces were analysed by digital procedures, obtaining quantifiable values of each ceramic sample by means of computer programs (modifications of colour) taking itself as it bases the same type of ceramics without protection. In the surface of the pieces ceramics dealt with painting antigraffiti, tones different from the original ones were observed from the piece without painting. The type of painting and the material of base, obtaining itself the following results, determine this variation: - The rustic ceramics is much more susceptible to modify its characteristics of colour that the industrialists. - In both types of analysed industrial ceramics in the investigation, the variation of the tone independently took place with the same characteristics or parameters of quantification of the type of painting. - In all the analysed types of ceramics dealt with painting antigraffiti, the colour modifies its tonality tending towards the called tones «cold», violates, by the presence of blue and the loss of the red one. Before a same painting, it was observed a greater alteration of tones and luminosity in the rustic ceramics in comparison with the industrialists.
Evaluation of performance of materials used in the ceramic materials restoration of the Plaza de España (Sevilla)
Authors: Alejandre Sánchez F. J. , Villegas Sánchez R. , Jurado Pérez M.
Published: April 2010

Different commercial mortars and stuecos used to cold restore the glazing on deteriorated tile in Seville s Plaza de España were tested for performance and durability. Five types of samples were applied to ceramic bisques and subsequently coloured and protected with resins. The samples were subjected to accelerated weathering consisting in salt crystallization, temperature and relative humidity cycles and ultraviolet radiation. Durability was assessed by visually comparing the effect of salt crystallization, determining the colour parameters with colourimetry and measuring adherence and capillary water absorption. The results obtained were used to differentiate the materials tested in two respects: stucco and protective resin performance under the environmental conditions prevailing in the Plaza de España on the one hand and colour stability on the other.
Effect of steel surface conditions on reinforcing steel corrosion in concrete exposed to marine environments
Authors: Anzola E. , Malavé R. , Contreras A. , Rivero M. , Bolognini H. , Rojas M. , Reyes I.
Published: April 2010

Laboratory methods and experimental tests were deployed in the present study to evaluate corrosion in reinforced concrete exposed to marine environments. Reinforcing steel exhibiting two different surface conditions prior to embedment in concrete were studied, one the one hand to assess the electrochemical behaviour of the bars during exposure of the concrete specimens to a simulated marine environment, and on the other to determine the strength of the steel/concrete bond. The reinforced concrete specimens prepared were adapted as required for electrochemical potential and corrosion rate testing. A total of 56 7x15-cm cylindrical specimens containing 3/8" steel rods anchored at a depth of 11.5 cm were made to evaluate the steel / concrete bond and exposed to a natural marine environment for 28 or 190 days prior to testing. All the specimens were made with ready-mixed concrete. It may be concluded from the results of the corrosion tests on reinforcing steel with different surface conditions that the oxide initially covering the bars was dissolved and the steel passivated by the alkalinity in the concrete. The chief finding of the bonding study was that the layer of oxide formed in pre-embedment steel deterioration contributed to establishing a better bond.
Coal fly ash-containing sprayed mortar for passive fire protection of steel sections
Authors: Vilches L. F. , Leiva C. , Olivares J. , Vale J. , Fernández C.
Published: April 2010

The present article addresses the possible use of coal fly ash as the chief component of sprayed mortars to fireproof steel structures. A pilot wet-mix gunning rig was specifically designed and built to spray different pastes on to sheet steel and sections with different surface/volume ratios. After gunning, the specimens were placed in a furnace and subjected to standard fire resistance testing. Product fire resistance was calculated from the test results. The mortar used in this study, with a high fly ash content, was found to have acceptable mechanical properties as well as afire resistance potential comparable to those of commercial passive fire protection products.
Recycled aggregates concrete: aggregate and mix properties
Authors: González-Fonteboa B. , Martínez-Abella F.
Published: April 2010

This study of structural concrete made with recycled concrete aggregate focuses on two issues: 1. The characterization of such aggregate on the Spanish market. This involved conducting standard tests to determine density, water absorption, grading, shape, flakiness and hardness. The results obtained show that, despite the considerable differences with respect to density and water absorption between these and natural aggregates, on the whole recycled aggregate is apt for use in concrete production. 2. Testing to determine the values of basic concrete properties: mix design parameters were established for structural concrete in non-aggressive environments. These parameters were used to produce conventional concrete, and then adjusted to manufacture recycled concrete aggregate (RCA) concrete, in which 50% of the coarse aggregate was replaced by the recycled material. Tests were conducted to determine the physical (density of the fresh and hardened material, water absorption) and mechanical (compressive strength, splitting tensile strength and modulus of elasticity) properties. The results showed that, from the standpoint of its physical and mechanical properties, concrete in which RCA accounted for 50% of the coarse aggregate compared favourably to conventional concrete.
Recycling industrial waste in brick manufacture. Part 1
Authors: Andreola F. , Barbieri L. , Lancelloti I. , Pozzi P.
Published: April 2010

The ongoing accumulation of industrial waste speaks to the need to seek cost-effective disposal methods. Brick manufacture would appear to be particularly promising in this regard. The present study analyzes the possibility of recycling the sludge generated in porcelain tile polishing, as well as coal, steel and municipal incinerator ash to make a special type of facing brick whose properties readily accommodate a full analysis of all the problems deriving from the incorporation of residue in its manufacture. Physical-chemical, mechanical and structural analyses were performed on bricks made with varying percentages of the different types of waste considered. This first paper reports the results of the physical arid technological characterization of the products; the second part of the research will address their chemical, mechanical and structural properties.
Modifications induced by adding natural zeolitic pozzolans to cement paste
Authors: Blanco-Varela M. T. , Martínez-Ramírez S. , Gener M. , Vázquez T.
Published: April 2010

Volcanic pozzolans owe their pozzolanic activity chiefly to the presence of vitreous or zeolitic material rich in SiO2, and Al20y compounds that react with the portlandite produced during cement hydration to generate amorphous gels with cementitious properties. The present study analyzes the modifications taking place in the composition, structure and micro structure of the hydra ted cement paste when 20% of the cement by weight is replaced by two finely ground zeolitic rocks from Cuban deposits. Hydrated cement pastes were prepared with a CEM I35 cement, as well as with mixes of the cement and two Cuban zeolitic rocks (20% by weight). After eight months of hydration, the pastes were characterized -mineralogically, chemically and microstructurally- with XRD, FTIR, 29Si and 27Al MAS NMR, DTA/TG, back scattered electron microscopy and mercury porosimetry techniques. The replacement of 20% by weight of the cement with two finely ground zeolitic rocks significantly modified the composition, structure, quantity and microstructure of the hydrated cement paste reaction product. The C-S-H gel formed in these pastes differed in quantity, which was larger, and composition from the original cement gel. Moreover, the gel formed in addition-free cement had a higher Ca and a lower Al content and shorter silicate chains than the C-S-H product formed in the pastes made with zeolitic rocks. Finally, the pastes with pozzolan additions had fewer and smaller pores.
Evaluation of the load carrying capacity of large cross section coniferous timber in standing structures
Authors: Arriaga F. , Esteban M. , Relea E.
Published: April 2010

A total of 85 large section timber pieces (Pinus sylvestris L. and Pinus pinaster Alt.) found in a number of old buildings were visually analyzed and graded pursuant to Spanish standard UNE 56544 and German standard 4074. The object was to formulate a non-destructive method to reliably and effectively determine the mechanical properties of existing timber structures with large cross sections. A new system is proposed based on the chief visual grading parameters and consisting in a single grade; the percentage of rejections with this system is low. In this regard, a specific strength class is established for large cross section members in existing coniferous wood structures, namely F14/E9/D380 (MOR of 14 N/mm2, MOE of 9 kN/mm2 and characteristic density of 380 kg/m3). The use of ultrasonic velocity is proposed to define the next higher strength class - F16/E10/D380, to which timber with velocities of 4,900 m/s or over would be assigned.
Behaviour of AR glass fibre for building structural applications
Authors: Miravete A. , Mieres J. M. , Calvo I. , Comino P. , Chiminelli A. , Cuatrero J. , Tolosana N.
Published: April 2010

The AR glass reinforcement fibres were designed to resist the alkalis from the concrete. This is the main reason for its utilisation as a short-fibre-reinforcement of mortar and concrete for the last decades. Originally, the AR glass fibre sizing was not compatible with synthetic resins, so that this type of reinforcement was applied exclusively to mortar and concrete matrices. Recently, due to the developments of sizing, which are compatible with synthetic resins, the AR- glass fibres may be used as reinforcement of organic matrix composite materials, broadening the range of structural applications. The mechanical properties of AR glass fibre and organic matrix composite materials will be studied in this paper. First, the behaviour of this material under stress corrosion will be analysed. Their mass loss will be compared to E, C, and boron free glass fibres. Second, an experimental study dealing with 3P test bending and short beam ofAR glass fibre/polyester will de described with the goal of obtaining their Young modulus and tensile and interlaminar shear strengths. Finally, these experimental results will be compared to E glass fibre/polyester and several conclusions about their structural applications will be drawn.
Risks for the readymix concrete producer and contractor according to the acceptance or rejection criteria specified in different standards (part I)
Authors: Prada Betancourt D. M. , Revuelta Crespo D. , Fernández Luco L. , Vega Catalán L.
Published: April 2010

The objective of the present work is the study and comparison of the criteria for conformity and acceptance of the EHE (1), EN206-I (2) and ACI 318 (3) series of standards, which are in use in Spain, the European Community, the US and many Latin-American countries. As such, the paper starts with a conceptual differentiation of the conformity and acceptance criteria of each standard. The results of this analysis are operating characteristic curves for each respective standard that allow for the practical application and comparison of both types of criteria. The study ends with a number of conclusions that have been derived from the previous analysis.
The Impact of Gender and Experience on the Strength of the Relationships Between Perceived Data Warehouse Flexibility, Ease-of-Use, and Usefulness
Authors: Goeke Richard J. , Hogue Mary , Faley Robert H.
Published: April 2010

Experienced end-users are more likely to leverage the flexibility embedded within an information system. System flexibility influences ease-of-use perceptions, which influence user perceptions of system usefulness. Because men tend to have more experience with information systems and possess less computer anxiety than women, the strength of the relationship between user perceptions of system flexibility and ease of use should be significantly stronger for men. Although the authors found that the strength of this relationship was significant for men and women, the relationship was significantly stronger for women. No significant differences were found based on user differences in the length of their experience with a data warehouse. These findings challenge the conventional wisdom about the effect of gender and experience on system use, and have ramifications for both researchers and practitioners interested in optimizing data warehouse usage.
Modeling User Training and Support for Information Technology Implementations
Authors: Shaw Neal G. , Sethi Vikram , Jeyaraj Anand , Duffy Kevin
Published: April 2010

Information technology implementations continue to be significant endeavors for both research and practice. Although prior studies have extensively examined user training and user support, a consensus is lacking on their conceptualizations. Prior research has argued for direct, as well as indirect, effects of user training and user support on perceived benefits while appealing to different theoretical perspectives. This study clarifies the roles of user training and user support in information technology implementations using data on 302 software implementations. Using a Bayesian model comparison strategy, the authors found that the effects of user training and user support on perceived benefits are mediated by individuals’ perceptions regarding the characteristics of the information technologies. These findings suggest that user training and user support should be treated as enablers in process of implementing information technologies.
Quantification, Optimization and Uncertainty Modeling in Information Security Risks
Authors: Goel Sanjay , Lauría Eitel J.M.
Published: April 2010

In this paper, the authors present a quantitative model for estimating security risk exposure for a firm. The model includes a formulation for the optimization of controls as well as determining sensitivity of the exposure of assets to different threats. The model uses a series of matrices to organize the data as groups of assets, vulnerabilities, threats, and controls. The matrices are then linked such that data is aggregated in each matrix and cascaded across the other matrices. The computations are reversible and transparent allowing analysts to answer what-if questions on the data. The exposure formulation is based on the Annualized Loss Expectancy (ALE) model, and uncertainties in the data are captured via Monte Carlo simulation. A mock case study based on a government agency is used to illustrate this methodology.
Study on the New Tendency of the International Industry Shifts and Chinese Enterprise Implementation Tactics
Authors: Sun Jing , Wang Mingyou
Published: April 2010

At the beginning of 21st century, the Multinational Corporation take globalization strategy as the foundation and the starting point, accelerate the industry restructure greatly, the industrial shift presented the depth and breadth tendency day by day, how does China hold this opportunity, attracted the foreign capital vigorously, promotion industrial structure, will be the next economic development strategic mission. This article analysis multinational corporation international industry shift new tendency and analysis China uses the international industrial shift‘s present situation and the superiority, proposed the development countermeasure.
Embracing Guanxi
Authors: Zhang Jilong , Pimpa Nattavud
Published: April 2010

Guanxi is deeply ingrained in Chinese society and business etiquette; therefore, it is critical to understand and appreciate it to gain a commercial foothold in China. This paper explores the fundamental differences between Chinese and Western approaches to business dealings, to identify the factors that make it difficult for Western managerial practises to adopt guanxi. The authors identify the differences in the perception of trust in both societies and how this ultimately leads to clashes in cultures. However, there is also a need for Western practices to be more flexible and appreciate guanxi and its implications if multinational corporations are to succeed in China. The paper concludes by suggesting a possibility for both approaches to co-operate well, given the relative success of each approach in their respective cultures.
Australian Businesses in China
Authors: Chung Mona , Menzies Jane
Published: April 2010

This paper indentifies a main barrier when doing business with China, the cultural gap, and provides the strategies that companies can use when entering the Chinese market. This empirical study examined 40 Australian organisations in their activities when entering the Chinese market. Alarmingly after 30 years of attempting to do business in China, companies are still not addressing the issue of cultural differences. Companies are also caught by surprises due to lack of preparation how large the cultural gap is between Australian and Chinese business culture. The findings of the study have important implications for businesses considering entry to China, and for Australian businesses already doing business in China. The strategies investigated include human resource strategies, dealing with Chinese staff, relationship building, getting outside support (employing consultants), learning about the culture, and adapting to the culture.
Privacy Preserving Integration of Health Care Data
Authors: He Xiaoyun , Vaidya Jaideep , Shafiq Basit , Adam Nabil , White Tom
Published: April 2010

For health care related research studies the medical records of patients may need to be retrieved from multiple sites with different regulations on the disclosure of health information. Given the sensitive nature of health care information, privacy is a major concern when patients’ health care data is used for research purposes. In this paper, the authors propose approaches for integration and querying of health care data from multiple sources in a secure and privacy preserving manner. In particular, the first approach ensures secure data integration based on unique identifiers, and the second one considers data integration based on quasi identifiers, for which a rule-based framework is proposed for cross-linking data records, including secure character matching.
Emerging Retail Strategies in Urban Canada
Authors: Hernandez Tony , Svindal Magnus
Published: April 2010

In this article, the authors examine the spatial distribution of major retail chains across Canada. Using store location data for 2001 and 2006, the geospatial approach adopted in this study allows for the analysis of retail chains’ store portfolios by the size of the resident population of the ‘markets’ within which they operate. The analysis presented highlights the dominance of chain locations within and proximal to Canada’s major urban markets and provides further evidence of increasing interest amongst a number of major chains in ‘small town’ (or ‘C’) markets. It points to a future in which these smaller markets will become more competitive with an increased presence of major retail chains. The findings reported can be seen as the locational imprint of the processes of corporate concentration taking place across Canada, fuelled by the interplay of increased competition, concerns over market saturation and the need to sustain growth.
Spatiotemporal Pattern Analysis of Rapid Urban Expansion Using GIS and Remote Sensing
Authors: Kim Hyun Joong
Published: April 2010

Rapidly growing urban areas tend to reveal distinctive spatial and temporal variations of land use/land cover in a locally urbanized environment. In this article, the author analyzes urban growth phenomena at a local scale by employing Geographic Information Systems, remotely sensed image data from 1984, 1994, and 2004, and landscape shape index. Since spatial patterns of land use/land cover changes in small urban areas are not fully examined by the current GIS-based modeling studies or simulation applications, the major objective of this research is to identify and examine the spatial and temporal dynamics of land use changes of urban growth at a local scale. Analytical results demonstrate that sizes, locations, and shapes of new developments are spatio-temporally associated with their landscape variations and major transportation arteries. The key findings from this study contribute to GIS-based urban growth modeling studies and urban planning practices for local communities.
A Geospatial Analysis of Convective Rainfall Regions Within Tropical Cyclones After Landfall
Authors: Matyas Corene J.
Published: April 2010

In this article, the author utilizes a GIS to spatially analyze radar reflectivity returns during the 24 hours following 43 tropical cyclone (TC) landfalls. The positions of convective rainfall regions and their areal extent are then examined according to storm intensity, motion, vertical wind shear, time until extratropical transition, time after landfall, and distance from the coastline. As forward velocity increases in conjunction with an extratropical transition, these regions move outward, shift from the right side to the front of the TC, and grow in size. A similar radial shift, but with a decrease in areal extent, occurs as TCs weaken. Further quantification of the shapes of these regions could yield a more spatially accurate assessment of where TCs may produce high rainfall totals.
Development of Trust During Large Scale System Implementation
Authors: Schlichter Bjarne Rerup
Published: April 2010

Implementations of information systems are complex and problematic with a reputation for being delayed and exceeding budget. A critical factor in implementations is trust in the system, trust in the project and trust between the various stakeholders. This case charts the evolution of trust in the implementation of the Faroese integrated healthcare system and shows how trust relations at various points in the project became difficult, what the causes and consequences of these trust difficulties were, and how they were successfully resolved in the project.
Challenges of Information Security Management in a Research and Development Software Services Company
Authors: Sridhar Varadharajan
Published: April 2010

WirelessComSoft, a software company based in India, provided research and development outsourcing support in an Intellectual Property strong wireless communication products and services space. Over a period, WirelessComSoft developed a robust information security infrastructure and complied with industry standard auditing procedures. However, implementing information security across its different world-wide sites, updating it in tune with evolving user needs, deploying robust business continuity architecture, and maintaining logical and physical isolation of clients’ off-shore development centers were challenges that WirelessComSoft’s security implementation team grappled with every day. The case presents how information security infrastructure at WirelessComSoft evolved, the challenges faced and the methods implemented by the information security team to overcome these challenges.
Exploring Type-and-Identity-Based Proxy Re-Encryption Scheme to Securely Manage Personal Health Records
Authors: Ibraimi Luan , Tang Qiang , Hartel Pieter , Jonker Willem
Published: April 2010

Commercial Web-based Personal-Health Record (PHR) systems can help patients to share their personal health records (PHRs) anytime from anywhere. PHRs are very sensitive data and an inappropriate disclosure may cause serious problems to an individual. Therefore commercial Web-based PHR systems have to ensure that the patient health data is secured using state-of-the-art mechanisms. In current commercial PHR systems, even though patients have the power to define the access control policy on who can access their data, patients have to trust entirely the access-control manager of the commercial PHR system to properly enforce these policies. Therefore patients hesitate to upload their health data to these systems as the data is processed unencrypted on untrusted platforms. Recent proposals on enforcing access control policies exploit the use of encryption techniques to enforce access control policies. In such systems, information is stored in an encrypted form by the third party and there is no need for an access control manager. This implies that data remains confidential even if the database maintained by the third party is compromised. In this paper we propose a new encryption technique called a type-and-identity-based proxy re-encryption scheme which is suitable to be used in the healthcare setting. The proposed scheme allows users (patients) to securely store their PHRs on commercial Web-based PHRs, and securely share their PHRs with other users (doctors).
Regulatory Compliance and the Correlation to Privacy Protection in Healthcare
Authors: Grandison Tyrone , Bhatti Rafae
Published: April 2010

Recent government-led efforts and industry-sponsored privacy initiatives in the healthcare sector have received heightened publicity. The current set of privacy legislation mandates that all parties involved in the delivery of care specify and publish privacy policies regarding the use and disclosure of personal health information. The authors’ study of actual healthcare privacy policies indicates that the vague representations in published privacy policies are not strongly correlated with adequate privacy protection for the patient. This phenomenon is not due to a lack of available technology to enforce privacy policies, but rather to the will of the healthcare entities to enforce strong privacy protections and their interpretation of minimum compliance obligations. Using available information systems and data mining techniques, this article describes an infrastructure for privacy protection based on the idea of policy refinement to allow the transition from the current state of perceived to be privacy-preserving systems to actually privacy-preserving systems.
Technological Supports for Onsite and Distance Education and Students' Perceptions of Acquisition of Thinking and Team-Building Skills
Authors: Thomas Jennifer D.E. , Morin Danielle
Published: April 2010

This paper compares students’ perceptions of support provided in the acquisition of various thinking and team-building skills, resulting from the various activities, resources and technologies (ART) integrated into an upper level Distributed Computing (DC) course. The findings indicate that students perceived strong support for their acquisition of higher-order thinking skills and team-building skills from the offline resources, but moderate support from the online resources and technologies provided in the course, which was in opposition to the grades received. It also seems that those in the traditional computer lab setting perceived online resources as more supportive of higher-order thinking skills than those in other sections and those in the electronic classroom perceived the least support. The results were mixed for team-building skills and for offline resources support for higher-order thinking skills. In particular, distance students deemed the text and material in Blackboard less important for developing these skills than onsite students.
Applying Learning Diagnosis Diagram in Computer Aided Instructions
Authors: Wu YuLung
Published: April 2010

In Taiwan, when students learn in experiment-related courses, they are often grouped into several teams. The familiar method of grouping learning is “Cooperative Learning”. A well-organized grouping strategy improves cooperative learning and increases the number of activities. This study proposes a novel pedagogical method by adopting the Learning Diagnosis Diagram to obtain students’ knowledge structure. According to each knowledge structure of the student, this study proposes dynamic grouping to solve problems in the conventional once-and-for-all grouping strategy. The dynamic grouping method achieves the best complementary groups for further learning stages. Two courses were applied to conduct the proposed Two-phase Cooperative Learning. Complementary grouping methods and more interaction among team members are helpful for increasing the effect of learning. Evaluation results indicate that the proposed method significantly improves the learning achievement of all learners.
On the Path to Exascale
Authors: Alvin Ken , Barrett Brian , Brightwell Ron , Dosanjh Sudip , Geist Al , Hemmert Scott , Heroux Michael , Kothe Doug , Murphy Richard , Nichols Jeff , Oldfield Ron , Rodrigues Arun , Vetter Jeffrey S.
Published: April 2010

There is considerable interest in achieving a 1000 fold increase in supercomputing power in the next decade, but the challenges are formidable. In this paper, the authors discuss some of the driving science and security applications that require Exascale computing (a million, trillion operations per second). Key architectural challenges include power, memory, interconnection networks and resilience. The paper summarizes ongoing research aimed at overcoming these hurdles. Topics of interest are architecture aware and scalable algorithms, system simulation, 3D integration, new approaches to system-directed resilience and new benchmarks. Although significant progress is being made, a broader international program is needed.
Application Performance on the Tri-Lab Linux Capacity Cluster - TLCC
Authors: Rajan Mahesh , Doerfler Douglas , Vaughan Courtenay T. , Epperson Marcus , Ogden Jeff
Published: April 2010

In a recent acquisition by DOE/NNSA several large capacity computing clusters called TLCC have been installed at the DOE labs: SNL, LANL and LLNL. TLCC architecture with ccNUMA, multi-socket, multi-core nodes, and InfiniBand interconnect, is representative of the trend in HPC architectures. This paper examines application performance on TLCC contrasting them with Red Storm/Cray XT4. TLCC and Red Storm share similar AMD processors and memory DIMMs. Red Storm however has single socket nodes and custom interconnect. Micro-benchmarks and performance analysis tools help understand the causes for the observed performance differences. Control of processor and memory affinity on TLCC with the numactl utility is shown to result in significant performance gains and is essential to attenuate the detrimental impact of OS interference and cache-coherency overhead. While previous studies have investigated impact of affinity control mostly in the context of small SMP systems, the focus of this paper is on highly parallel MPI applications.
Abstractions and Middleware for Petascale Computing and Beyond
Authors: Sbalzarini Ivo F.
Published: April 2010

As high-performance computing moves to the petascale and beyond, a number of algorithmic and software challenges need to be addressed. This paper reviews the main performance-limiting factors in today’s high-performance computing software and outlines a possible new programming paradigm to address them. The proposed paradigm is based on abstract parallel data structures and operations that encapsulate much of the complexity of an application, but still make communication overhead explicit. The authors argue that all numerical simulations can be formulated in terms of the presented abstractions, which thus define an abstract semantic specification language for parallel numerical simulations. Simulations defined in this language can automatically be translated to source code containing the appropriate calls to a middleware that implements the underlying abstractions. Finally, the structure and functionality of such a middleware are outlined while demonstrating its feasibility on the example of the parallel particle-mesh library (PPM).
A Simulator for Large-Scale Parallel Computer Architectures
Authors: Janssen Curtis L. , Adalsteinsson Helgi , Cranford Scott , Kenny Joseph P. , Pinar Ali , Evensky David A. , Mayo Jackson
Published: April 2010

Efficient design of hardware and software for large-scale parallel execution requires detailed understanding of the interactions between the application, computer, and network. The authors have developed a macro-scale simulator (SST/macro) that permits the coarse-grained study of distributed-memory applications. In the presented work, applications using the Message Passing Interface (MPI) are simulated; however, the simulator is designed to allow inclusion of other programming models. The simulator is driven from either a trace file or a skeleton application. Trace files can be either a standard format (Open Trace Format) or a more detailed custom format (DUMPI). The simulator architecture is modular, allowing it to easily be extended with additional network models, trace file formats, and more detailed processor models. This paper describes the design of the simulator, provides performance results, and presents studies showing how application performance is affected by machine characteristics.
Dimensionality Reduction with Unsupervised Feature Selection and Applying Non-Euclidean Norms for Classification Accuracy
Authors: Saxena Amit , Wang John
Published: April 2010

This paper presents a two-phase scheme to select reduced number of features from a dataset using Genetic Algorithm (GA) and testing the classification accuracy (CA) of the dataset with the reduced feature set. In the first phase of the proposed work, an unsupervised approach to select a subset of features is applied. GA is used to select stochastically reduced number of features with Sammon Error as the fitness function. Different subsets of features are obtained. In the second phase, each of the reduced features set is applied to test the CA of the dataset. The CA of a data set is validated using supervised k-nearest neighbor (k-nn) algorithm. The novelty of the proposed scheme is that each reduced feature set obtained in the first phase is investigated for CA using the k-nn classification with different Minkowski metric i.e. non-Euclidean norms instead of conventional Euclidean norm (L2). Final results are presented in the paper with extensive simulations on seven real and one synthetic, data sets. It is revealed from the proposed investigation that taking different norms produces better CA and hence a scope for better feature subset selection.
Graph-Based Modelling of Concurrent Sequential Patterns
Authors: Lu Jing , Chen Weiru , Keech Malcolm
Published: April 2010

Structural relation patterns have been introduced recently to extend the search for complex patterns often hidden behind large sequences of data. This has motivated a novel approach to sequential patterns post-processing and a corresponding data mining method was proposed for Concurrent Sequential Patterns (ConSP). This article refines the approach in the context of ConSP modelling, where a companion graph-based model is devised as an extension of previous work. Two new modelling methods are presented here together with a construction algorithm, to complete the transformation of concurrent sequential patterns to a ConSP-Graph representation. Customer orders data is used to demonstrate the effectiveness of ConSP mining while synthetic sample data highlights the strength of the modelling technique, illuminating the theories developed.
User-Centric Similarity and Proximity Measures for Spatial Personalization
Authors: Yang Yanwu , Claramunt Christophe , Aufaure Marie-Aude , Zhang Wensheng
Published: April 2010

Spatial personalization can be defined as a novel way to fulfill user information needs when accessing spatial information services either on the web or in mobile environments. The research presented in this paper introduces a conceptual approach that models the spatial information offered to a given user into a user-centered conceptual map, and spatial proximity and similarity measures that considers her/his location, interests and preferences. This approach is based on the concepts of similarity in the semantic domain, and proximity in the spatial domain, but taking into account user’s personal information. Accordingly, these spatial proximity and similarity measures could directly support derivation of personalization services and refinement of the way spatial information is accessible to the user in spatially related applications. These modeling approaches are illustrated by some experimental case studies.
Electronic Voting by Means of Digital Terrestrial Television The Infrastructure, Security Issues and a Real Test-bed
Authors: Caldelli Roberto , Becarelli Rudy , Filippini Francesco , Picchioni Francesco , Giorgetti Riccardo
Published: April 2010

In this paper a Digital Terrestrial Television (DTT) based voting system is presented. This electronic voting technology allows disabled users to cast their vote from home by using common well-known devices. The needed equipment are a TV set, a Set Top Box (STB) with its remote control and a telephone line. The complete infrastructure consists of an MHP (Multimedia Home Platform) application that acts as a client application, a server application that acts as a network/counting server for e-voting, and a security protocol based on asymmetric key encryption to ensure authentication and secrecy of the vote. The MHP application is broadcasted by a certified (e.g., national) TV channel that grants its originality. The user needs a smart card issued by a national authority and to sign the encrypted ballot. The voter can browse the application by acting on the STB remote control. The server application is in charge to verify user identity, to gather and store user’s encrypted ballots and finally to count votes. The communication between the client application and the server takes place by means of a secured channel (using HTTPS) while the voting operations are secured with the help of asymmetric keys encryption.
Requirements and Properties of Qualified Electronic Delivery Systems in eGovernment
Authors: Tauber Arne
Published: April 2010

Electronic mailing systems are the dominant communication systems in private and business matters. Public administrations deliver documents to citizens and businesses—subpoenas, legal verdicts, notifications, administrative penalties, and so forth. However, official activities are more strongly bound to legal regulations than in civil law. Delivery of crucial and personal documents raises the demand for qualified identification and non-repudiation services as featured by registered and certified mail in the paper world. Legal requirements for electronic delivery carried out by public administrations (eDelivery) cannot be fulfilled by standard mailing systems. Although the requirements for eDelivery systems may differ due to national legal regulations, this paper discusses common requirements and properties on an abstract level. Moreover, the author shows how these requirements have been addressed by introducing the Austrian eDelivery system for eGovernment applications.
Employees' Perceptions of Biometric Technology Adoption in E-Government
Authors: Alhussain Thamer , Drew Steve
Published: April 2010

This paper discusses an exploratory study of government employees’ perceptions of the introduction of biometric authentication at the workplace in the Kingdom of Saudi Arabia. The authors suggest that studying the factors affecting employees’ acceptance of new technology will help ease the adoption of biometric technology in other e-government applications. A combination of survey and interviews was used to collect the required data. Interviews were conducted with managers and questionnaires were given to employees from two different government organisations in Saudi Arabia to investigate the employees’ perceptions of using biometrics. The results of this study indicate a significant digital and cultural gap between the technological awareness of employees and the preferred authentication solutions promoted by management. A lack of trust in technology, its potential for misuse and management motives reflect the managers’ need to consider their responsibilities for narrowing these gaps. It was apparent that overcoming employees’ resistance is an essential issue facing biometric implementation. Based on the research the authors recommend that an awareness and orientation process about biometrics should take place before the technology is introduced into the organisation.
Collaborative Distance
Authors: Pallot Marc , Martínez-Carreras Maria Antonia , Prinz Wolfgang
Published: April 2010

This paper introduces the topic of “Collaborative Distance” within Distributed Collaboration as being an introduction to this Special Issue on Collaborative Working Environments1 (CWE). In this paper, the authors discuss various related concepts, identified during an extensive literature review, on both proximity and distance in distributed collaboration. Then, a Collaborative Distance Framework (CDF) is proposed in deriving its four dimensions and related factors from the existing body of knowledge. The following section discusses the interest of such a CDF and introduces the articles published in this special issue. The concluding section discusses the articles’ contributions, limitations and future work as well as recommendations for future research in this area.
Socio-Technical Influences on Virtual Research Environments
Authors: Ponti Marisa
Published: April 2010

A number of socio-technical aspects that influence interorganizational research collaboration are embedded in local work contexts. Thus, they should be a main concern for the design of virtual research environments. A review of forty papers from different research fields provided an understanding of the influence of eleven socio-technical aspects grouped according to the following categories: nature of work; common ground; collaboration readiness; management style and leadership; technology readiness. There are five main implications for the design of virtual research environments. Emphasis is placed on the importance of consulting the stakeholders so that they suggest solutions and ideas, and imbue the collaborative environment with the values required for it to be sustainable.
Information Technology and Microfinance Institutions
Authors: Iyengar Kishen Parthasarathy , Quadri Najam Ahmad , Singh Vikas Kumar
Published: April 2010

Microfinance Institutions have the potential to alleviate poverty across the world. However, they face many challenges before they can grow to meet set objectives. The use of information technology holds promise to enable such growth. There are some key challenges that must be addressed by microfinance institutions before the full potential of IT can be realized. This paper articulates five key challenges that microfinance institutions face, particularly those operating in rural undeveloped areas in the developing world. This paper also discusses how some of these challenges are being overcome by these institutions. Finally, the authors lay out a framework for building and operating effective information systems.
Strategic Use of Information Technology in the Spanish Microfinance Sector
Authors: Estapé-Dubreuil Glòria , Torreguitart-Mirada Consol
Published: April 2010

This paper analyzes the relationships between IT and microfinance in a developed country. Its main purpose is the study of the intensity of IT use in the sector, focusing on IT-related management of its organizations. Two different goals related to actual IT use have been identified. Information Technologies have indeed been used as a tool to provide information, both to prospective clients and with a more general scope. Furthermore, improvements on management due to IT use have also been encountered, such as on-line direct support to would-be entrepreneurs through specific software. The paper also considers whether IT use adds effective value to the performance of some or all Spanish Microfinance Institutions (MFIs). It is found that such strategic use of IT is less widespread, related primarily to financial transparency issues, more clearly shown by MFIs linked to the social economy.