bluuebunny/crossref_metadata_2025 huggingface dataset:
A Failure Detection System for Large Scale Distributed Systems
Authors: Lavinia Andrei , Dobre Ciprian , Pop Florin , Cristea Valentin
Published: October 2012

Failure detection is a fundamental building block for ensuring fault tolerance in large scale distributed systems. It is also a difficult problem. Resources under heavy loads can be mistaken as being failed. The failure of a network link can be detected by the lack of a response, but this also occurs when a computational resource fails. Although progress has been made, no existing approach provides a system that covers all essential aspects related to a distributed environment. This paper presents a failure detection system based on adaptive, decentralized failure detectors. The system is developed as an independent substrate, working asynchronously and independent of the application flow. It uses a hierarchical protocol, creating a clustering mechanism that ensures a dynamic configuration and traffic optimization. It also uses a gossip strategy for failure detection at local levels to minimize detection time and remove wrong suspicions. Results show that the system scales with the number of monitored resources, while still considering the QoS requirements of both applications and resources.
Lightweight Editing of Distributed Ubiquitous Environments
Authors: Schirmer Maximilian , Gross Tom
Published: October 2012

Cooperative ubiquitous environments support user interaction and cooperative work by adapting to the prevalent situation of the present users. They are typically complex and have many environment components—interconnected devices and software modules—that realise new interaction techniques and facilitate collaboration. Despite this complexity, users need to be able to easily adapt their environments to the respective needs of the workgroups. In this paper, the authors present the CollaborationBus Aqua editor, a sophisticated, yet lightweight editor for configuring ubiquitous environments in groups. The CollaborationBus Aqua editor simplifies the configuration and offers advanced concepts for sharing and browsing configurations among users.
Guaranteeing Correctness for Collaboration on Documents Using an Optimal Locking Protocol
Authors: Dekeyser Stijn , Hidders Jan
Published: October 2012

Collaboration on documents has been supported for several decades through a variety of systems and tools; recently a renewed interest is apparent through the appearance of new collaborative editors and applications. Some distributed groupware systems are plug-ins for standalone word processors while others have a purely web-based existence. Most exemplars of the new breed of systems are based on Operational Transformations, although some are using traditional version management tools and still others utilize document-level locking techniques. All existing techniques have their drawbacks, creating opportunities for new methods. The authors present a novel collaborative technique for documents which is based on transactions, schedulers, conflicts, and locks. It is not meant to replace existing techniques; rather, it can be used in specific situations where a strict form of concurrency control is required. While the approach of presentation in this article is highly formal with an emphasis on proving desirable properties such as guaranteed correctness, the work is part of a project which aims to fully implement the technique.
Collaboration Support for Activity Management in a Personal Cloud Environment
Authors: Ardissono Liliana , Bosio Gianni , Goy Anna , Petrone Giovanna , Segnan Marino , Torretta Fabrizio
Published: October 2012

This paper describes a framework supporting the development of open collaboration environments which integrate heterogeneous business services. The framework facilitates the user cooperation in the execution of shared activities by offering a workspace awareness support which abstracts from the business services employed to operate. The management of the workspaces of the user’s collaborations is based on the functions offered by the Collaborative Task Manager (CTM), which offers a lightweight and flexible model for handling more or less complex collaborations. The CTM is integrated with business services in a loosely coupled way which supports the management of parallel workspaces for accessing the user’s collaboration contexts, their objects and the related awareness information.
Adaptable Information Provisioning in Collaborative Networks
Authors: Thimm Heiko , Rasmussen Karsten Boye
Published: October 2012

Well-informed network participants are a necessity for successful collaboration in business networks. The widespread knowledge of the many aspects of the network is an effective vehicle to promote trust within the network, successfully resolve conflicts, and build a prospering collaboration climate. Despite their natural interest in being well informed about all the different aspects of the network, limited resources, e.g. time restrictions of the participants, often prevents reaching an appropriate level of shared information. It is possible to overcome this problem through the use of an active information provisioning service that allows users to adapt the provisioning of information to their specific needs. This paper presents an extensible information modeling framework and also additional complementary concepts that are designed to enable such an active provisioning service. Furthermore, a high-level architecture for a system that offers the targeted information provisioning service is described.
Design and Implementation of Hybrid Time (HT) Group Communication Protocol for Homogeneous Broadcast Groups
Authors: Tsuneizumi Isamu , Aikebaier Ailixier , Ikeda Makoto , Enokido Tomoya , Takizawa Makoto
Published: October 2012

To realize the cooperation of a group of multiple peer processes (peers), messages sent by peers must be causally delivered to every peer. In a scalable group, it is necessary to reduce the communication overhead to causally deliver messages. In this paper, the authors take advantage of the linear time (LT) and physical time (PT) protocols, as the message length is O(n) for the number n of peers. However, some pairs are unnecessarily ordered, that is, even if a pair of messages is ordered in the protocols, the messages may not be causally ordered. The greater the number of messages that are unnecessarily ordered, the larger the overhead is implied since the messages must be kept in a receipt queue if a message is lost or delayed. This paper discusses a hybrid time group communication (HT) protocol that reduces the number of messages unnecessarily ordered. The HT protocol is evaluated in terms of the number of unnecessarily ordered messages compared with the PT and LT protocols. It is demonstrated that the number of unnecessarily ordered messages can be reduced in the HT protocol compared with the LT and PT protocols.
A Next Generation Technology Victim Location and Low Level Assessment Framework for Occupational Disasters Caused by Natural Hazards
Authors: Bessis Nik , Asimakopoulou Eleana , Norrington Peter , Thomas Suresh , Varaganti Ravi
Published: October 2012

Much work is underway within the broad next generation technologies community on issues associated with the development of services to support interdisciplinary domains. Disaster reduction and emergency management are domains in which utilization of advanced information and communication technologies (ICT) are critical for sustainable development and livelihoods. In this article, the authors aim to use an exemplar occupational disaster scenario in which advanced ICT utilization could present emergency managers with some collective computational intelligence in order to prioritize their decision making. To achieve this, they adapt concepts and practices from various next generation technologies including ad-hoc mobile networks, Web 2.0, wireless sensors, crowd sourcing and situated computing. On the implementation side, the authors developed a data mashup map, which highlights the criticality of victims at a location of interest. With this in mind, the article describes the service architecture in the form of data and process flows, its implementation and some simulation results.
Geospatial Data Infrastructure (GDI) for Sharing Agro-Climatic Information to Improve Agricultural Productivity in Nigeria
Authors: Ayanlade A. , Olawole M. O. , Ayanlade O. S. , Bolarin O.
Published: October 2012

Geographic Information Systems (GIS) and Remote Sensing (RS) techniques are increasingly being used in agricultural management to more efficiently support emergency agro-climatic information needed in this century. Although several studies have been carried out on application of GIS and remote sensing for agricultural and rural development in other parts of the world, little research has been done in sub-Saharan Africa in terms of developing geospatial data infrastructure to enhance agricultural practices especially agricultural risk management in this age of climate change. This chapter therefore examines technological aspects of geographic information sharing as a useful platform for sharing information among agricultural agencies in Nigeria and to formulate relevant prescriptions for the future. The study shows how an integrated GIS modeling system can allow agricultural producer as well as policy makers to know the impact of variation in climate from one place/region to another for better management, productivity, and profitability. The study also develops agricultural GDI prototype for agricultural emergency management. This chapter concludes by suggesting that developing country (i.e. African countries) should embark on agricultural policy reform to enhance investment in ICT infrastructure in agricultural production.
Information and Communication Technology Uses in Agriculture
Authors: Wasihun Tizita Alemayehu , Maumbe Blessing
Published: October 2012

The world has experienced an unprecedented growth in information and communication technologies (ICT) through the widespread use of personal computers, Internet, and mobile phones. The objectives of this chapter are to examine trends in ICT use in agriculture, identify key success factors for ICT utilization in agriculture, and investigate the implications of ICT-enabled value chains for the agribusiness industry. The chapter describes the strategic role of ICT in the development of both e-commerce and mobile commerce in agriculture globally. The chapter identifies the leading areas of ICT use in agriculture and agribusinesses as input procurement, production, marketing, food traceability, and financial service delivery. Producers are increasingly seeking ways to add value to their businesses by integrating ICT in the value chain. Similarly, consumers are becoming more knowledgeable about how they could use ICT to articulate their preferences. The chapter discusses key success factors for ICT applications affecting both the internal and external environment of agribusiness firms. The chapter concludes by drawing implications for ICT use in agriculture and agribusiness value chains.
Economic, Political and Social Threats in the Information Age
Authors: Gelbstein Eduardo , Wuest Marcus , Fridakis Stephen
Published: October 2012

There does not appear to be a common framework for quantifying the impact of information security business disruption events resulting in the loss of availability, confidentiality and/or data integrity. Individual incidents are known to have had costs ranging from 1 million US dollars an hour to a bank loss of close of 6 billion Euro. Given the global nature of supply chains and electronic commerce, deliberate disruption through well conducted attacks could have devastating economic consequences. This chapter explores in some detail the various components of such consequences.
Attackers
Authors: Gelbstein Eduardo
Published: October 2012

Of the three groups of components of information security – tools, processes, and people- the last one should be considered as the weakest link. People range from the tired or unaware employee that clicks on a link that infects a computer or a network, to the security expert working for a criminal, military, or terrorist organization attacking a critical information infrastructure. This chapter examines the various classes of potential attackers and the techniques currently used to perpetrate such attacks.
Threats, Vulnerability, Uncertainty and Information Risk
Authors: Gelbstein Eduardo
Published: October 2012

Two other matters complicate this topic: the lack of statistical data relating to cyber-attacks and the vulnerabilities inherent in hardware, software and networks, many of which are unknown until someone exploits them.
ICT and Security Governance
Authors: Gelbstein Eduardo , Kellermann Tom
Published: October 2012

This chapter examines in summary form those standards and best practices that have been widely accepted as being the “right things the right way” and also discusses how to determine if things are done “well enough”.
Concerns About What Will Happen Next
Authors: Gelbstein Eduardo
Published: October 2012

This chapter discusses vulnerabilities that should be considered by decision makers as they could be seen as the soft underbelly of a society that has an irreversible and deep reliance on information technologies.
To Define or Not to Define
Authors: Reich Pauline C.
Published: October 2012

There have been three stages of Internet use: the happy days of e-commerce and optimistic sharing in military and academic circles; the growing awareness of Cybercrime issues to be addressed by law; and recent concerns about cyber attacks and national security issues and the paucity of national and international legal means to address them. This and the following two chapters analyze actual incidents and the applicability and inapplicability of law and policy; attempts to define terms that are thrown about in the media and by legislatures; such conundrums as attribution and anonymity, the lack of precedents and metaphors to guide legislators and policy makers; privacy and civil liberties issues; proposed legal and policy measures at national and international levels.
Case Study
Authors: Reich Pauline C.
Published: October 2012

The purpose of this chapter is to analyze terrorist use of technology in the Mumbai attacks of November 2008 and the use of law to prosecute terrorists availing themselves of technological measures to plan and carry out attacks. The Mumbai attacks are also placed in the context of terrorism in India, by looking at identified terrorist groups and incidents. It should be noted that India adopted amendments to its 2000 IT Act in December 2008, following the attacks, and these amendments include provisions related to cyber terrorism, which might be applied going forward if necessary. It should also be noted that Pakistan adopted similar legislation in 2007 and in 2008, and Bangladesh states that it is in the process of adopting such legislation. Both India and Pakistan have made cyber terrorism punishable by death penalties. The definitions of cyber terrorism in their legislation are provided in this chapter. The chapter also analyzes the level of technological know-how exhibited by the alleged terrorists currently on trial in India, Pakistan, and the United States for planning and executing the Mumbai attacks. Recent measures taken by the Indian government to avoid future use of technology by terrorists are also discussed in the context of a democracy needing to balance security with the privacy and liberty of its citizens.
The United Kingdom’s Centre for the Protection of National Infrastructure
Authors: Weinstein Stuart , Wild Charles
Published: October 2012

This chapter examines the effectiveness of the newly-formed CPNI in leading the United Kingdom’s response to cyber attacks on critical infrastructures.
Performance Evaluation of Hypervisors for Cloud Computing
Authors: Ahuja Sanjay P. , Sridharan Suganya
Published: October 2012

The virtualization of IT infrastructure enables consolidation and pooling of IT resources so they are shared over diverse applications to offset the limitation of shrinking resources and growing business needs. Virtualization provides a logical abstraction of physical computing resources and creates computing environments that are not restricted by physical configuration or implementation. Virtualization is very important for cloud computing because the delivery of services simplified by providing a platform for optimizing complex IT resources in a scalable manner, which makes cloud computing more cost effective. Hypervisor plays an important role in the virtualization of hardware. This software provides a virtual hardware to support running multiple operating systems concurrently using one physical server. This research quantitatively and qualitatively compares the performance of VMware ESXi 4.1, Citrix Systems Xen Server 5.6 and KVM Hypervisors using standard benchmark SPECvirt_sc2010v1.01 formulated by Standard Performance Evaluation Committee (SPEC), which generate various Workloads simulating real life situations.
Cloud Computing
Authors: Khan Nawsher , Ahmad Noraziah , Herawan Tutut , Inayat Zakira
Published: October 2012

Efficiency (in term of time consumption) and effectiveness in resources utilization are the desired quality attributes in cloud services provision. The main purpose of which is to execute jobs optimally, i.e., with minimum average waiting, turnaround and response time by using effective scheduling technique. Replication provides improved availability and scalability; decreases bandwidth use and increases fault tolerance. To speed up access, file can be replicated so a user can access a nearby replica. This paper proposes architecture to convert Globally One Cloud to Locally Many Clouds. By combining replication and scheduling, this architecture improves efficiency and easy accessibility. In the case of failure of one sub cloud or one cloud service, clients can start using another cloud under “failover” techniques. As a result, no one cloud service will go down.
Discriminative Zernike and Pseudo Zernike Moments for Face Recognition
Authors: Singh Chandan , Walia Ekta , Mittal Neerja
Published: October 2012

Usually magnitude coefficients of some selected orders of ZMs and PZMs have been used as invariant image features. The careful selection of the set of features, with higher discrimination competence, may increase the recognition performance. In this paper, the authors have used a statistical method to estimate the discrimination strength of all the extracted coefficients of ZMs and PZMs whereas for classification, only the coefficients with estimated higher discrimination strength are used in the feature vector. The performance of these selected Discriminative ZMs (DZMs) and Discriminative PZMs (DPZMs) features have been compared to that of their corresponding conventional approaches on YALE, ORL and FERET databases against illumination, expression, scale and pose variations. An extension to these DZMs and DPZMs have been proposed by combining them with PCA and FLD. It has been observed from the exhaustive experimentation that the recognition rate is improved by 2-6%, at reduced dimensions and with less computational complexity, than that of using the successive ZMs and PZMs features.
Digital Image Protection using Keyed Hash Function
Authors: Muraharirao Siva Charan , Das Manik Lal
Published: October 2012

Digital image authentication is an essential attribute for protecting digital image from piracy and copyright violator. Anti-piracy, digital watermarking, and ownership verification are some mechanisms evolving over the years for achieving digital image authentication. Cryptographic primitives, such as hash function, digital signature, and message authentication codes are being used in several applications including digital image authentication. Use of Least Significant Bit (LSB) is one of the classical approaches for digital image authentication. Although LSB approach is efficient, it does not provide adequate security services. On the other hand, digital signature-based image authentication provides better security, but with added computational cost in comparison with LSB approach. Furthermore, digital signature-based authentication approach requires managing public key infrastructure. Considering security weakness of LSB-based approach and cost overhead of public key based approach, the authors present a digital image authentication scheme using LSB and message authentication codes (MAC). The MAC-based approach for authenticating digital image is secure and efficient approach without public key management overhead. The authors also provide experimental results of the proposed scheme using MATLAB. The experimental results show that the proposed scheme is efficient and secure in comparisons with other schemes.
Local Linear Regression on Hybrid Eigenfaces for Pose Invariant Face Recognition
Authors: Jaiswal Ajay , Kumar Nitin , Agrawal R. K.
Published: October 2012

Pose variation leads to significant decline in the performance of the face recognition systems. In this paper, the authors propose a new approach HLLR, based on conjunction of hybrid-eigenfaces and local linear regression (LLR), to perform face recognition across pose. In this approach, LLR on hybrid-eigenfaces is used to generate virtual views. These virtual views in frontal and non-frontal poses are obtained using frontal gallery image. The performance of the proposed approach is compared for classification accuracy with another efficient method based on global linear regression on hybrid eigenface (HGLR). They also investigate the effect of number of images used to construct hybrid-eigenfaces on classification accuracy. Experimental results on two well known publicly available face databases demonstrate the effectiveness of the proposed approach. The suitability of proposed approach is also noticed when the number of available images is small.
An Improved Fingerprinting Algorithm for Detection of Video Frame Duplication Forgery
Authors: Hu Yongjian , Li Chang-Tsun , Wang Yufei , Liu Bei-bei
Published: October 2012

Frame duplication is a common way of digital video forgeries. State-of-the-art approaches of duplication detection usually suffer from heavy computational load. In this paper, the authors propose a new algorithm to detect duplicated frames based on video sub-sequence fingerprints. The fingerprints employed are extracted from the DCT coefficients of the temporally informative representative images (TIRIs) of the sub-sequences. Compared with other similar algorithms, this study focuses on improving fingerprints representing video sub-sequences and introducing a simple metric for the matching of video sub-sequences. Experimental results show that the proposed algorithm overall outperforms three related duplication forgery detection algorithms in terms of computational efficiency, detection accuracy and robustness against common video operations like compression and brightness change.
The “Technological Good” in the Multiliteracies Processes of Teachers and Students
Authors: Nuzzaci Antonella
Published: October 2012

This article focuses on the importance of media literacy and digital skills play in strengthening the cultural profiles of the population. In particular, it considers the “technological good” as an element that is part of a symbolic system of culture that can create new forms of “thin inequality.” In this sense, the contribution examines the relationship between new forms of literacy and media skills in an attempt to explore how technologies are transforming the traditional literacy of teachers and students, as well as of the rest of the population, and how this will lead to new ways of thinking, acting and being the teaching and learning. The heritage technological, individual, and social, reshapes the culture and its size, inducing the education, at all levels, to building curricular activities most appropriate to the needs of a knowledge society and the profile of the literate of the 20th century.
Building a Measurement Framework for m-Government Services
Authors: Stiakakis Emmanouil , Georgiadis Christos K.
Published: October 2012

This study develops and presents a proposed framework for the measurement of mobile government (m-government) services. The measurement framework consists of: (i) identification/categorisation of m-government services; (ii) sophistication stages of these services; and (iii) indicators to evaluate their progress. With respect to the methodological approach followed in the study, twenty e-government services clustered by type of activity and interaction level are ranked for importance in terms of criteria that characterise the mobile setting. Moreover, core indicators used for e-government are examined in terms of their appropriateness to the mobile setting. According to the authors’ findings, three m-government service clusters are established, assisting governments to prioritise services to mobile users. A modification in the sophistication model for e-services is recommended for application in m-government. Finally, the proposed indicators are mainly user-focused, in accordance with the personalised nature of services delivered through mobile devices.
Internet Privacy Concerns versus Behavior
Authors: Sousa Kenneth J. , MacDonald Laurie E. , Fougere Kenneth T.
Published: October 2012

This study examines the possible disconnect between student concerns about privacy when using the Internet and their behavior. The literature indicates that Internet users are concerned about privacy but their web-browsing habits consistently put their privacy at risk. Browsing habits were examined using five factors: (1) privacy concerns, (2) self-efficacy, (3) risk assessment, (4) threat assessment, and (5) privacy involvement. These factors were analyzed for their relationship to privacy behavior. A survey questionnaire was developed and administered to a sample drawn from university students.
Why Technologists Resist Negative Change
Authors: Cua Francisco Chia , Reames Steve
Published: October 2012

This paper is a critical and non-empirical review of innovation resistance and anti-consumption: the concepts, concerns, conflicts, and convergence. Both resistances to innovation and anti-consumptions converge to one another which influence the opinions (i.e., market mavens) of the market segment or non-adopters (voluntary simplifiers). Voluntary simplifiers or non-adopters represent over fifty percent (50%) of the market segment. This paper focuses on the embedded (hidden) assumptions of the resistance to innovation and anti-consumption and describes how the two concepts are different. When both converge, the exact reasons in favor of action will occur. The paper concludes that the technologist can adapt to negative change if they better understand why non-adopters resist innovation and consume products against their better judgment.
An Automated Workforce Clustering Method for Business Process Reengineering in Research and Development Organizations
Authors: Tavana Madjid , Sisti Alex F. , Trevisani Dawn A.
Published: October 2012

Business process reengineering (BPR) involves the radical redesign of functional organizations into cross-functional teams to achieve dramatic improvements in productivity. Redesigning complex and dynamic processes in research and development (R&D) organizations with multi-layer projects is a difficult task. Previous researchers have proposed many intuitive approaches for BPR utilizing intuition and subjective judgment from “experts” at various stages of their implementation. However, the complexities inherent in large R&D organizations have restricted the effectiveness of their use in practice. The authors present an automated and structured analytic algorithm that eliminates the need for subjective human judgment. The proposed method facilitates the reorganization of R&D processes into cross-functional work units and projects. The efficacy of the algorithm is confirmed with a small problem and the applicability of the proposed method is demonstrated at the Air Force Research Laboratory.
The involvement of a South African church in a changing society
Authors: Schoeman Willem J.
Published: October 2012

The church and its congregations are an important part of society. The aim of this article was to provide a description of the involvement of the Dutch Reformed Church (DRC) in a changing society. A short description of the changes in the South African society over the last 15�20 years was provided. The role and response of churches was then considered, and lastly, there was a more in-depth discussion on the involvement of the DRC, its leadership and its congregations in society. The argument of this article was that there is a movement towards less involvement in society by the DRC. The involvement of congregations is mostly on the level of welfare projects within an evangelist approach. It was argued that the challenge for congregations is to build partnerships of trust within their communities for the purpose of sustainable people development.
Practice Educator Perspectives of Multiple Mentoring in Diverse Clinical Settings
Authors: Copley Jodie , Nelson Alison
Published: October 2012

Introduction:

In a climate of overloaded health systems and limited opportunities for practice education, there is a need to provide high quality placements that prepare students adequately for contemporary practice. Group models of supervision are one way to address this. This study trialled a multiple mentoring (group supervision) model across three different settings: a university clinic, an acute hospital and a community-based service. The perceptions of practice educators regarding its use and essential implementation features of the model were explored.

Method:

The model was trialled over an 18-month period. A total of 15 practice educators participated in three focus groups.

Findings:

Following inductive analysis, three main themes emerged: being clear in the chaos; qualities of the service and people; and challenges and benefits. Findings indicated a range of factors that influenced practice educators' experiences, including the structure of the placement, communication processes and the organisational context.

Conclusion:

A multiple mentoring model of student supervision can be implemented across a range of practice settings, providing that care is taken to tailor the practicum for each setting. Practice educators perceived that the benefits to themselves, the students, the service and the clients outweighed the challenges.
Arthritis-Related Occupational Therapy: Making Invisible Ruling Relations Visible Using Institutional Ethnography
Authors: Prodinger Birgit , Shaw Lynn , Rudman Debbie Laliberte , Townsend Elizabeth
Published: October 2012

Introduction:

Occupational therapists' intention of enabling women with rheumatoid arthritis to participate in everyday life is fraught with challenges in everyday practice.

Method:

Inspired by institutional ethnography, this paper aims to make explicit how the work of occupational therapists in an outpatient rheumatology hospital setting is governed within invisible, ruling relations. An analytical description of the first author's clinical experience was a standpoint from which to explicate how occupational therapy is coordinated to the ruling relations of the Austrian health care system.

Findings:

Occupational therapy practice and research are ruled within a positivist, body-focused, medical apparatus, which renders largely invisible occupational therapists' knowledge of enabling people to engage in occupations that are meaningful to them.

Conclusion:

Occupational therapists have professional power that can be asserted by strategically using occupational therapy specific knowledge and language in textually mediated practices, from assessments and case files to media images, to give greater visibility and influence to the profession's work of enabling occupation.
Using population-Level Time Use Datasets to Advance Knowledge of Human Activity, Participation and Health
Authors: Hunt Eithne , McKay Elizabeth A
Published: October 2012

Time use is of enduring interest to occupational therapists and occupational scientists. However, occupational researchers have yet to exploit fully the potential of large population-level time use datasets. A brief overview of the historical development and current activities within time use research internationally is presented. Whilst acknowledging the challenging nature of this type of research, the authors explore some of the opportunities offered by the secondary analysis of large time use datasets for occupational therapy and occupational science researchers who seek to advance knowledge of human activity, participation and health.
The Effect of Mere Presence on Electronic Gaming Machine Gambling
Authors: Rockloff Matthew J. , Greer Nancy , Evans Lionel G.
Published: October 2012

Intensification of gambling behavior may partly result from arousal caused by the mere physical presence of others in the gaming venue moving through the gaming floor on their way to enjoy other amenities. In an experiment, 56 male and 76 female participants (N=132) gambled on a laptop-simulated electronic gaming machine (EGM), either alone or with a simulated crowd of 6 or 26 others who were wearing blindfolds and earphones. These crowds of other persons were falsely said to be participating in another experiment on sensory deprivation. Among players with preexisting gambling problems, the results showed that these crowds contributed to a particular style of gambling whereby players generally bet smaller amounts but were more persistent as losses mounted. These changes in persistence occurred despite the inability of these others to witness or evaluate the participants. The experiment suggests that the mere presence of others in a gaming venue can affect EGM betting behavior.
The Real of problem gambling households
Authors: Borch Anita
Published: October 2012

In this article, problem gambling stories of eight Norwegian households are interpreted in the light of Jacques Lacan's concept of the Real. It is argued that the concept of the Real may help us to see, formulate, and visualize aspects of these stories that usually elude our attention: the hidden and incomprehensible order of a household that impacts its members' everyday lives and concepts of self.
Eyjafjallajökull volcano plume particle-type characterization from space-based multi-angle imaging
Authors: Kahn R. A. , Limbacher J.
Published: October 2012

Abstract. The Multi-angle Imaging SpectroRadiometer (MISR) Research Aerosol algorithm makes it possible to study individual aerosol plumes in considerable detail. From the MISR data for two optically thick, near-source plumes of the spring 2010 Eyjafjallajökull volcano eruption, we map aerosol optical depth (AOD) gradients and changing aerosol particle types with this algorithm; several days downwind, we identify the occurrence of volcanic ash particles and retrieve AOD, demonstrating the extent and the limits of ash detection and mapping capability with the multi-angle, multi-spectral imaging data. Retrieved volcanic plume AOD and particle microphysical properties are distinct from background values near-source, as well as for over-water cases several days downwind. The results also provide some indication that as they evolve, plume particles brighten, and average particle size decreases. Such detailed mapping offers context for suborbital plume observations having much more limited sampling. The MISR Standard aerosol product identified similar trends in plume properties as the Research algorithm, though with much smaller differences compared to background, and it does not resolve plume structure. Better optical analogs of non-spherical volcanic ash, and coincident suborbital data to validate the satellite retrieval results, are the factors most important for further advancing the remote sensing of volcanic ash plumes from space.
Global simulations of nitrate and ammonium aerosols and their radiative effects
Authors: Xu L. , Penner J. E.
Published: October 2012

Abstract. We examine the formation of nitrate and ammonium on five types of externally mixed pre-existing aerosols using the hybrid dynamic method in a global chemistry transport model. The model developed here predicts a similar spatial pattern of total aerosol nitrate and ammonium to that of several pioneering studies, but separates the effects of nitrate and ammonium on pure sulfate, biomass burning, fossil fuel, dust and sea salt aerosols. Nitrate and ammonium boost the scattering efficiency of sulfate and organic matter but lower the extinction of sea salt particles since the hygroscopicity of a mixed nitrate-ammonium-sea salt particle is less than that of pure sea salt. The direct anthropogenic forcing of particulate nitrate and ammonium at the top of the atmosphere (TOA) is estimated to be −0.12 W m−2. Nitrate, ammonium and nitric acid gas also affect aerosol activation and the reflectivity of clouds. The first aerosol indirect forcing by anthropogenic nitrate (gas plus aerosol) and ammonium is estimated to be −0.09 W m−2 at the TOA, almost all of which is due to condensation of nitric acid gas onto growing droplets (−0.08 W m−2).
Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry
Authors: DiGangi J. P. , Henry S. B. , Kammrath A. , Boyle E. S. , Kaser L. , Schnitzhofer R. , Graus M. , Turnipseed A. , Park J-H. , Weber R. J. , Hornbrook R. S. , Cantrell C. A. , Maudlin III R. L. , Kim S. , Nakashima Y. , Wolfe G. M. , Kajii Y. , Apel E.C. , Goldstein A. H. , Guenther A. , Karl T. , Hansel A. , Keutsch F. N.
Published: October 2012

Abstract. We present simultaneous fast, in-situ measurements of formaldehyde and glyoxal from two rural campaigns, BEARPEX 2009 and BEACHON-ROCS, both located in Pinus Ponderosa forests with emissions dominated by biogenic volatile organic compounds (VOCs). Despite considerable variability in the formaldehyde and glyoxal concentrations, the ratio of glyoxal to formaldehyde, RGF, displayed a very regular diurnal cycle over nearly 2 weeks of measurements. The only deviations in RGF were toward higher values and were the result of a biomass burning event during BEARPEX 2009 and very fresh anthropogenic influence during BEACHON-ROCS. Other rapid changes in glyoxal and formaldehyde concentrations have hardly any affect on RGF and could reflect transitions between low and high NO regimes. The trend of increased RGF from both anthropogenic reactive VOC mixtures and biomass burning compared to biogenic reactive VOC mixtures is robust due to the short timescales over which the observed changes in RGF occurred. Satellite retrievals, which suggest higher RGF for biogenic areas, are in contrast to our observed trends. It remains important to address this discrepancy, especially in view of the importance of satellite retrievals and in situ measurements for model comparison. In addition, we propose that RGF represents a useful metric for biogenic or anthropogenic reactive VOC mixtures and, in combination with absolute concentrations of glyoxal and formaldehyde, furthermore represents a useful metric for the extent of anthropogenic influence on overall reactive VOC processing via NOx. In particular, RGF yields information about not simply the VOCs dominating reactivity in an airmass, but the VOC processing itself that is directly coupled to ozone and secondary organic aerosol production.
Simultaneous assimilation of satellite NO2, O3, CO, and HNO3 data for the analysis of tropospheric chemical composition and emissions
Authors: Miyazaki K. , Eskes H. J. , Sudo K. , Takigawa M. , van Weele M. , Boersma K. F.
Published: October 2012

Abstract. We have developed an advanced chemical data assimilation system to combine observations of chemical compounds from multiple satellites. NO2, O3, CO, and HNO3 measurements from the Ozone Monitoring Instrument (OMI), Tropospheric Emission Spectrometer (TES), Measurement of Pollution in the Troposphere (MOPITT), and Microwave Limb Sounder (MLS) satellite instruments are assimilated into the global chemical transport model CHASER for the years 2006–2007. The CHASER data assimilation system (CHASER-DAS), based on the local ensemble transform Kalman filter technique, simultaneously optimizes the chemical species, as well as the emissions of O3 precursors, while taking their chemical feedbacks into account. With the available datasets, an improved description of the chemical feedbacks can be obtained, especially related to the NOx-CO-OH-O3 set of chemical reactions. Comparisons against independent satellite, aircraft, and ozonesonde data show that the data assimilation results in substantial improvements for various chemical compounds. These improvements include a reduced negative tropospheric NO2 column bias (by 40–85%), a reduced negative CO bias in the Northern Hemisphere (by 40–90%), and a reduced positive O3 bias in the middle and upper troposphere (from 30–40% to within 10%). These changes are related to increased tropospheric OH concentrations by 5–15% in the tropics and the Southern Hemisphere in July. Observing System Experiments (OSEs) have been conducted to quantify the relative importance of each data set on constraining the emissions and concentrations. The OSEs confirm that the assimilation of individual data sets results in a strong influence on both assimilated and non-assimilated species through the inter-species error correlation and the chemical coupling described by the model. The simultaneous adjustment of the emissions and concentrations is a powerful approach to correcting the tropospheric ozone budget and profile analyses.
Atmospheric impacts on climatic variability of surface incident solar radiation
Authors: Wang K. C. , Dickinson R. E. , Wild M. , Liang S.
Published: October 2012

Abstract. The Earth's climate is driven by surface incident solar radiation (Rs). Direct measurements have shown that Rs has undergone significant decadal variations. However, a large fraction of the global land surface is not covered by these observations. Satellite-derived Rs has a good global coverage but is of low accuracy in its depiction of decadal variability. This paper shows that daily to decadal variations of Rs, from both aerosols and cloud properties, can be accurately estimated using globally available measurements of Sunshine Duration (SunDu). In particular, SunDu shows that since the late 1980's Rs has brightened over Europe due to decreases in aerosols but dimmed over China due to their increases. We found that variation of cloud cover determines Rs at a monthly scale but that aerosols determine the variability of Rs at a decadal time scale, in particular, over Europe and China. Because of its global availability and long-term history, SunDu can provide an accurate and continuous proxy record of Rs, filling in values for the blank areas that are not covered by direct measurements. Compared to its direct measurement, Rs from SunDu appears to be less sensitive to instrument replacement and calibration, and shows that the widely reported sharp increase in Rs during the early 1990s in China was a result of instrument replacement. By merging direct measurements collected by Global Energy Budget Archive with those derived from SunDu, we obtained a good coverage of Rs over the Northern Hemisphere. From this data, the average increase of Rs from 1982 to 2008 is estimated to be 0.87 W m−2 per decade.
Total OH reactivity measurements in Paris during the 2010 MEGAPOLI winter campaign
Authors: Dolgorouky C. , Gros V. , Sarda-Esteve R. , Sinha V. , Williams J. , Marchand N. , Sauvage S. , Poulain L. , Sciare J. , Bonsang B.
Published: October 2012

Abstract. Hydroxyl radicals play a central role in the troposphere as they control the lifetime of many trace gases. Measurement of OH reactivity (OH loss rate) is important to better constrain the OH budget and also to evaluate the completeness of measured VOC budget. Total atmospheric OH reactivity was measured for the first time in an European Megacity: Paris and its surrounding areas with 12 million inhabitants, during the MEGAPOLI winter campaign 2010. The method deployed was the Comparative Reactivity Method (CRM). The measured dataset contains both measured and calculated OH reactivity from CO, NOx and VOCs measured via PTR-MS, GC-FID and GC-MS instruments. The reactivities observed in Paris covered a range from 10 s−1 to 130 s−1, indicating a large loading of chemical reactants. The present study showed that, when clean marine air masses influenced Paris, the purely local OH reactivity (20 s−1) is well explained by the measured species. Nevertheless, when there is a continental import of air masses, high levels of OH reactivity were obtained (120–130 s−1) and the missing OH reactivity measured in this case jumped to 75%. Using covariations of the missing OH reactivity to secondary inorganic species in fine aerosols, we suggest that the missing OH reactants were most likely highly oxidized compounds issued from photochemically processed air masses of anthropogenic origin.
Global tropospheric ozone column retrievals from OMI data by means of neural networks
Authors: Di Noia A. , Sellitto P. , Del Frate F. , de Laat J.
Published: October 2012

Abstract. In this paper, a new Neural Network (NN) algorithm to retrieve the tropospheric ozone column from Ozone Monitoring Instrument (OMI) Level 1b data is presented. Such algorithm further develops previous studies in order to improve: (i) the geographical coverage of the NN, by extending its training set to ozonesonde data from midlatitudes, tropics and poles; (ii) the definition of the output product, by using tropopause pressure information from reanalysis data; and (iii) the retrieval accuracy, by using ancillary data to better constrain the tropospheric ozone retrievals from OMI radiances. The results indicate that the algorithm is able to retrieve the tropospheric ozone column with a Root Mean Square Error (RMSE) of about 5–6 DU in all the latitude bands. The design of the new NN algorithm is extensively discussed, validation results against independent ozone soundings and Chemistry/Transport Model (CTM) simulations are shown, and other characteristics of the algorithm – i.e. its capability to detect nonclimatological tropospheric ozone situations and its sensitivity to the tropopause pressure – are discussed.
The contribution of respiration in tree stems to the Dole Effect
Authors: Angert A. , Muhr J. , Negron Juarez R. , Alegria Muñoz W. , Kraemer G. , Ramirez Santillan J. , Chambers J. Q. , Trumbore S. E.
Published: October 2012

Abstract. Understanding the variability and the current value of the Dole Effect, which has been used to infer past changes in biospheric productivity, requires accurate information on the isotopic discrimination associated with respiratory oxygen consumption in each of the biosphere components. Respiration in tree stems is an important component of the land carbon cycle. Here we measured, for the first time, the discrimination associated with tree stem oxygen uptake. The measurements included tropical forest trees, which are major contributors to the global fluxes of carbon and oxygen. We found discrimination in the range of 12.6–21.5‰, indicating both diffusion limitation, resulting in O2 discrimination values below 20‰, and alternative oxidase respiration, which resulted in discrimination values greater than 20‰. Discrimination varied seasonally, between and within tree species. Calculations based on these results show that variability in woody plants discrimination can result in significant variations in the global Dole Effect.