bluuebunny/crossref_metadata_2025 huggingface dataset:
An Approach for ECG Characterization and Classification Using the Combination of Wavelet Transform and Decision Tree Methods
Authors: Charfi Faiza , Kraiem Ali
Published: August 2012

A new automated approach for Electrocardiogram (ECG) arrhythmias characterization and classification with the combination of Wavelet transform and Decision tree classification is presented. The approach is based on two key steps. In the first step, the authors adopt the wavelet transform to extract the ECG signals wavelet coefficients as first features and utilize the combination of Principal Component Analysis (PCA) and Fast Independent Component Analysis (FastICA) to transform the first features into uncorrelated and mutually independent new features. In the second step, they utilize some decision tree methods currently in use: C4.5, Improved C4.5, CHAID (Chi - Square Automatic Interaction Detection) and Improved CHAID for the classification of ECG signals, which are taken, from the MIT-BIH database, including normal subjects and subjects affected by arrhythmia. The authors’ results suggest the high reliability and high classification accuracy of C4.5 algorithm with the bootstrap aggregation.
Analyzing the Effectiveness of Pharmaceutical Marketing Using Business Intelligence Methods
Authors: Ricks Elizabeth H. , Yi John
Published: August 2012

Pharmaceutical companies have traditionally marketed their products through a combination of several channels: sales details to physicians, direct-to-consumer advertising, professional medical journal advertising, sponsorship of meetings and events and e-promotion. With an impending patent cliff and subsequent loss in revenue, the industry must depend on, among many factors, recently launched products to offset the revenue loss. Coupled with increased generic competition, companies must evaluate the return on investment of their marketing dollars. This paper analyzes the effectiveness of traditional marketing methods, both industry-wide and for recently launched products, using the latest Business Intelligent methods. The dataset used in this paper is a sample of prescription, promotional, competitive, and product data from SDI Health. The analysis in this paper reveals that traditional marketing methods have a decreasing level of impact with the number of prescriptions dispensed, and describes new potential channels for marketing, as well as collecting and analyzing data to aid the industry improve its resource utilization.
Infrared Communication Technology Applied to Indoor Mobile Healthcare Monitoring System
Authors: Torkestani S. S. , Sahuguede S. , Julien-Vergonjanne A. , Cances J. , Daviet J. C.
Published: August 2012

In the context of healthcare monitoring, it is necessary to transmit vital information from the patient to an interface managed by the hospital staff. In this paper, the authors consider a system in which a patient can move within a hospital room and the data collected by sensors are transmitted to a distant receiver placed on the ceiling. The authors investigate the potentiality of using infrared communications for the transmission of information in this mobile context, by considering the simplest modulation scheme based on On-Off Keying (OOK) technique. In order to represent patient mobility in the room, the authors use a model for the patient location based on a Gaussian distribution over the three axes of mobility in the room. In addition, they consider different scenarios, considering either a Line Of Sight (LOS) configuration or a diffuse one. From the obtained results, the authors can determine by evaluating the transmission probability of outage, the potentiality of this technology to ensure the communication between sensors and the collecting point.
Levels of Abstraction for Behavior Modeling in the GerHome Project
Authors: Pomponio Laura , Le Goc Marc , Anfosso Alain , Pascual Eric
Published: August 2012

Defining activity models in order to monitor human behavior in smart environments is one of the major issues at the moment of building systems of activity supervision for diagnosis, prediction and control. For the purpose of addressing this problem, this paper proposes a general theoretical approach based on the use of a Knowledge Engineering methodology and a Machine Learning process, which are funded on a general theory of dynamic process modeling, the Timed Observation Theory.
A Knowledge-Based User Interface to Optimize Curriculum Utility in an E-Learning System
Authors: Fazlollahtabar Hamed , Muhammadzadeh Amir
Published: August 2012

The Internet and the World Wide Web in particular provide a unique platform to connect learners with educational resources. Educational material in hypermedia formed in a Web-based educational system makes learning a task-driven process, motivating learners to explore alternative navigational paths through the domain knowledge and from different resources around the globe. Many researchers have focused on developing e-learning systems with personalized learning mechanisms to assist on-line Web-based learning and to adaptively provide learning paths. Although most personalized systems consider learner preferences, interests and browsing behaviors when providing personalized curriculum sequencing services, these systems usually neglect to consider whether learner ability and the difficulty level of the recommended curriculums are matched to each other. Therefore, the authors proposed approach is based on an integer program (IP) to optimize user curriculum accompanying with fuzzy logic approach which analyze the effective criteria by linguistic variables in a knowledge based system. The effectiveness of the proposed framework is shown by numerical illustrations which are inferenced from the designed user interface.
A Hybrid MCDM Approach for Solving the ERP System Selection Problem with Application to Steel Industry
Authors: Jafarnejad Ahmad , Ansari Manoucher , Youshanlouei Hossein Rahmany , Mood Mohammad
Published: August 2012

Selecting a proper system of Enterprise Resource Planning (ERP) is a major challenge for enterprise managers. Heavy expenses of incorrect decisions in selection of ERP systems have made academics and managers consider this phase as highly important. Several research studies proposed different approaches to selecting the ERP and many case studies of organizational experiences have been published. However, there has been less regard for simultaneous use of the findings of academic studies and judgments of industrial experts or organization mangers for making the most appropriate choice. This study proposes a combined multiple-criteria decision-making (MCDM) approach through which both previous studies and judgments of industrial experts or organization managers would be integrated in order to select the proper ERP system. Having studied the literature comprehensively and conducted interviews with experts and managers, this approach will determine the most important criteria in ERP selection using Shannon entropy technique. Then, based on the judgments obtained from experts and using DEMATEL technique, these criteria will be classified into the two groups of “Cause” and “Effect” and the most appropriate choice will be selected using Fuzzy AHP technique. Finally, a case study is conducted to demonstrate and prove the applicability of the proposed approach.
Dynamic Function Alternation to Realize Robust Wireless Sensor Network
Authors: Miyazaki Toshiaki
Published: August 2012

In this paper, a distributed algorithm to realize a dynamic function alternation is proposed. The algorithm enables sensor nodes to take over the damaged functions of their neighboring sensor nodes automatically in a wireless sensor network. After describing the concept of the function alternation, the algorithm is explained in detail with some evaluation results. Comparing the results obtained using the proposed algorithm with those obtained using non-function alternation methods shows that the proposed algorithm makes the initial functionality of each sensor function sustainable even if some sensor nodes are damaged. A wireless sensor network system dedicated to disaster monitoring is also introduced, as an application of the proposed function alternation algorithm.
Interactive Navigation and Exploration of Virtual Environments on Handheld Devices
Authors: Rodrigues Maria Andréia F. , Barbosa Rafael G. , Mendonça Nabor C.
Published: August 2012

Arbitrarily 3D scenes pose difficult challenges to real-time visualization, navigation and exploration on mobile devices. We have developed a framework for supporting interactive navigation and exploration of mobile virtual environments. Our framework can be used to load dynamically virtual environments from a remote PC server, navigate through them, find an optimal and collision-free path from one place to another, and obtain additional information on the objects of interest by directly pointing to their representation in the virtual world. As a proof of concept of the framework as well as to illustrate its use and main functionalities, we have run tests with a virtual world containing more than one hundred thousand triangles. A walkthrough of this world shows how the framework allocates resources (memory and processing time) to execute the tasks of rendering, geometric transformations, collision detection, and scenes loading, and how its performance is affected under different navigation scenarios.
Differences in Electronic Medical Record Implementation and Use According to Geographical Location and Organizational Characteristics of US Federally Qualified Health Centers
Authors: Beverley Charles S. , Probst Janice , Williams Edith M. , Rivers Patrick , Glover Saundra H.
Published: August 2012

Electronic medical records (EMRs) are at the forefront of the national healthcare agenda and this paper examines EMR implementation and usage based on data from the 2009 Commonwealth Fund National Survey of Federally Qualified Health Centers (FQHC). Chi-square analysis was used to examine differences in EMR implementation and usage. Logistic regression analysis was used to understand the adjusted associations between EMR implementation and usage. A significant finding of this study was that simple EMRs were implemented in more than half of FQHCs in the Northeast, Southern, and Western regions of the United States and EMRs in more than half of the FQHCs in the Southern and Western regions are not even utilized. These findings indicate simple EMR usage and full EMR implementation need improvement to meet the requirements of the American Recovery and Reinvestment Act by 2014, or face reduction in Medicare and Medicaid reimbursements.
Sources of Discovery, Reasons for Registration, and Expectations of an Internet-Based Register for Multiple Sclerosis
Authors: Osborne Lisa A. , Noble J. Gareth , Lockhart-Jones Hazel M. , Middleton Rodden , Thompson Simon , Maramba Inocencio D.C. , Jones Kerina H. , Ford David V.
Published: August 2012

Internet-registers are having an increasing role in healthcare informatics. Understanding the motivations and expectations of people choosing to use such registers is important, and these aspects were investigated regarding people with MS who registered on the UK MS Register. An objective was to explore relationships between these factors and the source from which participants first learned about this Register, as this is relevant to how registers are publicised. The responses from a large number of participants (N = 2,675) to questions about the source by which they discovered the Register, why they registered, and how they thought it should be used, were qualitatively analysed using a ‘word cloud’ technique and traditional content analysis strategy to provide a more detailed analysis. The significant trends that emerged from these analyses were the importance to the participants of: studying MS; raising awareness about MS; improving and developing services and policies regarding MS; assisting others with MS; the Register as a resource for people with, and affected by, MS; the Register as an aid to themselves; and it being an open resource for all professionals and government bodies.
The Crisis and the Complexity of Knowing
Authors: Jörg Ton
Published: August 2012

The crisis our society finds itself in is very much a crisis of knowledge; that is, a lack of knowledge about the complex world. Humanity ‘simply’ do not know what they do not know. This is true for the complexity of a nonlinear complex reality. Complexity is still taken for granted. Ignorance on complexity is still dominating our worldview. Complex organizations are trying to face the complexity of the world, but show at the same time their ignorance on the very complexity of complexity. Harnessing complexity is a hardy perennial for these complex organizations. They do not seem able to explore the very potential of complexity for their own organizations, in terms of fostering creativity and innovation. The only remedy for this is first to recognize their ignorance on the topic of complexity. To confront complexity you first need to become (more) knowledgeable about the very dynamics of complexity.
Information Provision Modules to Support Creation of Slides with Easily Understandable Presentation
Authors: Hayama Tessai , Kunifuji Susumu
Published: August 2012

Including visual information in slides is one of the important factors for enabling the audience to easily understand the content of a slide presentation. However, it’s difficult for an inexperienced preparer to improve the presentation of slides without adequate experience and awareness of the requirements of a good slide. The authors developed Presentation Gadgets, which consists of modules that can be used to support the creation of slides that represent information in an audience friendly manner. Presentation Gadgets provide information on web-based slides, web pages, web news, and web images, thus supporting replacement of content on slides with visual representations and illustrations of key points, and insertion of common topics and it helps identifying slides that need improvement. To construct the previously mentioned modules, the authors developed a novel slide search method and slide ranking method and to allow easy access to information, Presentation Gadgets has a user interface that automatically creates queries from the selected slide text or speech text that is recognized by a speech recognition engine. By using Presentation Gadgets, an inexperienced slide preparer can effectively create slides that are easily understandable because he/she can interactively refer to various information resources relating to the slide content based on the situation.
The Relationship Between Gardner’s Multiple Intelligence and Kolb’s Learning Style
Authors: Kian Neo Tse , Sabbaghan Sahar
Published: August 2012

In a diverse work environment, it’s important to have diverse managers, and people with different talents and intelligence in order to deal with different problems. The concept of learning styles is used to describe individual differences in the way people learn. According to Kolb (1984), each person has a unique way to absorb and process experiences and information. He has identified four statistically prevalent learning styles- diverging, assimilating, converging, and accommodating. Gardner’s Multiple Intelligence Theory is very helpful to recognize that people have differing aptitude in different subject areas. In the study, the participants consisted of 153 bachelor students of Management of Multimedia University of Malaysia. They were given two questionnaires, one for Kolb’s learning style and other for Gardner’s Multiple Intelligence inventory and a correlation was conducted. The results showed that there was a significant relationship between Kolb’s Learning Style and Multiple Intelligence. The relationship could be seen particularly in Abstract Conceptualization (AC) and Multiple Intelligences which were Nature, kinesthetic, music, word, interpersonal, and picture. And also a slight relationship between Concrete Experience (CE) and kinesthetic and nature. The results can be found deeper in this article.
Student Experiences with Mobile Electronic Updates from a Virtual Learning Environment
Authors: Crane Laura , Benachour Phillip , Coulton Paul
Published: August 2012

This paper describes the development of two mobile applications to disseminate course and module information to university students by sending notifications and electronic updates to their mobile devices. The two mobile applications are based on RSS and Twitter and provide notifications to users which are similar in format and transmission mode to these Web 2.0 entities. The aim of this study is to understand the potential benefits of using the mobile applications as assistive technologies to the existing virtual learning environment. The study uses the ARCS model of motivational design and instruction theory (attention, relevance, confidence, satisfaction) as a tool to enhance students’ experience and their subject engagement. User feedback revealed that although users were given flexibility with regards to temporal updates, they preferred temporal updates at specific times and not in real time. A lack of wireless access in some areas commonly used by students proved a further limitation.
Analyzing Management Style and Successful Implementation of Six Sigma
Authors: Jenab Kouroush , Staub Selva
Published: August 2012

This study reports on the effects of management style in successful implementation of Six Sigma. The authors collected data using a 18-item survey, classified managers from a wide range of industry, healthcare, military, and services into one of two management styles using Douglas McGregor’s Theory of X and Y, and compared these classifications among the survey respondents to determine the level of Six Sigma commitment and success. Six Sigma is just one of many tools used to improve processes within an organization that requires management commitment. This level of commitment will depend on a manager perception of worker motivation. Despite an existing body of literature on worker motivation, limited research has been conducted that explores the possible connection between manager perception of worker motivation and the organization’s commitment and success with Six Sigma. The results are explored further in the article.
Exploring mathematical discussion in word problem-solving
Authors: Sepeng Percy , Webb Paul
Published: August 2012

This study explored whether discussion as a teaching strategy in mathematics classrooms could have positive gains in improving learners’ problem-solving performance, as well as their ability to make sense of real wor(l)d problems. This article discusses the partial findings of a bigger study that used a pre-test intervention or post-test mixed-method design and utilised both quantitative and qualitative data. Analysis of the data generated from both pre-tests and post-tests suggests that the intervention strategy significantly improved the experimental group’s problem-solving skills and sense-making performance. The statistical results illustrate that the experimental group performed significantly better than the comparison group in the post-test. The main finding of this study is that in classrooms of experimental schools in which discussion technique was successfully implemented, there was a statistically significant improvement in the learners’ competence in solving word problems.
Study of histopathological features and proliferation markers in cases of Wilms′ tumor
Authors: Das Ram Narayan , Chatterjee Uttara , Sinha Swapan K , Ray Ashoke K , Saha Koushik , Banerjee Sugato
Published: August 2012

Context: The spectrum of pediatric renal tumors is different from adult renal tumors, and Wilms′ tumor (WT) forms the majority. The histological type and clinicopathological staging are the two important prognostic parameters. The role of newer prognostic factors is not clear. Aims: This study was performed to analyze the histopathological spectrum of pediatric renal tumors and to study the expression of proliferation markers (Ki-67 and p53) in WT and correlate its expression in epithelial and blastema components in different stages. Materials and Methods: Twenty-seven cases of pediatric renal tumors were collected over 2 years. Hematoxylin-eosin staining was used for diagnosis. Immunostaining was performed for Ki-67 and p53. Ki-67 proliferation index (PI) and p53 expression were determined in each case and for the epithelial and blastema components separately. Statistical Analysis and Results: We had 20 cases of WT (74.1%), three cases of mesoblastic nephroma (11.1%), three cases of clear cell sarcoma (11.1%) and one case of rhabdoid tumor (3.7%). It was observed that the PI of the epithelial component (57.2%) was significantly higher than that of blastema (39.53%) in all stages. The PI in Stage II is significantly higher than that in Stage I. Statistical analysis could not be performed in Stages III and IV due to the small number of cases. p53 expression did not show any significant difference in the epithelial and blastema components. There was also no significant difference between the stages. Conclusion: In this study, we found the differences between PI of different tissue components of WT, with the epithelial component having a higher PI, which correlated with the stage of advancement of the disease.
Angiosarcoma of the scalp associated with Xeroderma pigmentosum
Authors: Sharma Shilpi , Deshmukh Anuja D , Bal Munita M , Chaukar Devendra A , Dcruz Anil K
Published: August 2012

Xeroderma pigmentosum (XP) is a rare autosomal recessive genodermatosis associated with hypersensitivity to ultraviolet light due to defects in Deoxyribonucleic acid (DNA) repair. These patients have more than a 1000-fold increased risk of developing skin cancers. Although multiple cutaneous malignancies are common, the simultaneous occurrence of angiosarcoma and basal cell carcinoma is a rare phenomenon. We report a case of a 25-year-old male with XP with angiosarcoma scalp and basal cell carcinoma of face and occiput and discuss the treatment of this aggressive neoplasm with a review of the literature pertaining to it.
Representations and estimates for inverse operators in the harmonic potential theory for polyhedra
Authors: Maz'ya Vladimir G.
Published: August 2012

The paper mainly concerns the results by N. Grachev and the author in the harmonic potential theory for polyhedra. Pointwise estimates for kernels of inverse operators are presented which imply the invertibility of the integral operator generated by the double layer potential in the space of continuous functions and in

L_p

. Auxiliary pointwise estimates for Green’s kernel of the Neumann problem are proved.
Inequality for entire functions involving their maximum modulus and maximum term
Authors: Shaposhnikova Tatyana
Published: August 2012

An estimate of the Wiman-Valiron type for a maximum modulus on a polydisk of an entire function of several complex variables is obtained. The estimate contains a weight function involved also in the calculation of the radius of the admissible ball.
Measurements of ice nucleation by mineral dusts in the contact mode
Authors: Bunker K. W. , China S. , Mazzoleni C. , Kostinski A. , Cantrell W.
Published: August 2012

Abstract. Formation of ice in Earth's atmosphere at temperatures above approximately −20 °C is one of the outstanding problems in cloud physics. Contact nucleation has been suggested as a possible mechanism for freezing at relatively high temperatures; some laboratory experiments have shown contact freezing activity at temperatures as high as −4 °C. We have investigated Arizona Test Dust and kaolinite as contact nuclei as a function of size and temperature and find that the fraction of submicron particles that are active as contact ice nuclei is less than 10−3 for −18 °C and greater. We also find that the different dusts are quite distinct in their effectiveness as contact nuclei; Arizona Test Dust catalyzed freezing in the contact mode at all mobility diameters we tested at −18 °C whereas kaolinite triggered freezing only for mobility diameters of 1000 and 500 nm at that temperature.
A new method for nocturnal aerosol measurements with a lunar photometer prototype
Authors: Barreto A. , Cuevas E. , Damiri B. , Guirado C. , Berkoff T. , Berjón A. J. , Hernández Y. , Almansa F. , Gil M.
Published: August 2012

Abstract. This paper presents the preliminary results of nocturnal Aerosol Optical Depth (τa) and Angström Exponent (α) obtained from a new lunar photometer prototype, trade name Cimel CE-318U. Due to the variation of the moon's illumination inherent to the lunar cycle, the typical Langley-plot Method used in solar photometry to calibrate these instruments cannot be applied. In this paper we propose three different methods to carry out the lunar-photometer calibration. In order to validate the results we have selected three events, which encompass seven nights and ten days under different atmospheric conditions, including several saharan dust intrusions episodes. Method#1 is introduced in this work as a modification of the usual Langley Method. This technique, called Lunar-Langley Method, requires the extraterrestrial irradiances from a lunar irradiance model, providing similar accuracies on τa to those of AERONET (± 0.01–0.02). It makes comparable daytime and nighttime measurements. Method#2 consists of transferring the current calibration from a master used by sunphotometers. Its results are again within the limit of accuracy expected for the instrument. Method#3 uses an integrating sphere and the methodology proposed by Li et al. (2008) to determine sky calibration coefficients (Cj) and the instrument's solid angle field-of-view (Ω), respectively. We observe significant τa differences between Method#1 and #3 (up to 0.07), which might be attributed to the errors propagation in Method#3. The good results obtained from the comparison against a second CE-318U prototype, and against daytime data from a precision filter radiometer, constitute a valuable assessment of CE-318U performance. Results of α and its spectral variation (δα) show good agreement between daytime and nighttime, being able to identify the aerosol properties associated with each event.
Improved retrieval of global tropospheric formaldehyde columns from GOME-2/MetOp-A addressing noise reduction and instrumental degradation issues
Authors: De Smedt I. , Van Roozendael M. , Stavrakou T. , Müller J.-F. , Lerot C. , Theys N. , Valks P. , Hao N. , van der A R.
Published: August 2012

Abstract. We present a new data set of formaldehyde vertical columns retrieved from observations of GOME-2 onboard of the EUMETSAT MetOp-A platform between 2007 and 2011. The new retrieval scheme, which has been optimised for GOME-2, includes a two-step fitting procedure that strongly reduces the impact of spectral interferences between H2CO and BrO, and a modified DOAS approach that better handles ozone absorption effects at moderately low sun elevations. Owing to these new features, the noise in the H2CO slant columns is reduced by up to 40% in comparison to baseline retrieval settings used operationally. Also, the previously reported underestimation of the H2CO columns in tropical and mid-latitudes regions has been largely eliminated, improving the agreement with coincident SCIAMACHY observations. To compensate for the drift of the GOME-2 slit function and to mitigate the instrumental degradation effects on H2CO retrievals, an asymmetric Gaussian line shape is fitted during the irradiance calibration. Additionally, external parameters used in the tropospheric air mass factor computation (surface reflectances, cloud parameters and a priori profile shapes of H2CO) have been updated using most recent data bases. Similar updates were also applied to the historical data sets of GOME and SCIAMACHY leading to the generation of a consistent multi-mission H2CO data record covering the time period from 1997 until 2011. Comparing the resulting time series of monthly averaged H2CO vertical columns in 12 large regions worldwide, the correlation coefficient between SCIAMACHY and GOME-2 columns is generally higher than 0.8 in the overlap period, and linear regression slopes differ by less than 10% from unity in most of the regions. In comparison to SCIAMACHY, the largely improved spatial sampling of GOME-2 allows for a better characterisation of formaldehyde distribution at the regional scale and/or at shorter timescales, leading to a better identification of the emission sources of non-methane volatile organic compounds.
A comparison of two different techniques for deriving the quiet day curve from SARINET riometer data
Authors: Moro J. , Denardini C. M. , Correia E. , Abdu M. A. , Schuch N. J. , Makita K.
Published: August 2012

Abstract. In this work, an upgrade of the technique for estimating the Quiet Day Curve (QDC) as proposed by Tanaka et al. (2007) is suggested. To validate our approach, the QDC is estimated from data acquired by the Imaging Riometer for Ionospheric Studies (IRIS) installed at the Southern Space Observatory (SSO/CRS/CCR/INPE – MCT, 29°4´ S, 53°8´ W, 480 m a.s.l.), São Martinho da Serra – Brazil. The evaluation was performed by comparing the difference between the QDCs derived using our upgrade technique with the one proposed by Tanaka et al. (2007). The results are discussed in terms of the seasonal variability and the level of magnetic disturbance. Also, the cosmic noise absorption (CNA) images for IRIS data operated at SSO was built using both the techniques aiming to check the implications of the changes in the methods of QDC determination on the CNA that resulted from it.
Southern westerlies in LGM and future (RCP4.5) climates
Authors: Chavaillaz Y. , Codron F. , Kageyama M.
Published: August 2012

Abstract. Mid-latitude westerlies are a major component of the atmospheric circulation and understanding their behaviour under climate change is important for understanding changes in precipitation, storms and atmosphere-ocean momentum, heat and CO2 exchanges. The Southern Hemisphere westerlies, have been particularly studied in terms of the latter aspects, since the Southern Ocean is a key region for the global oceanic circulation as well as for CO2 uptake. In this study, we analyse, mainly in terms of maximum jet-stream position, the behaviour of the southern westerlies for the Last Glacial Maximum (LGM, 21 000 yr ago, which is the last past cold extreme) and for a future climate, obtained after stabilisation of the RCP4.5 scenario (hereafter RCP). The a priori guess would be that the behaviour of the westerly jet-stream would be similar when examining its changes from LGM to pre-industrial (PI) conditions and from PI to RCP, i.e. in both cases a poleward shift in response to global warming. We show that this is in fact not the case, due to the impact of altitude changes of the Antarctic ice-sheet and/or to sea-ice cover changes.
Robust optimization methodologies for water supply systems design
Authors: Marques J. , Cunha M. C. , Sousa J. , Savić D.
Published: August 2012

Abstract. Water supply systems (WSSs) are vital infrastructures for the well-being of people today. To achieve good customer satisfaction the water supply service must always be able to meet people's needs, in terms of both quantity and quality. But unpredictable extreme conditions can cause severe damage to WSSs and lead to poorer levels of service or even to their failure. Operators dealing with a system's day-to-day operation know that events like burst water mains can compromise the functioning of all or part of a system. To increase a system's reliability, therefore, designs should take into account operating conditions other than normal ones. Recent approaches based on robust optimization can be used to solve optimization problems which involve uncertainty and can find designs which are able to cope with a range of operating conditions. This paper presents a robust optimization model for the optimal design of water supply systems operating under different circumstances. The model presented here uses a hydraulic simulator linked to an optimizer based on a simulated annealing heuristic. The results show that robustness can be included in several ways for varying levels reliability and that it leads to more reliable designs for only small cost increases.
Quantifying the model structural error in carbon cycle data assimilation systems
Authors: Kuppel S. , Chevallier F. , Peylin P.
Published: August 2012

Abstract. This study explores the impact of the structural error of biosphere models when assimilating net ecosystem exchange (NEE) measurements or CO2 concentration measurements to optimize uncertain model parameters within carbon cycle data assimilation systems (CCDASs). This error has been proven difficult to identify and is often neglected in the total uncertainty budget. We propose a simple method which derives it from the model-minus-observation mismatch statistics. This diagnosis is applied to a state-of-the-art biogeochemical model using measurements of the net surface CO2 flux at twelve sites located in temperate deciduous broadleaf forests. We find that the structural model error in the NEE space has a standard deviation of 1.7 g C m−2 d−1, without a significant correlation structure beyond lags of a few days, and a large spatial structure that can be approximated with an exponential decay of e-folding length 500 km. In the space of concentrations, its characteristics are commensurate with the transport errors, both for surface air sample measurements and total column measurements. The inferred characteristics are confirmed by complementary optimality diagnostics performed after site-scale parameter optimizations.
Evaluation of high-resolution satellite precipitation products using rain gauge observations over the Tibetan Plateau
Authors: Gao Y. C. , Liu M. F.
Published: August 2012

Abstract. High-resolution satellite precipitation products are very attractive for studying the hydrologic processes in mountainous areas where rain gauges are generally sparse. Three high-resolution satellite precipitation products are evaluated using gauge measurements over different climate zones of the Tibetan Plateau (TP) within a 6 yr period from 2004 to 2009. The three satellite-based precipitation datasets are: Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA), Climate Prediction Center Morphing Technique (CMOPRH) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network (PERSIANN). TMPA and CMORPH, with higher correlation coefficients and lower root mean square errors (RMSEs), show overall better performance than PERSIANN. TMPA has the lowest biases among the three precipitation datasets, which is likely due to the correction process against monthly gauge observations from global precipitation climatology project (GPCP). The three products show better agreement with gauge measurements over humid regions than that over arid regions where correlation coefficients are less than 0.5. Moreover, the three precipitation products generally tend to overestimate light rainfall (0–10 mm) and underestimate moderate and heavy rainfall (>10 mm). PERSIANN produces obvious underestimation at low elevations and overestimation at high elevations. CMORPH and TMPA do not present strong bias-elevation relationships in most regions of TP.
Operational hydrological data assimilation with the Retrospective Ensemble Kalman Filter: use of observed discharge to update past and present model states for flow forecasts
Authors: McMillan H. K. , Hreinsson E. Ö. , Clark M. P. , Singh S. K. , Zammit C. , Uddstrom M. J.
Published: August 2012

Abstract. This paper describes the use of the Retrospective Ensemble Kalman Filter (REnKF) to assimilate streamflow data in an operational flow forecasting system of seven catchments in New Zealand. The REnKF updates past and present model states (soil water, aquifer and surface storages), with lags up to the concentration time of the catchment, to improve model initial conditions and hence flow forecasts. To our knowledge, this is the first time the REnKF has been applied in an operational setting, for a distributed model running over large catchments. We found the REnKF overcame instabilities in the standard EnKF which were associated with the natural lag time between upstream catchment wetness and flow at the gauging locations. The forecast system performance was correspondingly improved in terms of Nash Sutcliffe score and bounding of the measured flow by the model ensemble. We present descriptions of filter design parameters and explanations and examples of filter behaviour. The paper provides information and guidance valuable for other groups wishing to apply the REnKF for operational forecasting.
Combining inland and offshore paleotsunamis evidence: the Augusta Bay (eastern Sicily, Italy) case study
Authors: Smedile A. , De Martini P. M. , Pantosti D.
Published: August 2012

Abstract. Offshore and inland geological evidence for multiple tsunami inundations was found in the Augusta Bay area: (1) the main local historical tsunamis (1908, 1693, 1169), (2) two far-generated tsunamis (i.e. Crete 365 AD and Santorini, 3600 BP), and (3) seven unknown tsunamis). Average tsunami recurrence intervals from inland and offshore investigations of about 550 and 320 yr, respectively were obtained for the past 4 ka. The history of paleotsunamis from the marine record appears to be as complete as the historical one for the past millennium, yielding an average tsunami recurrence interval of 250 yr for the Augusta Bay. Geological data allow also estimating a minimum tsunami inundation distance of 530 m and a minimum run-up of 5 m. The marine record contains evidence for more paleotsunamis with respect to the inland one because of continuous sedimentation and better preservation of stratigraphy in the offshore with respect to coastal areas, which are commonly affected by intermittent-erosion and sedimentation and anthropic activities. This work shows that the integration of geological and historical data can provide critical information regarding the extent and age of tsunamis of the past (e.g. inundation distance, age, and frequency), which is of immediate relevance for tsunami hazard assessment.
Antarctic sea ice variability and trends, 1979–2010
Authors: Parkinson C. L. , Cavalieri D. J.
Published: August 2012

Abstract. In sharp contrast to the decreasing sea ice coverage of the Arctic, in the Antarctic the sea ice cover has, on average, expanded since the late 1970s. More specifically, satellite passive-microwave data for the period November 1978–December 2010 reveal an overall positive trend in ice extents of 17 100 ± 2300 km2 yr−1. Much of the increase, at 13 700 ± 1500 km2 yr−1, has occurred in the region of the Ross Sea, with lesser contributions from the Weddell Sea and Indian Ocean. One region, that of the Bellingshausen/Amundsen Seas, has (like the Arctic) instead experienced significant sea ice decreases, with an overall ice extent trend of −8200 ± 1200 km2 yr−1. When examined through the annual cycle over the 32-yr period 1979–2010, the Southern Hemisphere sea ice cover as a whole experienced positive ice extent trends in every month, ranging in magnitude from a low of 9100 ± 6300 km2 yr−1 in February to a high of 24 700 ± 10 000 km2 yr−1 in May. The Ross Sea and Indian Ocean also had positive trends in each month, while the Bellingshausen/Amundsen Seas had negative trends in each month, and the Weddell Sea and western Pacific Ocean had a mixture of positive and negative trends. Comparing ice-area results to ice-extent results, in each case the ice-area trend has the same sign as the ice-extent trend, but the magnitudes of the two trends differ, and in some cases these differences allow inferences about the corresponding changes in sea ice concentrations. The strong pattern of decreasing ice coverage in the Bellingshausen/Amundsen Seas region and increasing ice coverage in the Ross Sea region is suggestive of changes in atmospheric circulation. This is a key topic for future research.
Arctic sea ice variability and trends, 1979–2010
Authors: Cavalieri D. J. , Parkinson C. L.
Published: August 2012

Abstract. Analyses of 32 yr (1979–2010) of Arctic sea ice extents and areas derived from satellite passive microwave radiometers are presented for the Northern Hemisphere as a whole and for nine Arctic regions. There is an overall negative yearly trend of −51.5 ± 4.1 × 103 km2 yr−1 (−4.1 ± 0.3% decade−1) in sea ice extent for the hemisphere. The yearly sea ice extent trends for the individual Arctic regions are all negative except for the Bering Sea: −3.9 ± 1.1 × 103 km2 yr−1 (−8.7 ± 2.5% decade−1) for the Seas of Okhotsk and Japan, +0.3 ± 0.8 × 103 km2 yr−1 (+1.2 ± 2.7% decade−1) for the Bering Sea, −4.4 ± 0.7 × 103 km2 yr−1 (−5.1 ± 0.9% decade−1) for Hudson Bay, −7.6 ± 1.6 × 103 km2 yr−1 (−8.5 ± 1.8% decade−1) for Baffin Bay/Labrador Sea, −0.5 ± 0.3 × 103 km2 yr−1 (−5.9 ± 3.5% decade−1) for the Gulf of St. Lawrence, −6.5 ± 1.1 × 103 km2 yr−1 (−8.6 ± 1.5% decade−1) for the Greenland Sea, −13.5 ± 2.3 × 103 km2 yr−1 (−9.2 ± 1.6% decade−1) for the Kara and Barents Seas, −14.6 ± 2.3 × 103 km2 yr−1 (−2.1 ± 0.3% decade−1) for the Arctic Ocean, and −0.9 ± 0.4 × 103 km2 yr−1 (−1.3 ± 0.5% decade−1) for the Canadian Archipelago. Similarly, the yearly trends for sea ice areas are all negative except for the Bering Sea. On a seasonal basis for both sea ice extents and areas, the largest negative trend is observed for summer with the next largest negative trend being for autumn. Both the sea ice extent and area trends vary widely by month depending on region and season. For the Northern Hemisphere as a whole, all 12 months show negative sea ice extent trends with a minimum magnitude in May and a maximum magnitude in September, whereas the corresponding sea ice area trends are smaller in magnitude and reach minimum and maximum values in March and September.
Ikaite crystals in melting sea ice – implications for pCO2 and pH levels in Arctic surface waters
Authors: Rysgaard S. , Glud R. N. , Lennert K. , Cooper M. , Halden N. , Leakey R. J. G. , Hawthorne F. C. , Barber D.
Published: August 2012

Abstract. A major issue of Arctic marine science is to understand whether the Arctic Ocean is, or will be, a source or sink for air–sea CO2 exchange. This has been complicated by the recent discoveries of ikaite (a polymorph of CaCO3·6H2O) in Arctic and Antarctic sea ice, which indicate that multiple chemical transformations occur in sea ice with a possible effect on CO2 and pH conditions in surface waters. Here, we report on biogeochemical conditions, microscopic examinations and x-ray diffraction analysis of single crystals from a melting 1.7 km2 (0.5–1 m thick) drifting ice floe in the Fram Strait during summer. Our findings show that ikaite crystals are present throughout the sea ice but with larger crystals appearing in the upper ice layers. Ikaite crystals placed at elevated temperatures disintegrated into smaller crystallites and dissolved. During our field campaign in late June, melt reduced the ice floe thickness by 0.2 m per week and resulted in an estimated 3.8 ppm decrease of pCO2 in the ocean surface mixed layer. This corresponds to an air–sea CO2 uptake of 10.6 mmol m−2 sea ice d−1 or to 3.3 ton km−2 ice floe week−1. This is markedly higher than the estimated primary production within the ice floe of 0.3–1.3 mmol m−2 sea ice d−1. Finally, the presence of ikaite in sea ice and the dissolution of the mineral during melting of the sea ice and mixing of the melt water into the surface oceanic mixed layer accounted for half of the estimated pCO2 uptake.
Price Sensitivity to Tourism Activities: Looking for Determinant Factors
Authors: Masiero Lorenzo , Nicolau Juan L.
Published: August 2012

The literature contains evidence that there is a marked heterogeneity in price responses to tourism products, leading to a great variety of tourist sensitivities to price. Thus the role price plays is complex, and a particularly challenging aspect of this complexity is that its effect is not unambiguous, thereby negating the idea that the demand for tourism products and tourist activities can always be regarded as demand for ordinary goods. This article identifies and explains, as a novelty for the tourism industry, price sensitivities to tourism activities individual by individual. The operative formalization uses a mixed logit model to estimate the individual sensitivities to price, and then a regression analysis is applied to detect their determinants. The empirical application finds that motivations, influenced by age, and length of stay with a non-linear effect, are explanatory factors of tourists' price sensitivity to activities.
Tourism Income and Economic Growth in Greece: Empirical Evidence from Their Cyclical Components
Authors: Eeckels Bruno , Filis George , Leon Costas
Published: August 2012

This paper examines the relationship between the cyclical components of Greek GDP and international tourism income for Greece for the period 1976–2004. Using spectral analysis the authors find that cyclical fluctuations of GDP have a length of about nine years and that international tourism income has a cycle of about seven years. The volatility of tourism income is more than eight times the volatility of the Greek GDP cycle. VAR analysis shows that the cyclical component of tourism income is significantly influencing the cyclical component of GDP in Greece. The findings support the tourism-led economic growth hypothesis and are of particular interest and importance to policy makers, financial analysts and investors dealing with the Greek tourism industry.
Research Note: Economic Values in the Swedish Nature-Based Recreation Sector — A Synthesis
Authors: Fredman Peter , Boman Mattias , Lundmark Linda , Mattsson Leif
Published: August 2012

This research synthesis reports the main findings from a review of economic values associated with nature-based recreation in Sweden. The purpose of the work was to support policy and to identify areas for future research. Data came from over 150 scientific publications and other public sources. The authors find inter alia a lack of systematic data for several recreation activities (including nature-based tourism), a significant growth in the outdoor equipment industry and a relatively modest economic involvement by the public sector. The information is structured under different categories to illustrate the significance and range of different economic values. The authors conclude that there is a need for more comprehensive and systematically collected data, methodological development and interdisciplinary research.
A Parameter for Ramanujan's Function χ(q): Its Explicit Values and Applications
Authors: Saikia Nipen
Published: August 2012

We define a new parameter involving quotient of Ramanujan's function for positive real numbers and and study its several properties. We prove some general theorems for the explicit evaluations of the parameter and find many explicit values. Some values of are then used to find some new and known values of Ramanujan's class invariant .