119 research outputs found

    Interdisciplinary care clinics in chronic kidney disease

    Get PDF
    The burden of chronic kidney disease (CKD) is substantial, and is associated with high hospitalization rates, premature deaths, and considerable health care costs. These factors provide strong rationale for quality improvement initiatives in CKD care. The interdisciplinary care clinic (IDC) has emerged as one solution to improving CKD care. The IDC team may include other physicians, advanced practice providers, nurses, dietitians, pharmacists, and social workers--all working together to provide effective care to patients with chronic kidney disease. Studies suggest that IDCs may improve patient education and preparedness prior to kidney failure, both of which have been associated with improved health outcomes. Interdisciplinary care may also delay the progression to end-stage renal disease and reduce mortality. While most studies suggest that IDC services are likely cost-effective, financing IDCs is challenging and many insurance providers do not pay for all of the services. There are also no robust long-term studies demonstrating the cost-effectiveness of IDCs. This review discusses IDC models and its potential impact on CKD care as well as some of the challenges that may be associated with implementing these clinics

    Benefits of Location-Based Access Control:A Literature Study

    Get PDF
    Location-based access control (LBAC) has been suggested as a means to improve IT security. By 'grounding' users and systems to a particular location, \ud attackers supposedly have more difficulty in compromising a system. However, the motivation behind LBAC and its potential benefits have not been investigated thoroughly. To this end, we perform a structured literature review, and examine the goals that LBAC can potentially fulfill, \ud the specific LBAC systems that realize these goals and the context on which LBAC depends. Our paper has four main contributions:\ud first we propose a theoretical framework for LBAC evaluation, based on goals, systems and context. Second, we formulate and apply criteria for evaluating the usefulness of an LBAC system. Third, we identify four usage scenarios for LBAC: open areas and systems, hospitals, enterprises, and finally data centers and military facilities. Fourth, we propose directions for future research:\ud (i) assessing the tradeoffs between location-based, physical and logical access control, (ii) improving the transparency of LBAC decision making, and \ud (iii) formulating design criteria for facilities and working environments for optimal LBAC usage

    Managing server energy and reducing operational cost for online service providers

    Get PDF
    The past decade has seen the energy consumption in servers and Internet Data Centers (IDCs) skyrocket. A recent survey estimated that the worldwide spending on servers and cooling have risen to above $30 billion and is likely to exceed spending on the new server hardware . The rapid rise in energy consumption has posted a serious threat to both energy resources and the environment, which makes green computing not only worthwhile but also necessary. This dissertation intends to tackle the challenges of both reducing the energy consumption of server systems and by reducing the cost for Online Service Providers (OSPs). Two distinct subsystems account for most of IDC’s power: the server system, which accounts for 56% of the total power consumption of an IDC, and the cooling and humidifcation systems, which accounts for about 30% of the total power consumption. The server system dominates the energy consumption of an IDC, and its power draw can vary drastically with data center utilization. In this dissertation, we propose three models to achieve energy effciency in web server clusters: an energy proportional model, an optimal server allocation and frequency adjustment strategy, and a constrained Markov model. The proposed models have combined Dynamic Voltage/Frequency Scaling (DV/FS) and Vary-On, Vary-off (VOVF) mechanisms that work together for more energy savings. Meanwhile, corresponding strategies are proposed to deal with the transition overheads. We further extend server energy management to the IDC’s costs management, helping the OSPs to conserve, manage their own electricity cost, and lower the carbon emissions. We have developed an optimal energy-aware load dispatching strategy that periodically maps more requests to the locations with lower electricity prices. A carbon emission limit is placed, and the volatility of the carbon offset market is also considered. Two energy effcient strategies are applied to the server system and the cooling system respectively. With the rapid development of cloud services, we also carry out research to reduce the server energy in cloud computing environments. In this work, we propose a new live virtual machine (VM) placement scheme that can effectively map VMs to Physical Machines (PMs) with substantial energy savings in a heterogeneous server cluster. A VM/PM mapping probability matrix is constructed, in which each VM request is assigned with a probability running on PMs. The VM/PM mapping probability matrix takes into account resource limitations, VM operation overheads, server reliability as well as energy effciency. The evolution of Internet Data Centers and the increasing demands of web services raise great challenges to improve the energy effciency of IDCs. We also express several potential areas for future research in each chapter

    Forty Years of Distance Education: Challenges and implications at the Open University of Sri Lanka

    Get PDF
    Commencing its activities in 1980, the Open University of Sri Lanka (OUSL) has expanded over the years embracing emerging technologies periodically, undergoing a series of technological adoptions gradually through Generations of Distance Education (GDE). The aim of this study is to assess the current status of OUSL, based on Taylor’s conceptual framework of GDE, identify the challenges faced during these technological transformations, and how those challenges were mitigated during its forty years of existence as a single-mode national open and distance learning university in Sri Lanka. This study employs a qualitative research design based on reflective practices of the researchers, narrative accounts of past decision makers, reflections of academics and administrators, and cross-referenced with documentary evidences. The findings show how the OUSL has advanced towards the fifth GDE, amidst challenges and finally propose mitigation strategies that would be useful for future technological interventions

    Un esquema de autenticación de usuario basado en el cliente para el entorno de la nube de las cosas

    Get PDF
    The limited capabilities of IoT devices have resulted in some of the tasks of IoT applications being distributed to a cloud server, which witnessed the arisen of the cloud of things (COT). It enables IoT applications’ development and deployment as a service, providing additional data storage, enhanced processing performance, and fast communication between devices. As COT involves communication between IoT devices, a remote server, and users, remote user authentication is crucial to meeting security demands. Therefore, this study designs a client-based user authentication scheme utilizing smartphone fingerprint recognition technology to fill the gap. The scheme comprises six phases, namely (i) configuration phase, (ii) enrolment phase, (iii) authentication phase, (iv) password update phase, (v) fingerprint revocation phase, and (vi) smartphone revocation phase. The security analysis and automated verification using ProVerif suggested that the scheme is resistant to user impersonating attacks, replay attacks, and man-in-the-middle attacks. The study’s outcome could help secure user credentials from attacks on applications that involve IoT and the cloud.Las capacidades limitadas de los dispositivos IoT han dado como resultado que algunas de las tareas de las aplicaciones IoT se distribuyan a un servidor en la nube, lo que es testigo del surgimiento de la Nube de las Cosas (COT). Esta permite el desarrollo y la implementación de aplicaciones IoT como un servicio, proporcionando almacenamiento de datos adicional, mayor rendimiento de procesamiento y comunicación rápida entre dispositivos. Dado que la COT implica la comunicación entre dispositivos IoT, un servidor remoto y usuarios, la autenticación de usuarios remotos es crucial para satisfacer las demandas de seguridad. Por lo tanto, este estudio diseña un esquema de autenticación de usuario basado en el cliente que utiliza tecnología de reconocimiento de huellas digitales en teléfonos inteligentes para colmar la brecha. El esquema consta de seis fases: (i) fase de configuración, (ii) fase de inscripción, (iii) fase de autenticación, (iv) fase de actualización de contraseña, (v) fase de revocación de huellas digitales y (vi) fase de revocación de teléfonos inteligentes. A partir del análisis de seguridad y la verificación automatizada con ProVerif surge que el esquema es resistente a diferentes ataques, por ejemplo ataques de suplantación de identidad del usuario, los ataques de repetición y los ataques manin- the-middle. El resultado del estudio podría ayudar a proteger las credenciales de los usuarios de los ataques a las aplicaciones que involucran IoT y la nube.Facultad de Informátic

    A Designer's Log: Case Studies in Instructional Design

    Get PDF
    Books and articles on instructional design in online learning abound but rarely do we get such a comprehensive picture of what instructional designers do, how they do it, and the problems they solve as their university changes. Power documents the emergence of an adapted instructional design model for transforming courses from single-mode to dual-mode instruction, making this designer’s log a unique contribution to the fi eld of online learning

    HSCLOUD: CLOUD ARCHITECTURE FOR SUPPORTING HOMELAND SECURITY

    Full text link

    THE DEVELOPMENT OF A COUPLE OBSERVATIONAL CODING SYSTEM FOR COMPUTER-MEDIATED COMMUNICATION

    Get PDF
    Many romantic couples integrate text and computer-mediated communication (CMC) into their relationship dynamics, both for general relationship maintenance and for complex dynamics such as problem solving and conflict. Romantic couple dynamics are interactional, dynamic, and sequenced in nature, and a common method for studying interactions of this nature is observational analyses. However, no behavioral or observational coding systems exist that are able to capture text-based transactional couple communication. The main purpose of this dissertation was to develop an observational coding system that can be used to assess sequenced computer- mediated, text-based communication that takes place between romantic partners. This process included assessing couples’ text communication to determine how verbal and non-verbal communication behaviors are enacted in CMC, modifying an observational coding system, and establishing reliability and validity of the revised coding system. Secondary data was utilized, including 48 logs of romantic couples engaging in problem-solving discussions using online chatting for 15 minutes, where a log of the conversation was saved for future research purposes. For this dissertation, the researcher evaluated the dynamics in these logs to determine if behaviors and sequences were similar to basic romantic relationship dynamics that are present in face-to-face (FtF) couples’ dynamics. The researcher determined that the dynamics between CMC and FtF were similar, and that modifying a couple observational coding system would be appropriate. The Interaction Dimensions Coding System was selected for use and modification for this study, and the training manual and codebook were updated to integrate CMC examples. Multiple avenues of assessing face validity were also pursued and feedback from the coding team and original authors of a couple coding system were integrated into the modified coding system. The modified coding system, IDCS-CMC, was used to code 43 text-based chat logs. A team of 4 coders was trained on the coding system, where they provided ratings from 1 to 9 on each partner for different dimensions of communication behaviors that were observed and they also rated each couple on 5 dyadic categories of relationship functioning. Interrater reliability was assessed throughout the training and independent coding process using the intraclass correlation coefficient. Results indicate that good or excellent interrater reliability was established for the individual dimensions of Positive Affect, Negative Affect, Problem Solving, Support/Validation, Denial, Conflict, and Communication Skills and for the dyadic codes of Positive Escalation, Negative Escalation, Commitment, Satisfaction, and Stability. There were only two dimensions that resulted in fair or poor interrater reliability, which were Dominance and Withdrawal, both of which warrant additional study in how these dynamics are enacted in and coded in CMC. Overall, the IDCS-CMC demonstrated good interrater reliability, and construct validity was established for the coding system in a variety of ways. Construct validity was established by assessing face, content, and convergent validity. Face validity was established by eliciting feedback on the IDCS-CMC from the coding team as well as one of the authors of the system used to inform the development of the IDCS-CMC. Content validity was established by assessing the degree to which the couples in the chat logs engaged in conversations of a similar nature in their real lives, and also by determining the degree to which the couple participants followed instructions to focus on a problem-solving topic during the chats. Convergent validity was assessed by comparing the IDCS-CMC dimensions and positive and negative communication composite scores to a measure of relationship satisfaction. Overall, this dissertation details the process by which a couple observational coding system was developed and tested, and puts forth a methodological tool that can be used to better assess transactional use of CMC by romantic couples by researchers as well as practitioners and therapists

    A data preparation approach for cloud storage based on containerized parallel patterns

    Get PDF
    In this paper, we present the design, implementation, and evaluation of an efficient data preparation and retrieval approach for cloud storage. The approach includes a deduplication subsystem that indexes the hash of each content to identify duplicated data. As a consequence, avoiding duplicated content reduces reprocessing time during uploads and other costs related to outsource data management tasks. Our proposed data preparation scheme enables organizations to add properties such as security, reliability, and cost-efficiency to their contents before sending them to the cloud. It also creates recovery schemes for organizations to share preprocessed contents with partners and end-users. The approach also includes an engine that encapsulates preprocessing applications into virtual containers (VCs) to create parallel patterns that improve the efficiency of data preparation retrieval process. In a study case, real repositories of satellite images, and organizational files were prepared to be migrated to the cloud by using processes such as compression, encryption, encoding for fault tolerance, and access control. The experimental evaluation revealed the feasibility of using a data preparation approach for organizations to mitigate risks that still could arise in the cloud. It also revealed the efficiency of the deduplication process to reduce data preparation tasks and the efficacy of parallel patterns to improve the end-user service experience.This research was supported by "Fondo Sectorial de Investigación para la Educación";, SEP-CONACyT Mexico, through projects 281565 and 285276
    corecore