26 resultados para quality of service, web services, composite web services, optimisation, genetic algorithms

em Digital Commons at Florida International University


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The development of 3G (the 3rd generation telecommunication) value-added services brings higher requirements of Quality of Service (QoS). Wideband Code Division Multiple Access (WCDMA) is one of three 3G standards, and enhancement of QoS for WCDMA Core Network (CN) becomes more and more important for users and carriers. The dissertation focuses on enhancement of QoS for WCDMA CN. The purpose is to realize the DiffServ (Differentiated Services) model of QoS for WCDMA CN. Based on the parallelism characteristic of Network Processors (NPs), the NP programming model is classified as Pool of Threads (POTs) and Hyper Task Chaining (HTC). In this study, an integrated programming model that combines both of the two models was designed. This model has highly efficient and flexible features, and also solves the problems of sharing conflicts and packet ordering. We used this model as the programming model to realize DiffServ QoS for WCDMA CN. ^ The realization mechanism of the DiffServ model mainly consists of buffer management, packet scheduling and packet classification algorithms based on NPs. First, we proposed an adaptive buffer management algorithm called Packet Adaptive Fair Dropping (PAFD), which takes into consideration of both fairness and throughput, and has smooth service curves. Then, an improved packet scheduling algorithm called Priority-based Weighted Fair Queuing (PWFQ) was introduced to ensure the fairness of packet scheduling and reduce queue time of data packets. At the same time, the delay and jitter are also maintained in a small range. Thirdly, a multi-dimensional packet classification algorithm called Classification Based on Network Processors (CBNPs) was designed. It effectively reduces the memory access and storage space, and provides less time and space complexity. ^ Lastly, an integrated hardware and software system of the DiffServ model of QoS for WCDMA CN was proposed. It was implemented on the NP IXP2400. According to the corresponding experiment results, the proposed system significantly enhanced QoS for WCDMA CN. It extensively improves consistent response time, display distortion and sound image synchronization, and thus increases network efficiency and saves network resource.^

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3D geographic information system (GIS) is data and computation intensive in nature. Internet users are usually equipped with low-end personal computers and network connections of limited bandwidth. Data reduction and performance optimization techniques are of critical importance in quality of service (QoS) management for online 3D GIS. In this research, QoS management issues regarding distributed 3D GIS presentation were studied to develop 3D TerraFly, an interactive 3D GIS that supports high quality online terrain visualization and navigation. ^ To tackle the QoS management challenges, multi-resolution rendering model, adaptive level of detail (LOD) control and mesh simplification algorithms were proposed to effectively reduce the terrain model complexity. The rendering model is adaptively decomposed into sub-regions of up-to-three detail levels according to viewing distance and other dynamic quality measurements. The mesh simplification algorithm was designed as a hybrid algorithm that combines edge straightening and quad-tree compression to reduce the mesh complexity by removing geometrically redundant vertices. The main advantage of this mesh simplification algorithm is that grid mesh can be directly processed in parallel without triangulation overhead. Algorithms facilitating remote accessing and distributed processing of volumetric GIS data, such as data replication, directory service, request scheduling, predictive data retrieving and caching were also proposed. ^ A prototype of the proposed 3D TerraFly implemented in this research demonstrates the effectiveness of our proposed QoS management framework in handling interactive online 3D GIS. The system implementation details and future directions of this research are also addressed in this thesis. ^

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Voice communication systems such as Voice-over IP (VoIP), Public Switched Telephone Networks, and Mobile Telephone Networks, are an integral means of human tele-interaction. These systems pose distinctive challenges due to their unique characteristics such as low volume, burstiness and stringent delay/loss requirements across heterogeneous underlying network technologies. Effective quality evaluation methodologies are important for system development and refinement, particularly by adopting user feedback based measurement. Presently, most of the evaluation models are system-centric (Quality of Service or QoS-based), which questioned us to explore a user-centric (Quality of Experience or QoE-based) approach as a step towards the human-centric paradigm of system design. We research an affect-based QoE evaluation framework which attempts to capture users' perception while they are engaged in voice communication. Our modular approach consists of feature extraction from multiple information sources including various affective cues and different classification procedures such as Support Vector Machines (SVM) and k-Nearest Neighbor (kNN). The experimental study is illustrated in depth with detailed analysis of results. The evidences collected provide the potential feasibility of our approach for QoE evaluation and suggest the consideration of human affective attributes in modeling user experience.

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With the exponential growth of the usage of web-based map services, the web GIS application has become more and more popular. Spatial data index, search, analysis, visualization and the resource management of such services are becoming increasingly important to deliver user-desired Quality of Service. First, spatial indexing is typically time-consuming and is not available to end-users. To address this, we introduce TerraFly sksOpen, an open-sourced an Online Indexing and Querying System for Big Geospatial Data. Integrated with the TerraFly Geospatial database [1-9], sksOpen is an efficient indexing and query engine for processing Top-k Spatial Boolean Queries. Further, we provide ergonomic visualization of query results on interactive maps to facilitate the user’s data analysis. Second, due to the highly complex and dynamic nature of GIS systems, it is quite challenging for the end users to quickly understand and analyze the spatial data, and to efficiently share their own data and analysis results with others. Built on the TerraFly Geo spatial database, TerraFly GeoCloud is an extra layer running upon the TerraFly map and can efficiently support many different visualization functions and spatial data analysis models. Furthermore, users can create unique URLs to visualize and share the analysis results. TerraFly GeoCloud also enables the MapQL technology to customize map visualization using SQL-like statements [10]. Third, map systems often serve dynamic web workloads and involve multiple CPU and I/O intensive tiers, which make it challenging to meet the response time targets of map requests while using the resources efficiently. Virtualization facilitates the deployment of web map services and improves their resource utilization through encapsulation and consolidation. Autonomic resource management allows resources to be automatically provisioned to a map service and its internal tiers on demand. v-TerraFly are techniques to predict the demand of map workloads online and optimize resource allocations, considering both response time and data freshness as the QoS target. The proposed v-TerraFly system is prototyped on TerraFly, a production web map service, and evaluated using real TerraFly workloads. The results show that v-TerraFly can accurately predict the workload demands: 18.91% more accurate; and efficiently allocate resources to meet the QoS target: improves the QoS by 26.19% and saves resource usages by 20.83% compared to traditional peak load-based resource allocation.

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The purpose of this study is to identify the determinants of local officials' preferences of performance measures under the assumption that public officials' consensus on performance measures can enhance the accountability in public service delivery. This research consists of two steps: multiple case studies and a survey. The author conducted the case studies in five general-purpose municipalities in Florida, interviewing 25 local officials, attending community meetings, and reviewing relevant local documents. Based on the case studies and the relevant literature, a survey was developed and sent to 445 local officials in 67 general-purpose municipalities in Dade, Broward, and Palm Beach Counties, Florida. The findings of the case studies and the survey suggest that local officials' preferences of performance measures are influenced by their perception of utilities of performance measures and their desire to measure the achievement of organizational goals. The author concludes that a consensus among local officials for outcome-oriented performance measures is easier to achieve if a prospective performance measurement system is designed for reporting and management purposes rather than for budgeting purposes. ^

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The population of older adults is rapidly increasing, creating a need for community services that assist vulnerable older adults in maintaining independence and quality of life. Recent evidence confirms the importance of food and nutrition in reaching this objective. The Elderly Nutrition Program (ENP) is part of a system of federally funded community based programs, authorized through the Older Americans Act. ENP services include the home-delivered meals program, which targets frail homebound older adults at nutritional risk. Traditionally, ENP services provide a noon meal 5 days/week. This study evaluated the impact of expanding the home-delivered meals service to include breakfast + lunch, on the nutritional status, quality of life and health care utilization of program participants. ^ This cross-sectional study compared 2 groups. The Breakfast group (n = 167) received a home-delivered breakfast + lunch, 5 days/week. The Comparison group (n = 214) received lunch 5 days/week. Participants, recruited from 5 ENP programs, formed a geographically, racially/ethnically diverse sample. Participants ranged in age from 60–100 years, they were functionally limited, at high nutritional risk, low income, and they lived alone and had difficulty shopping or preparing food. Participant data were collected through in-home interviews and program records. A 24-hour food recall and information on participant demographics, malnutrition risk, functional status, health care use, and applicable quality of life factors were obtained. Service and cost data were collected from program administrators. ^ Breakfast group participants had greater energy/nutrient intakes (p < .05), fewer health care contacts (p < .05), and greater quality of life measured as food security (p < .05) and fewer depressive symptoms (p < .05), than comparison group participants. These benefits were achieved for $1.30/person/day. ^ The study identified links from improvements in nutritional status to enhanced quality of life to diminished health care utilization and expenditures. A model of health, loneliness, food enjoyment, food insecurity, and depression as factors contributing to quality of life for this population, was proposed and tested (p < .01). ^ The breakfast service is an inexpensive addition to traditional home-delivered meals services and can improve the lives of frail homebound older adults. Agencies should be encouraged to expand meals programs to include a breakfast service. ^

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This research presents several components encompassing the scope of the objective of Data Partitioning and Replication Management in Distributed GIS Database. Modern Geographic Information Systems (GIS) databases are often large and complicated. Therefore data partitioning and replication management problems need to be addresses in development of an efficient and scalable solution. ^ Part of the research is to study the patterns of geographical raster data processing and to propose the algorithms to improve availability of such data. These algorithms and approaches are targeting granularity of geographic data objects as well as data partitioning in geographic databases to achieve high data availability and Quality of Service(QoS) considering distributed data delivery and processing. To achieve this goal a dynamic, real-time approach for mosaicking digital images of different temporal and spatial characteristics into tiles is proposed. This dynamic approach reuses digital images upon demand and generates mosaicked tiles only for the required region according to user's requirements such as resolution, temporal range, and target bands to reduce redundancy in storage and to utilize available computing and storage resources more efficiently. ^ Another part of the research pursued methods for efficient acquiring of GIS data from external heterogeneous databases and Web services as well as end-user GIS data delivery enhancements, automation and 3D virtual reality presentation. ^ There are vast numbers of computing, network, and storage resources idling or not fully utilized available on the Internet. Proposed "Crawling Distributed Operating System "(CDOS) approach employs such resources and creates benefits for the hosts that lend their CPU, network, and storage resources to be used in GIS database context. ^ The results of this dissertation demonstrate effective ways to develop a highly scalable GIS database. The approach developed in this dissertation has resulted in creation of TerraFly GIS database that is used by US government, researchers, and general public to facilitate Web access to remotely-sensed imagery and GIS vector information. ^

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Successful introduction of information technology applications in various operations of hotel management is vital to most service firms. In recent decades, technologies of information, automation, and communication are increasingly recognized as essential components of a hotel company’s strategic plan. In this study, 62 super-deluxe hotels (5 star), deluxe hotels (4 star), and tourist hotels (3 star) in Korea are examined for differences in the impact of information technology services on guest’ satisfaction, guest convenience, and operational efficiency. The findings generally suggest that the impacts of information technology-enhanced services vary according to the category of hotels in Korea. The results of the study are expected to assist managers in the selections and implementation of information technology systems in their hotel.

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This study aimed to evaluate the effectiveness of the Independent Living (IL) program targeting foster youths to prepare them for effective adulthood. The study employed a pre-post, two-group comparative research design. The IL group was composed of 49 young adults who participated in the IL or SIL (subsidized IL) program prior to their emancipation from foster care (mean age, 20.6 years). The comparison was made up of 18 young adults who experienced foster care but never participated in the IL or SIL programs (mean age, 20.2 years). Data were collected via a mailed survey that included the Daniel Memorial Independent Living Assessment (DMILA) and an additional questionnaire developed by the researcher. The study also examined: (1) why youth in foster care do not participate in IL programs, (2) how participating youth evaluate IL services and what recommendations they make to improve services, and (3) the internal consistency of the DMILA. Results suggest that the DMILA assessment has mediocre reliability. IL program participation is associated with better educational, employment, income, housing, early parenting-prevention, transportation, anger control, criminal-prevention, and self-evaluation outcomes. However, IL participation is not associated with better social support, perceived parenting competence, substance abuse-prevention, sexual risk-prevention outcomes, increased knowledge in money management skills, job seeking and job maintenance skills, interpersonal skills, or lower depression. Results also suggest that the outreach activities of the IL program may be flawed. IL participants reported the IL program was doing best in educational preparation, criminal involvement prevention, and money management preparation and least well in parenting preparation, housing preparation, employment preparation, and substance abuse prevention. To improve services, youths recommended primarily that IL counselors develop closer relationships with youths, that IL training better address organizational skills, and that monthly subsidy be raised and SIL eligibility requirements softened. The study's political context and limitations are also discussed and implications are derived regarding prevention, intervention, outreach, mentorship, empowerment, cross-systems collaboration, and future research. ^

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The purpose of this study was to explain how exemplary service providers in luxury hotels provide consistently excellent service. Using a case study framework, the study investigated the service provider's strategies and concepts of service delivery, the importance and implementation of organizational and individual controls, and the role of training and learning. The study identified barriers to service provision and characteristics of the exemplary individuals that affect their ability to deliver luxury service. This study sought to better understand how exemplary service providers learn, think about, and do their work. The sample population of three Five-Diamond-Award winning resorts was selected for their potential for learning about the phenomenon of interest. The results demonstrate that exemplary service providers possess individual characteristics that are enhanced by the organizations for which they work. Exemplary service providers are often exemplary communicators who are emotionally generous and genuinely enjoy helping and serving others. Exemplary service organizations treat their employees as they treat their customers, as suggested by the Service-Profit Chain (Heskett, Sasser & Schlesinger, 1997). Further, they have systems and standards to guarantee satisfactory service experiences for every guest. They also encourage their service providers to personalize their service delivery and to seek opportunities to delight their guests, using a combination of controls, traditions and cultural values. Several customer service theories are discussed in relationship to whether they were or were not supported by the data. The study concluded that the delivery of exemplary service is a complex phenomenon that requires successful interactions between guests, service providers and the organization. A Model of Exemplary Service Delivery is presented and discussed that demonstrates the components of service quality as shown in the data. The model can be used by practitioners seeking to create, enhance, or evaluate their service quality, and by researchers seeking insights into the complex concepts in service quality research. Implications for future research are discussed.

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The convergence of data, audio and video on IP networks is changing the way individuals, groups and organizations communicate. This diversity of communication media presents opportunities for creating synergistic collaborative communications. This form of collaborative communication is however not without its challenges. The increasing number of communication service providers coupled with a combinatorial mix of offered services, varying Quality-of-Service and oscillating pricing of services increases the complexity for the user to manage and maintain ‘always best’ priced or performance services. Consumers have to manually manage and adapt their communication in line with differences in services across devices, networks and media while ensuring that the usage remain consistent with their intended goals. This dissertation proposes a novel user-centric approach to address this problem. The proposed approach aims to reduce the aforementioned complexity to the user by (1) providing high-level abstractions and a policy based methodology for automated selection of the communication services guided by high-level user policies and (2) providing services through the seamless integration of multiple communication service providers and providing an extensible framework to support the integration of multiple communication service providers. The approach was implemented in the Communication Virtual Machine (CVM), a model-driven technology for realizing communication applications. The CVM includes the Network Communication Broker, the layer responsible for providing a network-independent API to the upper layers of CVM. The initial prototype for the NCB supported only a single communication framework which limited the number, quality and types of services available. Experimental evaluation of the approach show the additional overhead of the approach is minimal compared to the individual communication services frameworks. Additionally the automated approach proposed out performed the individual communication services frameworks for cross framework switching.

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We estimated trophic position and carbon source for three consumers (Florida gar, Lepisosteus platyrhincus; eastern mosquitofish, Gambusia holbrooki; and riverine grass shrimp, Palaemonetes paludosus) from 20 sites representing gradients of productivity and hydrological disturbance in the southern Florida Everglades, U.S.A. We characterized gross primary productivity at each site using light/dark bottle incubation and stem density of emergent vascular plants. We also documented nutrient availability as total phosphorus (TP) in floc and periphyton, and the density of small fishes. Hydrological disturbance was characterized as the time since a site was last dried and the average number of days per year the sites were inundated for the previous 10 years. Food-web attributes were estimated in both the wet and dry seasons by analysis of δ15N (trophic position) and δ13C (food-web carbon source) from 702 samples of aquatic consumers. An index of carbon source was derived from a two-member mixing model with Seminole ramshorn snails (Planorbella duryi) as a basal grazing consumer and scuds (amphipods Hyallela azteca) as a basal detritivore. Snails yielded carbon isotopic values similar to green algae and diatoms, while carbon values of scuds were similar to bulk periphyton and floc; carbon isotopic values of cyanobacteria were enriched in C13compared to all consumers examined. A carbon source similar to scuds dominated at all but one study site, and though the relative contribution of scud-like and snail-like carbon sources was variable, there was no evidence that these contributions were a function of abiotic factors or season. Gar consistently displayed the highest estimated trophic position of the consumers studied, with mosquitofish feeding at a slightly lower level, and grass shrimp feeding at the lowest level. Trophic position was not correlated with any nutrient or productivity parameter, but did increase for grass shrimp and mosquitofish as the time following droughts increased. Trophic position of Florida gar was positively correlated with emergent plant stem density.

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In the article - Past, Present, and Future: The Food Service Industry and Its Changes - by Brother Herman E. Zaccarelli, International Director, Restaurant, Hotel and Institutional Management Institute at Purdue University, Brother Zaccarelli initially states: “Educators play an important role in the evolution of the food service industry. The author discusses that evolution and suggests how educators can be change agents along with management in that evolutionary progression.” The author goes on to wax philosophically, as well as speak generically about the food service industry; to why it offers fascinating and rewarding careers. Additionally, he writes about the influence educators have on students in this regard. “Educators can speak about how the food service industry has benefited them both personally and professionally,” says Brother Zaccarelli. “We get excited about alerting students to the many opportunities and, in fact, serve as “salespersons” for the industry to whoever (school administrators, legislators, and peers in the educational institution) will listen.” Brother Zaccarelli also speaks to growth and changes in food service, and even more importantly about the people and faces behind everything that food service, and hospitality in general comprise. The author will have you know, that people are what drive an educator. “What makes the food service industry so great? At the heart of this question's answer is people: the people whom it serves in institutional and commercial operations of all types; the people who work within it; the people who provide the goods, services, and equipment to it; the people who study it,” says Brother Zaccarelli. “All of these groups have, of course, a vested personal and/or professional interest in seeing our industry improve.” Another concept the author would like you to absorb, and it’s even more so true today than yesterday, is the prevalence of convergence and divergence within food service. For food service and beyond, it is the common denominators and differences that make the hospitality-food service industry so dynamic and vibrant. These are the winds of change presented to an educator who wants to have a positive impact on students. The author warns that the many elements involved in the food service industry conspire to erode quality of service in an industry that is also persistently expanding, and whose cornerstone principles are underpinned by service itself. “The three concerns addressed - quality, employees, and marketing - are intimately related,” Brother Zaccarelli says in stripping-down the industry to bare essentials. He defines and addresses the issues related to each with an eye toward how education can reconcile said issues.

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The authors investigate the relationship between loyalty and perceived service quality of hotel customers and discus managerial implications to develop strategies to enhance loyalty of hotel customers. A survey was conducted among customers in the San Francisco Bay Area. Results indicate that customer loyalty is dependent on perceived service quality which is observed in terms of timelines, facilities, and ambience.