8 resultados para 150701 Air Transportation and Freight Services

em Digital Commons at Florida International University


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Recently, wireless network technology has grown at such a pace that scientific research has become a practical reality in a very short time span. Mobile wireless communications have witnessed the adoption of several generations, each of them complementing and improving the former. One mobile system that features high data rates and open network architecture is 4G. Currently, the research community and industry, in the field of wireless networks, are working on possible choices for solutions in the 4G system. 4G is a collection of technologies and standards that will allow a range of ubiquitous computing and wireless communication architectures. The researcher considers one of the most important characteristics of future 4G mobile systems the ability to guarantee reliable communications from 100 Mbps, in high mobility links, to as high as 1 Gbps for low mobility users, in addition to high efficiency in the spectrum usage. On mobile wireless communications networks, one important factor is the coverage of large geographical areas. In 4G systems, a hybrid satellite/terrestrial network is crucial to providing users with coverage wherever needed. Subscribers thus require a reliable satellite link to access their services when they are in remote locations, where a terrestrial infrastructure is unavailable. Thus, they must rely upon satellite coverage. Good modulation and access technique are also required in order to transmit high data rates over satellite links to mobile users. This technique must adapt to the characteristics of the satellite channel and also be efficient in the use of allocated bandwidth. Satellite links are fading channels, when used by mobile users. Some measures designed to approach these fading environments make use of: (1) spatial diversity (two receive antenna configuration); (2) time diversity (channel interleaver/spreading techniques); and (3) upper layer FEC. The author proposes the use of OFDM (Orthogonal Frequency Multiple Access) for the satellite link by increasing the time diversity. This technique will allow for an increase of the data rate, as primarily required by multimedia applications, and will also optimally use the available bandwidth. In addition, this dissertation approaches the use of Cooperative Satellite Communications for hybrid satellite/terrestrial networks. By using this technique, the satellite coverage can be extended to areas where there is no direct link to the satellite. For this purpose, a good channel model is necessary.

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Recently, wireless network technology has grown at such a pace that scientific research has become a practical reality in a very short time span. One mobile system that features high data rates and open network architecture is 4G. Currently, the research community and industry, in the field of wireless networks, are working on possible choices for solutions in the 4G system. The researcher considers one of the most important characteristics of future 4G mobile systems the ability to guarantee reliable communications at high data rates, in addition to high efficiency in the spectrum usage. On mobile wireless communication networks, one important factor is the coverage of large geographical areas. In 4G systems, a hybrid satellite/terrestrial network is crucial to providing users with coverage wherever needed. Subscribers thus require a reliable satellite link to access their services when they are in remote locations where a terrestrial infrastructure is unavailable. The results show that good modulation and access technique are also required in order to transmit high data rates over satellite links to mobile users. The dissertation proposes the use of OFDM (Orthogonal Frequency Multiple Access) for the satellite link by increasing the time diversity. This technique will allow for an increase of the data rate, as primarily required by multimedia applications, and will also optimally use the available bandwidth. In addition, this dissertation approaches the use of Cooperative Satellite Communications for hybrid satellite/terrestrial networks. By using this technique, the satellite coverage can be extended to areas where there is no direct link to the satellite. The issue of Cooperative Satellite Communications is solved through a new algorithm that forwards the received data from the fixed node to the mobile node. This algorithm is very efficient because it does not allow unnecessary transmissions and is based on signal to noise ratio (SNR) measures.

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This study is an exploratory analysis of an operational measure for resource development strategies, and an exploratory analysis of internal organizational contingencies influencing choices of these strategies in charitable nonprofit organizations. The study provides conceptual guidance for advancing understanding about resource development in the nonprofit sector. The statistical findings are, however, inconclusive without further rigorous examination. A three category typology based on organization technology is initially presented to define the strategies. Three dimensions of internal organizational contingencies explored represent organization identity, professional staff, and boards of directors. Based on relevant literature and key informant interviews, an original survey was administered by mail to a national sample of nonprofit organizations. The survey collected data on indicators of the proposed strategy types and selected contingencies. Factor analysis extracted two of the initial categories in the typology. The Building Resource Development Infrastructure Strategy encompasses information technology, personnel, legal structures, and policies facilitating fund development. The Building Resource Development Infrastructure Strategy encompasses the mission, service niche, and type of service delivery forming the basis for seeking financial support. Linear regressions with each strategy type as the dependent variable identified distinct and common contingencies which may partly explain choices of strategies. Discriminant analysis suggests the potential predictive accuracy of the contingencies. Follow-up case studies with survey respondents provide additional criteria for operationalizing future measures of resource development strategies, and support and expand the analysis on contingencies. The typology offers a beginning framework for defining alternative approaches to resource development, and for exploring organization capacity specific to each approach. Contingencies that may be integral components of organization capacity are funding, leadership frame, background and experience, staff and volunteer effort, board member support, and relationships in the external environment. Based on these findings, management questions are offered for nonprofit organization stakeholders to consider in planning for resource development. Lessons learned in designing and conducting this study are also provided to enhance future related research. ^

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Historically, some grandparents have had to assume the responsibility for raising their grandchildren. More recently, with increasing frequency grandparents are serving as full-time surrogate parents to their grandchildren.^ The term "grandfamily" was coined by this researcher to identify families where children are raised by grandparents. "Supergrands" are the grandparents and "grandkin" are children in these families.^ Supergrands who raise their grandkin tend to have elevated levels of stress that negatively impact their well-being. Grandkin tend to develop problems with attachment and establishing social networks, which can lead to poor psychological adjustment. School personnel believe grandkin evidence behavioral problems and occupy disproportionate amounts of their time each day. However, there is a dearth of data to support this belief.^ This study empirically investigated the impact of grandfamilies on students and school services. The results revealed grandkin experienced significantly greater levels of emotional and behavior problems than similar schoolmates. However, they were not referred for discipline problems in substantially larger numbers.^ These results indicate the practice of education should change to allow for the development and provision of social support procedures in schools. Social support will serve to buffer the stress, manifested in emotional and behavioral problems, encountered by children living with surrogate parents. A case study was presented along with a proposed intervention project that has potential to ameliorate the problems experienced by grandfamilies. ^

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Despite the frequency with which fevers occur in children ages 1–3 years, lack of knowledge and understanding about the implications of fever and methods of fever management often results in anxiety among caretakers, sometimes prompting them to seek help at nearby emergency departments. Caretakers often look to health care professionals for advice and guidance over the telephone. The purpose of this study was to investigate caretakers' knowledge of the implications of fever, methods of fever management, perceptions of pediatric telephone triage and advice services regarding fever, and the effectiveness of after hour telephone triage directed toward improving the caretakers' ability to manage their child's fever at home. Pre-triage questionnaires were completed by 72 caretakers over the telephone before the triage encounter. Twenty-two of those same caretakers whose children were triaged using the fever guideline completed and returned the mailed post-triage questionnaire. Descriptive statistics were used to analyze responses for the larger pre-intervention group and describe comparisons for the pre and post-triage responses in the smaller sample subset (n = 22). ^

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The authors report the pilot study focused on identifying the emotional intelligence (El) of leaders in the automatic merchandising and coffee service industries. The data were collected from 39 executives, members of National Automatic Merchandising Association (NM), who attended 2005 Executive Development Program on the campus of Michigan State University. Three elements of EI- IN, OUT, RELATIONSHIP for these leaders are discussed.

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This descriptive study examined whether discharge planning ensures that food and nutrition services are provided to older adults following hospital discharge. The questionnaire was distributed to discharge planning professionals in 11 South Florida hospitals. Of the 84 respondents (88% response rate), most were female nurse case managers. Almost all reported job barriers including excessive patient loads, too many responsibilities, and limited community services. While physicians, registered nurses, social workers, physical therapists, were deemed "very important" in discharge planning,registered dietitians were not, and almost half consulted them infrequently, if at all. Over 84% said nutrition-related medical conditions/factors, "strongly influenced" discharge planning. Many did not have adequate information about nutrition-related community resources, eg, home delivered meals, food stamps, outpatient registered dietitians. Therewere no universal approaches in meeting the nutrition needs in 6 case scenarios. More communication among community services and hospitals is needed.