16 resultados para hydroelectric power and aquatic macrophytes
em Digital Commons at Florida International University
Resumo:
The purpose of this research was to apply the concepts of power and influence tactics to the joint venture context by examining how they relate to venture performance. In addition, culture and the expectations of future cooperation were examined for their association with influence tactic use and joint venture performance. Data were collected from 58 parent firms of U.S.-based domestic and international joint ventures about their relationships with their partners.^ Under the theories of social exchange and power dependence, a parent's level of power is based on its partner's dependence on the relationship. The statistical results indicated that: (1) the greater the total of power of both parents in an equal power relationship, the greater the joint venture's performance; and (2) the greater the inequality between each parent's level of power, the lower the joint venture's performance. It was also found that the way in which a parent firm tried to influence its partner was related to joint venture performance. Specifically, the use of references to a partner's legitimate authority was negatively related to performance, while the use of rational arguments and compromises was positively related.^ Contrary to expectations, the cultural backgrounds of the parents were not shown to have a relationship to influence tactic use or joint venture's performance. On the other hand, greater expectation of future cooperation had a positive association with performance, and a significant relationship with influence tactic use. The greater the expectation, the less partners used more confrontational tactics such as pressure or legitimate authority. ^
Resumo:
Over the past few decades, we have been enjoying tremendous benefits thanks to the revolutionary advancement of computing systems, driven mainly by the remarkable semiconductor technology scaling and the increasingly complicated processor architecture. However, the exponentially increased transistor density has directly led to exponentially increased power consumption and dramatically elevated system temperature, which not only adversely impacts the system's cost, performance and reliability, but also increases the leakage and thus the overall power consumption. Today, the power and thermal issues have posed enormous challenges and threaten to slow down the continuous evolvement of computer technology. Effective power/thermal-aware design techniques are urgently demanded, at all design abstraction levels, from the circuit-level, the logic-level, to the architectural-level and the system-level. ^ In this dissertation, we present our research efforts to employ real-time scheduling techniques to solve the resource-constrained power/thermal-aware, design-optimization problems. In our research, we developed a set of simple yet accurate system-level models to capture the processor's thermal dynamic as well as the interdependency of leakage power consumption, temperature, and supply voltage. Based on these models, we investigated the fundamental principles in power/thermal-aware scheduling, and developed real-time scheduling techniques targeting at a variety of design objectives, including peak temperature minimization, overall energy reduction, and performance maximization. ^ The novelty of this work is that we integrate the cutting-edge research on power and thermal at the circuit and architectural-level into a set of accurate yet simplified system-level models, and are able to conduct system-level analysis and design based on these models. The theoretical study in this work serves as a solid foundation for the guidance of the power/thermal-aware scheduling algorithms development in practical computing systems.^
Resumo:
Using high-resolution measures of aquatic ecosystem metabolism and water quality, we investigated the importance of hydrological inputs of phosphorus (P) on ecosystem dynamics in the oligotrophic, P-limited coastal Everglades. Due to low nutrient status and relatively large inputs of terrestrial organic matter, we hypothesized that the ponds in this region would be strongly net heterotrophic and that pond gross primary production (GPP) and respiration (R) would be the greatest during the “dry,” euhaline estuarine season that coincides with increased P availability. Results indicated that metabolism rates were consistently associated with elevated upstream total phosphorus and salinity concentrations. Pulses in aquatic metabolism rates were coupled to the timing of P supply from groundwater upwelling as well as a potential suite of hydrobiogeochemical interactions. We provide evidence that freshwater discharge has observable impacts on aquatic ecosystem function in the oligotrophic estuaries of the Florida Everglades by controlling the availability of P to the ecosystem. Future water management decisions in South Florida must include the impact of changes in water delivery on downstream estuaries.
Resumo:
Context: While research suggests whole body vibration (WBV) positively affects measures of neuromuscular performance in athletes, researchers have yet to address appropriate and effective vibration protocols. Objective: To identify the acute effects of continuous and intermittent WBV on muscular power and agility in recreationally active females. Design: We used a randomized 3-period cross-over design to observe the effects of 3 vibration protocols on muscular power and agility. Setting: Sports Science and Medicine Research Laboratory at Florida International University. Patients or Other Participants: Eleven recreationally active female volunteers (age=24.4±5.7y; ht=166.0±10.3cm; mass=59.7±14.3kg). Interventions: Each session, subjects stood on the Galileo WBV platform (Orthometrix, White Plains, NY) and received one of three randomly assigned vibration protocols. Our independent variable was vibration length (continuous, intermittent, or no vibration). Main Outcome Measures: An investigator blinded to the vibration protocol measured muscular power and agility. We measured muscular power with heights of squat and countermovement jumps. We measured agility with the Illinois Agility Test. Results: Continuous WBV significantly increased SJ height from 97.9±7.6cm to 98.5±7.5cm (P=0.019, β=0.71, η2 =0.07) but not CMJ height [99.1±7.4cm pretest and 99.4±7.4cm posttest (P=0.167, β=0.27)] or agility [19.2±2.1s pretest and 19.0±2.1s posttest (P=0.232, β=0.21)]. Intermittent WBV significantly enhanced SJ height from 97.6±7.7cm to 98.5±7.7cm (P=0.017, β=0.71, η2 =0.11) and agility 19.4±2.2s to 19.0±2.1s (P=0.001, β=0.98, η2=0.16), but did not effect CMJ height [98.7±7.7cm pretest and 99.3±7.3cm posttest (P=0.058, β=0.49)]. Conclusion: Continuous WBV increased squat jump height, while intermittent vibration enhanced agility and squat jump height. Future research should continue investigating the effect of various vibration protocols on athletic performance.
Resumo:
In this paper, we examine Florida’s sixth-eighth grade geography standards to determine the potential for teaching critical geography, a field that interrogates space, place, power, and identity. While 57% of the standards demonstrated evidence of critical thinking, only six standards foster higher levels of critique consistent with critical geography.
Resumo:
Catering to society's demand for high performance computing, billions of transistors are now integrated on IC chips to deliver unprecedented performances. With increasing transistor density, the power consumption/density is growing exponentially. The increasing power consumption directly translates to the high chip temperature, which not only raises the packaging/cooling costs, but also degrades the performance/reliability and life span of the computing systems. Moreover, high chip temperature also greatly increases the leakage power consumption, which is becoming more and more significant with the continuous scaling of the transistor size. As the semiconductor industry continues to evolve, power and thermal challenges have become the most critical challenges in the design of new generations of computing systems. ^ In this dissertation, we addressed the power/thermal issues from the system-level perspective. Specifically, we sought to employ real-time scheduling methods to optimize the power/thermal efficiency of the real-time computing systems, with leakage/ temperature dependency taken into consideration. In our research, we first explored the fundamental principles on how to employ dynamic voltage scaling (DVS) techniques to reduce the peak operating temperature when running a real-time application on a single core platform. We further proposed a novel real-time scheduling method, “M-Oscillations” to reduce the peak temperature when scheduling a hard real-time periodic task set. We also developed three checking methods to guarantee the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research from single core platform to multi-core platform. We investigated the energy estimation problem on the multi-core platforms and developed a light weight and accurate method to calculate the energy consumption for a given voltage schedule on a multi-core platform. Finally, we concluded the dissertation with elaborated discussions of future extensions of our research. ^
Resumo:
In a post-Cold War, post-9/11 world, the advent of US global supremacy resulted in the installation, perpetuation, and dissemination of an Absolutist Security Agenda (hereinafter, ASA). The US ASA explicitly and aggressively articulates and equates US national security interests with the security of all states in the international system, and replaced the bipolar, Cold War framework that defined international affairs from 1945-1992. Since the collapse of the USSR and the 11 September 2001 terrorist attacks, the US has unilaterally defined, implemented, and managed systemic security policy. The US ASA is indicative of a systemic category of knowledge (security) anchored in variegated conceptual and material components, such as morality, philosophy, and political rubrics. The US ASA is based on a logic that involves the following security components: (1) hyper militarization, (2) intimidation,(3) coercion, (4) criminalization, (5) panoptic surveillance, (6) plenary security measures, and (7) unabashed US interference in the domestic affairs of select states. Such interference has produced destabilizing tensions and conflicts that have, in turn, produced resistance, revolutions, proliferation, cults of personality, and militarization. This is the case because the US ASA rests on the notion that the international system of states is an extension, instrument of US power, rather than a system and/or society of states comprised of functionally sovereign entities. To analyze the US ASA, this study utilizes: (1) official government statements, legal doctrines, treaties, and policies pertaining to US foreign policy; (2) militarization rationales, budgets, and expenditures; and (3) case studies of rogue states. The data used in this study are drawn from information that is publicly available (academic journals, think-tank publications, government publications, and information provided by international organizations). The data supports the contention that global security is effectuated via a discrete set of hegemonic/imperialistic US values and interests, finding empirical expression in legal acts (USA Patriot ACT 2001) and the concept of rogue states. Rogue states, therefore, provide test cases to clarify the breadth, depth, and consequentialness of the US ASA in world affairs vis-à-vis the relationship between US security and global security.
Resumo:
This deconstruction of employee engagement, power, and privilege was focused toward exploring four principal questions: (a) who controls the context of work, (b) who determines the experience of engagement, (c) who defines the value of engagement, and (d) who benefits from high levels of engagement? Because of the potential for privilege to influence the experience of engagement, the purpose of our work was to critically examine the construct of employee engagement as a privileged state
Resumo:
In a post-Cold War, post-9/11 world, the advent of US global supremacy resulted in the installation, perpetuation, and dissemination of an Absolutist Security Agenda (hereinafter, ASA). The US ASA explicitly and aggressively articulates and equates US national security interests with the security of all states in the international system, and replaced the bipolar, Cold War framework that defined international affairs from 1945-1992. Since the collapse of the USSR and the 11 September 2001 terrorist attacks, the US has unilaterally defined, implemented, and managed systemic security policy. The US ASA is indicative of a systemic category of knowledge (security) anchored in variegated conceptual and material components, such as morality, philosophy, and political rubrics. The US ASA is based on a logic that involves the following security components: 1., hyper militarization, 2., intimidation, 3., coercion, 4., criminalization, 5., panoptic surveillance, 6., plenary security measures, and 7., unabashed US interference in the domestic affairs of select states. Such interference has produced destabilizing tensions and conflicts that have, in turn, produced resistance, revolutions, proliferation, cults of personality, and militarization. This is the case because the US ASA rests on the notion that the international system of states is an extension, instrument of US power, rather than a system and/or society of states comprised of functionally sovereign entities. To analyze the US ASA, this study utilizes: 1., official government statements, legal doctrines, treaties, and policies pertaining to US foreign policy; 2., militarization rationales, budgets, and expenditures; and 3., case studies of rogue states. The data used in this study are drawn from information that is publicly available (academic journals, think-tank publications, government publications, and information provided by international organizations). The data supports the contention that global security is effectuated via a discrete set of hegemonic/imperialistic US values and interests, finding empirical expression in legal acts (USA Patriot ACT 2001) and the concept of rogue states. Rogue states, therefore, provide test cases to clarify the breadth, depth, and consequentialness of the US ASA in world affairs vis-a-vis the relationship between US security and global security.
Resumo:
Catering to society’s demand for high performance computing, billions of transistors are now integrated on IC chips to deliver unprecedented performances. With increasing transistor density, the power consumption/density is growing exponentially. The increasing power consumption directly translates to the high chip temperature, which not only raises the packaging/cooling costs, but also degrades the performance/reliability and life span of the computing systems. Moreover, high chip temperature also greatly increases the leakage power consumption, which is becoming more and more significant with the continuous scaling of the transistor size. As the semiconductor industry continues to evolve, power and thermal challenges have become the most critical challenges in the design of new generations of computing systems. In this dissertation, we addressed the power/thermal issues from the system-level perspective. Specifically, we sought to employ real-time scheduling methods to optimize the power/thermal efficiency of the real-time computing systems, with leakage/ temperature dependency taken into consideration. In our research, we first explored the fundamental principles on how to employ dynamic voltage scaling (DVS) techniques to reduce the peak operating temperature when running a real-time application on a single core platform. We further proposed a novel real-time scheduling method, “M-Oscillations” to reduce the peak temperature when scheduling a hard real-time periodic task set. We also developed three checking methods to guarantee the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research from single core platform to multi-core platform. We investigated the energy estimation problem on the multi-core platforms and developed a light weight and accurate method to calculate the energy consumption for a given voltage schedule on a multi-core platform. Finally, we concluded the dissertation with elaborated discussions of future extensions of our research.
Resumo:
The assessment of organic matter (OM) sources in sediments and soils is a key to better understand the biogeochemical cycling of carbon in aquatic environments. While traditional molecular marker-based methods have provided such information for typical two end member (allochthonous/terrestrial vs. autochthonous/microbial)-dominated systems, more detailed, biomass-specific assessments are needed for ecosystems with complex OM inputs such as tropical and sub-tropical wetlands and estuaries where aquatic macrophytes and macroalgae may play an important role as OM sources. The aim of this study was to assess the utility of a combined approach using compound specific stable carbon isotope analysis and an n-alkane based proxy (Paq) to differentiate submerged and emergent/terrestrial vegetation OM inputs to soils/sediments from a sub-tropical wetland and estuarine system, the Florida Coastal Everglades. Results show that Paq values (0.13–0.51) for the emergent/terrestrial plants were generally lower than those for freshwater/marine submerged vegetation (0.45–1.00) and that compound specific δ13C values for the n-alkanes (C23 to C31) were distinctively different for terrestrial/emergent and freshwater/marine submerged plants. While crossplots of the Paq and n-alkane stable isotope values for the C23n-alkane suggest that OM inputs are controlled by vegetation changes along the freshwater to marine transect, further resolution regarding OM input changes along this landscape was obtained through principal component analysis (PCA), successfully grouping the study sites according to the OM source strengths. The data show the potential for this n-alkane based multi-proxy approach as a means of assessing OM inputs to complex ecosystems.
Resumo:
1. Our goal was to quantify short-term phosphorus (P) partitioning and identify the ecosystem components important to P cycling in wetland ecosystems. To do this, we added P radiotracer to oligotrophic, P-limited Everglades marshes. 32PO4 was added to the water column in six 1-m2 enclosed mesocosms located in long-hydroperiod marshes of Shark River Slough, Everglades National Park. Ecosystem components were then repeatedly sampled over 18 days. 2. Water column particulates (>0.45 μm) incorporated radiotracer within the first minute after dosing and stored 95–99% of total water column 32P activity throughout the study. Soluble (<0.45 μm) 32P in the water column, in contrast, was always <5% of the 32P in surface water. Periphyton, both floating and attached to emergent macrophytes, had the highest specific activity of 32P (Bq g−131P) among the different ecosystem components. Fish and aquatic macroinvertebrates also had high affinity for P, whereas emergent macrophytes, soil and flocculent detrital organic matter (floc) had the lowest specific activities of radiotracer. 3. Within the calcareous, floating periphyton mats, 81% of the initial 32P uptake was associated with Ca, but most of this 32P entered and remained within the organic pool (Ca-associated = 14% of total) after 1 day. In the floc layer, 32P rapidly entered the microbial pool and the labile fraction was negligible for most of the study. 4. Budgeting of the radiotracer indicated that 32P moved from particulates in the water column to periphyton and floc and then to the floc and soil over the course of the 18 day incubations. Floc (35% of total) and soil (27%) dominated 32P storage after 18 days, with floating periphyton (12%) and surface water (10%) holding smaller proportions of total ecosystem 32P. 5. To summarise, oligotrophic Everglades marshes exhibited rapid uptake and retention of labile 32P. Components dominated by microbes appear to control short-term P cycling in this oligotrophic ecosystem.
Resumo:
Two key solutions to reduce the greenhouse gas emissions and increase the overall energy efficiency are to maximize the utilization of renewable energy resources (RERs) to generate energy for load consumption and to shift to low or zero emission plug-in electric vehicles (PEVs) for transportation. The present U.S. aging and overburdened power grid infrastructure is under a tremendous pressure to handle the issues involved in penetration of RERS and PEVs. The future power grid should be designed with for the effective utilization of distributed RERs and distributed generations to intelligently respond to varying customer demand including PEVs with high level of security, stability and reliability. This dissertation develops and verifies such a hybrid AC-DC power system. The system will operate in a distributed manner incorporating multiple components in both AC and DC styles and work in both grid-connected and islanding modes. The verification was performed on a laboratory-based hybrid AC-DC power system testbed as hardware/software platform. In this system, RERs emulators together with their maximum power point tracking technology and power electronics converters were designed to test different energy harvesting algorithms. The Energy storage devices including lithium-ion batteries and ultra-capacitors were used to optimize the performance of the hybrid power system. A lithium-ion battery smart energy management system with thermal and state of charge self-balancing was proposed to protect the energy storage system. A grid connected DC PEVs parking garage emulator, with five lithium-ion batteries was also designed with the smart charging functions that can emulate the future vehicle-to-grid (V2G), vehicle-to-vehicle (V2V) and vehicle-to-house (V2H) services. This includes grid voltage and frequency regulations, spinning reserves, micro grid islanding detection and energy resource support. The results show successful integration of the developed techniques for control and energy management of future hybrid AC-DC power systems with high penetration of RERs and PEVs.
Resumo:
In this study three aspects of sexual reproduction in Everglades plants were examined to more clearly understand seed dispersal and the allocation of resources to sexual reproduction— spatial dispersal process, temporal dispersal of seeds (seedbank), and germination patterns in the dominant species, sawgrass (Cladium jamaicense). Community assembly rules for fruit dispersal were deduced by analysis of functional traits associated with this process. Seedbank ecology was investigated by monitoring emergence of germinants from sawgrass soil samples held under varying water depths to determine the fate of dispersed seeds. Fine-scale study of sawgrass fruits yielded information on contributions to variation in sexually produced propagules in this species, which primarily reproduces vegetatively. It was hypothesized that Everglades plants possess a set of functional traits that enhance diaspore dispersal. To test this, 14 traits were evaluated among 51 species by factor analysis. The factorial plot of this analysis generated groups of related traits, with four suites of traits forming dispersal syndromes. Hydrochory traits were categorized by buoyancy and appendages enhancing buoyancy. Anemochory traits were categorized by diaspore size and appendages enhancing air movement. Epizoochory traits were categorized by diaspore size, buoyancy, and appendages allowing for attachment. Endozoochory traits were categorized by diaspore size, buoyancy, and appendages aiding diaspore presentation. These patterns/trends of functional trait organization also represent dispersal community assembly rules. Seeds dispersed by hydrochory were hypothesized to be caught most often in the edge of the north side of sawgrass patches. Patterns of germination and dispersal mode of all hydrochorous macrophytes with propagules in the seedbank were elucidated by germination analysis from 90 soil samples collected from 10 sawgrass patches. Mean site seed density was 486 seeds/m2 from 13 species. Most seeds collected at the north side of patches and significantly in the outer one meter of the patch edge (p = 0.013). Sawgrass seed germination was hypothesized to vary by site, among individual plants, and within different locations of a plant’s infructescence. An analysis of sawgrass fruits with nested ANOVAs found that collection site and interaction of site x individual plant significantly affect germination ability, seed viability, and fruit size (p < 0.050). Fruit location within a plant’s infructescence did not significantly affect germination. As for allocation of resources to sexual reproduction, only 17.9% of sawgrass seeds germinated and only 4.8% of ungerminated seeds with fleshy endosperm were presumed viable, but dormant. Collectively, only 22% of all sawgrass seeds produced were viable.