Current Search: soft power (x)
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- Title
- SOFT POWER AND HARD POWER APPROACHES IN U.S. FOREIGN POLICY: A CASE STUDY COMPARISON IN LATIN AMERICA.
- Creator
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Weinbrenner, John, Dolan, Chris, University of Central Florida
- Abstract / Description
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The purpose of this study was to examine the effects of soft power versus hard power in U.S. policy towards Latin America. In recent years America's unipolar moment has been challenged from populist leaders in the region to its inability to get a handle on the flow of illegal immigrants and illicit drugs that reach its shores. This thesis is a step to understanding the difference between power and influence as well as the effects of hard power and soft power in U.S. foreign policy. A...
Show moreThe purpose of this study was to examine the effects of soft power versus hard power in U.S. policy towards Latin America. In recent years America's unipolar moment has been challenged from populist leaders in the region to its inability to get a handle on the flow of illegal immigrants and illicit drugs that reach its shores. This thesis is a step to understanding the difference between power and influence as well as the effects of hard power and soft power in U.S. foreign policy. A historical comparative case study analysis has been conducted utilizing the cases of FDR's Good Neighbor policy and Reagan's contra war policies. This qualitative approach examined specific short-term and long-term goals of each policy and analyzed each strategy's ability to achieve those stated goals. The results of the study reveal that both soft and hard power approaches can have positive as well as negative effects on American influence in Latin America.
Show less - Date Issued
- 2007
- Identifier
- CFE0001600, ucf:47175
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001600
- Title
- IRGC AND IRANIAN SOFT AND HARD POWER INFLUENCE WITHIN THE MIDDLE EAST.
- Creator
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Urbina, Daryl F, Sadri, Houman A., University of Central Florida
- Abstract / Description
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The IRGC, or the Iranian Revolutionary Guard Corps, and Iran have utilized soft power to increase their influence within the Middle East. By using military superiority; ideological influence; and trade, both the Iran and the IRGC established dependency between themselves and patron states. Of these patron states, the research focuses on Iraq; Syria; and Yemen, and how Iran and the IRGC affect them through soft power. This research suggests that Iran and the IRGC is using the disability of the...
Show moreThe IRGC, or the Iranian Revolutionary Guard Corps, and Iran have utilized soft power to increase their influence within the Middle East. By using military superiority; ideological influence; and trade, both the Iran and the IRGC established dependency between themselves and patron states. Of these patron states, the research focuses on Iraq; Syria; and Yemen, and how Iran and the IRGC affect them through soft power. This research suggests that Iran and the IRGC is using the disability of the aforementioned states to increase their own influence by making them dependent on Iranian military supplies; cultural indoctrination to align with Iranian ideology; and economic dependent on Iran. As Iran's influence grows within these states, its power in the Middle East grows and becomes a security risk for Saudi Arabia; Israel; and any other regime that does not have its interests align with the Iranian regime.
Show less - Date Issued
- 2018
- Identifier
- CFH2000444, ucf:45770
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000444
- Title
- HIGH-DENSITY AND HIGH-EFFICIENCY SOFT SWITCHING MODULAR BI-DIRECTIONAL DC-DC CONVERTER FOR HYBRID ELECTRIC VEHICLES.
- Creator
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Elmes, John, Batarseh, Issa, University of Central Florida
- Abstract / Description
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This dissertation presents the design of a high-density and high-efficiency soft-switching bi-directional DC-DC converter for hybrid-electric vehicles. The converter operates in a new bi-directional interleaved variable-frequency quasi-square-wave (QSW) mode, which enables high efficiency, high switching frequency, and high power-density. The converter presented utilizes a new variable frequency interleaving approach which allows for each module to operate in an interleaved position while...
Show moreThis dissertation presents the design of a high-density and high-efficiency soft-switching bi-directional DC-DC converter for hybrid-electric vehicles. The converter operates in a new bi-directional interleaved variable-frequency quasi-square-wave (QSW) mode, which enables high efficiency, high switching frequency, and high power-density. The converter presented utilizes a new variable frequency interleaving approach which allows for each module to operate in an interleaved position while allowing for tolerance in inductance and snubber capacitor values. The variable frequency interleaved soft-switching operation paired with a high-density nanocrystalline inductor and high-density system structure results in a very high performance converter, well exceeding that of the current technology. The developed converter is intended to achieve three specific performance goals: high conversion efficiency, high power density, and operation with 100 ÃÂÃÂÃÂðC coolant. Two markedly different converter prototype designs are presented, one converter using evaporative spray cooling to cool the switching devices, with the second converter using a more traditional coldplate design to cool the switching devices. The 200 kW (25 kW per module) prototype converters exhibited power density greater than 8 kilowatts/liter (kW/L), and peak efficiency over 98%, while operating with 100 ÃÂÃÂÃÂðC coolant.
Show less - Date Issued
- 2010
- Identifier
- CFE0003366, ucf:48436
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003366
- Title
- Control Based Soft Switching Three-phase Micro-inverter: Efficiency and Power Density Optimization.
- Creator
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Amirahmadi, Ahmadreza, Batarseh, Issa, Lotfifard, Saeed, Mikhael, Wasfy, Wu, Xinzhang, Kutkut, Nasser, University of Central Florida
- Abstract / Description
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In the field of renewable energy, solar photovoltaic is growing exponentially. Grid-tied PV micro-inverters have become the trend for future PV system development because of their remarkable advantages such as enhanced energy production due to MPPT implementation for each PV panel, high reliability due to redundant and distributed system architecture, and simple design, installation, and management due to its plug-and-play feature. Conventional approaches for the PV micro-inverters are mainly...
Show moreIn the field of renewable energy, solar photovoltaic is growing exponentially. Grid-tied PV micro-inverters have become the trend for future PV system development because of their remarkable advantages such as enhanced energy production due to MPPT implementation for each PV panel, high reliability due to redundant and distributed system architecture, and simple design, installation, and management due to its plug-and-play feature. Conventional approaches for the PV micro-inverters are mainly in the form of single-phase grid connected and they aim at the residential and commercial rooftop applications. It would be advantageous to extend the micro-inverter concept to large size PV installations such as MW-class solar farms where three-phase AC connections are used.The relatively high cost of the three-phase micro-inverter is the biggest barrier to its large scale deployment. Increasing the switching frequency may be the best way to reduce cost by shrinking the size of reactive components and heat-sink. However, this approach could cause conversion efficiency to drop dramatically without employing soft switching techniques or using costly new devices.This dissertation presents a new zero voltage switching control method that is suitable for low power applications such as three-phase micro-inverters. The proposed hybrid boundary conduction mode (BCM) current control method increases the efficiency and power density of the micro-inverters and features both reduced number of components and easy digital implementation. Zero voltage switching is achieved by controlling the inductor current bi-directional in every switching cycle and results in lower switching losses, higher operating frequency, and reduced size and cost of passive components, especially magnetic cores. Some practical aspects of hybrid control implementation such as dead-time insertion can degrade the performance of the micro-inverter. A dead-time compensation method that improves the performance of hybrid BCM current control by decreasing the output current THD and reducing the zero crossing distortion is presented.Different BCM ZVS current control modulation schemes are compared based on power losses breakdown, switching frequency range, and current quality. Compared to continuous conduction mode (CCM) current control, BCM ZVS control decreases MOSFET switching losses and filter inductor conduction losses but increases MOSFET conduction losses and inductor core losses. Based on the loss analysis, a dual-mode current modulation method combining ZVS and zero current switching (ZCS) schemes is proposed to improve the efficiency of the micro-inverter.Finally, a method of maintaining high power conversion efficiency across the entire load range of the three-phase micro-inverter is proposed. The proposed control method substantially increases the conversion efficiency at light loads by minimizing switching losses of semiconductor devices as well as core losses of magnetic components. This is accomplished by entering a phase skipping operating mode wherein two phases of an inverter are disabled and three inverters are combined to form a new three-phase system with minimal grid imbalance. A 400W prototype of a three-phase micro-inverter and its hybrid control system have been designed and tested under different conditions to verify the effectiveness of the proposed controller, current modulation scheme, and light load efficiency enhancement method.
Show less - Date Issued
- 2014
- Identifier
- CFE0005125, ucf:50703
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005125
- Title
- CONTROL STRATEGY FOR MAXIMIZING POWER CONVERSION EFFICIENCY AND EFFECTIVENESS OF THREE PORT SOLAR CHARGING STATION FOR ELECTRIC VEHICLES.
- Creator
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Hamilton, Christopher, Batarseh, Issa, University of Central Florida
- Abstract / Description
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Recent trends in the energy sector have provided opportunities in the research of alternative energy sources and optimization of systems that harness these energy sources. With the rising cost of fossil fuel and rising concern about detrimental effects that fossil fuel consumption has on the environment, electric vehicles are becoming more prevalent. A study put out in 2009 gives a prediction that in the year 2025, 20% of new vehicles will be PHEVs. As energy providers become more concerned...
Show moreRecent trends in the energy sector have provided opportunities in the research of alternative energy sources and optimization of systems that harness these energy sources. With the rising cost of fossil fuel and rising concern about detrimental effects that fossil fuel consumption has on the environment, electric vehicles are becoming more prevalent. A study put out in 2009 gives a prediction that in the year 2025, 20% of new vehicles will be PHEVs. As energy providers become more concerned about a growing population and diminishing energy source, they are looking into alternative energy sources such as wind and solar power. Much of this is done on a large scale with vast amounts of land used for solar or wind farms to provide energy to the grid. However, as population grows, requirements of the physical components of a power transmission system will become more demanding and the need for remote micro-grids will become more prevalent. Micro-grids are essentially smaller subsystems of a distribution system that provide power to a confined group of loads, or households. Using the idea of micro grid technology, a solar charging station can be used as a source to provide energy for the immediate surroundings, or also to electric vehicles that are demanding energy from the panels. Solar charging stations are becoming very popular, however the need for improvement and optimization of these systems is needed. This thesis will present a method for redesigning the overall architecture of the controls and power electronics of typical carports so that efficiency, reliability and modularity are achieved. Specifically, a typical carport, as seen commonly today, has been built on the University of Central Florida campus in Orlando. This carport was designed in such a way that shifting from conventional charging methods is made easy while preserving the fundamental requirements of a practical solar carport.
Show less - Date Issued
- 2010
- Identifier
- CFE0003490, ucf:48954
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003490
- Title
- Adaptive Architectural Strategies for Resilient Energy-Aware Computing.
- Creator
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Ashraf, Rizwan, DeMara, Ronald, Lin, Mingjie, Wang, Jun, Jha, Sumit, Johnson, Mark, University of Central Florida
- Abstract / Description
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Reconfigurable logic or Field-Programmable Gate Array (FPGA) devices have the ability to dynamically adapt the computational circuit based on user-specified or operating-condition requirements. Such hardware platforms are utilized in this dissertation to develop adaptive techniques for achieving reliable and sustainable operation while autonomously meeting these requirements. In particular, the properties of resource uniformity and in-field reconfiguration via on-chip processors are exploited...
Show moreReconfigurable logic or Field-Programmable Gate Array (FPGA) devices have the ability to dynamically adapt the computational circuit based on user-specified or operating-condition requirements. Such hardware platforms are utilized in this dissertation to develop adaptive techniques for achieving reliable and sustainable operation while autonomously meeting these requirements. In particular, the properties of resource uniformity and in-field reconfiguration via on-chip processors are exploited to implement Evolvable Hardware (EHW). EHW utilize genetic algorithms to realize logic circuits at runtime, as directed by the objective function. However, the size of problems solved using EHW as compared with traditional approaches has been limited to relatively compact circuits. This is due to the increase in complexity of the genetic algorithm with increase in circuit size. To address this research challenge of scalability, the Netlist-Driven Evolutionary Refurbishment (NDER) technique was designed and implemented herein to enable on-the-fly permanent fault mitigation in FPGA circuits. NDER has been shown to achieve refurbishment of relatively large sized benchmark circuits as compared to related works. Additionally, Design Diversity (DD) techniques which are used to aid such evolutionary refurbishment techniques are also proposed and the efficacy of various DD techniques is quantified and evaluated.Similarly, there exists a growing need for adaptable logic datapaths in custom-designed nanometer-scale ICs, for ensuring operational reliability in the presence of Process, Voltage, and Temperature (PVT) and, transistor-aging variations owing to decreased feature sizes for electronic devices. Without such adaptability, excessive design guardbands are required to maintain the desired integration and performance levels. To address these challenges, the circuit-level technique of Self-Recovery Enabled Logic (SREL) was designed herein. At design-time, vulnerable portions of the circuit identified using conventional Electronic Design Automation tools are replicated to provide post-fabrication adaptability via intelligent techniques. In-situ timing sensors are utilized in a feedback loop to activate suitable datapaths based on current conditions that optimize performance and energy consumption. Primarily, SREL is able to mitigate the timing degradations caused due to transistor aging effects in sub-micron devices by reducing the stress induced on active elements by utilizing power-gating. As a result, fewer guardbands need to be included to achieve comparable performance levels which leads to considerable energy savings over the operational lifetime.The need for energy-efficient operation in current computing systems has given rise to Near-Threshold Computing as opposed to the conventional approach of operating devices at nominal voltage. In particular, the goal of exascale computing initiative in High Performance Computing (HPC) is to achieve 1 EFLOPS under the power budget of 20MW. However, it comes at the cost of increased reliability concerns, such as the increase in performance variations and soft errors. This has given rise to increased resiliency requirements for HPC applications in terms of ensuring functionality within given error thresholds while operating at lower voltages. My dissertation research devised techniques and tools to quantify the effects of radiation-induced transient faults in distributed applications on large-scale systems. A combination of compiler-level code transformation and instrumentation are employed for runtime monitoring to assess the speed and depth of application state corruption as a result of fault injection. Finally, fault propagation models are derived for each HPC application that can be used to estimate the number of corrupted memory locations at runtime. Additionally, the tradeoffs between performance and vulnerability and the causal relations between compiler optimization and application vulnerability are investigated.
Show less - Date Issued
- 2015
- Identifier
- CFE0006206, ucf:52889
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006206