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(1 - 3 of 3)
- Title
- HOW SYMPTOMS OF ANXIETY, DEPRESSION, ATTENTION DEFICIT DISORDER (ADD) OR ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD) CONTRIBUTE TO STUDENTS SELF-MEDICATING VIA MARIJUANA AND NON-MEDICAL PRESCRIPTION DRUGS.
- Creator
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Thomas, Maria, Donley, Dr. Amy, University of Central Florida
- Abstract / Description
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This study examines student's nonmedical prescription drug (NMPD) and marijuana use and whether anxiety, depression, ADD or ADHD symptoms are associated with their use and if students are self-medicating to alleviate symptoms. The method of obtaining this information was provided by a total of 278 college students who voluntarily and anonymously completed a Web-based survey. This study fills in the gaps of previous research and reveals the most frequent NMPD's used by students and their...
Show moreThis study examines student's nonmedical prescription drug (NMPD) and marijuana use and whether anxiety, depression, ADD or ADHD symptoms are associated with their use and if students are self-medicating to alleviate symptoms. The method of obtaining this information was provided by a total of 278 college students who voluntarily and anonymously completed a Web-based survey. This study fills in the gaps of previous research and reveals the most frequent NMPD's used by students and their overall perceptions of their intended effects of the drug and answers why students do not seek professional help for their anxiety, depression and impulsivity symptoms. Results from the survey indicate that students who report NMPD use self- reported higher symptoms of anxiety, depression and impulsivity. NMPD users reported higher percentages of other substance abuse compared to nonusers. The most prominent NMPD's used by students are Adderall and Vicoden or Codeine. Data also indicates student's primary reasons for their NMPD use are related to academic purposes; as opposed to nonacademic. This analysis is further supported by the fact that the majority of NMPD users did not use before they began college and do not use while classes are not is session. Furthermore, students perceive their overall intended effects of their NMPD use to be beneficial, despite the known risks associated with their drug use. By examining college student's current NMPD use we can provide alternative solutions to students who are self-medicating as a coping mechanism for underlying issues or mental health disorders. Also, we can provide them with the necessary services in order to address their problems professionally.
Show less - Date Issued
- 2013
- Identifier
- CFH0004445, ucf:45114
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004445
- Title
- LIQUID CRYSTAL OPTICS FOR COMMUNICATIONS, SIGNAL PROCESSING AND 3-D MICROSCOPIC IMAGING.
- Creator
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Khan, Sajjad, Riza, Nabeel, University of Central Florida
- Abstract / Description
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This dissertation proposes, studies and experimentally demonstrates novel liquid crystal (LC) optics to solve challenging problems in RF and photonic signal processing, freespace and fiber optic communications and microscopic imaging. These include free-space optical scanners for military and optical wireless applications, variable fiber-optic attenuators for optical communications, photonic control techniques for phased array antennas and radar, and 3-D microscopic imaging. At the heart of...
Show moreThis dissertation proposes, studies and experimentally demonstrates novel liquid crystal (LC) optics to solve challenging problems in RF and photonic signal processing, freespace and fiber optic communications and microscopic imaging. These include free-space optical scanners for military and optical wireless applications, variable fiber-optic attenuators for optical communications, photonic control techniques for phased array antennas and radar, and 3-D microscopic imaging. At the heart of the applications demonstrated in this thesis are LC devices that are non-pixelated and can be controlled either electrically or optically. Instead of the typical pixel-by-pixel control as is custom in LC devices, the phase profile across the aperture of these novel LC devices is varied through the use of high impedance layers. Due to the presence of the high impedance layer, there forms a voltage gradient across the aperture of such a device which results in a phase gradient across the LC layer which in turn is accumulated by the optical beam traversing through this LC device. The geometry of the electrical contacts that are used to apply the external voltage will define the nature of the phase gradient present across the optical beam. In order to steer a laser beam in one angular dimension, straight line electrical contacts are used to form a one dimensional phase gradient while an annular electrical contact results in a circularly symmetric phase profile across the optical beam making it suitable for focusing the optical beam. The geometry of the electrical contacts alone is not sufficient to form the linear and the quadratic phase profiles that are required to either deflect or focus an optical beam. Clever use of the phase response of a typical nematic liquid crystal (NLC) is made such that the linear response region is used for the angular beam deflection while the high voltage quadratic response region is used for focusing the beam. Employing an NLC deflector, a device that uses the linear angular deflection, laser beam steering is demonstrated in two orthogonal dimensions whereas an NLC lens is used to address the third dimension to complete a three dimensional (3-D) scanner. Such an NLC deflector was then used in a variable optical attenuator (VOA), whereby a laser beam coupled between two identical single mode fibers (SMF) was mis-aligned away from the output fiber causing the intensity of the output coupled light to decrease as a function of the angular deflection. Since the angular deflection is electrically controlled, hence the VOA operation is fairly simple and repeatable. An extension of this VOA for wavelength tunable operation is also shown in this dissertation. A LC spatial light modulator (SLM) that uses a photo-sensitive high impedance electrode whose impedance can be varied by controlling the light intensity incident on it, is used in a control system for a phased array antenna. Phase is controlled on the Write side of the SLM by controlling the intensity of the Write laser beam which then is accessed by the Read beam from the opposite side of this reflective SLM. Thus the phase of the Read beam is varied by controlling the intensity of the Write beam. A variable fiber-optic delay line is demonstrated in the thesis which uses wavelength sensitive and wavelength insensitive optics to get both analog as well as digital delays. It uses a chirped fiber Bragg grating (FBG), and a 1xN optical switch to achieve multiple time delays. The switch can be implemented using the 3-D optical scanner mentioned earlier. A technique is presented for ultra-low loss laser communication that uses a combination of strong and weak thin lens optics. As opposed to conventional laser communication systems, the Gaussian laser beam is prevented from diverging at the receiving station by using a weak thin lens that places the transmitted beam waist mid-way between a symmetrical transmitter-receiver link design thus saving prime optical power. LC device technology forms an excellent basis to realize such a large aperture weak lens. Using a 1-D array of LC deflectors, a broadband optical add-drop filter (OADF) is proposed for dense wavelength division multiplexing (DWDM) applications. By binary control of the drive signal to the individual LC deflectors in the array, any optical channel can be selectively dropped and added. For demonstration purposes, microelectromechanical systems (MEMS) digital micromirrors have been used to implement the OADF. Several key systems issues such as insertion loss, polarization dependent loss, wavelength resolution and response time are analyzed in detail for comparison with the LC deflector approach. A no-moving-parts axial scanning confocal microscope (ASCM) system is designed and demonstrated using a combination of a large diameter LC lens and a classical microscope objective lens. By electrically controlling the 5 mm diameter LC lens, the 633 nm wavelength focal spot is moved continuously over a 48 ƒÝm range with measured 3-dB axial resolution of 3.1 ƒÝm using a 0.65 numerical aperture (NA) micro-objective lens. The ASCM is successfully used to image an Indium Phosphide twin square optical waveguide sample with a 10.2 ƒÝm waveguide pitch and 2.3 ƒÝm height and width. Using fine analog electrical control of the LC lens, a super-fine sub-wavelength axial resolution of 270 nm is demonstrated. The proposed ASCM can be useful in various precision three dimensional imaging and profiling applications.
Show less - Date Issued
- 2005
- Identifier
- CFE0000750, ucf:46596
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000750
- Title
- An Agile Roadmap for Live, Virtual and Constructive-Integrating Training Architecture (LVC-ITA): A Case Study Using a Component based Integrated Simulation Engine.
- Creator
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Park, Tae Woong, Lee, Gene, Rabelo, Luis, Elshennawy, Ahmad, Kincaid, John, University of Central Florida
- Abstract / Description
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Conducting seamless Live Virtual Constructive (LVC) simulation remains the most challenging issue of Modeling and Simulation (M(&)S). There is a lack of interoperability, limited reuse and loose integration between the Live, Virtual and/or Constructive assets across multiple Standard Simulation Architectures (SSAs). There have been various theoretical research endeavors about solving these problems but their solutions resulted in complex and inflexible integration, long user-usage time and...
Show moreConducting seamless Live Virtual Constructive (LVC) simulation remains the most challenging issue of Modeling and Simulation (M(&)S). There is a lack of interoperability, limited reuse and loose integration between the Live, Virtual and/or Constructive assets across multiple Standard Simulation Architectures (SSAs). There have been various theoretical research endeavors about solving these problems but their solutions resulted in complex and inflexible integration, long user-usage time and high cost for LVC simulation. The goal of this research is to provide an Agile Roadmap for the Live Virtual Constructive-Integrating Training Architecture (LVC-ITA) that will address the above problems and introduce interoperable LVC simulation. Therefore, this research describes how the newest M(&)S technologies can be utilized for LVC simulation interoperability and integration. Then, we will examine the optimal procedure to develop an agile roadmap for the LVC-ITA.In addition, this research illustrated a case study using an Adaptive distributed parallel Simulation environment for Interoperable and reusable Model (AddSIM) that is a component based integrated simulation engine. The agile roadmap of the LVC-ITA that reflects the lessons learned from the case study will contribute to guide M(&)S communities to an efficient path to increase interaction of M(&)S simulation across systems.
Show less - Date Issued
- 2015
- Identifier
- CFE0005682, ucf:52867
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005682
