Browsing ETD -- Graduate theses by Date
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ItemEFFICIENT CALCULATION OF FISHER INFORMATION MATRIX: MONTE CARLO APPROACH USING PRIOR INFORMATION(Johns Hopkins University, 2007-06-21T20:47:34Z) Das, SonjoyThe Fisher information matrix (FIM) is a critical quantity in several aspects of mathematical modeling, including input selection and con¯dence region calculation. Analytical determination of the FIM in a general setting, specially in nonlinear mod- els, may be di±cult or almost impossible due to intractable modeling requirements and/or intractable high-dimensional integration. To circumvent these di±culties, a Monte Carlo (MC) simulation-based technique, resampling algorithm, based on the values of log-likelihood function or its exact stochastic gradient computed by using a set of pseudo data vectors, is usually rec- ommended. The current work proposes an extension of the resampling algorithm in order to enhance the statistical qualities of the estimator of the FIM. This modi¯ed resampling algorithm is useful in those cases where the FIM has a structure with some elements being analytically known from prior information and the others being unknown. The estimator of the FIM, obtained by using the proposed algorithm, si- multaneously preserves the analytically known elements and reduces variances of the estimators of the unknown elements by capitalizing on information contained in the ii known elements. Numerical illustrations considered in this work show considerable improvement of the new FIM estimator (in the sense of mean-squared error reduction as well as variance reduction) based on the modi¯ed MC based resampling algorithm over the FIM estimator based on the current MC based resampling algorithm. ItemTopics in Financial Globalization and Immigration Flows(jhu, 2008) Balin, Bryan J.; Sobol, Dorothy; Roett, Riordan J.; Gonzalez, Francisco Item“Walking Around” in Central Mozambique: Meanings and Normative Perceptions Encasing Concurrent Sexual Partnerships(jhu, 2008-04) Holman, Emily S.; Rimal, Rajiv N.Concurrent sexual partnering is commonly discussed as a factor contributing to the epidemic spread of the HIV virus through sexual transmission in parts of Africa, including Mozambique. This paper explores the concept of sexual concurrency within a broader human behavior context, reflecting on a series of discussion groups conducted in Dec. 2007 in semirural communities in Central Mozambique. The objective is to better map the dimensions of sexual concurrency as it is perceived by adults in this setting, and to understand what normative social perceptions and other psychosocial factors may be contributing to community members’ opinions of and engagement in concurrent sexual partnerships. I first explicate the concept of sexual concurrency in the broader literature, looking across the definitional variations in the scholarly community in order to arrive at an operational definition of the phenomenon. Given the diversity of etiological lenses that researchers have applied to explain the causes of sexual concurrency, scholars offer a wide range of value judgments as to the behavior’s ultimate utility. The literature findings do not lend themselves to the assertion of a single, universally-applicable evaluation of concurrency as either good or bad for humankind. Subsequent analysis explicates the concept of concurrent partnering as it was expressed by the semi-rural Zambezian respondents. A model was proposed revealing five distinct categorical definitions of concurrency which all fall under a broader behavior respondents refer to as “walking outside the home.” Just as scholars tend to inscribe their particular interpretations of concurrency according to their disciplinary affiliation, similarly Zambezian respondents were encircled by predominant social norms that framed their evaluations of a given concurrent partnering behavior. Just as a scholar could not confidently pose a value label for concurrent partnering without neglecting a field of research, similarly Zambezian participants’ characterizations did not consistently condone or condemn all concurrency occurrences across the community, instead passing judgment according to the specific categorical location of that behavior vis-à-vis social norms, disease ramifications and anticipated life events. That is, each specific concurrency behavior appeared to carry its own distinct social norm. Community members may support a “mild” form of concurrency while simultaneously discouraging a more “extreme form,” just as an individual may alternately engage in or avoid that same behavior at different moments in his or her personal life. While HIV risk was found to be an important factor to community members in judging whether a specific degree of sexual concurrency is acceptable, there were additional psychosocial factors beyond economic need that factored into this judgment. Prevention practitioners in the area of HIV and sexual health could benefit from learning local social categories that lie within a given sexual “risk behavior” and learn to gauge the local social and personal risks which are also at play in defining these categories. Behavior change programs could likely increase their effectiveness if they could target each subcategory of concurrency separately, and account for the community’s distinct perceptions of each in messaging strategies or activity type. Research and practice can work together to identify such societal complexities, and not assume a state of consistent attitudes across a broad behavior, nor assume attitude-consistent behaviors within members of community. Finally, existing behavioral models for sexual concurrency or similar behaviors tend to focus either on situational factors or contextual (social) factors. A more comprehensive model could shift from a single behavioral outcome (concurrent partnering) to multiple behavioral outcomes (for each specific local concurrency behavior), and could specify social and situational factors for each. ItemCELL BLOCKS AND STREET BLOCKS: A THREE STATE ANALYSIS OF EX-OFFENDER REENTRY(Johns Hopkins University, 2008-05-20T17:58:10Z) Reed, JosephThe recidivism rate of ex-offenders in America continues to increase each decade, and each decade the debate on the subject of recidivism begins and ends with nothing truly accomplished. Many studies on this subject state that it is through rehabilitation that the recidivism rate can truly be reduced. Can the recidivism rate be lowered with a revision of the reentry and rehabilitation programs available to ex-offenders? After analyzing three states identified as having the best, worst, and mid-range reentry systems in the country, it was concluded in this thesis that the key to reducing recidivism is to create a national recidivism program by which all states can follow. This program needs to have a centralized management structure, be adequately funded, address issues such as ex-offender housing, finding affordable health insurance for ex-offenders, reducing the effects of prisonization, helping ex-offenders to find employment and maintaining inmates relationships with family members, and continuing education for skill enhancement. By adequately addressing these issues and centralizing the management of the reentry programs nationwide, a reduction of the recidivism rate should follow. ItemRACIAL DIFFERENCES IN MAGAZINE COVERAGE OF MAMMOGRAPHY(Johns Hopkins University, 2008-05-21T19:47:45Z) Petrak, Gina A.This study examined messages regarding mammography in mass circulation African- American and European-American women’s magazines. There were significant differences in the content of African-American and European-American magazines. African-American magazines had a higher grade level, more difficult readability, and more passive sentences. Further, the African-American magazines contained more references to religiosity, activity, positive and negative emotions, risk factors, and racial references than their European-American counterparts. It can be proposed that African- American women view mammography, and perhaps many other health issues, from a weltanschauung of deep emotions, strong religious beliefs, and an abiding faith in their special status in the world --- that their survival from cancer rests in God’s hands. These findings have important implications for communicating information regarding mammography to African-American women. ItemTHE PINNACLE OF UNITED STATES-PERU RELATIONS: A SURVEY OF THE MOTIVATIONS FOR AND THE RATIFICATION PROCESS OF THE UNITED STATES-PERU TRADE PROMOTION AGREEMENT(Johns Hopkins University, 2008-05-27T17:45:10Z) Stephenson, Hollie E.On December 14, 2007, President George W. Bush signed the United States Peru Trade Promotion Agreement Implementation Act (H.R. 3688), now Public Law No: 110-138, thus ratifying the United States Peru Trade Promotion Agreement (USPTPA). The objective of this thesis is to survey the environment surrounding the negotiation and ratification of USPTPA and to comment generally on the motivational circumstances for entering into the agreement on the part of both the United States and Peru. The survey includes capturing information on the history of the United States-Peru relationship leading up to present-day, discussing the relevant policies and processes that led up to the USPTPA, summarizing the most relevant content of the USPTPA and how stakeholders participated on behalf of their own interests, and looking at what some of the motivations for undertaking the negotiation and ratification process of the USPTPA might have been. It would seem that, in United States-Peru relations, the entangling of the philosophies of political realism and liberal internationalism in making foreign policy decisions has proved positive. The result, the USPTPA, is a functional (and probably largely positive) mechanism that will have practical and measurable implications for both the United States and Peru, whether or not the political implications are ever fully realized or measured. ItemU.S. Energy Policy: Impacts of an Increased Federal Revenue Neutral Gasoline Tax(Johns Hopkins University, 2008-05-27T17:45:18Z) Kraus, AaronThe future holds significant challenges for the United States with regard to clean, inexpensive, and reliable energy resources. Of these energy challenges, issues relating to transportation fuels appear to be some of the most acute and serious. The price of gasoline does not reflect the true societal costs due to a variety of market externalities. Domestic energy policy must investigate new proposals that offer insight into possible solutions. The following thesis reviews geopolitical risks associated with current U.S. petroleum consumption trends. It also discusses the role gasoline taxes might have in mitigating certain amounts of demand growth. The gasoline taxes that are investigated are revenue neutral. This concept entails returning all revenue raised by any increased tax to consumers with reductions in other tax burdens. While this idea is somewhat radical in nature and politically complex, the consequences of increased gasoline taxes may be socially beneficial. The following study finds that gasoline is one of the most important products in modern society. As such, reducing its consumption is extremely difficult. However, increasing the cost of gasoline by raising taxes can influence demand to some degree. An increased revenue neutral gasoline tax could prove to be part of an effective overall U.S. energy policy. ItemTRYING PEREMPTORY CHALLENGES: ARE THESE TOOLS EFFECTIVE IN SELECTING AN IMPARTIAL JURY?(Johns Hopkins University, 2008-05-27T19:31:29Z) Gioia, Alexis M.This thesis addresses the use of peremptory challenges as an effective tool in impaneling an impartial jury. Up until the twentieth century, peremptory challenges had remained unquestioned. However, once the implications of a defendant’s “Batson claim” surfaced, scholars produced questions regarding the efficacy and constitutionality of the challenges’ existence. Through the review of relevant literature, fundamental trials and numerous interviews with attorneys the author of this work concluded that when peremptory challenges are used effectively, their goal is to promote fairness and impartiality within a jury. This thesis describes how the very tactics used by attorneys when exercising peremptory challenges are consistent with normal psychological behavioral patterns exercised by individuals on a daily basis. In addition to peremptory challenges, this thesis also supports the use of jury consultants in complex and high-profile cases as another mechanism exercised in order to secure the rights of a defendant, as well as to further promote fairness within a jury. It is recommended that in order to continually affirm that peremptory challenges are used properly, the United States should institute a greater and more thorough process for jury selection. In addition, this thesis wishes to convey that the use of jury consultants is effective in providing supplemental support when impaneling impartial juries. In regards to special cases, such as those terrorists standing trial, this thesis recommends that the U.S. continues to utilize its protective statutes and hold military tribunals so as not to danger the lives of civilian jurors. This thesis encourages further research to be conducted on the uses of peremptory challenges, the implementation of jury consultants and the development of additional measures served to protect civilian jurors. ItemTHE U.S. GOVERNMENT’S STRATEGIC COMMUNICATION CHALLENGES WITH THE WAR ON TERROR(Johns Hopkins University, 2008-06-04T19:12:50Z) Davis, CherylAn organization’s reputation, productivity, and even its existence often depend on the way the media and the public perceive its goals and policies. As a massive organization, the United States government relies on the success of the messages it disseminates to clearly communicate its mission in regards to the current war on terror. The U.S. government and the Bush administration face challenges in the monumental task of putting together a strategic communications plan to support their policies. U.S. government agencies, including members of the defense, intelligence, diplomatic and security communities, have their own challenges in formulating and executing individual, albeit collaborative strategies in promoting their mission regarding the war on terror. This thesis lies in evaluating strategic communication practices and interagency cooperation. As a partial result of the war on terror, the United States’ global credibility has waned and therefore its efficiency in promoting its policies has been called into question. This thesis studies the government’s planning and execution of communication tactics in regards to the war on terror. A better organized strategic communication, interagency solution may change the world’s attitudes towards certain policy decisions and ultimately the way the public views the war on terror. By exploring how strategic communication methods have been implemented and analyzing lessons learned post September 11, 2001, this thesis explores the U.S. government’s need for a tailored and refined interagency communication plan for the ever-changing war on terror. ItemIS COMPREHENSIVE FEDERAL DATA SECURITY LEGISLATION NECESSARY TO PROTECT U.S. BUSINESSES, CONSUMERS AND THE GOVERNMENT FROM IDENTITY THEFT AND OTHER CRIMES?(Johns Hopkins University, 2008-06-04T19:19:59Z) Garner, Elizabeth L.This thesis reviews the growing problem of identity theft and fraud that result from the misuse of stolen personal data, and seeks to determine whether or not comprehensive federal legislation is necessary to protect U.S. businesses, consumers and government from identity theft and other crimes. This thesis outlines the different ways identity theft can occur, the different risk levels associated with breaches, and who identity theft affects and how. This thesis explores existing laws and safeguards and their effectiveness in protecting financial institutions, business entities, education establishments, the federal government, and consumers from identity theft crimes and the theft of sensitive personal information. This thesis addresses two schools of thought: 1) the data security status quo is sufficient, and 2) data security should be more highly regulated at a federal level. In doing so, it analyzes pending federal data security legislation and the potential for movement in the 110th Congress. Lastly, this thesis reviews emerging technologies and how they relate to the growing threat of identity theft. This thesis finds that a national standard for data security breach notification, credit freeze policy, and social security number safeguards would be beneficial because of confusing state laws. However, this thesis guardedly recommends a national standard since the private sector has relatively strict data security regulations and compliance standards in place, and during the political process, pre-emptive federal legislation could end up creating unnecessary mandates for the private sector, and with ever-increasing criminal technologies, it will be virtually impossible to thwart identity theft criminals’ attacks one hundred percent of the time. This thesis finds cybersecurity to be a more imminent threat than identity theft and recommends that federal lawmakers address cybercrime before basic data security standards. Cyber criminals are becoming more organized, and with emerging technologies, the anonymity of the Internet, and use of the Internet as a sharing tool, cyber criminals pose a real threat to U.S. national security. Coupled with deficient information security standards at the majority of U.S. federal agencies, the threat of a large scale cyber attack on U.S. infrastructure is imminent and must be addressed first and foremost. ItemSELLING SMART GROWTH(Johns Hopkins University, 2008-06-06T17:48:50Z) Mooney, John C.“Selling Smart Growth” analyzes some of the effects unplanned development has on a city’s gross metropolitan product (GMP). “Selling Smart Growth” uses the case study method to illustrate the effects of unplanned development by comparing a Green GMP to standard GMP. The difference between the two GMPs represents the cost of unplanned development. “Selling Smart Growth” concludes that planned development’s cost over time is lower. Using this data, smart growth public policy advocates can increase their chances of implementing smart growth policies by selling it to the American people by arguing that it will save them money. The principle advisors to this thesis are Dr. Kathy Wagner Hill, the Associate Program Chair for the Government Program at The Johns Hopkins University, Dr. Dorothea Wolfson, former U.S. Rep. William Clinger of Pennsylvania, and Dr. Benjamin Ginsberg, the David Bernstein Professor of Political Science, Director of the Center for the Study of American Government, and Chair of the Government Program of Advanced Academic Programs at The Johns Hopkins University. ItemFINANCIAL SECTOR DISTRESS AND POLICYMAKING(Johns Hopkins University, 2008-06-06T19:19:09Z) Banjo, MartinThe purpose of this thesis is to attempt to determine how policymakers should respond to incidents of financial crisis. It finds that during such times policymakers are faced with two critical tasks. These are to identify and appropriately address the issues critical to the crisis and secondly to ensure the sector reaches a new equilibrium. It finds the first task to be important given the resource constraints of policymakers and distinguishes it from addressing the causes of the crisis. The thesis also suggests that to address the second task it is important the policymakers understand three fundamental pillars of financial sector stability and development. The importance and precise nature of these tasks are illustrated using evidence from the Asian Financial Crisis and the U.S. Savings and Loans Crisis. In addition to identifying these tasks, the thesis proposes policymaking frameworks to address each of the identified tasks. These frameworks are developed from a critical reading of the relevant literature and a study of the cases reviewed. ItemA STUDY ON WHY THE UNITED STATES MUST BE CAUTIOUS IN ATTEMPTS TO ACCELERATE APPRECIATION OF THE RMB(Johns Hopkins University, 2008-09-04T17:34:37Z) Gates, Chazmon Q.China’s economy has grown exponentially, a level of growth unmatched by any modern economy. Millions of Chinese citizens have been lifted out of poverty as a result, and the standard of living for many Chinese has reached a new trajectory. In addition, with a growing middle class and increased money supply, real estate and other domestic industries are flourishing. Lastly, the U.S.-China bilateral trade reached some of its highest levels throughout the past decade, which has further integrated two economies that had little to no exchange just 30 years prior. However, while China’s economy is benefiting from broad growth on many different levels, the U.S. is currently facing a grime economic outlook. Many economists and policymakers attribute an undervalued Chinese currency as the underpinning from which many of the economic concerns in the U.S. ranging from an unprecedented trade deficit to the unfolding of many domestic industries are possible. As a result, a variety of legislative remedies have been proposed in the U.S. Congress to recompense for the adverse effects that come as a direct result of China’s undervalued currency. This thesis provides a thorough analysis of the policy proposals introduced in Congress as well as current policies of the Executive Branch. In doing so, the effects of similar aggressive policies currently being deliberated that were employed during the 1970s and 1980s to address the undervaluation of the Japanese yen will also be examined. Given the significance that a growing Chinese economy has on the global market, in addition to the strong calls for reform in the U.S., this thesis advocates for careful policy measures that fall short of aggressive unilateral action taken by the U.S. In contrast to accelerating appreciation, this thesis argues that allowing a gradual increase could prove helpful in maintaining a stable Chinese economy and the long-term interest of the U.S. economy as over 1 billion Chinese consumers increasingly began to purchase American goods. ItemTRIMMING THE FAT: A SENSIBLE APPROACH TO THE CHILDHOOD OBESITY DIAGNOSIS (AND THE PRESCRIPTION)(Johns Hopkins University, 2008-09-08T19:54:48Z) Ruddock, Neil T. IIIA significant amount of information on dietary habits, children’s Body Mass Index, exercise patterns, television watching habits and other elements have flown through the popular airwaves and policymaker circles regarding childhood obesity. A 2004 report by the Institute of Medicine depicted the issue as a problem of epic proportions, while other authors have condemned that work and research supporting it as inflated and based upon questionable research methods. The following work offers a brief review of the literature, research, and policy actions (both Federal and state) taken on childhood obesity to date, and argues that the problem is legitimate, but not on a scope comparable to the solutions offered by the 2004 report. Global warming is used as a means of comparative leverage over the question of exactly where childhood obesity lies in the policy issue life cycle, and analysis is offered regarding the tactical mistakes made by childhood obesity stakeholders in their efforts to achieve both public awareness and policy progress. The work proceeds to argue that the combination of a well-targeted public relations campaign, combined with structural reforms to the Food Stamp and child nutrition programs, would provide the most appropriate solution to childhood obesity. Research from the Center for Disease Control’s VERB campaign earlier this decade is drawn upon to help shape the public relations campaign recommendations, and the chapter on nutrition program reforms argues that these programs should be shifted towards the Food Stamp program model where meals are provided via consumer purchases rather than school kitchen staff. That chapter also suggests allowing states the option of taking part in a pilot program where the state could bring Food Stamps, School Lunch and School Breakfast-eligible foods under one purchasing regimen and then negotiate with food companies for lower rates, which could account for the increased costs of providing healthier food via these programs. Equally important, it is argued that these recommendations and the necessary funding for them are politically viable. ItemThe Persistence of Fraud and the False Claims Act(Johns Hopkins University, 2008-09-17T19:54:45Z) Speight, Renita K.An abstract of the thesis of Renita K. Speight for the Master of Arts in Government presented August 27, 2008. Title: The Persistence of Fraud and the False Claims Act. The focus of this thesis will be to evaluate the False Claims Act (FCA) and in particular its Qui Tam provisions. A closer look will be taken at the emergence of a very lucrative type of fraud in the United States. This type of fraud has only been on the scene for less than twenty years. However, it has drawn incredible attention from both the criminal and anti-criminal factions. This fraud is Health Care Fraud and although the FCA was not originally intended in the use of fighting fraud in this area, it has been the weapon of choice. However, there are still some loopholes and problems that are interfering with the effectiveness of the FCA as a fraud fighting tool. Because of the rapid growth in health care fraud, it is considerably important that all Americans are informed about this wide spread fraud. As indicated in this thesis, the United States government has recovered large amounts of money due to whistleblowers, however they are still losing out on lots of money because of the revolving door of fraudulent activities. The FCA has been effective in fighting health care fraud in some aspects, but as Senator Grassley believes, the FCA has a long way to go before it can efficiently and effectively fight fraud. ItemEVALUATION OF HAPTIC FEEDBACK METHODS FOR TELEOPERATED EXPLOSIVE ORDNANCE DISPOSAL ROBOTS(Johns Hopkins University, 2011-01) Burtness, Alex J.This thesis reports on the effects of sensory substitution methods for force feedback during teleoperation of robotic systems used for Explosive Ordnance Disposal (EOD). Existing EOD robotic systems do not feature any type of haptic feedback. It is currently unknown what benefits could by gained by supplying this information to the operator. In order to assess the benefits of additional feedback, a robotic gripper was procured and instrumented in order to display the forces applied by the end effector to an object. In a contact-based event detection task, users were asked to slowly grasp an object as lightly as possible and stop when a grasp was achieved. The users were supplied with video feedback of the gripper and either (1) no haptic feedback, (2) surrogate visual feedback, or (3) surrogate vibrotactile feedback. The force information came exclusively from the current being used to drive the gripper. Peak grasp forces were measured and compared across conditions. The improvements gained from vibrotactile over no haptic feedback feedback were statistically significant and reduced the threshold at which event detection took place from an average of 8.43 N to an average of 5.97 N. Qualitative information from the users showed a significant preference for this type of feedback. Vibrotactile feedback was shown to be very useful, while surrogate visual force feedback was not found to be helpful quantitatively nor was it preferred by the users. This feedback information would be inexpensive to implement and could be easily added to existing systems, thereby improving their capabilities to the EOD technician. ItemSecond Generation Hispanic-American Young Adults' Response to Political Advertisements from the 2008 Presidential Election Campaign(jhu, 2012-08) Salazar-Chávez, Cristina G.; Beck, DeborahPolitical campaigns use television advertisements to win Latinos’ votes. These advertisements, which are solely for electoral purposes, may not fully understand the differences in the Latino population that can influence their political views and tend to clump Latinos as one homogenous group just because they all speak Spanish. This study used focus groups to examine the opinions of second-generation Hispanic American young adults about Spanish and English political television advertisements from the 2008 Obama and McCain Presidential campaigns. Male and female participants thought that neither the Spanish nor the English advertisements were targeted at them, and their thoughts differed slightly according to their gender. Furthermore, participants disliked attack advertisements and advertisements they thought were misleading or contained false information. They were more receptive to those that contained policy information and those that specifically talked about education. ItemCultural health hybrid: an exploration of changing health beliefs and attitudes among Hispanic and Hispanic American women(jhu, 2013-04) Paredes, Sandra L.Using two focus groups with 8 Hispanic and 9 Hispanic American women, this study compared health beliefs and attitudes between Hispanic and American women. This study identified strategies that both groups of women use to negotiate health information from two distinct health cultures: traditional Hispanic culture and American clinical culture. Findings indicate that both Hispanic and Hispanic American women see health as having a physical and psychological component, see themselves as responsible for protecting their health, and practice preventive behaviors. However, Hispanic American women do not believe in culture-bound syndromes the way Hispanic women do, nor do Hispanic American women believe in a connection between culture-bound syndromes and chronic disease. Interestingly, both groups of women adapt to a clinical health culture in their own way. Hispanic women adopt clinical practices while maintaining their traditional practices. In contrast, Hispanic American women pick and choose practices from traditional and clinical health culture. This study proposes the theory of cultural health hybrid to examine changing health attitudes and beliefs in Hispanic and Hispanic American women. ItemValidation of the automated segmentation for the hippocampal subfields using Large Deformation Diffeomorphic Metric Mapping on 7T MR images and its application to volumetric and shape analysis for patients with temporal lobe epilepsy(Johns Hopkins University, 2013-09-19) Trinh, Thi Lan Huong; Barker, Peter B.; Lin, Doris; Ratnanather, J. TilakThis thesis first aims to validate the Large Deformation Diffeomorphic Metric Mapping (LDDMM) method used in the automated segmentation of three major subfields of the hippocampus known as Cornu Ammonis (CA), dentate gyrus (DG) and subiculum (SUB) on the 7T T1 MR images with the isotropic resolution of 0.6 × 0.6 × 0.6 〖mm〗^3. Our results showed that using a population template to generate automated subfield segmentation gave better results than diffeomorphically transferring the subfields directly from one subject to another. Our averaged distances are within one voxel size (Left CA: 0.73 mm, left DG: 0.70 mm, left SUB: 0.66 mm, right CA: 0.79 mm, right DG: 0.71 mm, right SUB: 0.74 mm). Our Dice overlap coefficients are reasonable enough for thin structures and more consistent among different subfield than others (Van Leemput et al., 2012) (Left CA: 0.72, left DG: 0.76, left SUB: 0.76, right CA: 0.67, right DG: 0.76, right SUB: 0.70). Based on the validation results, we further implemented our volumetric and shape analysis for the hippocampus and its subfields to the study of patients with temporal lobe epilepsy (TLE) to detect any malformation that has been observed in histopathology of hippocampal sclerosis (HS). 25 subjects in the study were divided into four groups: Group A (control group), Group B (patients with unilateral temporal lobe epilepsy with clear 3T abnormality), Group C (patients with unilateral TLE with no clear 3T abnormality) and Group D (patients with subtle malformation of cortical development seen on 3T). The histogram with Gaussian kernel estimation of the Jacobian determinants showed enormous local shrinkage on all subfields in Group B, on left CA and left DG in Group D and left SUB in Group C. In the permutation test with the two-sample Kolmogorov-Smirnov statistics and in the Wilcoxon Mann-Whitney test with False Discovery Rate adjusted p-values, we obtained significant results indicating differences in the subfields among groups that can be explained by the two major pathological processes of HS observed in patients with TLE. Thus, we can detect specific changes on subfields for patients with TLE based on in-vivo ultrahigh field medical images. ItemEnhancing the Control of Upper Limb Myoelectric Prostheses Using Radio Frequency Identification(Johns Hopkins University, 2013-10-04) Vilarino, Martin; Yarema, Kevin J.; Thakor, Nitish V.; Chi, Albert; Acharya, SoumyadiptaMulti-articulating prosthetic devices are yet to meet a control method that can match their potential. Outdated methods, like using electromyography (EMG) triggers to switch among different grips, have led people to frustration, fatigue and loss of faith. User experiences and statistics on myoelectric use and abandonment have indicated that an easier and more reliable solution is needed. It is my belief that radio frequency identification (RFID) holds the key to mitigating many of the limitations present in current methods. By allowing users to access the grips they need by approaching different RFID tags in their environment or on person, this alternative reduces the risk of uncertainty and frustration present in current methods. Furthermore, by creating a hybrid approach that allows both RFID and EMG triggers as control switches, the user can personalize the solution and decide which approach is more favorable based on different situations. The introductory chapter of this thesis provides an overview of EMG-based control for myoelectric devices. It includes both literature and a user needs analysis that highlight the strengths and weaknesses of the approach. Chapter 2 discusses RFID-based control, and introduces its enabler, morph, the Myoelectrically-Operated RFID Prosthetic Hand. It presents preliminary research on morph that served as the motivation for improving the design and the evaluation process. Chapter 3 explains the design improvements that were implemented to bring morph to a market level design that better addresses the needs of amputees. Chapter 4 presents the clinical evaluation study that is used to evaluate RFID-based control in comparison to EMG-based control. It includes tests for both able-bodied subjects and amputee subjects. Chapter 5 presents the results of a subset of experiments from the clinical evaluation study, and discusses further improvements to optimize the clinical evaluation. The concluding chapter provides a future direction for the design and evaluation. It also presents my opinion on how the myoelectric prosthesis will evolve, and how I envision morph as fitting into the future of the myoelectric device. By the end of the thesis, I hope that the reader better understands the challenges in controlling myoelectric devices, and how morph may increase function and confidence in myoelectric users.