Multiple Ssid Framework for RSS-Fingerprint Based Indoor Positioning Systems

Abed, Ahmed Western Michigan University ProQuest Dissertations 2019 해외박사(DDOD)

Location-Based Indoor positioning systems significance stems from the bloom of recent applications in various fields such as in tracking services for an elder or a patient within large living communities, mobile robot localization, and several other security applications. Currently, Global Positioning Systems (GPS) are the most widely used location-sensing technique. However, satellite-based GPS signals require line of sight (LOS) to work correctly, which is something cannot be achieved inside buildings. Fortunately, wireless LAN can be employed in indoor positioning systems (IPS), and since all large buildings such as malls, hospitals, airports, schools, and museums have hundreds of Wi-Fi access points, it can provide accurate IPS without any additional infrastructure. Of special significance, the Wi-Fi fingerprinting-based techniques that offer a much less complex when compared to other methods such as the angle of arrival (AOA) and time difference of arrival (TDOA). Wi-Fi fingerprinting-based techniques use the received signal strength (RSS) to build radio maps. However, RSS value is a function of the distance between the Mobile System (MS) and Access Point (AP), which varies due to the multipath propagation phenomenon and human body blockage. Furthermore, fingerprinting approaches have several disadvantages such as labor, computational cost, and diversity (in signals and environment). In this dissertation, a novel approach that uses Multiple Service Set Identifiers (MSSID) to tackle these challenges is presented. MSSID means each AP can be configured to transmit N signals instead of one signal, to serve different clients’ categories simultaneously. IPS MSSID-based framework using three different realizations is proposed, implemented, and verified inside the College of Engineering and Applied Sciences (CEAS) building at Western Michigan University.First, a MSSID Probabilistic Neural Network (PNN)-based multi-classifier is proposed with a spatial voting scheme as a tool to determine the location of the user. Spatial voting is designed specifically to tackle the negative impact of multi-path propagation. The performance of the proposed system compared to some of the conventional methods such as K-Nearest Neighbors (K-NN) and multi-class support vector machine (SVM). Experimental results show that spatial voting of three PNN classifiers can significantly mitigate the adverse effects of RSS variation. The precision of the proposed system for PNN and K-NN at distance error of 2m is 90% and 85%, respectively. As a comparison to the proposed systems, the precision of the traditional techniques for PNN and K-NN is 82% and 78%, respectively. In addition, the experimental results show that the average distance error for PNN-based proposed system is less than 0.73 m when the length of AP (L) is 18. Furthermore, the distance error of proposed system shows high stability where it has lowest standard deviation as compared with other traditional techniques.Second, an MSSID-based adaptive K-nearest neighbor (K-NN) is proposed to tackle the challenges associated with static K-NN based-systems. The K-nearest neighbors (KNN) is selected for its significant performance with ease of realization. However, the static nature of K-NN, that is, in using a constant number of the nearest neighbors, leads to a serious shortcoming in its accuracy. In addition, the nature of the RSS-IPS challenges such as fading due to the multipath of electromagnetic waves inside buildings would mislead the solution of nearest neighbors. These reasons often result in lower perform than expected because of the increase in the distant neighbors’ biasing error. In this part, we address these challenges by proposing a new method based on multiple services set identifiers (MSSID) to select adaptively the appropriate nearest neighbors, and reject undesired ones. The ensemble technique is utilized to enhance the performance by combining the outputs of three adaptive K-NN estimators. The experimental results demonstrate the superiority of the adaptive K-NN based-proposed system over static KNN. The results show that the precision of the proposed system for the adaptive K-NN at distance error of 2m is 73%, and the average distance error is less than 1.3 m. As a comparison to the proposed systems, the precision of the traditional K-NN at distance error of 2m is 61%, and the average distance error is 1.85 m.Third, an MSSID- based particle swarm optimization (PSO) system is proposed. PSO technique is designed to select the most informative APs at each clustered area and combined with the K-means clustering method to confine location of the user into a smaller area and thus enhance positioning accuracy. WLAN-fingerprint based methods require recording RSS data of the surrounding APs, which results in including much more than the needed number of APs. Therefore, eliminating redundant or non-informative APs not only reduces the computational cost but also improves performance accuracy. At each cluster, PSO is applied to select the best joint combination of APs decided by the minimum mean of distance error. The results show that the proposed system outperforms other commonly proposed selection methods such as random, strongest APs, and Fisher criterion. Moreover, with reduction of 68% AP vector’s length (L=11), the results report that the proposed system achieves a positioning accuracy of 0.85 m over 3000 m2, with an accumulative density function (CDF) of 88% with a distance error of 2 m.The use of the multiple SSID technique supports IPS classifiers and produces higher precision than with single SSID. The proposed algorithms show a notable improvement over its counterpart with single SSID along with the distance error and reduction of RSS-vector’s length.

Primary Caregiver Attitudes and Counseling Centers in High Poverty Elementary Schools

Westra, Emma C Western Michigan University ProQuest Dissertations 2022 해외박사(DDOD)

Children living in poverty are in high need of mental health services, yet do not receive them (Allegria et al., 2010; Hodgkinson et al., 2017) due to barriers including cost of services, inaccessible location, and transportation issues (Allegria et al., 2015). Additionally, primary caregivers are important gatekeepers for children receiving mental health services (Reardon et al., 2017). While the presence of counseling centers in elementary schools can reduce multiple barriers children living in high poverty areas experience, it is unknown if primary caregivers would select these services for their children. The present study used quantitative analysis to explore hypotheses regarding the relationship between primary caregivers’ help-seeking attitudes, help-seeking intentions, felt stigmatization, and perception of child’s problems. Eighty-one participants were recruited from three Midwest elementary public schools. The measures used in the study included a demographic questionnaire, previous mental health experience questionnaire, the Parental Attitudes Toward Psychological Services Inventory (PATSI; Turner, 2012), and the Brief Problem Monitor–Parent form for Ages 6–18 (BPM-P;Achenbach & Rescorla, 2001). Primary analyses were conducted using multiple t tests and linear regression.Results of this study indicate that primary caregivers, who have previously received mental health services, are more likely to consider mental health services for their children. Findings also support primary caregivers seeking mental health services for their children if the child is engaging in external behaviors, e.g., fighting, yelling, not following directions vsinternalizing behaviors, e.g., symptoms of worrying, anxiety, depression. The findings of this study may be helpful for mental health professionals who work within schools, professionals planning to increasing counseling centers in schools, and professionals interested in increasing community engagement. Results of the study should also be incorporated within curricula that prepare mental health professionals and other school staff for work in schools.

Development of Flexible Hybrid Electronics for Sterilization and Structural Health Monitoring Applications

Bose, Arnesh Kumar Western Michigan University ProQuest Dissertations 2022 해외박사(DDOD)

Traditional MicroElectroMechanical systems (MEMS) devices are fabricated utilizing Integrated Circuit (IC) based batch processing techniques. These systems are capable of sensing, controlling, and actuating on the micro scale and function/operate individually or in arrays. However, such devices typically utilize rigid substrates and are therefore not flexible. The upfront cost of research and development phase, investment for cleanroom and foundry facilities, testingand quality equipment is very expensive. Flexible Hybrid Electronics (FHE) refers to devices and systems that are fabricated utilizing an amalgamation of functional materials, films, membranes and integrated with functional electronic components that are mechanically flexible and stretchable. FHE combines the flexibility and low cost of printed functional inks on plastic film substrates with the performance of semiconductor devices to create a new category of electronics. Microplasma discharge devices have been fabricated using MEMS processes. One application of microplasma is for sterilization of pathogenic microorganisms. Sterilization using microplasma has been of great interest in research as it provides a low-cost, safe, clean and more effective alternative to traditional methods. Among the various electrode design configurations available for microplasma discharge, planar dielectric barrier discharge (DBD) configuration was identified as the most suitable for a microplasma device where FHE fabrication method such as laser ablation can be utilized. The cross-section of a microplasma discharge device (MDD)consisting of a polyimide-based dielectric sandwiched between two copper electrodes was used for modelling the microplasma discharge characteristics in an argon environment. The sterilization efficacy of the fabricated comb and honeycomb patterned electrode configurations was investigated. It was inferred that the honeycomb structured MDD was more effective in inactivating bacteria. The effectiveness of the honeycomb MDD for inactivating bacterial cells in liquid media was also demonstrated. The honeycomb MDD was then further characterized to calculate the power density of the discharge, optical spectra of the microplasma radiation and surface temperature of the MDD. In structural health monitoring (SHM) applications, one of the most common sensors utilized for monitoring the health of load bearing components are strain gauges. Conventional strain gauges are typically manufactured using MEMS based technology. The traditional additive printing process of screen printing is more advantageous since it involves fewer manufacturing steps, roll-to-roll (R2R) fabrication capabilities and low operating temperatures during fabrication. A silver ink was blended with a carbon ink to achieve a silver-carbon (Ag/C) composite ink. The composite ink was then screen printed on a polyimide substrate in a meandering pattern to achieve a desired gauge resistance of ~350 Ω. The printed strain gauge was bonded to a flat aluminum beam and the capability of the printed strain gauge to detect linear and transverse strain were investigated by applying varying tensile and compressive loads on the aluminum beam, to simulate micro strain. Corresponding linear and transverse gauge factors for tensile and compressive loads were calculated and compared to a commercial strain gauge of similar gauge resistance. The temperature coefficient resistance of the Ag/C ink was calculated and its invariance to humidity was also investigated.

Simultaneous X-ray Emission Accompanying Two Electron Capture for Fluorine on Gas Targets

La Mantia, David S Western Michigan University ProQuest Dissertations 2019 해외박사(DDOD)

The collision between a charged ion and an atom resulting in the capture of two electrons, simultaneous with the emission of a single photon is referred to as radiative double electron capture (RDEC). For ion-atom collisions, this process can be considered the inverse of double photoionization. The study of either process, where just two electrons are involved without in uence from neighboring electrons, promises new insight into electron correlation and the role it plays in quantum mechanics. Such a study for photoionization has not yet been done experimentally for two-electron ions because the only target system for which two electrons are available is atomic helium. The ability to gain information on pure correlation will thus be important to fundamental studies of RDEC and double photoionization and to applications in astrophysics and in plasma physics. RDEC is related to the well-known process of radiative electron capture (REC), in which a single electron is captured to a bound state with the simultaneous emission of a photon, considered the ion-atom analog of radiative recombination. Several attempts have been made to observe RDEC experimentally but without definitive results using mid- to high-Z, high-energy projectiles on thin-foil and gaseous targets. Several theoretical studies have been performed over the last 25 years, with recent results suggesting that mid-Z, lower-energy projectiles would yield better results by giving larger cross sections. The first successful observation of RDEC was performed at Western Michigan University using 2.38 MeV/u O8+ projectiles incident on thin-foil carbon targets. This result was followed by measurements for 2.21 MeV/u F9+ also on carbon foils, which however suffered from contaminants in the target. Multiple-collision effects were present as expected for thinfoil targets, causing the RDEC events to be distributed over the double and single capture channels. These previous measurements provide the motivation for the present RDEC work with gaseous targets. Presented in this study are the results for RDEC by 2.11 MeV/u fully-stripped, and also one-electron uorine ions colliding with N2 and Ne. Cross sections for both projectiles are determined and compared with theoretical calculations to the extent possible, as well as with each other. The measurements were done under single-collision conditions to prevent complication from multiple collision events. High purity target gases were used to minimize the effects of contaminants.

Three Essays in the Economics of Education

Islam, Md. Ohiul Western Michigan University ProQuest Dissertations 2022 해외박사(DDOD)

This dissertation explores three distinct topics in the economics of education. These topics explore the relationship between race, gender, national origin, and educational and labor market outcomes. Educational attainment in the STEM (Science, Technology, Engineering, and Mathematics) areas receives a major focus in this dissertation; a college-level specialization in STEM areas generally leads to high income-yielding career tracks. Below I briefly explain the research objectives and findings of each chapter.The first chapter focuses on the impact of teacher-student demographic mismatch on student success in classrooms at the high school level. When students, particularly disadvantaged, are assigned to teachers with different racial and/or gender identities, they may become subject to the "Golem effect", which is lower expectations and biases the teachers may have about them. In this paper, using restricted-access data from the High School Longitudinal Survey of 2009 (HSLS:09), I investigate whether demographic mismatch between teachers and students in high schools has a negative impact on achievement. I find consistent evidence that having a different-sex teacher is disadvantageous for students of all racial backgrounds. Having a different-sex and different-race teacher is associated with achievement loss, especially for Black female students. The second chapter focuses on the impact of parental occupation in STEM fields on the child's selection of a STEM major at the post-secondary level. For empirical analysis, I use data from HSLS:09 again. The economic literature suggests that parents' occupational identities can influence children's selection into different fields of major through different channels. Parents may provide positive feedback on the educational decisions of children at multiple stages throughout the children's school life. I find that having at least one parent in the fields of computer science and engineering positively impacts the child's selection into college majors in computer science and IT and Engineering. Moreover, I find that in two-parent households, both the mother's and father's occupations in STEM positively impact the child's selection into STEM college major sections.The third chapter examines the historical positive wage gap between U.S. natives and international college graduates in STEM and non-STEM fields participating in the U.S. labor force. I show that between 1993 and 2019, in STEM occupations, naturalized citizens and permanent residents earned on average higher than U.S. natives; temporary workers consistently earned less on average than U.S. natives, and permanent residents consistently earned more on average than temporary workers. The evidence shows that the wage gap is not just due to differences in factors such as primary activities on the job, highest degree attained, and working in STEM fields, but also because of "unexplained" factors; one of them could be the labor market laws restricting the entry of foreign-born workers into the U.S. labor market. In a panel data analysis, I find that the effect of change in immigration status resulting in naturalization and permanent residency positively impacts mean wage.

The Influence of Integrated Behavioral Health Primary Care Setting on the Utilization of Mental Health Services and Depression Treatment Response among Men

Masiriri, Tendai Western Michigan University ProQuest Dissertations 2022 해외박사(DDOD)

The 2010–2013 National Health Interview Survey showed that nearly 9% of men had daily feeling of anxiety or depression, yet less than 41% sought help for their symptoms (Blumberg et al., 2016). Men are more reluctant than women to seek help (Angst et al., 2002; Brownhill et al., 2005). The failure to seek help among men is associated with multiple factors related to stigma and gender; yet male suicide rates are approximately 3–5 times higher than their female counterparts. However, they have overall higher likelihood of seeking help from a medical provider rather than a mental health provider. If men were able to get mental health treatment in a primary care setting where they already receive physical care, would it improve their use of services and depression treatment response? Therefore, the study sought to determine whether integrated behavioral health primary care setting improves the utilization and/or treatment participation and outcomes among male patients compared to non-integrated primary care setting. The study used secondary data of male patients who received care from 12 clinics of a large healthcare provider organization in the Pacific Northwest. Six clinics were integrated behavioral health primary care practices and the other six were non-integrated primary care practices. A retrospective cross-sectional study was utilized to investigate the influence of integrated behavioral health primary care on two outcomes among men: (a) mental health services utilization and (b) depression treatment response. The investigator developed two models for the two outcomes. The analysis involved a descriptive cross-tabulation analysis followed by a binary logistic regression analysis of both models. Results of the binomial logistic analysis indicated that the multivariate model predicted mental health services utilization among men at a statistically significant level, χ2(20, N = 648) = 93.398, p < 0.01. Men were 4.44 times (CI = 2.917, 6.748) more likely to use of behavioral health services in an integrated care setting as in a non-integrated primary care setting. The results also revealed that Baby Boomers (1955–1964) and older adults were 67.8% (CI = .134, .771) less likely than Generation Z (born 1997–2012) to use mental health services. Generation Z patient included in the study were 18 years or older. The second model predicting depression treatment response was also statistically significant, χ2(20, N = 648) = 32.134, p = 0.042. Firstly, integrated behavioral health primary care setting was approximately 68% (CI = 1.11, 2.547) more likely than non-integrated primary care setting to have men respond to depression treatment while adjusting for other variables. Secondly, men who used psychotherapeutic medications were 92% (CI = 1.294, 2.842) more likely than those who did not use medication to respond to depression treatment. Thirdly, men who did not disclose their relational supports in this sample were 3.99 times (CI = 1.394, 11.436) as likely to respond to depression treatment as the group that were married, lived with significant other or domestic partner.

Change in Attribution Perspective, Shame, and Academic Identity for Freshmen on Probation Enrolled in University Academic Recovery Courses: A Mixed Methods Study

Robinson, Christine L Western Michigan University ProQuest Dissertations 2019 해외박사(DDOD)

Student retention is critical to the success of the student, the college or university, and society in general. Consequently, institutions of higher education continue to focus efforts on student retention strategies and one such strategy utilizes academic recovery courses to support probationary freshmen. Previous research studies of these courses largely focus on academic outcomes without examining the “why” or “how” behind such outcomes. Some studies also discuss constructs including attribution perspective, shame, and academic identity. However, the relationship between these constructs has not been researched, particularly with regard to any change that may occur for probationary freshmen engaged with an academic recovery course. This sequential, mixed-methods study, framed by Shame Resilience Theory (Brown, 2006), Attribution Theory (Weiner, 2008), and Academic Identity (Marcia, 1963; Was & Isaacson, 2008), researches change in these constructs for probationary freshmen enrolled in an academic recovery course at one mid-sized research university in the Midwest, and explores how students made meaning of their academic recovery process. A pre- and post-course survey was utilized in the quantitative phase of the study. Results indicated a statistically significant difference between mean shame scores for male and female probationary freshmen indicating that females experienced more shame while on probation than males. Concerning academic identity, over 50% of probationary freshmen resided in a moratorium academic identity status, while those with an achieved identity status represented 27.7% of the students. Relationships were found between the constructs wherein academic identity was statistically correlated with shame and attribution perspective. As moratorium identity decreased, achieved identity increased; as moratorium identity increased, shame increased; and as moratorium identity increased, attribution perspective decreased. Concerning construct change and racial groups, White students experienced a significant change in shame from pre- to post-course such that their post-course shame score was four points lower than the pre-course shame score. With regard to academic standing, higher attribution perspective scores significantly correlated with retention compared to academic dismissal. Post-course interviews, utilized in the qualitative phase of the study, revealed several major themes. Probationary freshmen experienced difficulty transitioning from high school to college with regard to insufficient life management skills, underdeveloped academic identity, selfawareness and shame resilience, and hardships that occurred during the semester. Factors contributing to positive growth for the freshmen included the importance of having a champion, improved life management skills, a positive attribution perspective, improved self-awareness and shame resilience, and improved academic identity. This study is the first to examine change in constructs for probationary freshmen engaged in an academic recovery course, and for which a mixed-methods approach gave voice to the students regarding their experiences. Results reveal how colleges and universities can better support probationary freshmen through the employment of academic recovery courses. The study opens up further research ideas to continue addressing the challenge of retention for this at-risk population.

Analyzing Impacts of Transportation and Non-Transportation Activities on Human Health with an Advanced Platform for Collecting Travel and Physical Activity Data

Hasan, Raed Abdullah Western Michigan University ProQuest Dissertations 2019 해외박사(DDOD)

Recently much attention is paid to the lack of physical activities that may cause the health problems in many counties. Travel activities provide a certain amount of physical activities, and the active transportation, such as walking and cycling, becomes more important as an essential element of transportation. The active transportation is expected to contribute to improving human health by reducing cardiovascular disease, obesity, and premature death. However, detailed relationship between the transportation choices and human health has not been well understood. Therefore, there is a need for investigating traveler behaviors and how their choices affect physical activities and public health. The first part of the dissertation explores the role of societal cultures and their impact on choosing active transportation modes. Through a multinational survey conducted in the selected cities of the United States, South Korea, Saudi Arabia, and Iraq, the sociocultural factors that influence transportation mode choices especially active transportation are identified. The second part of the study involves using a mobile application platform named Physical Activity through Smart Travel Activity (PASTA) to monitor the travel and physical activities of transportation users. The PASTA platform includes mobile data communication, big data analysis, activity classification, transportation mode detection, and physical activity quantification on different interfaces, such as smartphones, cloud databases, and computers. The platform provides data to compare physical activities attributable to transportation across different geographical areas. The PASTA platform is tested in Texas and Michigan and proves to be useful in apportioning the total physical activity into travel-related physical activities and non-travel related physical activities. A transportation mode detection (TMD) system is also developed to process the data collected from PASTA based on machine learning techniques. The third part of the dissertation employs the integrated transportation and health impact model (ITHIM) and enhances the concept of ITHIM by adding the quantitative data obtained from PASTA. Mechanisms for collecting data on physical activities (PA) related to or not related to transportation in previous studies relied on questionnaires and interviews of specific samples in the community. Instead, the PASTA platform provides an automated mechanism for gathering the daily activities of people, especially with regard to physical activities and travel behaviors. The study also introduces the physical activity minute (PAM), an indicator of changes in activity levels, which is an alternative to the metabolic equivalence of the task (METs), which is often a constant value for any type of physical activity. By coupling the data from PASTA, this research substantially reduces the limitations in the previous ITHIM and upgrades the model to conform to the current technological advances.The last part of the dissertation discusses the relationship between the levels of physical activity of individuals, their socio-economic features and body shapes using descriptive analysis and path analysis. Three sets of data are used in this study, such as the questionnaire, body shape tests, and physical activity levels associated with transportation. Socio-economic and body shape factors such as race, age, gender, state of residence, percent of body fat, are found to have significant direct and indirect effects on physical activity. The findings of this study help in incorporating human health into transportation planning by addressing health outcomes impacted by physical activities associated with transportation choices considering peoples socioeconomic and body composition profiles. This dissertation makes an effort to analyze and quantify participants actual physical activities by using recent wearable devices with sensing and GPS tracking technology. The dissertation addresses health outcomes impacted by physical activities associated with transportation options. The study provides information that can be used to enhance community awareness of the health benefits that resulted from different transportation mode choices. Overall, the findings of this study can be used to incorporate human health in transportation planning.

College Students with Physical Disabilities: An Exploratory Investigation within Counselor Education

Wall, Adam Tolbert Western Michigan University ProQuest Dissertations 2019 해외박사(DDOD)

Attempts to Reduce Elopement Using Blocking, a Time-Out Procedure, and Differential Reinforcement

Harbaugh, Sydney M Western Michigan University ProQuest Dissertations 2019 해외박사(DDOD)